Author Topic: Recommendations on Radio Test Set  (Read 731 times)

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Offline axel

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Recommendations on Radio Test Set
« on: August 14, 2019, 03:46:12 pm »
Hi all!

Ham radio operator and fresh-outta-school engineer here. Recently graduated from university, which means I no longer get access to all the fun RF test gear that our ham club at school had (and some of which I helped acquire!). I do a lot of tuning & troubleshooting of radios as a part of the hobby and I really need want  to get my hands on a decent RF test set. At the club, we had a CMU200 which was fantastic for general radio troubleshooting because it could easily measure FM deviation as well as frequency error in one setup. We also had a tank of a VNA, an HP 4195, that was great for filter & amplifier measurements. Now I'm in a 1-bedroom apartment and don't exactly have the room for a huge lab bench, so I'm looking for a compromise.

The older HP cell test sets seem like very attractive options. I've also been considering a CMU200 since they're relatively cheap as well. I really, really want to stay under $1k if I can because even though I'm employed I don't have a lot of disposable income.

My short list of requirements, in order from must-have to would-be-nice:
  • Spectrum Analyzer
  • Modulation Measurement (FM mostly)
  • Decent input power limit (at least 10W)
  • Tracking Generator
  • Relatively small form factor (test bench real-estate is limited)[l/i]
So far what I've found that seem like good options (prices are all averages seen on eBay):
  • HP 8922H, ~$300, can handle 25W and does FM measurements (thanks AMPS!)
  • HP 8935, ~$500, newer unit but less info on capabilities
  • R&S CMU200, ~$600, have used it and love it, but bulky and hardware options can make or break usability
  • Moto R20xx series, ~$800, have also used an R2012 before and it was very useful but limited in feature scope
[li]HP 8920, ~$1500, over budget by a lot but would be a "holy grail" unit for radio testing
[/li][/list]

I'm open to any other suggestions! This is just what I've gathered from primarily research and stuff I've used before.

Thanks in advance!
 

Online 0culus

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Re: Recommendations on Radio Test Set
« Reply #1 on: August 14, 2019, 11:28:21 pm »
OK, it seems to me that you're looking for something that's "one stop shopping", and I understand having space issues. However, to meet your modulation measurement criteria, consider looking for an HP 53310A Modulation Domain Analyzer, preferably with Option 31 (I think) that is the RF comms test that gives you Channel C and LO ports. 2.5 GHz (edit: if you have Channel C), which should more than cover typical amateur radio use.
« Last Edit: August 15, 2019, 12:04:39 am by 0culus »
 

Offline tautech

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Re: Recommendations on Radio Test Set
« Reply #2 on: August 15, 2019, 12:47:28 am »
SVA1015X, 1.5 GHz SA/VNA combo $ 1395 plus options.

10" touch display and a very compact unit with a power of capability.
Avid Rabid Hobbyist
 

Offline kj7e

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Re: Recommendations on Radio Test Set
« Reply #3 on: August 15, 2019, 01:02:32 am »
IFR-500 and a separate spectrum analyzer, or an IFR-1200s.
 

Offline TheSteve

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Re: Recommendations on Radio Test Set
« Reply #4 on: August 15, 2019, 06:20:51 am »
SVA1015X, 1.5 GHz SA/VNA combo $ 1395 plus options.

10" touch display and a very compact unit with a power of capability.

A very cool box, but certainly not an RF test set.

IFR-1200S is a very nice unit, if you do come across a deal or up your budget though you can't say no to an HP-8920 or 8921. It does need to have the mechanical attenuator so it has full performance below 30 MHz.
VE7FM
 

Offline bob91343

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Re: Recommendations on Radio Test Set
« Reply #5 on: August 15, 2019, 06:30:38 am »
I have a Singer-Gertsch FM-10C that needs some work but does it all.

I also have a Lampkin deviation meter.

Both units are up for sale if anyone is interested.  Old stuff but has great reputation.

