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Products => Test Equipment => Topic started by: 0culus on October 17, 2018, 09:43:59 pm

Title: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 17, 2018, 09:43:59 pm
Hi all!

First, a little background on me.

I am a hobbyist in electronics (cybersecurity research is my day job, so to speak) and I've been finally working on getting back into the hobby and building myself a small lab. I've been acquiring test equipment and other things slowly this year, most recently a nice refurbished Tek 2465B scope that I have really been enjoying. RF is something I've always been interested in (I would like to get my ham license at some point too), so I've been looking at spectrum analyzers, including reading many older threads right here on this forum.

I really have a thing for top quality old test equipment, and I understand the risks of buying them now because of caps degrading and other reliability issues that can result in repairs and scrounging for old parts. One of my goals is to eventually acquire knowledge to work on things like this myself. So my question is primarily 2 things:

1) What are reasonable prices in 2018 to be paying for working HP "big iron" SAs such as 8566, 8568? Some of the ones I'm seeing on ebay seem to be very highly priced considering their age, even considering the instrument cost as much as a nice car or even a house new.

2) I understand that the low end modern SAs from Rigol and Siglent simply don't match up with the RF performance of the top end old ones, but what do I really lose as a hobbyist by getting one instead of going old, other than bandwidth? On the flip side, these are often seem to be around the same price as old HPs but you aren't getting as much for your money, at least looking at it from my perspective.

I guess as an addendum, I've also looked at stuff like the HP 8562A (which is portable, at least compared to the 66 and 68). Are these worthwhile?

Thanks!
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: Tony_G on October 17, 2018, 10:11:11 pm
I haven't tracked the prices but I feel that around $500 for an 8568 and around $1500 for an 8566 would be reasonable. They're big beasts though which is why I spent more to get an 8563E.

For my use I was happy with an 8590E as a starter but they're nowhere near as good as the 856XE for similar frequencies. I've never used a new Rigol/Siglent SA so my guess would be that you would have smaller space and quieter operation for the same money at the cost of bandwidth, noise floor, etc.

TonyG
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 17, 2018, 10:53:08 pm
I haven't tracked the prices but I feel that around $500 for an 8568 and around $1500 for an 8566 would be reasonable. They're big beasts though which is why I spent more to get an 8563E.

For my use I was happy with an 8590E as a starter but they're nowhere near as good as the 856XE for similar frequencies. I've never used a new Rigol/Siglent SA so my guess would be that you would have smaller space and quieter operation for the same money at the cost of bandwidth, noise floor, etc.

TonyG

Hi Tony, thanks for your reply. I simply don't have space for a 140 lb beast right now, but I want one when I have a bigger bench. :)  But if  I found a deal, I might not be able to pass it up. If anything though, something smaller and lighter to cut my teeth on is probably better. If I can score it for under $1000 it may still beat out the new ones on bandwidth and stuff. Some of the Siglents are listed for 2-3k, USD.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: tkamiya on October 17, 2018, 11:28:27 pm
HP8568 and 8566 prices vary widely.  A couple of things to be aware....  If cables do not come with it, you'll need additional $150 for a set of cables.  Try to get B models.  A models are awfully slow.  I have a several 8568Bs here.  They may be big but performance/price is great.  It goes down to 10Hz resolution.

HP859x models (smaller portable) ones are fairly reasonably priced.
HP856x models are still priced at premium.

They are both the same size.  856x models have better resolution.  (10Hz verses 1Hz) I have HP8591EM and 8592E.

Where are you in US?  Are you close to Central Florida?
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: jjoonathan on October 18, 2018, 12:11:26 am
Big Iron Advantages (Advantest, but HP is similar):
* More Bandwidth (see those harmonics!)
* Faster Large-Span Sweep (seriously underrated, especially in comparison to low-end rigol/siglent which are awful)
* IF Out (so you can put it in zero span and time correlate events with an oscilloscope or use it as a frequency converter for an analog discovery and make a ghetto RTSA -- bolded because I think this is especially relevant for a security researcher)
* LO Out (nominally to support harmonic mixers for waveguides and ludicrous bandwidth but also useful for tracking circuits -- either DIY TG or DIY TG+Offset for mixer measurement)
* EMI is standard, not optional (not on HPs but maybe they're hacked?)
* Access to schematics
* Better phase noise

Disadvantages:
* Big, heavy
* No USB -- so you either need GPIB (I bought an adapter) or to be comfortable with the sticky-note-and-phone-camera workflow (what I actually do, even for devices with USB, but I'd never put these in a professional report).
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: tautech on October 18, 2018, 12:17:58 am
I haven't tracked the prices but I feel that around $500 for an 8568 and around $1500 for an 8566 would be reasonable. They're big beasts though which is why I spent more to get an 8563E.

For my use I was happy with an 8590E as a starter but they're nowhere near as good as the 856XE for similar frequencies. I've never used a new Rigol/Siglent SA so my guess would be that you would have smaller space and quieter operation for the same money at the cost of bandwidth, noise floor, etc.

TonyG

Hi Tony, thanks for your reply. I simply don't have space for a 140 lb beast right now, but I want one when I have a bigger bench. :)  But if  I found a deal, I might not be able to pass it up. If anything though, something smaller and lighter to cut my teeth on is probably better. If I can score it for under $1000 it may still beat out the new ones on bandwidth and stuff.
Really how much BW will you need ?
If you're gunna be working predominantly in the HAM range a 1.5 GHz SA will serve your needs.

Be aware a lot of the 'old iron' doesn't have a tracking generator which means further additional cost.

Quote
Some of the Siglents are listed for 2-3k, USD.
Only the SSA3032X, a 3.2 GHz unit @ ~$2600.

But as others have mentioned just the SA is only the start, cabling, adapters, attenuators, loads, and directional couplers can soak up a heap more funds to become even moderately well equipped.

Based on the bit of RF I do and if BW is of little concern I'm getting to think the new SVA1015X is a better RF hobbyist SA, particularly for the VNA option it has and the antenna work you can do with it without the need for a directional coupler as in these models it's inbuilt.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: DaJMasta on October 18, 2018, 01:08:55 am
How big are you talking?  There are larger, capable, affordable (or affordableish.... it is an SA) that are 40 pounds or so and are a 3 or 4 U rack sized cases - not small, not like the Rigol or Siglent, but not the 80+ pound multipart boat anchors some of those older HP SAs can get to.  If that form factor sounds doable, there are a good number of other options: advantest, anritsu, rohde and schwarz (they command a premium, but something like the FSE series can sometimes be found reasonably (and while physically large, they aren't particularly heavy).

