Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 1727398 times)

morris6, capt bullshot, URI and 9 Guests are viewing this topic.

Offline bitseeker

  • Super Contributor
  • ***
  • Posts: 7853
  • Country: us
  • Lots of engineer-tweakable parts inside!
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32925 on: June 11, 2019, 02:44:50 am »
Maybe not as splendid as mnementh or med6753 work shown before but here's my today's' small contribution to rehabilitation process of poor, mishandled test instruments :)

First before, two another after soapy bath, and last two after final touches.

Nice cleanup. Does this mean the gasoline worked without melting the panel label?
I TEA.
 

Offline mnementh

  • Super Contributor
  • ***
  • Posts: 4665
  • Country: us
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32926 on: June 11, 2019, 04:18:36 am »
@med, well done with that Heathkit scope, considering what it was like when you got, it been a real labour of love this, it must be because you have so much more usable ones already in your ownership, its just been an exhibition of you doggedness to see it through. Personally, I'd have never started it in the first place, I would have skipped it straight away  :-DD

So credit to you for sticking to it and seeing it through, question is now, what do you plan to do with it now?  :-// :clap:

I'm not sure what I'm going to do with it just yet. Let's face it, it ain't good for nothing expect perhaps working on audio gear. And it certainly looks out of place surrounded by Tek scopes. But I've wanted a vacuum tube project for quite a while to dust off old skills and bring back memories of my youth. It certainly has done that and it's been fun. And when I saw it in that pile of electronics that Kosmic picked up I knew I had to have it. It was the perfect size and while it appeared to be a total basket case I knew it had potential.

I changed both 12AU7's in the vertical amp and it still has a hum issue. So tomorrow I'll start signal tracing with a 300MHz 2465 to fix a 400KHz OL-1.  :-DD

That is BIZZACKLY what I was talking about back when you got all huffy about the BNC jack and said something like "It's not a museum piece; I'm building it to use...!"
To which I responded "What for? Anything (other than a door stop) you could use that for is better diag-ed by EAR!"  :-DD

   I have some WS2812 strip and discrete Led's but to much bother for just 6 of them. It's Nice to now have the 5V RGB strip option easily available for little projects for not much money. Dropped the wrappers off them for a look, close clones of each other but different board maker and take the switches off the IR version and swap the driver chip on the same board. I think I will make a version for the IR board vertically inside the base as it should go through a few mm of smoke grey.

That's exactly what I was thinking when you were talking about doing a board with WS2812s; unless you have a NEED to do the "unicorn blarff" blinking/chasing/wave sequence thing on your projects, then an awful lot of assache for very little return when 5V & 12V RGB is so cheap and easy.  |O  You've got plenty of focal length in most of yours that the "footlighting effect" really doesn't show in the subject matter itself anyways.  :-+

Yup... I've got several of both of those, plus a handful of others. Several years ago I modded one of the 12V ones to run on 5V as I had 5V regulated on the board vs 11.1-9.6V unregulated otherwise.
   Maybe not as splendid as mnementh or med6753 work shown before but here's my today's' small contribution to rehabilitation process of poor, mishandled test instruments :)

First before, two another after soapy bath, and last two after final touches.

Regards
Nice cleanup. Does this mean the gasoline worked without melting the panel label?

What hey? GASOLINE? I don't remember anybody suggesting gasoline...  :o  Nothing on that bezel that Goo-Gone wouldn't make short work of anyhoo. No need to drag out the liquid explosives. YET.  ;)

As you and med have both recently shown; it's amazing what a little patience and a lot of soapy water little soapy water and a lot of patience can accomplish.  :-+

I dunno that I've done anything lately in the same class... though I used to do a dozen pieces a week or more back in my old "Recycled Electronics" business days.  ;)

mnem
*toddling off to ded*
 

Offline med6753

  • Super Contributor
  • ***
  • Posts: 3775
  • Country: us
  • Tek nut
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32927 on: June 11, 2019, 05:08:31 am »
@med, well done with that Heathkit scope, considering what it was like when you got, it been a real labour of love this, it must be because you have so much more usable ones already in your ownership, its just been an exhibition of you doggedness to see it through. Personally, I'd have never started it in the first place, I would have skipped it straight away  :-DD

So credit to you for sticking to it and seeing it through, question is now, what do you plan to do with it now?  :-// :clap:

I'm not sure what I'm going to do with it just yet. Let's face it, it ain't good for nothing expect perhaps working on audio gear. And it certainly looks out of place surrounded by Tek scopes. But I've wanted a vacuum tube project for quite a while to dust off old skills and bring back memories of my youth. It certainly has done that and it's been fun. And when I saw it in that pile of electronics that Kosmic picked up I knew I had to have it. It was the perfect size and while it appeared to be a total basket case I knew it had potential.