Bob in Los Angeles
 

Offline jhov

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Re: Recommendations on Radio Test Set
« Reply #6 on: August 16, 2019, 04:25:34 pm »
Anritsu MT8801 or MT8802 with options 01 and 07 might fit your needs. Its rather large and heavy but has nearly everything you require in one box. The only thing is doesn't have is a tracking generator, only a 10MHz to 3GHz RF generator and a 20Hz to 20kHz AF generator.
« Last Edit: August 16, 2019, 04:33:20 pm by jhov »
 

Offline Howardlong

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Re: Recommendations on Radio Test Set
« Reply #7 on: August 16, 2019, 05:08:18 pm »
I've had three radiocommunications test sets that I've used extensively.

The first is a Marconi 2955A which is getting a bit long in the tooth now and has no spec an. But it is excellent for getting most other jobs done, the UI is easy to use after a couple of minutes of familiarisation. Probably the easiest I have to use, mainly because there's no cellular nonsense getting in the way. The one I have has a 75W power capability, I'm not sure if that's standard or not. It'll demodulate AM and FM through an internal speaker. Limited to 1GHz. I had to fix the power transistor on the CRT line output transformer once. Quick boot time.

The second I use is an Anritsu MT8802A with option 7, the spec an. The UI is a PITA because it's designed primarily for cellular use. It has limited power protection (10W), I managed to bust the attenuator in one because of that. I couldn't figure out how to replace the attenuator, the fasteners wouldn't budge. I ended up buying another one. There is no speaker, but it works up to 3GHz including the spec an. The screens go dim, I found that after re-capping the entire unit, my screen suddenly was much brighter. Put aside at least a day to re-cap one of these. Very slow to boot.

The third unit is an Agilent 8935 E6380A. While it's mainly designed for cellular use, you can tailor the unit to power up in a pre-configured mode, and you can store a number of tailored modes on the device itself that you can easily recall. Mine had a power supply fault when it arrived so from memory it looked like it worked but when you hooked anything up to it nothing happened. It turned out to be an easy fix (love those!) a simple LM317 replacement which I had in stock. It operates up to 1GHz plus some random cellular bands above that. It has a tracking generator as well as the spec an. There is a speaker, and composite video out. 75W power continuous. Medium slow to boot.

My use case is 99% final test in production, 1% listening to FM radio ;-)
« Last Edit: August 16, 2019, 05:19:31 pm by Howardlong »
 

Offline axel

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Re: Recommendations on Radio Test Set
« Reply #8 on: August 16, 2019, 05:27:10 pm »
Thanks for the good advice everyone! This really is a fantastic community.

There was a Marconi 2955 on eBay that I missed for $500 shipped & fully tested. Definitely kicking myself for passing that one up.

The club I was in also had an MT8801 (I think) for a brief time as well that was replaced by our current CMU. I remember using it and thinking the same thing about the user interface. Very clunky.

I really do like the idea of the HP 8935 more and more. They seem to be all over eBay for not very much and have a ton of extra features. Anything I need to know that might put me off of the purchase?

To answer others' questions - yes, the one-stop-shop concept is what I'm really going for here. I have room for maybe one large piece of test gear and a small scope to plop down on top of that. I still need to get a proper bench supply as well. These things add up space-wise (and money-wise) pretty quickly.
 

Online 0culus

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Re: Recommendations on Radio Test Set
« Reply #9 on: August 16, 2019, 05:43:25 pm »
Another thing, if you decide to get an HP unit, a 53310A will likely stack nicely on top of it. It has more uses than simply modulation measurements, as k7je can attest. It's also a very good counter, basically a "frequency microscope".
 

Offline Howardlong

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Re: Recommendations on Radio Test Set
« Reply #10 on: August 16, 2019, 05:50:09 pm »
The 8935 is a big and heavy unit compared to the 8920, and the connectors are on the side. Because mine is used in a static environment for a single job, it's not a big deal, but if you intend to use it for lots of different things. consider how you might want to use it.

I have used it old school for a couple of weeks while I was moving, with it sat on its butt on the floor, screen facing up. This is how I often used to work with CRT scopes, with the instrument just to one's side under the bench, it works well if you lack bench space. This mode will afford you easier access to the various ports.

Keep in mind that these units were built like tanks because they were used extensively on cellular base station sites, so are unlikely to be pristine. On the plus side, apart from the regulator problem I mentioned, it's been very reliable (touch wood).

The screen is electroluminescent. It's very readable. I don't know if these have a reputation for being troublesome or not, but mine's been fine.
 

