Test Equipment Anonymous (TEA) group therapy thread

[bd139]

Can wear both 

[khs]

Since I cleaned up my workbench last weekend, and all this talk about Rohde & Schwarz PSUs with BU508A, I decided to finally pull out the NGPV 40/3 and have a look at it:



It worked a whole lot better than expected, albeit being dusty and full of nasty stickers on the front panel. 30.00 Volts set, 29.96 measured. Not too far off.
The device has a fan, but totally silent. Maybe it is temperature controlled, 10 MΩ is not exactly a heavy load.
After a few minutes however, a well known smell seeped out of the thing. Something inside seemed to rise its temperature and heat the dust.
Maybe the fan wasn't temperature controlled after all?

The ubiquitous porn shot:



Here's the fan, blowing into a heat sink tunnel.



Did the rotate-with-finger thing. Boy, that needed some torque! No motor in the single-digit watts class would turn it!
Removed the whole power transistor assembly and the fan (which actually does have some temp control; a bi-metal switch puts it into full power when the heat sink gets too hot):



At first I went to my motor department to see whether I might have something to replace it with. Of course not. It's a rather small department anyway.
There was just one thing left to dot: try to fix it.
By now you should know that I'm not the greatest friend of riveted ties, but sure as hell the brackets are riveted to the stator. Grrr.
After drilling them off, the front bracket and bearing would slide off the axle without a hitch. Holding the back bracket and turning the rotor did turn the bearing in the bracket instead of the axle in the bearing! It took quite some force to get the axle out of its bearing.
I cleaned it all with IPA and reassembled the thing. To my amazement, the motor now ran smoothly.



Putting all together again, the PSU now runs with a blowing fan and without that distinctive smell.



Now it really deserved to be de-stickerized and cleaned.



One fine day I will have to check the GPIB functionality. This PSU is not really meant to be used by the front panel controls.

Here a similar and maybe older intrument: Dual +-50.00V or +-9.999V, 1.5A.
Manual control via mouse piano.
GPIB programming is a nightmare: Enter a code, then enter a digit, after entering all digits enter the code to shift it into the DAC.

[Saskia]

Hell. Bloody.
Muscle cramps like hell in my neck area. Plus a fever. And trouble swallowing because of the muscle cramps.
On pain killers and capsaicin/Campher rubs to relieve the cramps so that I can lift my head again
Fuck, that hurts ...

[Zucca]

New TEA project, sort of: building a conductive brush probe.
I already contacted a vape wire seller in Ebay....

Got a 10m NI80 32GA vape wire for 6.95€ shipped

1 hour of patience later...



I used all of it.... will it work?



happy like a puppy!

Money shot on my Knipex, also today a joy to use.

[tautech]

Hell. Bloody.
Muscle cramps like hell in my neck area. Plus a fever. And trouble swallowing because of the muscle cramps.
On pain killers and capsaicin/Campher rubs to relieve the cramps so that I can lift my head again
Fuck, that hurts ...

Oh dear, do we start polishing another bullet for you ?
The one for Brumby is getting pretty shiny if you want that one. 

[khs]

Hell. Bloody.
Muscle cramps like hell in my neck area. Plus a fever. And trouble swallowing because of the muscle cramps.
On pain killers and capsaicin/Campher rubs to relieve the cramps so that I can lift my head again
Fuck, that hurts ...

You may try magnesium..

[Saskia]

If you have an engraver just write my name on it ...
My spine was shot 11 years ago when I got rear ended by a vw  tuareg. Driver said I did not get out of his way  fast enough and he did not find it necessary to brake.
My left arm was paralyzed for years.

.

[bd139]

I have checked the tants  and they are fine. Think Q30 just died.

Edit; going to throw 24v at the decoupling network off a bench supply with current limit and check that the IC isn’t toast first. That could have gone bad and caused the SOA to be exceeded of the transistor.

Ok fixed it.

1. Removed Q30, the ZTX 550 pass transistor B-E short.
2. Stuffed 24v into the decoupling network and fired up a VHF TX next to it. Bingo readout.
3. Checked current and dropout. Turns out it was blowing 1/3 of a watt off on that pissy little Zetex transistor. Probably why it snuffed it. 
4. Looked in junk box and found a BD140 and bodged that in.
5. Fired it up. Working.

Pictures attached.

I’m not proud of the use of an inline package in a TO18 shaped hole but it works. I would use a 2N2905A or 2N2907A with a hat heatsink if I had one but I don’t.


