Test Equipment Anonymous (TEA) group therapy thread

[med6753]

med if you need white graticules instaed of the red turn the plexy headstanding.

Good to know but I prefer the red anyway. 

[bd139]

Cheap nixie tube alert !

https://www.ebay.com/itm/Vintage-General-Radio-1192-B-Nixie-Tube-Frequency-Counter-Powers-On-Nice/233458017081?_mwBanner=1&ul_ref=https%3A%2F%2Frover.ebay.com%2Frover%2F0%2Fe11021.m43.l1120%2F7%3Feuid%3D3aebd2910f5d456b8127759f70b705d8%26bu%3D43194197782%26ut%3DRU%26loc%3Dhttps%253A%252F%252Fwww.ebay.com%252Fulk%252Fitm%252F233458017081%26sojTags%3Dbu%3Dbu%2Cut%3Dut%26srcrot%3De11021.m43.l1120%26rvr_id%3D0%26rvr_ts%3D80595fe316f0aaa7341111abffff2301&ul_noapp=true&pageci=5b5c392d-03fc-4db5-837e-22b59e59821f

Very nice, and I'd be tempted if it weren't for the concern that by the time it reached the UK, the valves would be in the form of a 10 thousand piece jigsaw puzzle...

Yep. Still annoyed about that.

[Specmaster]

What I find amazing, and I may jinx myself for saying this, is that so far I have NOT had to replace any parts. I swear these old Tek's could survive a well placed nuke. 

And just as a side comment. The contents of this thread for the past week or so have been absolutely stellar. The diversity of TEA interests from boat anchors to 110GHz scopes. And from dragons (mnem) to pyromaniacs (bd139).   Isn't it nice when we stay away from politics/bitching/bellyaching and concentrate on our hobby and flip the bird to shit around us? Although maintain a sense awareness but keep it out of here.   

I think you're right about the nuke, the quality of the engineering is evident in those photos, they built to a specification rather than a price.

Interesting point re mnem (Dragon) and bd139 (Pyromaniac), surely they are infact at the same end of the spectrum, I mean isn't a pyromaniac just a wannabe dragon 

[Sam Spastic]

But it's a Push-to-KILL button on this one; UP is HOT.

I've lost count on the times I, in haste, resoldered my Yamaha footswitch used to control outboard audio gear like reverbs and delays because some device wanted NO, other devices wanted NC.  (Probably should take the little ON-ON DPDT switch I speculatively bought at Elfa today and wire it for selection of NO vs NC. in the footswitch. Especially if it fails to fit in the mixer I perhaps bought it for. )

Thus, I wonder whether it was possible to revert the action of said PTK to a PTT.

Yeah a PITA.  Some of my gear, like keyboards could be preferenced in settings.  Others such as effects could be powered on with the switch either held or released to change the operation.  Still the easiest option was have a couple of each and grab what you need.  But I was NOT organized enough to label which was which.

[Cerebus]

currently researching silent mute/unmute button circuits for integrating in mic preamps

The problem with doing it that way is a lot of this kind of software has an AGC algorithm and often they are NFG. So if the software is not muted using some control that it recognises (USB headset mute switch, on screen mute switch) then it just cranks up the gain until it gets some measurable signal - which at this point is pure noise. Thus if you mute the analogue audio, the input gain gets cranked up on the computer side and the noise floor with it; when you unmute the analogue side the AGC gain is too high and you come over way too loud until the AGC control loop catches up. Rinse and repeat every time you mute/unmute yourself.

[mnementh]

But it's a Push-to-KILL button on this one; UP is HOT.

I've lost count on the times I, in haste, resoldered my Yamaha footswitch used to control outboard audio gear like reverbs and delays because some device wanted NO, other devices wanted NC.  (Probably should take the little ON-ON DPDT switch I speculatively bought at Elfa today and wire it for selection of NO vs NC. in the footswitch. Especially if it fails to fit in the mixer I perhaps bought it for. )

Thus, I wonder whether it was possible to revert the action of said PTK to a PTT.

In this case I feel it is entirely a semantic argument; as the switch is a push-button toggle and the light is still ON when HOT, the only difference functionally is whether the switch is UP or DOWN when hot. This REALLY only matters when the PC is powered off or asleep and you want to reassure your baser paranoid instincts that the mic is indeed dead; and then it is purely a matter of knowing which state is which. 

Now that we've had this conversation, I have no doubt I'll be able to remember for the rest of its life... mine as well, probably. 



