Test Equipment Anonymous (TEA) group therapy thread

[bitseeker]

Had a bad day cooking out yesterday... 

Woah, mnem! What happened? Forgot to change the batteries for the onboard structural integrity field generator?

Or was it...tants!

[bd139]

Always the damn tants! 

Here's the 34401A pics. As I said looks brand new. The cal count is 75 though so it'd be interesting to know what it's been doing all these years. The freq. spec is up to 300 kHz but it works well far above that. No other issues noted.

(Yea the comma is off now  )

Wow, xrunner! That really does look fresh out of the box. Congrats!

As for the cal count, a complete adjustment increases the count by about 35 (if they get everything right in one go). So, yours may have had one full adjustment (or a couple of partials) since its original setup at the factory.

That looks excellent. Congratulations!

My cal count is 35. It’s not unusual for them to have to run the cal cycle ten times before the monkey in charge gets it right each time.

Sounds like yours hasn't been touched since it was released into the wild, bd.

(Out of curiosity, checked my count and it's 48. Revision is 11-05-02.)

That's good news 

I'm going to order the new display for mine on Monday then it'll be perfect. I just managed to palm off some non electronics crap I'm trying to sell which will cover it.

Trying to clear my mind of impure thoughts today. The HPAK fanboy in me has fallen in love with a DSOX1204G and the credit card is empty 

[Kosmic]

As for the cal count, a complete adjustment increases the count by about 35 (if they get everything right in one go). So, yours may have had one full adjustment (or a couple of partials) since its original setup at the factory.

That looks excellent. Congratulations!

My cal count is 35. It’s not unusual for them to have to run the cal cycle ten times before the monkey in charge gets it right each time.

Sounds like yours hasn't been touched since it was released into the wild, bd.

(Out of curiosity, checked my count and it's 48. Revision is 11-05-02.)

Interesting, I was wondering about the cal count. Mine is Rev 10-05-02 and cal count 47.

[bsfeechannel]

Cold blood perhaps 

And I’m not sure crashing off the road was really driving 

Well, I was being a little sarcastic, but to his credit he gave up his licence and apologised in writing to the others involved in the crash.

This is usually what happens here when people get really old

https://youtu.be/MR0deRfvAw0

Bloody old people. We're all becoming old, aren't we? In some places of the world, they are granted free public transportation as a means to encourage them to give up driving.

[bd139]

Public transport is universally shit everywhere other than large cities on this planet so you're screwed when you get old. One reason I live in a large city!

Proof I'm over the Tek thing: I just turned down a FREE limping Tektronix 475A about 5 mins drive from here. I just can't do another one 

[Specmaster]

Had a bad day cooking out yesterday... 

Woah, mnem! What happened? Forgot to change the batteries for the onboard structural integrity field generator?

Or was it...tants!

I reckon it just the sheer size of his burger, it still had hooves attached to it 

[xrunner]

That looks excellent. Congratulations!

My cal count is 35. It’s not unusual for them to have to run the cal cycle ten times before the monkey in charge gets it right each time.

Wow, xrunner! That really does look fresh out of the box. Congrats!

As for the cal count, a complete adjustment increases the count by about 35 (if they get everything right in one go). So, yours may have had one full adjustment (or a couple of partials) since its original setup at the factory.

Thanks, interesting on the cal count thanks. I'm sending the seller a message now asking if he can reveal any details of where this 34401A came from. Will let you know what I find out.

 

[bd139]

Had a bad day cooking out yesterday... 

Woah, mnem! What happened? Forgot to change the batteries for the onboard structural integrity field generator?

Or was it...tants!

I reckon it just the sheer size of his burger, it still had hooves attached to it 

Delivery incoming! 

[mnementh]

Had a bad day cooking out yesterday... 

WTF happen? 

Woah, mnem! What happened? Forgot to change the batteries for the onboard structural integrity field generator?

Or was it...tants!

Yeah... yeah... that sounds good, lets go widdat!!!