Edit: this is the first thing I’ve got to fix in TE space for months. Am stoked again 

[med6753]

I have checked the tants  and they are fine. Think Q30 just died.

Edit; going to throw 24v at the decoupling network off a bench supply with current limit and check that the IC isn’t toast first. That could have gone bad and caused the SOA to be exceeded of the transistor.

Ok fixed it.

1. Removed Q30, the ZTX 550 pass transistor B-E short.
2. Stuffed 24v into the decoupling network and fired up a VHF TX next to it. Bingo readout.
3. Checked current and dropout. Turns out it was blowing 1/3 of a watt off on that pissy little Zetex transistor. Probably why it snuffed it. 
4. Looked in junk box and found a BD140 and bodged that in.
5. Fired it up. Working.

Pictures attached.

I’m not proud of the use of an inline package in a TO18 shaped hole but it works. I would use a 2N2905A or 2N2907A with a hat heatsink if I had one but I don’t.


Edit: this is the first thing I’ve got to fix in TE space for months. Am stoked again 

Hey, it works don't beat yourself up over it. Chances no one except you will know for eternity. Unless you sell it to one of us. 

[Zucca]

Ok fixed it.

Now you can take your time to put it up on Ebay so you can lose your money again because Herpes thought it is gold shit.

[bd139]

Haha.

No more selling. I’m done. This is a keeper

[PA0PBZ]

404 - that's not an amateur radio frequency, that's "Page not found" 

[bd139]

Partial count of 3rd harmonic of 144Mhz

[BU508A]

Since I cleaned up my workbench last weekend, and all this talk about Rohde & Schwarz PSUs with BU508A, I decided to finally pull out the NGPV 40/3 and have a look at it:



It worked a whole lot better than expected, albeit being dusty and full of nasty stickers on the front panel. 30.00 Volts set, 29.96 measured. Not too far off.
The device has a fan, but totally silent. Maybe it is temperature controlled, 10 MΩ is not exactly a heavy load.
After a few minutes however, a well known smell seeped out of the thing. Something inside seemed to rise its temperature and heat the dust.
Maybe the fan wasn't temperature controlled after all?

The ubiquitous porn shot:



Here's the fan, blowing into a heat sink tunnel.



Did the rotate-with-finger thing. Boy, that needed some torque! No motor in the single-digit watts class would turn it!
Removed the whole power transistor assembly and the fan (which actually does have some temp control; a bi-metal switch puts it into full power when the heat sink gets too hot):



At first I went to my motor department to see whether I might have something to replace it with. Of course not. It's a rather small department anyway.
There was just one thing left to dot: try to fix it.
By now you should know that I'm not the greatest friend of riveted ties, but sure as hell the brackets are riveted to the stator. Grrr.
After drilling them off, the front bracket and bearing would slide off the axle without a hitch. Holding the back bracket and turning the rotor did turn the bearing in the bracket instead of the axle in the bearing! It took quite some force to get the axle out of its bearing.
I cleaned it all with IPA and reassembled the thing. To my amazement, the motor now ran smoothly.



Putting all together again, the PSU now runs with a blowing fan and without that distinctive smell.



Now it really deserved to be de-stickerized and cleaned.



One fine day I will have to check the GPIB functionality. This PSU is not really meant to be used by the front panel controls.

That NGPV40/3 is looking very nice. The construction with the fan and the heatsink tunnel is looking very similar to
the ones in my NGB 70/5 and NGB 32/10. I had to remove the motor as well and after some cleaning and lubricating
with silicone oil it is running smoothley.

Today my second  NGT 20 arrived. Very well packed I must say. The seller did some extra protection for the front and he added also some Klepse (red and black). 
The PSU itself is in nearly mint condition. No brittle power chord, no dust, no scuffs, no rust. All knobs and swiches are working nicely.
Will test it now, pictures will follow.

I think, I'll order next month an electronic load from Maynuo @Welectron.
This one: https://www.welectron.com/Maynuo-M9812-Electronic-Load


Anybody an idea where to get these nice 4mm banana adapters for the input jacks?

[tautech]

Anybody an idea where to get these nice 4mm banana adapters for the input jacks?

There's an Aliexpress link in the SDL1000X thread for them.....bit busy to dig it out ATM.

[factory]

I have checked the tants  and they are fine. Think Q30 just died.

Edit; going to throw 24v at the decoupling network off a bench supply with current limit and check that the IC isn’t toast first. That could have gone bad and caused the SOA to be exceeded of the transistor.

Ok fixed it.