There's also the portable SA option, which is going to have a similar footprint to the Rigol or Siglent, but usually offer good features/bandwidth/noise floor though often at the expense of sweep speed.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: TK on October 18, 2018, 01:11:38 am
The Agilent E4406A is a good cheap option (some are listed for around $300 on eBay).  7MHz to 4GHz.  The main drawback is the 10MHz SPAN, but it is a nice introductory SA for novice RF hobbyist.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: tkamiya on October 18, 2018, 01:47:05 am
It's kind of hard to recommend anything because OP's intended use isn't clear.  Being a ham (me, too), I'm guessing he wants SpecAn to play with and being able to see his own signal, as well as his future projects.

Even then, spec requirement will vary wildly if he wants to see far harmonics or close end one with two tone test of SSB transmitters. 

To give you a real example....  My 8668B ended up costing me around $1000 after it was acquired ($600), repaired, and calibrated. ($500)  Then I spent few hundred for adapters, cables, attenuators, and directional couplers.  I'm waiting for tracking signal generator in mail.  ($400).  So total of about $2000

My HP8591EM with tracking generator was purchased for $1800 ready to go with calibration.

I also have HP9593E and it was $1000.  It did not include tracking generator.  Calibration was spot on.

With tracking generator and a directional coupler, it can turn itself into a lab grade antenna analyzer.  For evaluating filters and amplifiers, signal source is necessary.  TrackGen can do this.  HP959x series are small (but deep) and semi-portable.  Price has dropped since my purchase, too.  Difficult part is to get one that doesn't need repairs.  One of mine needed extensive repair that I ended up trading it in for parts and buy anew. 

The one I use the most is HP8591EM with tracking generator. 
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: Mr. Scram on October 18, 2018, 01:59:52 am
The Agilent E4406A is a good cheap option (some are listed for around $300 on eBay).  7MHz to 4GHz.  The main drawback is the 10MHz SPAN, but it is a nice introductory SA for novice RF hobbyist.
That 10MHz kills it, but is probably why you can pick them up cheaply.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: BravoV on October 18, 2018, 02:03:53 am
A member here compiled list of used SA and it's details (avg. price too) -> Used spectrum analyzer buyer's guide (https://www.eevblog.com/forum/testgear/used-spectrum-analyzer-buyer_s-guide/)
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 18, 2018, 02:31:41 am
To add a little more context, I would like to work in the ham region, but also have the bandwidth to look at harmonics and do other exploratory stuff later as I learn more and find things I want to play with. I realize this will probably ultimately mean more than one SA, but I'm trying to narrow down what might be a good purchase for a first SA that will also be reasonably capable.

Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: DaJMasta on October 18, 2018, 02:48:29 am
No need for more than one, unless you mean one and then upgrade it.  While maybe considering one product generation of older gear you may run into limitations that would need multiple units, but if you're comparing what's available on the whole used market, there are a lot of general purpose, very capable units around.  I'd say away from dedicated modulation analyzers or units that need the SA software option to use as one, as you're generally going to be more limited on your choice of RBW and your noise floor, but finding an SA with some additional outputs, some signal analysis capability, hardware demodulation, tracking generators, etc., is all very doable given the choice of models.

The used SA buyer's guide mentioned above is a good place to get your bearings.  Then when you have an idea of what's out there and what features seem useful (maybe you really want THD analysis or phase noise plotting and lots of models don't offer it or don't have the option installed), then you can narrow the list to things with enough performance and options and start looking around.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: tautech on October 18, 2018, 02:55:17 am
It could also be advisable to look carefully at RF input ratings especially with limited SA use experience as many older models have delicate front ends.
You wouldn't want to fry a new toy !  :scared:
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 18, 2018, 03:03:19 am
No need for more than one, unless you mean one and then upgrade it.  While maybe considering one product generation of older gear you may run into limitations that would need multiple units, but if you're comparing what's available on the whole used market, there are a lot of general purpose, very capable units around.  I'd say away from dedicated modulation analyzers or units that need the SA software option to use as one, as you're generally going to be more limited on your choice of RBW and your noise floor, but finding an SA with some additional outputs, some signal analysis capability, hardware demodulation, tracking generators, etc., is all very doable given the choice of models.

The used SA buyer's guide mentioned above is a good place to get your bearings.  Then when you have an idea of what's out there and what features seem useful (maybe you really want THD analysis or phase noise plotting and lots of models don't offer it or don't have the option installed), then you can narrow the list to things with enough performance and options and start looking around.

Been reading through the buyer's guide, definitely a big help. I've been looking at HP 8562As  on ebay, which is "portable", RBW 100 Hz to 1 MHz. 22 GHz though, which none of the other models listed in the buying guide even get close to other than the boat anchors. No tracking generator though.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: DaJMasta on October 18, 2018, 03:25:43 am
Been reading through the buyer's guide, definitely a big help. I've been looking at HP 8562As  on ebay, which is "portable", RBW 100 Hz to 1 MHz. 22 GHz though, which none of the other models listed in the buying guide even get close to other than the boat anchors. No tracking generator though.

With those somewhat older units, you can get a fair amount of GHz for your dollar, but do you think you need anywhere near 22GHz?  Once you get above 8GHz or so the price of cables and connectors really start going up, and while there are certainly applications that need the huge bandwidth, most radio applications, EMI measurements, tinkering projects... it's unlikely that those double digit GHz ranges will be of much use.  Since you generally pay pretty well for the extra bandwidth, it's not always the best way to spend your bucks.

Personally, I'd pick sweep speed, low RBW (down to 1Hz is isn't always expensive), and low phase noise over raw bandwidth beyond applications you're thinking about, just because looking at the very faint signals and looking in very fine detail is more of interest.  That said, if you have a satellite dish and want to look at X band signals, while the low RBW and DANL is really helpful, if you've got an LNA on the dish, you don't need a downconverting mixer and source if you have the bandwidth to read it directly.

Tracking generators are great for filter measurements, but they very often aren't full the full bandwidth of the instrument, so while a 3GHz SA probably has a 3GHz tracking gen, a 10GHz SA is almost never going to have a 10GHz source... it probably has a 3GHz, in some cases maybe a 6GHz.  You can also do this same kind of transmission measurement with a wideband noise source, not the same, but perfectly functional for characterizing filters and such.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 18, 2018, 04:13:49 am
Been reading through the buyer's guide, definitely a big help. I've been looking at HP 8562As  on ebay, which is "portable", RBW 100 Hz to 1 MHz. 22 GHz though, which none of the other models listed in the buying guide even get close to other than the boat anchors. No tracking generator though.