I went to push it into the garage, just like a thousand other times; something in the underneath caught on the concrete and the bottom cabinet half just folded up like an accordion. I figure it heard me offering to gift it to my neighbor and decided it was time to check out.   

I dragged it down to the curb just in time to catch the trash truck; I stood at attention, salute & all, humming a little dirge as the truck crushed it into oblivion. The trash guys just laughed & shook their heads at el guero loco... 

That BBQ served me well; it deserved proper last rites. 



It's all good... I have my old reliable just tested working, with a brand-new baggie full of cooking tiles; all ready for the next time I need to do some manly-man cooking. 

mnem
*back out into the suck*

[mnementh]

I reckon it just the sheer size of his burger, it still had hooves attached to it 

Delivery incoming!     

BRING IT!!!   

mnem
No regrets.

[Specmaster]

Public transport is universally shit everywhere other than large cities on this planet so you're screwed when you get old. One reason I live in a large city!

Proof I'm over the Tek thing: I just turned down a FREE limping Tektronix 475A about 5 mins drive from here. I just can't do another one 

Yeh, transport in the big smoke is a zillion times better then out in the sticks although that said, I do have a 10min bus service in theory, in practise though because of the traffic around here, a city in the sticks, that often means that the buses run a few minutes late so you end up with one just behind the other, leapfrogging each other at stops. To get my car serviced at the dealers (3 miles away) if I use buses to get back home, it means using 2 bus routes and almost 6 miles and takes around 80 minutes  nut it is with my OAP pass, free. I've had my pass now for 3 years and used it just once. I get the dealer to drop me at home and then collect me when the car is ready, again its free and takes 10 minutes. Is it any wonder there are so many cars on the road.

My wife if she uses the bus to go to work, 2 miles, cost her £4 each way and at night it can take her best part of an hour to get home. So there's you answer right there, its cheaper to use a car this especially true if you have a family, so if we both and our 2 sons want to go to the city centre, its £12 (£16 if I forgot my free pass) fecking stupid, they should be offering free public transport and get people out of cars and reduce the carbon footprint and wear and tear on the roads, but nope, over here they focus on grabbing your money from you. 

[Specmaster]

I reckon it just the sheer size of his burger, it still had hooves attached to it 

Delivery incoming!     

BRING IT!!!   

mnem
No regrets.

Haha, thats exactly what I had in mind, the Top Gear road trip and the "Road Kill" BBQ 

[bd139]

And now for some time nuttery....

OCXO installed in the 5334B. All you have to do is move one capacitor over slightly. The thing is currently warming up. Since I took the photo it has settled on 9.99999983 MHz so will need a trim but it's a dual oven so you need to wait 5 mins for the inner oven to do its thing then 60 minutes for the outer one before even touching it. When the 5334B is plugged into the mains, powered up or not, the oven is actually active so usually there's no warm up time.

The benefit of this counter over other HP models is it is 100% silent. The transformer doesn't even hum!



Pictured also is the bodnar GPSDO which is pretty excellent. I'm very happy with it.

[med6753]

Oculus, this should interest you because you mentioned having contact issues with a 7A26 plug-in. I have 2 of them and one has been giving me issues on channel 1 so decided today to tear it down and try to fix it. The fix was ultimately unsuccessful because the cam switch assembly is worn out but if yours is just simply dirty contacts this should help you.

My issue was a gross misalignment of the cam switch to the attenuator deck. Simply installing or removing the attenuator shield would cause different contact issues. Here's the shield removed in prep for disassembly.



Remove the attenuator blocks. Then remove the bracket between the switch deck and the pre-amp board. You do NOT have to unsolder those delicate wires between the attenuator assembly and the pre-amp board.



If doing channel 1 the vertical position control has to be loosened and pulled back to gain access to a screw. Also unplug the DC blocking capacitor. Now the 4 stand offs and 2 screws can be removed.