I eventually conceded to reality and scabbed a short piece of wire onto the original microphone so I could easily isolate the PCB (pic taken away from my most heinous desktop to safeguard med's delicate sensibilities ); results were quite good. Now comes the fun part; finding a solution where my mic does not have to lay about eviscerated in my way all the time.

mnem
Whoodat say dat...?

[tautech]

currently researching silent mute/unmute button circuits for integrating in mic preamps

The problem with doing it that way is a lot of this kind of software has an AGC algorithm and often they are NFG. So if the software is not muted using some control that it recognises (USB headset mute switch, on screen mute switch) then it just cranks up the gain until it gets some measurable signal - which at this point is pure noise. Thus if you mute the analogue audio, the input gain gets cranked up on the computer side and the noise floor with it; when you unmute the analogue side the AGC gain is too high and you come over way too loud until the AGC control loop catches up. Rinse and repeat every time you mute/unmute yourself.

Yet in Discord you can override the AGC to set the input sensitivity.

.............
playing with hacks for mic's............

[bd139]

What I find amazing, and I may jinx myself for saying this, is that so far I have NOT had to replace any parts. I swear these old Tek's could survive a well placed nuke. 

And just as a side comment. The contents of this thread for the past week or so have been absolutely stellar. The diversity of TEA interests from boat anchors to 110GHz scopes. And from dragons (mnem) to pyromaniacs (bd139).   Isn't it nice when we stay away from politics/bitching/bellyaching and concentrate on our hobby and flip the bird to shit around us? Although maintain a sense awareness but keep it out of here.   

I think you're right about the nuke, the quality of the engineering is evident in those photos, they built to a specification rather than a price.

Interesting point re mnem (Dragon) and bd139 (Pyromaniac), surely they are infact at the same end of the spectrum, I mean isn't a pyromaniac just a wannabe dragon 

I just like blowing shit up

Getting seriously pissed off with selling stuff on eBay:

1. No I won’t send you photos of receipts before you buy something.
2. No I won’t take 33% off the price
3. No I won’t ship it to Mars
4. No I won’t take £10 off if you want to use Hermes instead of UPS fully insured.
5. No you can’t come and inspect it at 23:45 this evening.
6. No I don’t have any others that are cheaper.
7. No I won’t split this singular item and leave me with a hunk of shit worth 10% of the whole value.
8. No I can’t make it fit through a letterbox because you’re not in.

Argh. Seriously considering having a strop and just canning eBay sales.

[Cerebus]

Still have not dusted my desktop. 

mnem
*tinker-ily*

Get to it. These work. 

Little household secret from Chez Cerebus, home of a house-dust allergic aardvark, is not to buy the overpriced Swiffer dusters (or local equivalent) at about £1 each but to use carpenters tack rags like these:



which are £10-15 for a box of 50 and individually last a lot longer than the Swiffer type.

[mansaxel]

This is a post on a clothes dryer.

Follow-up:

[Specmaster]

What I find amazing, and I may jinx myself for saying this, is that so far I have NOT had to replace any parts. I swear these old Tek's could survive a well placed nuke. 

And just as a side comment. The contents of this thread for the past week or so have been absolutely stellar. The diversity of TEA interests from boat anchors to 110GHz scopes. And from dragons (mnem) to pyromaniacs (bd139).   Isn't it nice when we stay away from politics/bitching/bellyaching and concentrate on our hobby and flip the bird to shit around us? Although maintain a sense awareness but keep it out of here.   

I think you're right about the nuke, the quality of the engineering is evident in those photos, they built to a specification rather than a price.

Interesting point re mnem (Dragon) and bd139 (Pyromaniac), surely they are infact at the same end of the spectrum, I mean isn't a pyromaniac just a wannabe dragon 

I just like blowing shit up

Getting seriously pissed off with selling stuff on eBay:

1. No I won’t send you photos of receipts before you buy something.
2. No I won’t take 33% off the price
3. No I won’t ship it to Mars
4. No I won’t take £10 off if you want to use Hermes instead of UPS fully insured.
5. No you can’t come and inspect it at 23:45 this evening.
6. No I don’t have any others that are cheaper.
7. No I won’t split this singular item and leave me with a hunk of shit worth 10% of the whole value.
8. No I can’t make it fit through a letterbox because you’re not in.

Argh. Seriously considering having a strop and just canning eBay sales.