With those somewhat older units, you can get a fair amount of GHz for your dollar, but do you think you need anywhere near 22GHz?  Once you get above 8GHz or so the price of cables and connectors really start going up, and while there are certainly applications that need the huge bandwidth, most radio applications, EMI measurements, tinkering projects... it's unlikely that those double digit GHz ranges will be of much use.  Since you generally pay pretty well for the extra bandwidth, it's not always the best way to spend your bucks.

Personally, I'd pick sweep speed, low RBW (down to 1Hz is isn't always expensive), and low phase noise over raw bandwidth beyond applications you're thinking about, just because looking at the very faint signals and looking in very fine detail is more of interest.  That said, if you have a satellite dish and want to look at X band signals, while the low RBW and DANL is really helpful, if you've got an LNA on the dish, you don't need a downconverting mixer and source if you have the bandwidth to read it directly.

Tracking generators are great for filter measurements, but they very often aren't full the full bandwidth of the instrument, so while a 3GHz SA probably has a 3GHz tracking gen, a 10GHz SA is almost never going to have a 10GHz source... it probably has a 3GHz, in some cases maybe a 6GHz.  You can also do this same kind of transmission measurement with a wideband noise source, not the same, but perfectly functional for characterizing filters and such.

Thanks for the insights. So I get the impression from what you wrote that going for 22 GHz isn't going to be worthwhile unless I'm also getting one of the huge 2 part HP boat anchors anyway? Are there any specific SAs that meet the criteria you mention, including phase noise? That isn't mentioned in the buyers guide.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 18, 2018, 04:14:25 am
HP8568 and 8566 prices vary widely.  A couple of things to be aware....  If cables do not come with it, you'll need additional $150 for a set of cables.  Try to get B models.  A models are awfully slow.  I have a several 8568Bs here.  They may be big but performance/price is great.  It goes down to 10Hz resolution.

HP859x models (smaller portable) ones are fairly reasonably priced.
HP856x models are still priced at premium.

They are both the same size.  856x models have better resolution.  (10Hz verses 1Hz) I have HP8591EM and 8592E.

Where are you in US?  Are you close to Central Florida?

Unfortunately I'm not; southwest region.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: DaJMasta on October 18, 2018, 04:40:26 am
Thanks for the insights. So I get the impression from what you wrote that going for 22 GHz isn't going to be worthwhile unless I'm also getting one of the huge 2 part HP boat anchors anyway? Are there any specific SAs that meet the criteria you mention, including phase noise? That isn't mentioned in the buyers guide.

Not specifically in regards to the boat anchors, but just generally.  The price scales up pretty significantly with bandwidth and with product generation, so if you don't need those top 10-15GHz, going with the lower bandwidth option will probably get you a product generation or better more advanced of an instrument which will mean lower noise, probably higher sweep speed, and more features, so if you don't have a direct need for the bandwidth, you can save a bit or get some other performance and quality of life benefits instead.  Nearly every newer generation of SAs by the same company is going to have somewhat better performance across the board, and is more likely to have nice UI enhancements, connectivity options, or extra analysis features.


For phase noise, generally finding something with an upgraded oscillator will almost always be better than the base version, but if you look through the datasheet and find a phase noise analysis software option, then the rest of the system's hardware is already designed around being able to measure those aspects.  You also very rarely find it on instruments without 10Hz RBW or lower - the small fluctuations just don't show up that well with a 100Hz RBW.  But in mentioning it, don't forget to figure what options it comes with into what you're considering - sometimes you can still buy upgrades, but they will be expensive, so if you find a unit that has some extra options enabled that look interesting, it could be worth some premium over a regular unit since it's otherwise difficult to get them.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: Bud on October 18, 2018, 04:50:17 am
Old big iron for work, new Chinese plastic for shelf decoration. Your choice.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 18, 2018, 05:34:00 am
Thanks for the insights. So I get the impression from what you wrote that going for 22 GHz isn't going to be worthwhile unless I'm also getting one of the huge 2 part HP boat anchors anyway? Are there any specific SAs that meet the criteria you mention, including phase noise? That isn't mentioned in the buyers guide.

Not specifically in regards to the boat anchors, but just generally.  The price scales up pretty significantly with bandwidth and with product generation, so if you don't need those top 10-15GHz, going with the lower bandwidth option will probably get you a product generation or better more advanced of an instrument which will mean lower noise, probably higher sweep speed, and more features, so if you don't have a direct need for the bandwidth, you can save a bit or get some other performance and quality of life benefits instead.  Nearly every newer generation of SAs by the same company is going to have somewhat better performance across the board, and is more likely to have nice UI enhancements, connectivity options, or extra analysis features.


For phase noise, generally finding something with an upgraded oscillator will almost always be better than the base version, but if you look through the datasheet and find a phase noise analysis software option, then the rest of the system's hardware is already designed around being able to measure those aspects.  You also very rarely find it on instruments without 10Hz RBW or lower - the small fluctuations just don't show up that well with a 100Hz RBW.  But in mentioning it, don't forget to figure what options it comes with into what you're considering - sometimes you can still buy upgrades, but they will be expensive, so if you find a unit that has some extra options enabled that look interesting, it could be worth some premium over a regular unit since it's otherwise difficult to get them.

Awesome, thanks again for your feedback. This has been a huge help! I'm going to keep shopping around for a while till I become very familiar with what's out there...and who knows? Could find a good deal. :)
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: Mr. Scram on October 18, 2018, 09:20:51 am
Old big iron for work, new Chinese plastic for shelf decoration. Your choice.
We know that you have a strong dislike for anything Chinese, but can you back your point of view up with arguments?
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 18, 2018, 04:31:32 pm
It could also be advisable to look carefully at RF input ratings especially with limited SA use experience as many older models have delicate front ends.
You wouldn't want to fry a new toy !  :scared:

Will do! Thanks for the reminder!
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: taydin on October 18, 2018, 05:49:58 pm
Nobody mentioned this so far, but another BIG difference is, old SA's have YIG oscillators and YIG filters in them, which means much cleaner LO generation. That's one reason I'm working hard to get my 22 GHz HP 8592B to work!