I changed both 12AU7's in the vertical amp and it still has a hum issue. So tomorrow I'll start signal tracing with a 300MHz 2465 to fix a 400KHz OL-1.  :-DD

That is BIZZACKLY what I was talking about back when you got all huffy about the BNC jack and said something like "It's not a museum piece; I'm building it to use...!"
To which I responded "What for? Anything (other than a door stop) you could use that for is better diag-ed by EAR!"  :-DD


News Flash.....my initial response to you was because you got your panties twisted in a bunch about the BNC jack. Turns out I'm using that BNC jack as I had anticipated to easily connect in the function generator for testing. And as far as using it, yea....it's gonna be limited for any use but the point is it will be useful because my intention is to have it 100% functional. But ultimately that's MY decision whether to use it or not and if I chose it to be a shelf queen then so be it.  :P ;D

So.......take your huffy and ride off into the sun set partner...... >:D :-DD
An old gray beard with an attitude.
 

Offline bitseeker

  • Super Contributor
  • ***
  • Posts: 7853
  • Country: us
  • Lots of engineer-tweakable parts inside!
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32928 on: June 11, 2019, 05:12:39 am »
   Maybe not as splendid as mnementh or med6753 work shown before but here's my today's' small contribution to rehabilitation process of poor, mishandled test instruments :)

First before, two another after soapy bath, and last two after final touches.

Regards
Nice cleanup. Does this mean the gasoline worked without melting the panel label?

What hey? GASOLINE? I don't remember anybody suggesting gasoline...  :o  Nothing on that bezel that Goo-Gone wouldn't make short work of anyhoo. No need to drag out the liquid explosives. YET.  ;)

Oh, oops, that was a different thread where someone suggested petrol. 'Twas not I. One cannot have such things around open (dwagon) flame.
I TEA.
 

Offline mnementh

  • Super Contributor
  • ***
  • Posts: 4665
  • Country: us
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32929 on: June 11, 2019, 07:55:26 am »
@med, well done with that Heathkit scope, considering what it was like when you got, it been a real labour of love this, it must be because you have so much more usable ones already in your ownership, its just been an exhibition of you doggedness to see it through. Personally, I'd have never started it in the first place, I would have skipped it straight away  :-DD

So credit to you for sticking to it and seeing it through, question is now, what do you plan to do with it now?  :-// :clap:

I'm not sure what I'm going to do with it just yet. Let's face it, it ain't good for nothing expect perhaps working on audio gear. And it certainly looks out of place surrounded by Tek scopes. But I've wanted a vacuum tube project for quite a while to dust off old skills and bring back memories of my youth. It certainly has done that and it's been fun. And when I saw it in that pile of electronics that Kosmic picked up I knew I had to have it. It was the perfect size and while it appeared to be a total basket case I knew it had potential.

I changed both 12AU7's in the vertical amp and it still has a hum issue. So tomorrow I'll start signal tracing with a 300MHz 2465 to fix a 400KHz OL-1.  :-DD

That is BIZZACKLY what I was talking about back when you got all huffy about the BNC jack and said something like "It's not a museum piece; I'm building it to use...!"
To which I responded "What for? Anything (other than a door stop) you could use that for is better diag-ed by EAR!"  :-DD


News Flash.....my initial response to you was because you got your panties twisted in a bunch about the BNC jack. Turns out I'm using that BNC jack as I had anticipated to easily connect in the function generator for testing. And as far as using it, yea....it's gonna be limited for any use but the point is it will be useful because my intention is to have it 100% functional. But ultimately that's MY decision whether to use it or not and if I chose it to be a shelf queen then so be it.  :P ;D

So.......take your huffy and ride off into the sun set partner...... >:D :-DD

Down boy... down... it's okay, he's a friendly. ;)

   "grrrrrrr..."

Ummm.... okay... would you chill out for a Scooby Snak?  :-DD


I didn't get my panties in a bunch; I gave my opinion and also grudgingly accepted yours as it was you who took on this costly expedition.