Offline TheDefpom

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Re: Recommendations on Radio Test Set
« Reply #11 on: August 16, 2019, 09:42:55 pm »
Having service info and circuit diagrams are an important consideration.

The HP8920 has service info and circuit diagrams available, I found that out when I was repairing a HP8648B RF signal generator, they have either the same or similar boards in some places, and as the 8648B didn't have diagrams the 8920 ones were used, which allowed me to repair the 8648B unit.

The similarity was pointed out to me by one of the regulars on the live stream I was doing at the time.

Other units likely have repair info too, I know the 2955 does, I have one of those too.

The Rohde & Schwarz CMU200 is another unit I have, it has some nice features, but also some limitations, and there are no circuit diagrams for it.
« Last Edit: August 16, 2019, 09:45:39 pm by TheDefpom »
 

Offline axel

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Re: Recommendations on Radio Test Set
« Reply #12 on: August 17, 2019, 08:25:22 pm »
The 8920 or 8921 would be the Cadillac units I'd love to get my hands on, but the cheapest one I've seen is still $1500 which is a lot to swallow, especially when I'm still building the other parts of my bench as well. But yeah, they're definitely great units in a great form factor.
 

Offline Howardlong

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Re: Recommendations on Radio Test Set
« Reply #13 on: August 17, 2019, 08:38:20 pm »
I agree, had 8920s with the right options been more affordable, I’d have probably gone for one.

In the meantime here is the thread on my initial experiences with the 8935: it’s been working faultlessly ever since (touching wood, crossing fingers etc).

https://www.eevblog.com/forum/testgear/agilent-8935-e6380a-test-set-repair-solved/
 

Offline axel

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Re: Recommendations on Radio Test Set
« Reply #14 on: August 18, 2019, 12:46:53 am »
Thinking the 8935 is probably the way to go, between the internal tracking gen, the 75W input power limit, and the nice screen. It's definitely not "compact" or even "relatively small" but I think the features make up for it. I gotta do some dimensioning on my workbench to see if it'll fit. I've got basically 60"x30" to work with (sorry for the freedom units) and the 8935 will take a huge chunk outta that.
 

Offline Howardlong

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Re: Recommendations on Radio Test Set
« Reply #15 on: August 18, 2019, 01:52:55 pm »
Post #111 here, last two images, it’s at the bottom of the corner stack.

https://www.eevblog.com/forum/chat/sod-your-work-bench-what-can-you-see-from-your-window!/msg2600673/#msg2600673
« Last Edit: August 18, 2019, 01:54:42 pm by Howardlong »
 

Offline Howardlong

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Re: Recommendations on Radio Test Set
« Reply #16 on: August 18, 2019, 02:06:40 pm »
On my old bench, I had it on a relatively high shelf, and had a flat fold down LCD monitor just above the bench relaying the composite video from the 8935. This was fine as I rarely ever needed to access the ports once it was set up, as it’s used almost exclusively as part of a final production test. If you need to be able to access the ports frequently, such as for ad hoc testing, this is not so great.

As I mentioned earlier, you could put it on its butt under the bench. Perhaps put it on a small dolly platform so you can easily wheel it in and out?
 

Offline axel

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Re: Recommendations on Radio Test Set
« Reply #17 on: August 18, 2019, 04:53:30 pm »
On my old bench, I had it on a relatively high shelf, and had a flat fold down LCD monitor just above the bench relaying the composite video from the 8935. This was fine as I rarely ever needed to access the ports once it was set up, as it’s used almost exclusively as part of a final production test. If you need to be able to access the ports frequently, such as for ad hoc testing, this is not so great.

As I mentioned earlier, you could put it on its butt under the bench. Perhaps put it on a small dolly platform so you can easily wheel it in and out?

That actually might be the best solution; the side ports make that a nice and clean way to do it.

Thanks for the help and suggestions everyone! Made an offer on one of the 8935's on eBay and we'll see how it goes.
 

Offline axel

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Re: Recommendations on Radio Test Set
« Reply #18 on: August 19, 2019, 01:47:35 pm »
Alright, managed to win the offer of $400 for a fully working 8935! Now begins the fun waiting period until it gets here.
 


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