The lower price SA's from Siglent and Rigol don't have YIG oscillators/filters in them. But the big bux Keysight/Tektronix/RS probably have YIG's in them, not sure about that. How much impact will the YIG vs VCO LO generation have, that I don't know ...
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 18, 2018, 11:15:10 pm
Nobody mentioned this so far, but another BIG difference is, old SA's have YIG oscillators and YIG filters in them, which means much cleaner LO generation. That's one reason I'm working hard to get my 22 GHz HP 8592B to work!

The lower price SA's from Siglent and Rigol don't have YIG oscillators/filters in them. But the big bux Keysight/Tektronix/RS probably have YIG's in them, not sure about that. How much impact will the YIG vs VCO LO generation have, that I don't know ...

Good to know, thanks. I've pretty much settled on waiting a while keep my eyes open for a deal on a really top end SA. Hopefully by then I'll have the bench space too. :)
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: BravoV on October 19, 2018, 04:20:39 am
But as others have mentioned just the SA is only the start, cabling, adapters, attenuators, loads, and directional couplers can soak up a heap more funds to become even moderately well equipped.

+1 , beware of these accessories which personally I called "RF plumbing stuffs", top brand ones even used can still quite pricey. In my case, as I got my SA pretty cheap (posted at used SA guide too), these overall plumbing stuffs even at minimal, cost almost the same as my SA.  :'(

Depends on the SA acquired, suggesting to start learn/look/lurk for these stuffs too apart from the SA, cause sometimes this activity alone will take quite sometimes & energy to accumulate, let alone the cost.

As tautech pointed above, my suggestion for starting point sorted by priority imo : sacrificial connector, DC block (if needed) .. various attenuators ... and so on ...  :palm:

Just an example of small portion part of the plumbing stuffs, these used things alone cost > 50 bucks  ..  ::)
(https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=411425;image)
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 19, 2018, 04:48:31 am
But as others have mentioned just the SA is only the start, cabling, adapters, attenuators, loads, and directional couplers can soak up a heap more funds to become even moderately well equipped.

+1 , beware of these accessories which personally I called "RF plumbing stuffs", top brand ones even used can still quite pricey. In my case, as I got my SA pretty cheap (posted at used SA guide too), these overall plumbing stuffs even at minimal, cost almost the same as my SA.  :'(

Depends on the SA acquired, suggesting to start learn/look/lurk for these stuffs too apart from the SA, cause sometimes this activity alone will take quite sometimes & energy to accumulate, let alone the cost.

As tautech pointed above, my suggestion for starting point sorted by priority imo : sacrificial connector, DC block (if needed) .. various attenuators ... and so on ...  :palm:

Just an example of small portion part of the plumbing stuffs, these used things alone cost > 50 bucks  ..  ::)
(https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=411425;image)

Hmm, good point. Additionally, I thought Tek oscilloscope probes were expensive till I saw the prices that even old HP RF probes go for too.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: BravoV on October 19, 2018, 05:39:24 am
Hmm, good point. Additionally, I thought Tek oscilloscope probes were expensive till I saw the prices that even old HP RF probes go for too.

LOL ... I can see you've seen and opened a nasty can of worm, arent you ?  :-DD

Yep, those high freq GHz range RF probes are pricey, trust me, I've lurked and waited patiently for years, and finally able to grab one at decent price. Its a HP 54701A 2.5GHz active probe, aged > 3 decades  ::), complete with it's "accessories", emphasized on the word "accessories" as at above few hundreds of MHz, probing technique and accessories becomes really matter, plain probe alone won't cut it, say compared like using passive probe. So take note on this tiny matter if you plan to buy an used one.

(https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=445120;image)


I have similar situation as you, as hobbyist, my best scope is Tek 2465B too, which is max at 400MHz as you aware of. Below photo quoted from your post from other 2465B thread if you don't mind, as signal above 400Mhz will be attenuated, coupled with a RF probe + a SA + correct probing technique & tools, I've been acquiring signals that I've never been able to see and measure with decent accuracy before.

As only hobbyist, I'm content and find this situation is a decent & reasonable compromise, rather than buying GHz capable scope which is overkill, at least for me.

(https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/?action=dlattach;attach=551057;image)
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 19, 2018, 06:55:36 am
Hmm, good point. Additionally, I thought Tek oscilloscope probes were expensive till I saw the prices that even old HP RF probes go for too.

LOL ... I can see you've seen and opened a nasty can of worm, arent you ?  :-DD

Yep, those high freq GHz range RF probes are pricey, trust me, I've lurked and waited patiently for years, and finally able to grab one at decent price. Its a HP 54701A 2.5GHz active probe, aged > 3 decades  ::), complete with it's "accessories", emphasized on the word "accessories" as at above few hundreds of MHz, probing technique and accessories becomes really matter, plain probe alone won't cut it, say compared like using passive probe. So take note on this tiny matter if you plan to buy an used one.

(https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=445120;image)


I have similar situation as you, as hobbyist, my best scope is Tek 2465B too, which is max at 400MHz as you aware of. Below photo quoted from your post from other 2465B thread if you don't mind, as signal above 400Mhz will be attenuated, coupled with a RF probe + a SA + correct probing technique & tools, I've been acquiring signals that I've never been able to see and measure with decent accuracy before.

As only hobbyist, I'm content and find this situation is a decent & reasonable compromise, rather than buying GHz capable scope which is overkill, at least for me.

(https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/?action=dlattach;attach=551057;image)

Yeah...it's one hell of a can of worms.  :-DD No worries on the photo; definitely illustrative of your point. I might have missed it above, what what SA do you run?

Looks like that model of probe is actually within reach pricewise...I was finding newer ones than that in the $3-5000 range (or more) and they were STILL old. 
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: BravoV on October 19, 2018, 07:18:40 am
Yeah...it's one hell of a can of worms.  :-DD No worries on the photo; definitely illustrative of your point. I might have missed it above, what what SA do you run?

Looks like that model of probe is actually within reach pricewise...I was finding newer ones than that in the $3-5000 range (or more) and they were STILL old.

Its not widely known, a Korean made called Nex1 NS-30 9KHz-3GHz, posted the detail in the "Used SA guide" too, the OP didn't update it in the list, click here -> Nex1 NS-30 , 9KHz-3GHz & photos (https://www.eevblog.com/forum/testgear/used-spectrum-analyzer-buyer_s-guide/msg1474192/#msg1474192)
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 19, 2018, 08:22:40 am
Yeah...it's one hell of a can of worms.  :-DD No worries on the photo; definitely illustrative of your point. I might have missed it above, what what SA do you run?