In case you haven't noticed, I've been quite supportive since I came to terms with your dogged determination to do it sideways... err, "Do it my wa-a-a-a-ay..."  ;) Go back through the last few pages especially.

mnem
 :P pppppppppttttttttbbbbbbbbbppppppp!!!
« Last Edit: June 11, 2019, 08:04:20 am by mnementh »
 

Offline BU508A

  • Frequent Contributor
  • **
  • Posts: 789
  • Country: de
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32930 on: June 11, 2019, 08:31:48 am »
Really nice pile of things for just the cost of shipping. A lot of GR-874 stuff, of which I had none. The trombone line is pretty cool, and apparently quite expensive according to some fleabay sellers...

This reminds me of something:
Is anyone of you guys at the HAM Radio in Friedrichshafen (Germany) around 21st of June?

https://www.hamradio-friedrichshafen.com/

I'll be there on Friday (21.6.2019)

Mounty
“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 

Offline No.Mad

  • Contributor
  • Posts: 40
  • Country: pl
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32931 on: June 11, 2019, 08:59:47 am »
   Maybe not as splendid as mnementh or med6753 work shown before but here's my today's' small contribution to rehabilitation process of poor, mishandled test instruments :)

First before, two another after soapy bath, and last two after final touches.

Regards
Nice cleanup. Does this mean the gasoline worked without melting the panel label?

What hey? GASOLINE? I don't remember anybody suggesting gasoline...  :o  Nothing on that bezel that Goo-Gone wouldn't make short work of anyhoo. No need to drag out the liquid explosives. YET.  ;)

Oh, oops, that was a different thread where someone suggested petrol. 'Twas not I. One cannot have such things around open (dwagon) flame.

This thread: https://www.eevblog.com/forum/repair/repair-replace-the-textured-vinylpaint-on-hp-and-other-te/msg2476245/#msg2476245

Maybe not gasoline, cause in UK there are limited options with getting flammable stuff (but you can get acid easily from Ebay  :-// ). Good luck getting 100ml from petrol station, as minimum is 3L that you can get. I used a thinner with aromatics (see photo for brand), cottonbuds and a lot of patience. Then polishing with toothpaste.
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 11224
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32932 on: June 11, 2019, 09:12:17 am »
I'd just siphon some out of the car if I wanted a small amount.

I usually use generic antibacterial spray + kitchen roll on stickers. Have to work at them a bit but never damages the surface. If I need something a bit stronger, isopropyl alcohol: https://uk.rs-online.com/web/p/precision-cleaners-degreasers/0567890/

Latter also works nicely getting flux off PCBs. Usually scrub them with that and a paint brush then rinse them under the tap and then stick them on the radiator for an hour.
 

Online Ice-Tea

  • Super Contributor
  • ***
  • Posts: 1432
  • Country: be
    • Freelance Hardware Engineer
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32933 on: June 11, 2019, 09:13:55 am »
Already posted this in the equipment score thread but I wouldn't want to miss the opportunity to trigger your addtictions so croosposting  :-DD

19"Power (about 13kW of it..)

2 Channel SDA. Stacked three high, that means 6 channel. Riggght?

Need BW?

Do you need a probe with that order, Sir?
eBay shop with all the gear you need!
FS: Agilent 54815A, 54825A, R&S CMU200, CRTU, SFU, SMIQ06L, Marconi 6201B, Lecroy WP 950, 9354TM, Tek THS720P, Anritsu MG3671A 2.75G I/Q RF gen, Keithley 238 SMU
 
The following users thanked this post: med6753, mnementh

Online tggzzz

  • Super Contributor
  • ***
  • Posts: 9666
  • Country: gb
    • Having fun doing more, with less
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32934 on: June 11, 2019, 09:36:38 am »
Maybe not gasoline, cause in UK there are limited options with getting flammable stuff (but you can get acid easily from Ebay  :-// ). Good luck getting 100ml from petrol station, as minimum is 3L that you can get. I used a thinner with aromatics (see photo for brand), cottonbuds and a lot of patience. Then polishing with toothpaste.

Liquid lighter fluid is readily available and made from naptha, e.g. 100ml of https://www.tesco.com/groceries/en-GB/products/274057144
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline VK5RC

  • Supporter
  • ****
  • Posts: 2225
  • Country: au
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32935 on: June 11, 2019, 09:44:10 am »
A bit of a quiz, what is the below part?
SMA 50 ohm for size.
For the jammy git award what piece of test gear uses it?
Rob
Whoah! Watch where that landed we might need it later.
 