You seem to get all the oddballs in life after your eBay sales and it seems behind you in the checkout queue 

[mnementh]

@med, @ Cerebus:

   We use these for day-to-day traffic area cleaning; they're cheap and last 30-50 washings. We keep one dry for dust-mopping, and we don't use the Swiffer pads for spot-cleaning either; just steal a couple baby wipes from the bathroom when we need a quick spill cleanup.

mnem
time to shovel the drive...

[bd139]

Right some TEA stuff for a change from me. Christmas tree is gone and I've got my power strip back so it was rework the bench time. Thus it's LED time, an objective of mine for a long time.

Das blinkenlights as they currently stand:



Think I've got room for another power supply.... 

[Specmaster]

Right some TEA stuff for a change from me. Christmas tree is gone and I've got my power strip back so it was rework the bench time. Thus it's LED time, an objective of mine for a long time.

Das blinkenlights as they currently stand:



Think I've got room for another power supply.... 

Looking good, now to turf out that HP signal generator for something with red LEDs.    Look at the variation in the red of those LEDs

[bd139]

?



 

[Specmaster]

Thats more like it  Now for a bigger bench 

[Specmaster]

I know that we all from time to time knock Chinese goods but the reality is that there really is some very good Chinese factories churning out first-rate products like this non-official battery plant making after market batteries for iPhones and looking at this video, their QA and testing etc is probably equal or exceeds Apples own product testing.

[BU508A]

Hello TEA

here, as promised, some pictures of my General Radio 1192-B counter.
With Nixie tubes! 
I've bought it end of November 2019 from a very nice guy (retired engineer).
He wants to get rid of some gear and offered this unit for a (imho) reasonable price of CHF 60.-

So, let's start with the front (I've fed 19876MHz into it from the arb gen of my R&S RTM 2004)


This is the backside. Opening this unit reqires only to loose these two screws.


Here is an overview. The latest date code I've found was back to 1974, other parts were from 1969.


This is the switch for the gate time:


An IC from Raytheon in a funny looking DIL package:


The backside of the nixie tubes and their drivers:


The crystal and the oscillator circuit etc.


The PSU with the transformer and some Sprague electrolytics.


Bottom view of the PSU.


A hotspot but imo nothing serious.


The counter is a bit off, but I'm planning to purchase a Efratom Rubidium 10MHz standard
and I have an eye on a nice Fluke PM6681 which I want to add a OCXO and a 3 GHz divider extension.
Then I'll adjust and calibrate the 1192-B. 
And no, I will NOT follow this time-nut rabbit hole any further!   

Hope you enjoyed this little teardown. 

Edit: corrected the sizes of the pictures 

[BU508A]

Right some TEA stuff for a change from me. Christmas tree is gone and I've got my power strip back so it was rework the bench time. Thus it's LED time, an objective of mine for a long time.

Das blinkenlights as they currently stand:



Think I've got room for another power supply.... 

I'm missing the HP calculator, which is mandatory for a high quality bench.   

[bd139]

I'm missing the HP calculator, which is mandatory for a high quality bench.   

Oops! Fixed!

[bd139]

An IC from Raytheon in a funny looking DIL package:

Very cool post.

Interesting. Looks like their unobtainium "TTL I" range which turned up just before the 74-series was standardised on TI's parts.

[bitseeker]

So to celebrate post #1000, I did another round of probe testing 

For those interested, round #1 is located here

...

Very interesting! Added to your previous entry in the POI.

[Specmaster]

I'm missing the HP calculator, which is mandatory for a high quality bench.   

Oops! Fixed!

No No its not fixed....LCD with LEDs is just so wrong man 

[bitseeker]

Happy to report the seller outback6 on ebay is legit.  Received my new to me HP 8920A which I think I damn near stole and its in great shape, fully functional, with the options listed.  It was well packed and arrived safe.   Only had a hour to play with it last night (almost brought it into work with me today).

Thanks for the update, kj. Good to hear the outcome was favorable. That's a nice unit with those options.

The seller has another one listed starting at $600, but only has the OCXO option, no spectrum analyzer.
https://www.ebay.com/itm/C164770-HP-8920A-RF-Communications-Test-Set-Option-001-RF-Gen-Anl-AF-Anl-Osc/333469043207

Yeah, that one was $800 the last time it was listed. I'd be more tempted if it was more like the one you grabbed. Good thing we weren't both bidding on yours.

[bd139]

Good but very long read. Someone's massive test gear collection:

https://emperoroftestequipment.weebly.com/

LOTS of test gear. I mean lots and lots.