Looks like that model of probe is actually within reach pricewise...I was finding newer ones than that in the $3-5000 range (or more) and they were STILL old.

Its not widely known, a Korean made called Nex1 NS-30 9KHz-3GHz, posted the detail in the "Used SA guide" too, the OP didn't update it in the list, click here -> Nex1 NS-30 , 9KHz-3GHz & photos (https://www.eevblog.com/forum/testgear/used-spectrum-analyzer-buyer_s-guide/msg1474192/#msg1474192)

Very interesting! At this point I'm thinking my best bet is to learn as much as I can and wait for a deal, preferably when I am able to get more bench space. Then steel myself for the accessories purchases. I think I really want a nice 8566B...not only is it a fine instrument but my inner nerd just loves the fact that you can buy a lab grade instrument that cost as much as a house new and have it at home today.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: nctnico on October 19, 2018, 10:04:01 am
1) What are reasonable prices in 2018 to be paying for working HP "big iron" SAs such as 8566, 8568? Some of the ones I'm seeing on ebay seem to be very highly priced considering their age, even considering the instrument cost as much as a nice car or even a house new.
IMHO the old SAs from HP are way overprized. These are also very old and their specs are not as good as modern gear. Other brands like Anritsu and Advantest also make very good spectrum analysers and good deals can be found on Ebay if you have a little bit of patience.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 19, 2018, 08:34:11 pm

IMHO the old SAs from HP are way overprized. These are also very old and their specs are not as good as modern gear. Other brands like Anritsu and Advantest also make very good spectrum analysers and good deals can be found on Ebay if you have a little bit of patience.

But I'd have to get a mortgage to afford a new one with similar capabilities, so there's no free lunch. I'm keeping my eyes open and I'm not in a hurry to buy anything just yet. :)
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: Bud on October 19, 2018, 08:46:28 pm
1) What are reasonable prices in 2018 to be paying for working HP "big iron" SAs such as 8566, 8568? Some of the ones I'm seeing on ebay seem to be very highly priced considering their age, even considering the instrument cost as much as a nice car or even a house new.
IMHO the old SAs from HP are way overprized. These are also very old and their specs are not as good as modern gear. Other brands like Anritsu and Advantest also make very good spectrum analysers and good deals can be found on Ebay if you have a little bit of patience.

I am curious which specs exactly are not as good?
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: nctnico on October 19, 2018, 09:21:28 pm

IMHO the old SAs from HP are way overprized. These are also very old and their specs are not as good as modern gear. Other brands like Anritsu and Advantest also make very good spectrum analysers and good deals can be found on Ebay if you have a little bit of patience.
But I'd have to get a mortgage to afford a new one with similar capabilities, so there's no free lunch. I'm keeping my eyes open and I'm not in a hurry to buy anything just yet. :)
You don't need a mortgage. For less than $2000 you can buy very nice used gear from Advantest or Anritsu for example.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: DaJMasta on October 19, 2018, 09:39:58 pm
I am curious which specs exactly are not as good?

Looking at the datasheet for the HP 8568, a more modern instrument would have....
Lower DANL, spurious harmonics, level accuracy uncertainty, RBW options, VBW options
And better sweep speed, number of points in sweep, timebase spectral purity and phase noise, measurement capabilities (number of markers, channel power, etc.), input protection in many cases...

And that's just looking at the surface level stuff.  Look at the amplitude range on the 8568A, +30dBm to -135dBm.  Even with a 10Hz RBW (instead of 1Hz with averaging to get best results), the DANL of either the Rigol or the Siglent is lower than the 8568A can even display according to specification, the sweep has many more measurement points and is still very fast, the timebase has lower phase noise, etc.


People often put old gear they grew up revering on a pedestal, and while there is some very good old gear and some old gear which is nearly as good as the top of the line stuff (I'm looking at you 8.5 digit DMMs), the vast majority of equipment has improved DRAMATICALLY from the early 80s or wherever your vintage HP bit of kit of choice is from.  An entry level modern bench SA will preform better than nearly any top end system from the 80s.... and why would anyone expect differently?  Now, there are service manuals available, and the build quality is good, and you're probably used to the interface if you've used them before... there are a lot of value propositions for valuing the older gear, but there is really no benefit to assuming a giant old SA is going to preform better than a newer one, especially when nothing on the datasheet suggests it.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: KE5FX on October 20, 2018, 12:38:44 am
IMHO the old SAs from HP are way overprized. These are also very old and their specs are not as good as modern gear. Other brands like Anritsu and Advantest also make very good spectrum analysers and good deals can be found on Ebay if you have a little bit of patience.

Not all specs appear on a spec sheet.  The ability to flip the power switch on my 8566B and instantly measure power levels within 0.5 dB of a comparable measurement made 6 months ago is why that particular boatanchor is still on my bench.

Quote
You don't need a mortgage. For less than $2000 you can buy very nice used gear from Advantest or Anritsu for example.

... which you may not be able to maintain due to lack of service information. 

Those companies' business model was to copy similar instruments from -- you guessed it -- HP.  At this point, you might as well get the real thing.

The best advice is really to buy something cheap and see what limitations you encounter with it, then use that insight to decide what to get next.   You don't want to be the guy who buys the most expensive guitar in the store before you take your first lesson.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: KE5FX on October 20, 2018, 12:43:16 am
Looking at the datasheet for the HP 8568, a more modern instrument would have....
Lower DANL, spurious harmonics, level accuracy uncertainty, RBW options, VBW options
And better sweep speed

Yes, hard to beat an FFT in that department.

Quote
number of points in sweep

1001 is plenty.

Quote
timebase spectral purity and phase noise

LOL, fat chance.  Maybe out past 100 kHz...

Quote
Even with a 10Hz RBW (instead of 1Hz with averaging to get best results), the DANL of either the Rigol or the Siglent is lower than the 8568A can even display according to specification, the sweep has many more measurement points and is still very fast, the timebase has lower phase noise, etc.

Lower DANL == they put a $2 preamp in front of the first mixer.  That's about what it would cost you to add your own to an 8568.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: tkamiya on October 20, 2018, 01:24:50 am
If it wasn't HP's popularity and abundance in market, I wouldn't have FOURTEEN SAs in my house. :scared:

Parts are plenty available too....  In fact, I have my own stock of parts.