Online tautech

  • Super Contributor
  • ***
  • Posts: 15737
  • Country: nz
  • Taupaki Technologies Ltd. NZ Siglent Distributor
    • Taupaki Technologies Ltd.
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32936 on: June 11, 2019, 10:01:45 am »
Maybe not gasoline, cause in UK there are limited options with getting flammable stuff (but you can get acid easily from Ebay  :-// ). Good luck getting 100ml from petrol station, as minimum is 3L that you can get. I used a thinner with aromatics (see photo for brand), cottonbuds and a lot of patience. Then polishing with toothpaste.

Liquid lighter fluid is readily available and made from naptha, e.g. 100ml of https://www.tesco.com/groceries/en-GB/products/274057144
Cleaning up decades of grime off a 1970 lathe I found White Spirits to be the magic potion beating all manner of solvents I had on hand and whats more it was probably the least nasty of what I had planned to use.  :phew:
Avid Rabid Hobbyist
 

Offline Vgkid

  • Super Contributor
  • ***
  • Posts: 2504
  • Country: us
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32937 on: June 11, 2019, 10:05:28 am »
A bit of a quiz, what is the below part?
SMA 50 ohm for size.
For the jammy git award what piece of test gear uses it?
Rob
Looks like a rms to dc thermocouple converter, but it is missing a wire(I think).
If you own any North Hills Electronics gear, message me. L&N Fan
 

Offline VK5RC

  • Supporter
  • ****
  • Posts: 2225
  • Country: au
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32938 on: June 11, 2019, 10:19:10 am »
Too easy, you got it, three wires, matched pair, for a HP 3400a
Whoah! Watch where that landed we might need it later.
 

Online tggzzz

  • Super Contributor
  • ***
  • Posts: 9666
  • Country: gb
    • Having fun doing more, with less
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32939 on: June 11, 2019, 10:36:10 am »
Some good news and a couple of buggers.

The (old) bad news was that I got a modulation domain analyser that will be going to the tip.

The (new) good news was that I was able to rescue the hp10811 10MHz OCXO (and some BNC sockets!), and that I've now built that into a box, which works nicely.

The OCXO box I built consisted of the hp80111-60111 OCXO, a Sziklai-based capacitance multiplier (as per TAoE), and a 12V regulator made from an LM732 (as recommended in the old data sheet, but the LM732 still has a good low-noise voltage reference).

At the voltnut meetup in Cardiff a couple of days ago I was able to measure its frequency against a rubidium oscillator, courtesy of dkozel. Without tweaking, the result was a rather gratifying....

There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline med6753

  • Super Contributor
  • ***
  • Posts: 3775
  • Country: us
  • Tek nut
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32940 on: June 11, 2019, 10:49:17 am »


Down boy... down... it's okay, he's a friendly. ;)

   "grrrrrrr..."

Ummm.... okay... would you chill out for a Scooby Snak?  :-DD


I didn't get my panties in a bunch; I gave my opinion and also grudgingly accepted yours as it was you who took on this costly expedition.

In case you haven't noticed, I've been quite supportive since I came to terms with your dogged determination to do it sideways... err, "Do it my wa-a-a-a-ay..."  ;) Go back through the last few pages especially.

mnem
 :P pppppppppttttttttbbbbbbbbbppppppp!!!

This is TEA. If I have to explain myself then you don't get it.  ;D But I know you get it. But I also know that you like to bust my balls. For every action there will be an equal and opposite reaction....so back at ya.  :P :-DD

I know you've been supportive. And I greatly appreciate it.  :-+

Now put the Huffy away....you're too big for it.  >:D :-DD :-DD

« Last Edit: June 11, 2019, 10:50:58 am by med6753 »
An old gray beard with an attitude.
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 11224
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32941 on: June 11, 2019, 10:52:48 am »
Some good news and a couple of buggers.

The (old) bad news was that I got a modulation domain analyser that will be going to the tip.

The (new) good news was that I was able to rescue the hp10811 10MHz OCXO (and some BNC sockets!), and that I've now built that into a box, which works nicely.

The OCXO box I built consisted of the hp80111-60111 OCXO, a Sziklai-based capacitance multiplier (as per TAoE), and a 12V regulator made from an LM732 (as recommended in the old data sheet, but the LM732 still has a good low-noise voltage reference).

At the voltnut meetup in Cardiff a couple of days ago I was able to measure its frequency against a rubidium oscillator, courtesy of dkozel. Without tweaking, the result was a rather gratifying....