Turn over the plug-in and unscrew the readout board and pull it off. The switch cam assembly can now be partially pulled out to gain access to the leaf contacts. Once cleaned replace the cam assembly back against the attenuator board and reinstall the 4 stand offs and 2 screws BEFORE reinstalling the readout board. This insures proper alignment. Then reinstall the readout board and continue with the reassembly.



This 7A26 showed evidence that Magilla Gorilla was in here which figures. I was able to fix the gross misalignment but I still have contact issues. In short, the deck is worn out. I've seen this before. So this plug-in will now become a parts mule. But hopefully this will help you in the repair of your 7A26.   

[xrunner]

And now for some time nuttery....

OCXO installed in the 5334B. All you have to do is move one capacitor over slightly. The thing is currently warming up. Since I took the photo it has settled on 9.99999983 MHz so will need a trim but it's a dual oven so you need to wait 5 mins for the inner oven to do its thing then 60 minutes for the outer one before even touching it. When the 5334B is plugged into the mains, powered up or not, the oven is actually active so usually there's no warm up time.

The benefit of this counter over other HP models is it is 100% silent. The transformer doesn't even hum!

Cool I have one of those too - we must have the same TEA tastes LOL.

I actually took my timebase out for a couple of years because I have it hooked to a GPSDO and it doesn't need it in there using power all the time with that capability available. I put it back in though so it wouldn't get misplaced. 

I did a lot of work to the push button switches when I first got it to get them to push in without the hard click. Finally got 'em all working smoothly. I wouldn't want to go back into them again. 

[bsfeechannel]

That BBQ served me well; it deserved proper last rites. 

You can always repurpose  your porcelainware.

[xrunner]

You can always repurpose  your porcelainware.

In Texas we'd call that a redneck BBQ pit. 

[grbk]

All this talk recently of 34401As and how reliable they are... mine picked last night to decide to start refusing to turn on.

It started rapidly beeping incessantly (each beep accompanied by the asterisk lit up on the display that indicates it's performing a measurement), as if it were receiving spurious triggers. I turned it off and back on, but now it hangs when the VFD turns on all segments, so it's not getting past the power on self test. The buzzer turns on as well which makes debug somewhat painful 

I verified the power rails all look good, and nothing is obviously borked on either PCB. My understanding is that at power up, both the front panel and back processors do a self-check of sorts, and then verify they can communicate with each other, so it seems this is where it's getting stuck. I have a bad feeling this may turn out to be a beyond-economical-repair issue, but I need to look into it further.

And this is my most modern piece of test equipment 

If anyone has any pointers I'm all ears...

I haven't encountered that particular behavior, but if it is because the front and rear panels aren't talking to each other correctly, try disconnecting and reconnecting the ribbon cable between the display assembly and the main board. I've run into a couple that were having issues because of oxidation. A few re-insertions cleans them off. You can also try some DeoxIT.

For what it's worth, it appears that I fixed my 34401a problem, and it doesn't look like it was a hardware issue.

I hooked the meter up to my GPIB adapter to see if I could talk to it, even though the meter didn't seem to be booting. To my surprise, it responded to an *IDN command, so I sent it a *CLS which eventually got it past the "all segments illuminated" state and into a normal mVDC reading screen.

I checked if there were any errors and the only thing that came up was Error 550 ("Command not allowed in local: The multimeter received a READ? command while in the local mode. For RS-232 operation, you should always execute the SYSTem:REMote command before sending other commands over the interface."). I was playing around with some GPIB scripting before the meter "broke" so this was undoubtedly my fault.

But after clearing the error, it passed a selftest and now turns back on just fine. So it looks like by sending bad GPIB commands I was able to put the meter into a state that was unrecoverable except by more GPIB commands, and furthermore didn't give any obvious indications of what the error condition was? 

Knocking on wood that this was actually the problem, and not something unrelated 

[bd139]

And now for some time nuttery....