If I have to carry it around, I would go with Rigol or Siglent in a heartbeat.  But for stationary lab work, I like my setup.  One difference between old stuff and new are use of buttons vs menus.  I have a modern scope.  It's nice to hit AUTO and get something to show on display.  But if I have to change anything, it's often menu, up, up, push, twist, push.  I can't remember what's where.  Old stuff has each function assigned to well labeled knobs and switches.  I don't have to refer to manuals so often.  It took me a read on manual to find where AC/DC couplings were hiding.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 20, 2018, 02:00:42 am


The best advice is really to buy something cheap and see what limitations you encounter with it, then use that insight to decide what to get next.   You don't want to be the guy who buys the most expensive guitar in the store before you take your first lesson.

I may have found a deal on a 8569B that the seller says works, actually. I think I understand from the buyer's guide that the 856X is always better in RF performance than other models. I don't think it has as low RBW as the big boys, but it could be fun for a first one.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: tkamiya on October 20, 2018, 02:23:30 am
Oh, one more thing....

I had a conversation with calibration/repair technician and he mentioned that:

If you go outside of HP/Agilent/whatevernext, parts availability and documentation availability can suffer.  For HP, owner's manual, technical manual, repair guide, tuning guide, etc, are readily available.  Parts show up often on eBay.  Not so for other brands.  Many Japanese makes did not release their manuals to public like HP did, and parts are almost non-existent.  You'll end up needing to do a parts level repair without much of guides.  This is why I stay with HP and Tektronix.  Everything is SO available.  Being an old stuff, they will need maintenance.  Before you make a decision, my recommendation is to look to online resources to see what you can get, parts and manual wise.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 20, 2018, 02:29:35 am
Oh, one more thing....

I had a conversation with calibration/repair technician and he mentioned that:

If you go outside of HP/Agilent/whatevernext, parts availability and documentation availability can suffer.  For HP, owner's manual, technical manual, repair guide, tuning guide, etc, are readily available.  Parts show up often on eBay.  Not so for other brands.  Many Japanese makes did not release their manuals to public like HP did, and parts are almost non-existent.  You'll end up needing to do a parts level repair without much of guides.  This is why I stay with HP and Tektronix.  Everything is SO available.  Being an old stuff, they will need maintenance.  Before you make a decision, my recommendation is to look to online resources to see what you can get, parts and manual wise.

Repairability is definitely always a plus. I have found PDF of the 8569B operators and service manuals online already.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: KE5FX on October 20, 2018, 02:43:56 am
I may have found a deal on a 8569B that the seller says works, actually. I think I understand from the buyer's guide that the 856X is always better in RF performance than other models. I don't think it has as low RBW as the big boys, but it could be fun for a first one.

At the right price, sure.  It's less capable than either the huge benchtop analyzers or the newer portables, so the price should be lower as well. 
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 20, 2018, 03:31:08 am
I may have found a deal on a 8569B that the seller says works, actually. I think I understand from the buyer's guide that the 856X is always better in RF performance than other models. I don't think it has as low RBW as the big boys, but it could be fun for a first one.

At the right price, sure.  It's less capable than either the huge benchtop analyzers or the newer portables, so the price should be lower as well.

It's listed for 350 and the seller is taking offers.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: Tony_G on October 20, 2018, 04:30:36 am
Repairability is definitely always a plus. I have found PDF of the 8569B operators and service manuals online already.


Artem Manuals is a great resource for quality scans of old manuals. KO4BB is also outstanding.

TonyG
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: rx8pilot on October 20, 2018, 04:32:41 am

Artem Manuals is a great resource for quality scans of old manuals. KO4BB is also outstanding.

TonyG

ARTEK
http://artekmanuals.com/ (http://artekmanuals.com/)
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 20, 2018, 07:51:42 am

ARTEK
http://artekmanuals.com/ (http://artekmanuals.com/)

Wow, that is a nice resource! Thanks!
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: rf-loop on October 20, 2018, 08:17:20 am


The best advice is really to buy something cheap and see what limitations you encounter with it, then use that insight to decide what to get next.   You don't want to be the guy who buys the most expensive guitar in the store before you take your first lesson.

I may have found a deal on a 8569B that the seller says works, actually. I think I understand from the buyer's guide that the 856X is always better in RF performance than other models. I don't think it has as low RBW as the big boys, but it could be fun for a first one.

Check carefully that all front panel adjustments works 100% and not just intermittently or some step not at all. It is real nightmare if they are not in good condition. If it need repair it really need know how to do and then even more importantly, what must not do.  (there is available quite good instructions for repair - service work)

Years ago I have owned one of this SA (yes it was nearly like "new")

This front panel is this SA's "Achilles heel"  if it is handled using "heavy hand". Also there is some plastic parts what may break even without touching just due to some material ageing.

Here is one example what I mean is "Achilles heel" (http://www.simonsdialogs.com/2016/01/hp-8569b-front-panel-assy-repair-rotary-switches/)
 And here. (http://www.simonsdialogs.com/2015/11/hp-8569b-spectrum-analyzer-reference-level-adjust-repair-broken-contact/)
(I think some years in history HP use this construction in many places. It can ask what they smoke these years there)

Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 20, 2018, 08:21:52 am


The best advice is really to buy something cheap and see what limitations you encounter with it, then use that insight to decide what to get next.   You don't want to be the guy who buys the most expensive guitar in the store before you take your first lesson.

I may have found a deal on a 8569B that the seller says works, actually. I think I understand from the buyer's guide that the 856X is always better in RF performance than other models. I don't think it has as low RBW as the big boys, but it could be fun for a first one.

Check carefully that all front panel adjustments works 100% and not just intermittently or some step not at all. It is real nightmare if they are not in good condition. If it need repair it really need know how to do and then even more importantly, what must not do.  (there is available quite good instructions for repair - service work)

Years ago I have owned one of this SA (yes it was nearly like "new")

This front panel is this SA's "Achilles heel"  if it is handled using "heavy hand". Also there is some plastic parts what may break even without touching just due to some material ageing.

Here is one example what I mean is "Achilles heel" (http://www.simonsdialogs.com/2015/11/hp-8569b-spectrum-analyzer-reference-level-adjust-repair-broken-contact/)
(I think some years in history HP use this construction in many places. It can ask what they smoke these years there)

Thanks for the heads-up! At least it's fixable. TBH if the deal works out the price is low enough I'm not too worried.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: KE5FX on October 20, 2018, 09:17:14 am
Thanks for the heads-up! At least it's fixable. TBH if the deal works out the price is low enough I'm not too worried.