Excellent result  :-+

I'm going to try and do something with my two remaining Bliley surplus OCXO modules similar. GPS locking one is an option as well but I haven't found a decent GPS module with a 10KHz output and don't want to wait several hours for a 1ppm output module to phase lock potentially. I also don't have the patience to debug something which takes damn forever to lock and then drifts past the expected lock point like a whippet after a sausage.

Talking of counters, does this sound reasonable for a basic DMM style handheld counter? Mainly interested in tempco. It'll be checked against a frequency standard regularly once I've got a GPSDO sorted. It's not GPSDO referenced though.



Measurement frequency is always sub-30MHz for me with some finger in the air "it'll do" at 144MHz-1GHz. Figure that once it's properly calibrated, that's a total drift of 150Hz/year at 30MHz which I can live with. It will go to 3GHz but that's mostly unnecessary.
« Last Edit: June 11, 2019, 10:54:47 am by bd139 »
 

Offline Specmaster

  • Super Contributor
  • ***
  • Posts: 7340
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32942 on: June 11, 2019, 02:21:14 pm »
I'd just siphon some out of the car if I wanted a small amount.

I usually use generic antibacterial spray + kitchen roll on stickers. Have to work at them a bit but never damages the surface. If I need something a bit stronger, isopropyl alcohol: https://uk.rs-online.com/web/p/precision-cleaners-degreasers/0567890/

Latter also works nicely getting flux off PCBs. Usually scrub them with that and a paint brush then rinse them under the tap and then stick them on the radiator for an hour.
Or you could get a can of lighter fuel and be in greater control of if while in use to.

Sent from my POT-LX1 using Tapatalk

Who let Murphy in?
 

Offline Specmaster

  • Super Contributor
  • ***
  • Posts: 7340
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32943 on: June 11, 2019, 02:23:53 pm »
Maybe not gasoline, cause in UK there are limited options with getting flammable stuff (but you can get acid easily from Ebay  :-// ). Good luck getting 100ml from petrol station, as minimum is 3L that you can get. I used a thinner with aromatics (see photo for brand), cottonbuds and a lot of patience. Then polishing with toothpaste.

Liquid lighter fluid is readily available and made from naptha, e.g. 100ml of https://www.tesco.com/groceries/en-GB/products/274057144
Gah, I just made the same point but not given a brand name [emoji16]

Sent from my POT-LX1 using Tapatalk

Who let Murphy in?
 

Online tggzzz

  • Super Contributor
  • ***
  • Posts: 9666
  • Country: gb
    • Having fun doing more, with less
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32944 on: June 11, 2019, 02:30:28 pm »
Some good news and a couple of buggers.

The (old) bad news was that I got a modulation domain analyser that will be going to the tip.

The (new) good news was that I was able to rescue the hp10811 10MHz OCXO (and some BNC sockets!), and that I've now built that into a box, which works nicely.

The OCXO box I built consisted of the hp80111-60111 OCXO, a Sziklai-based capacitance multiplier (as per TAoE), and a 12V regulator made from an LM732 (as recommended in the old data sheet, but the LM732 still has a good low-noise voltage reference).

At the voltnut meetup in Cardiff a couple of days ago I was able to measure its frequency against a rubidium oscillator, courtesy of dkozel. Without tweaking, the result was a rather gratifying....



Excellent result  :-+

I'm going to try and do something with my two remaining Bliley surplus OCXO modules similar. GPS locking one is an option as well but I haven't found a decent GPS module with a 10KHz output and don't want to wait several hours for a 1ppm output module to phase lock potentially. I also don't have the patience to debug something which takes damn forever to lock and then drifts past the expected lock point like a whippet after a sausage.

The 80111 has a tuning voltage input, but I disabled it. I stuck an extra BNC socket and LED on the box with a view to disciplining it later, but I'm seriously hoping I don't need to. Ensuring that a closed loop feedback system with time constants measured in hours/days would require knowlege and patience.

Quote
Talking of counters, does this sound reasonable for a basic DMM style handheld counter? Mainly interested in tempco. It'll be checked against a frequency standard regularly once I've got a GPSDO sorted. It's not GPSDO referenced though.



Measurement frequency is always sub-30MHz for me with some finger in the air "it'll do" at 144MHz-1GHz. Figure that once it's properly calibrated, that's a total drift of 150Hz/year at 30MHz which I can live with. It will go to 3GHz but that's mostly unnecessary.

Only you can decide what it sufficient; I presume it would depend on how a receiver would cope with frequency offset and drift, and that would depend on the signal bandwidth and "carriers" present.