OCXO installed in the 5334B. All you have to do is move one capacitor over slightly. The thing is currently warming up. Since I took the photo it has settled on 9.99999983 MHz so will need a trim but it's a dual oven so you need to wait 5 mins for the inner oven to do its thing then 60 minutes for the outer one before even touching it. When the 5334B is plugged into the mains, powered up or not, the oven is actually active so usually there's no warm up time.

The benefit of this counter over other HP models is it is 100% silent. The transformer doesn't even hum!

Cool I have one of those too - we must have the same TEA tastes LOL.

I actually took my timebase out for a couple of years because I have it hooked to a GPSDO and it doesn't need it in there using power all the time with that capability available. I put it back in though so it wouldn't get misplaced. 

I did a lot of work to the push button switches when I first got it to get them to push in without the hard click. Finally got 'em all working smoothly. I wouldn't want to go back into them again. 

I think we do indeed 

Similar here. I had an external timebase for this until recently. It was a Bliley NV47 in a box. For completeness, another OCD issue I have, I wanted this fully optioned so I did the 1.3GHz upgrade and added the OCXO  . This suits my requirements perfectly and I don't need to distribute a frequency reference as such so it's perfect.

The buttons on this aren't great actutally. They require a good stab to work. I could probably sort it but I can't be bothered. I do actually have a bunch of spare ones just in case though



I was going to sell them but I get the feeling I'll end up with a duff one.

[grbk]

My 34401A reports a cal count of 76. Last cal'd in 2010, according to the sticker on top. This was an eBay purchase a few months back so I don't know the history.

Also, my case has ventilation holes on the bottom. I've never seen another 34401A with a perforated case, so I have to assume the case was swapped from another HP instrument with the same chassis style.  Anyone else ever seen one in a perforated case?

[URI]

My 34401A reports a cal count of 76. Last cal'd in 2010, according to the sticker on top. This was an eBay purchase a few months back so I don't know the history.

Also, my case has ventilation holes on the bottom. I've never seen another 34401A with a perforated case, so I have to assume the case was swapped from another HP instrument with the same chassis style.  Anyone else ever seen one in a perforated case?

(Attachment Link)

My HP 34401A and also my Agilent 34401A don't have vent holes on the bottom. I thought similarly that it could be swapped from another instrument from that line. And indeed this case most probably comes from a HP/Agilent 33120A:

(linked from this ebay-offer)

[xrunner]

My HP 34401A and also my Agilent 34401A don't have vent holes on the bottom. I thought similarly that it could be swapped from another instrument from that line. And indeed this case most probably comes from a HP/Agilent 33120A:

(linked from this ebay-offer)

No holes here either - might have changed the design so it ran cooler, or swapped with some other compatible case ... from what hmmm ... 

[URI]

My HP 34401A and also my Agilent 34401A don't have vent holes on the bottom. I thought similarly that it could be swapped from another instrument from that line. And indeed this case most probably comes from a HP/Agilent 33120A:

(linked from this ebay-offer)

No holes here either - might have changed the design so it ran cooler, or swapped with some other compatible case ... from what hmmm ...

I think someone swapped the cases.   
The 34401A is a non-fan design from the beginning. There's no reason for vent holes actually.

[nixiefreqq]

And now for some time nuttery....

OCXO installed in the 5334B. All you have to do is move one capacitor over slightly. The thing is currently warming up. Since I took the photo it has settled on 9.99999983 MHz so will need a trim but it's a dual oven so you need to wait 5 mins for the inner oven to do its thing then 60 minutes for the outer one before even touching it. When the 5334B is plugged into the mains, powered up or not, the oven is actually active so usually there's no warm up time.

The benefit of this counter over other HP models is it is 100% silent. The transformer doesn't even hum!



Pictured also is the bodnar GPSDO which is pretty excellent. I'm very happy with it.

are those new rifa's or old rifa's?

(seems like maybe you changed them out a while ago?)

[bd139]

New RIFAs. Don't worry