Yeah, you'll get $350 worth of entertainment value out of it if nothing else.  :-+ That's a good price for an instrument with coverage from HF to K-band, as long as it works or can be fixed economically.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: nctnico on October 20, 2018, 10:22:57 am
Quote
You don't need a mortgage. For less than $2000 you can buy very nice used gear from Advantest or Anritsu for example.
... which you may not be able to maintain due to lack of service information. 
So far Advantest SAs have proven to be perfectly fixable without schematics or service manual. But then again equipment which is newer is less likely to break anyway.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 20, 2018, 09:14:59 pm
Thanks for the heads-up! At least it's fixable. TBH if the deal works out the price is low enough I'm not too worried.

Yeah, you'll get $350 worth of entertainment value out of it if nothing else.  :-+ That's a good price for an instrument with coverage from HF to K-band, as long as it works or can be fixed economically.

I may be able to get it for $300, waiting on the seller.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: G0HZU on October 20, 2018, 10:04:19 pm
Quote
1) What are reasonable prices in 2018 to be paying for working HP "big iron" SAs such as 8566, 8568?
I bought my HP8566B as an ex rental from a large TE rental company for £1000 about 7 or 8 years ago. At the time this was a huge bargain but I did have to do a few minor repairs to it over the first couple of years. Nothing difficult or expensive but these old analysers are starting to suffer with cap failures that often affect the YIG operation. So the analyser can show signs of sweep instability when this happens.

Today, I'd still expect a healthy HP8566B to be about £1200-£1500 here in the UK. A less healthy example might be half this price but you can expect to be taking it apart quite a bit to clear all the niggles.

In 2018 I'd run a mile from the HP8569B unless I was just going to use it for very basic ham related testing across various ham bands up into the microwave bands. $300 is a good price but I'd still rather spend more and get something decent. Are you sure you know what you are compromising if you buy the HP8569? In 2018 this analyser is a bit of a dog compared to the alternatives unless you need a cheap analyser that can cover up to 20GHz or so. I haven't used a HP8569B for many years (and I don't want to) and I recall it doesn't work well at low frequencies so best used for VHF through the microwave bands.

The Siglent analyser looks to be a good alternative for home/hobby use. It has a digital IF and modern display and connectivity and lots of modern features. It can't compare to something like the HP8566B when you compare the design integrity of the RF converter section but it does have a significant advantage for many applications because of its modern digital IF. It is also new and comes with a warranty.  Unless you need the RF design integrity of something like the HP8566B then the Siglent analyser is going to be the more powerful choice IMO.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 20, 2018, 10:08:54 pm
Quote
1) What are reasonable prices in 2018 to be paying for working HP "big iron" SAs such as 8566, 8568?
I bought my HP8566B as an ex rental from a large TE rental company for £1000 about 7 or 8 years ago. At the time this was a huge bargain but I did have to do a few minor repairs to it over the first couple of years. Nothing difficult or expensive but these old analysers are starting to suffer with cap failures that often affect the YIG operation. So the analyser can show signs of sweep instability when this happens.

Today, I'd still expect a healthy HP8566B to be about £1200-£1500 here in the UK. A less healthy example might be half this price but you can expect to be taking it apart quite a bit to clear all the niggles.

In 2018 I'd run a mile from the HP8569B unless I was just going to use it for very basic ham related testing across various ham bands up into the microwave bands. $300 is a good price but I'd still rather spend more and get something decent. Are you sure you know what you are compromising if you buy the HP8569? In 2018 this analyser is a bit of a dog compared to the alternatives unless you need a cheap analyser that can cover up to 20GHz or so. I haven't used a HP8569B for many years (and I don't want to) and I recall it doesn't work well at low frequencies so best used for VHF through the microwave bands.

The Siglent analyser looks to be a good alternative for home/hobby use. It has a digital IF and modern display and connectivity and lots of modern features. It can't compare to something like the HP8566B when you compare the design integrity of the RF converter section but it does have a significant advantage for many applications because of its modern digital IF. It is also new and comes with a warranty.  Unless you need the RF design integrity of something like the HP8566B then the Siglent analyser is going to be the more powerful choice IMO.

Yes, I am aware that it is a compromise. I mainly intend to use it for basic testing in and around ham bands. I suspect it won't be my only SA in coming years anyway.  :-DD At the very least, it will let me learn what I want in my next one for reasonable money, rather than spending $1500 or so and realizing it doesn't quite meet my needs.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: tkamiya on October 21, 2018, 03:27:25 pm
I think this is actually a reasonable approach.  $300 ish is an excellent price for ANY working spectrum analyzer.  Using it to learn will help him understand what his real requirements are.  My only concern is, because of price, I hope this is not too-good-to-be-true situation.  That's how I started with 1.8GHz box and recently got a 26.5GHz box. 

Pretty much with hobbyist budget, every SpecAn will be a compromise.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 21, 2018, 04:35:40 pm
I think this is actually a reasonable approach.  $300 ish is an excellent price for ANY working spectrum analyzer.  Using it to learn will help him understand what his real requirements are.  My only concern is, because of price, I hope this is not too-good-to-be-true situation.  That's how I started with 1.8GHz box and recently got a 26.5GHz box. 

Pretty much with hobbyist budget, every SpecAn will be a compromise.

On the other hand, if it turns out to be a repair project, I'll learn from that too. I think it should be serviceable though. Seller has 100% positive rep. He says the front panel is in good order.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: KE5FX on October 21, 2018, 08:34:14 pm
The 8569B could be a good companion to an SSA3021X or similar unit.  It'd be very cost-effective for troubleshooting or experimentation in the microwave range, while the Siglent would give you a lot of useful features in the HF-2 GHz range. 

If you did want to look at the 2.4 GHz or 5 GHz band with the Siglent, you could put the 8569B in zero-span mode and use it as a downconverter.  Not sure if the 8569B had a wideband IF output jumper like the 8566B, but it's easy enough to add one if not.  At $300 it would make sense to view it as a good platform for modification.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 22, 2018, 02:54:05 am
The 8569B could be a good companion to an SSA3021X or similar unit.  It'd be very cost-effective for troubleshooting or experimentation in the microwave range, while the Siglent would give you a lot of useful features in the HF-2 GHz range. 

If you did want to look at the 2.4 GHz or 5 GHz band with the Siglent, you could put the 8569B in zero-span mode and use it as a downconverter.  Not sure if the 8569B had a wideband IF output jumper like the 8566B, but it's easy enough to add one if not.  At $300 it would make sense to view it as a good platform for modification.

That's a great point. I'll definitely keep that in mind as the budget allows. In the meantime, I got on artek manuals and got all the manuals both for this SA and my HP 8657A signal generator.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 22, 2018, 06:06:43 am
Now that I have an instrument on the way, I perused an old question someone asked about what accessories are must-have. So far on my shopping list:

1. Adapters. Lots of adapters.
2. RF attentuators (these seem to be rather expensive, so I'm going to check out a local surplus store I like first, before buying new)
3. DC block
4. Coax

Additionally, I figured on getting a few antennas. I was looking at the RF Explorer nearfield antenna set [1] on Amazon, as well as their power limiter [2]. Reasonably priced, but I assume you get what you pay for. Anything else in the must-have category? Recommended antennas? I was looking at these relatively cheap PCB based antennas [3]. Perhaps a directional antenna of some sort? Perhaps I should also make a post in the RF forum too.

[1]: https://www.amazon.com/gp/product/B01NBTPTOZ/ (https://www.amazon.com/gp/product/B01NBTPTOZ/)
[2]: https://www.amazon.com/gp/product/B00IF8N1BO/ (https://www.amazon.com/gp/product/B00IF8N1BO/)
[3]: https://www.amazon.com/dp/B074QGYHJ2/ (https://www.amazon.com/dp/B074QGYHJ2/)
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: G0HZU on October 25, 2018, 04:15:46 pm
The 8569B could be a good companion to an SSA3021X or similar unit.  It'd be very cost-effective for troubleshooting or experimentation in the microwave range, while the Siglent would give you a lot of useful features in the HF-2 GHz range. 

Yes, I agree... it could be a powerful combination if the budget permits :)
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: tkamiya on October 25, 2018, 06:33:25 pm
Mini circuits have DC blocks that are much reasonably priced and they even go as high as 18GHz.

MCL has coax adapters with good spec for reasonable prices, too. 
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 26, 2018, 04:39:55 pm
Thanks, all!

I received The Beast! It seems to be working fine, I followed the initial adjustment procedure from the manual on the 100 MHz cal signal. The seller happened to have a bag of spare contacts for the front panel, too. He threw them in for free.



Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: tkamiya on October 26, 2018, 04:45:35 pm
You got yourself a heck of a deal!  Was this eBay? 

Your SpecAn looks beautiful and nearly new!  Often times, CRT of this vintage is dim and fuzzy.  Yours looks great!
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 26, 2018, 05:01:56 pm
You got yourself a heck of a deal!  Was this eBay? 

Your SpecAn looks beautiful and nearly new!  Often times, CRT of this vintage is dim and fuzzy.  Yours looks great!

Yep, ebay. It's got a few scuffs but considering it's age it looks great! I'm happy!
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: TheSteve on October 26, 2018, 05:31:35 pm
You gotta love that green screen!
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 27, 2018, 05:00:11 am
You gotta love that green screen!

Heck yes! The only issue I uncovered was that the sweep speed dial may be messed up. All the settings work but they don't match up on the dial to what the screen readout is. Not a big deal though, since I have spare parts for the front panel.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: Tony_G on October 27, 2018, 06:55:55 pm
The dial may have just been put back on incorrectly. If they used the same set screw from other units then a small Allen key is used to remove it.

TonyG
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 28, 2018, 04:25:19 am
The dial may have just been put back on incorrectly. If they used the same set screw from other units then a small Allen key is used to remove it.

TonyG

Good call, I'll take a look at that.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 30, 2018, 03:33:25 am
The knob was indeed loose, which I fixed. However, it's still a bit odd, as it ends up being one off when you turn it a full 360. I wonder if this is intended or not? Every single point of the switch makes contact though, as all the sweep times do work.

 Also, there's a rather strong signal that appears at 0.0 MHz that appears to be internal? There's nothing connected to the input in the attached image.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: DaJMasta on October 30, 2018, 04:06:30 am
That's the low frequency rolloff of the instrument and, because you're centered at zero, it's showing a sideband with power at a negative frequency, which of course is not really present.

It's good down to 10MHz by specification, and these are typically AC coupled (high pass filter), so you're going to have a peak that goes right up as the frequency approaches zero, but because you can move that over to the center, you also see the part of the plot that really doesn't represent data.


Just pointing out that the entire pictured range is out of spec - a 5MHz span centered around 0 would be real readings from 0-2.5MHz, but the specified performance starts at 10MHz.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on October 30, 2018, 04:28:32 am
That's the low frequency rolloff of the instrument and, because you're centered at zero, it's showing a sideband with power at a negative frequency, which of course is not really present.

It's good down to 10MHz by specification, and these are typically AC coupled (high pass filter), so you're going to have a peak that goes right up as the frequency approaches zero, but because you can move that over to the center, you also see the part of the plot that really doesn't represent data.


Just pointing out that the entire pictured range is out of spec - a 5MHz span centered around 0 would be real readings from 0-2.5MHz, but the specified performance starts at 10MHz.

Thanks, that makes sense. So basically I can ignore it.
Title: Re: Spectrum Analyzers: Old Big Iron or New from China?
Post by: 0culus on November 03, 2018, 06:37:43 am
So I did some tuning accuracy tests on this 8569B and I'm impressed; it actually sits inside the specifications in the manual. I unfortunately don't have a microwave source yet, so I could only test the 0.1-1.8 GHz band with my RF generator, which is a limitation, but this is the band I'm using most at the moment anyway!

The manual states that tuning accuracy for the instrument's entire band (0.1-115 GHz; external mixing is required over 22 GHz) is +/- 5 MHz or 0.2% of center frequency (whichever is larger) +20% of frequency span per division.

My results are as follows. All measurements were taken with 500 KHz/div coupled 100 KHz RBW and no internal attenuation.

Internal 100 MHz calibration signal:

100 MHz signal from my 8657A @ -10 dBm, no modulation (which is bang on accurate according to my refurbed Tek 2465B):

Down in the low part of the band the SA is bang on.

1000 MHz signal from the 8657A @ -10 dBm, no modulation:

So up at 1 GHz, it's off by almost exactly +1.5 MHz. 0.2% of 1000 MHz is 2 MHz < 5 MHz, so it's easily in spec according to the manual, adding the 20% of [edit] RBW freq span/div is irrelevant in this case.

Now I realize there are probably way more precise ways to do this (and there are probably variables I'm not accounting for and it's likely farther off in higher bands...), but working with what I have, I'm quite impressed for the price and 34 years old.