1. Removed Q30, the ZTX 550 pass transistor B-E short.
2. Stuffed 24v into the decoupling network and fired up a VHF TX next to it. Bingo readout.
3. Checked current and dropout. Turns out it was blowing 1/3 of a watt off on that pissy little Zetex transistor. Probably why it snuffed it. 
4. Looked in junk box and found a BD140 and bodged that in.
5. Fired it up. Working.

Pictures attached.

I’m not proud of the use of an inline package in a TO18 shaped hole but it works. I would use a 2N2905A or 2N2907A with a hat heatsink if I had one but I don’t.


Edit: this is the first thing I’ve got to fix in TE space for months. Am stoked again 

Apparently I have some ZTX550, if you want one.

David

[mansaxel]

Haha.

No more selling. I’m done. This is a keeper

I'm bookmarking this message to use against you for comical effect; in less than 6 months when you've changed your mind. 

[Specmaster]

Can wear both 

You could, but it only appear as if you were only wearing the one

[BU508A]

Anybody an idea where to get these nice 4mm banana adapters for the input jacks?

There's an Aliexpress link in the SDL1000X thread for them.....bit busy to dig it out ATM.

You mean this one?
https://www.aliexpress.com/item/32778229464.html

Similar ones on ebay:
https://www.ebay.com/itm/2pcs-M6-60-copper-40A-Binding-Post-for-Speaker-Cable-Amplifiers-power-supply/222096799349


I meant more the PCB adapters with the 4mm banana inputs.
Like this:
https://www.ebay.com/itm/DC-Electronic-Load-Banana-Jack-Adapter-Board-/154246499734


Edit:

I've found a seller in Germany on tindie:

https://www.tindie.com/products/labshack/dc-electronic-load-banana-plug-adapter-pcb-only/

[Mr. Scram]

Haha.

No more selling. I’m done. This is a keeper

I give it 6 months tops.

[Specmaster]

Hell. Bloody.
Muscle cramps like hell in my neck area. Plus a fever. And trouble swallowing because of the muscle cramps.
On pain killers and capsaicin/Campher rubs to relieve the cramps so that I can lift my head again
Fuck, that hurts ...

Shit, sounds like you need a test and quick, fingers crossed it isn't.

[mnementh]

Now... can we please let it go, or do we need to pummel me some more with quotes out of context...?

mnem
 

No, not when you claim a quote is 'out of context' when it is provided complete with context. 

Except for the context where I did exactly what you claimed I didn't. THAT silly little bit of irrelevant context. 

mnem

[tautech]

C'mon mnem give it a rest. No one likes hot under the collar dwagons.

Every manufacturer has made stuff ups in designs and that's how things get improved.

Take the old 4cyl Landrover donk that has a 3 bearing crankshaft ......petrol or diesel....who ever thought that was a good idea other than bloody bean counters ! 

[bd139]

I have checked the tants  and they are fine. Think Q30 just died.

Edit; going to throw 24v at the decoupling network off a bench supply with current limit and check that the IC isn’t toast first. That could have gone bad and caused the SOA to be exceeded of the transistor.

Ok fixed it.

1. Removed Q30, the ZTX 550 pass transistor B-E short.
2. Stuffed 24v into the decoupling network and fired up a VHF TX next to it. Bingo readout.
3. Checked current and dropout. Turns out it was blowing 1/3 of a watt off on that pissy little Zetex transistor. Probably why it snuffed it. 
4. Looked in junk box and found a BD140 and bodged that in.
5. Fired it up. Working.

Pictures attached.

I’m not proud of the use of an inline package in a TO18 shaped hole but it works. I would use a 2N2905A or 2N2907A with a hat heatsink if I had one but I don’t.


Edit: this is the first thing I’ve got to fix in TE space for months. Am stoked again 

Apparently I have some ZTX550, if you want one.

David

Thanks for the offer but I think the transistor is a little marginal for the job in this case. Looks like there was a TO18 in there but they cheaped out with the Zetex one.

Quite honestly I’ve had to replace countless ZTX series transistors over the years so not a fan 

[mnementh]

C'mon mnem give it a rest. No one likes hot under the collar dwagons. Every manufacturer has made stuff ups in designs and that's how things get improved.

Take the old 4cyl Landrover donk that has a 3 bearing crankshaft ......petrol or diesel....who ever thought that was a good idea other than bloody bean counters ! 

Yeah, and nobody like being beleaguered, either. Robert drops it, and C picks it up. So in the end, I can either take it or defend myself. I'm sick of taking it.

Cheers,

mnem