Someone that is interested in measuring/reducing phase noise would have rather different requirements to someone nattering on HF or doing QRP or moonbounce.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 11224
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32945 on: June 11, 2019, 02:51:55 pm »
Fair points. This is mostly for checking TX / VCO frequency which isn't exactly terrible as everyone stays a KHz or so away from band edges. Filters are as narrow as 200Hz. Need something reliable as my efforts to replace the transformer on the 9915 aren't going particularly well so far. Bought one anyway. It's not exactly expensive, especially when you don't pay VAT on it :-DD. TTi PFM3000. Review coming tomorrow.
 

Online tggzzz

  • Super Contributor
  • ***
  • Posts: 9666
  • Country: gb
    • Having fun doing more, with less
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32946 on: June 11, 2019, 04:24:03 pm »
Some good news and a couple of buggers.

The (old) bad news was that I got a modulation domain analyser that will be going to the tip.

The (new) good news was that I was able to rescue the hp10811 10MHz OCXO (and some BNC sockets!), and that I've now built that into a box, which works nicely.

The OCXO box I built consisted of the hp80111-60111 OCXO, a Sziklai-based capacitance multiplier (as per TAoE), and a 12V regulator made from an LM732 (as recommended in the old data sheet, but the LM732 still has a good low-noise voltage reference).

At the voltnut meetup in Cardiff a couple of days ago I was able to measure its frequency against a rubidium oscillator, courtesy of dkozel. Without tweaking, the result was a rather gratifying....



I've used that OCXO to adjust the XO frequency of my frequency meter, and local gravity clearly affects the frequency; that 0.5Hz delta is repeatable.

Previously it was 3.2Hz off (i.e. 3.2ppm, well within spec), but now it seems that there are two stable modes:



Given how little I had to tweak the trimcap, my suspicion is that the frequency changes because the trimcap's vanes are closer/further apart depending on orientation :)

Yes, I am guilty of over-interpreting the significance of the displayed frequency :)
« Last Edit: June 11, 2019, 04:26:08 pm by tggzzz »
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 11224
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32947 on: June 11, 2019, 04:26:40 pm »
Being Philips, something has probably broken off inside and resting on the capacitor  :-DD
 

Online tggzzz

  • Super Contributor
  • ***
  • Posts: 9666
  • Country: gb
    • Having fun doing more, with less
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32948 on: June 11, 2019, 04:41:33 pm »
Being Philips, something has probably broken off inside and resting on the capacitor  :-DD

Actually it is remarkably clean in and out, and I haven't even felt an overwhelming urge to replace the few big electrolytics.

The spec is +-10Hz, so +-0.4Hz isn't bad :)
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline mnementh

  • Super Contributor
  • ***
  • Posts: 4665
  • Country: us
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #32949 on: June 11, 2019, 04:42:21 pm »
Already posted this in the equipment score thread but I wouldn't want to miss the opportunity to trigger your addictions so crossposting  :-DD

   19"Power (about 13kW of it..)(SNIP)

MMmmmm.... Juicy!!!  :-+



Down boy... down... it's okay, he's a friendly. ;)

   "grrrrrrr..."

Ummm.... okay... would you chill out for a Scooby Snak?  :-DD


I didn't get my panties in a bunch; I gave my opinion and also grudgingly accepted yours as it was you who took on this costly expedition.

In case you haven't noticed, I've been quite supportive since I came to terms with your dogged determination to do it sideways... err, "Do it my wa-a-a-a-ay..."  ;) Go back through the last few pages especially.

mnem
 :P pppppppppttttttttbbbbbbbbbppppppp!!!
This is TEA. If I have to explain myself then you don't get it.  ;D But I know you get it. But I also know that you like to bust my balls. For every action there will be an equal and opposite reaction....so back at ya.  :P :-DD

I know you've been supportive. And I greatly appreciate it.  :-+  Now put the Huffy away....you're too big for it.  >:D :-DD :-DD

   Fair dinkum... Just so long as you don't feel singled-out. Y'all know I'm a equal-opportunity asshat agitator.  ;)

   You're right... I am too big for the Huffy. That's why I'm upgrading to a Mongoose. That's a lot of bike for $275. Thinking about modding it to an eBike with one of the gazillions of BL motors I have; or maybe stalk fleaBay for a 1KW+ hub motor at a sufferable price. We'll see.

mnem
*Caffeine-deficient*
« Last Edit: June 11, 2019, 05:34:21 pm by mnementh »
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf