Test Equipment Anonymous (TEA) group therapy thread

[bd139]

Ok that's weird indeed as those are about right. It does look like something is pulling voltages around.

Can you check the voltages on pins 2 and 3 of IC7 using the same process. Pin 2 should be the measured current and Pin 3 should be the desired current. I suspect this is going to be an issue with C18, C19 or the MUX pulling them down via IPHI. I would go ahead and replace them if you haven't already and the 4052.

Think cheapest 1 off qty of 4052 is bitsbox: https://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=140_157&products_id=1104

Early indications are pointing towards the 4052, extracted C18 and checked it, and it is 1uF @50V  with ESR of 6.2 , seems to be just perfect. Strangely although the schematic shows a C19, the parts list does not and neither does the variations table for the single units 310 and 320. The spot on the PCB looks as if it was never fitted so I'm going to have to call TTi again on Monday, unless anyone here has a PL310 with version 4 boards who could advise if it is fitted on the Main PCB  and its value at all?

Ahem,
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3278010/#msg3278010

The voltages measured indicate leakage currents........

Yep.

It should run without the 4052 in it. I’d desolder it and see if it works then.

The metering will probably wedge at 4095 though. Just ignore and measure at terminals.

Edit: just ordered a week's shopping on Amazon  which is fulfilled by Morrisons. Apparently it'll be picked and at my door in 1h 45m !!!

[Specmaster]

Ok that's weird indeed as those are about right. It does look like something is pulling voltages around.

Can you check the voltages on pins 2 and 3 of IC7 using the same process. Pin 2 should be the measured current and Pin 3 should be the desired current. I suspect this is going to be an issue with C18, C19 or the MUX pulling them down via IPHI. I would go ahead and replace them if you haven't already and the 4052.

Think cheapest 1 off qty of 4052 is bitsbox: https://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=140_157&products_id=1104

Early indications are pointing towards the 4052, extracted C18 and checked it, and it is 1uF @50V  with ESR of 6.2 , seems to be just perfect. Strangely although the schematic shows a C19, the parts list does not and neither does the variations table for the single units 310 and 320. The spot on the PCB looks as if it was never fitted so I'm going to have to call TTi again on Monday, unless anyone here has a PL310 with version 4 boards who could advise if it is fitted on the Main PCB  and its value at all?

Ahem,
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3278010/#msg3278010

The voltages measured indicate leakage currents........

Thanks, I looked through the other source mentioned in your post and I noticed that the voltmeter reading was the same, 40.95V and was uncontrollable. This is now fully controllable following a full recap of both boards, a new pass transistor 2N3055, a new 7805 and new TIP120 on the driver board. Its the current that I cannot get to go above 130mA when a load is connected. A load that is taking uA such as a DMM is not a problem and with a DMM connected, I can set the output to 32.1V at the main output terminals as detailed in the calibration section of the service manual. With the load switched OFF via the load switch, I can preset the output current in the normal fashion upto the maximum which is just over 1,000mA, but closing the load switch puts it straight into CC mode with any load apart from a DDM as a load.

The fact I can connect external ammeter and confirm that the LED display displays the same reading as the ammeter, and likewise the voltmeter is the same as an external voltmeter connected to the output terminals, I believe indicates the PIC is working correctly.

The only item on the unit that is getting warm is the black heat sink on the driver board which has the TIP120 and 7805 mounted on it. So I'm inclined to think that the 4052 is the next thing to replace.

BD139 thinks that I could eliminate that from the equation by desoldering and removing it, and the then powering the PSU and see what happens using external metering, so that is what I'll do later today before ordering a 4052 replacement.

[Specmaster]

Ok that's weird indeed as those are about right. It does look like something is pulling voltages around.

Can you check the voltages on pins 2 and 3 of IC7 using the same process. Pin 2 should be the measured current and Pin 3 should be the desired current. I suspect this is going to be an issue with C18, C19 or the MUX pulling them down via IPHI. I would go ahead and replace them if you haven't already and the 4052.

Think cheapest 1 off qty of 4052 is bitsbox: https://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=140_157&products_id=1104

Early indications are pointing towards the 4052, extracted C18 and checked it, and it is 1uF @50V  with ESR of 6.2 , seems to be just perfect. Strangely although the schematic shows a C19, the parts list does not and neither does the variations table for the single units 310 and 320. The spot on the PCB looks as if it was never fitted so I'm going to have to call TTi again on Monday, unless anyone here has a PL310 with version 4 boards who could advise if it is fitted on the Main PCB  and its value at all?

Ahem,
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3278010/#msg3278010

The voltages measured indicate leakage currents........

Yep.

It should run without the 4052 in it. I’d desolder it and see if it works then.

The metering will probably wedge at 4095 though. Just ignore and measure at terminals.

Edit: just ordered a week's shopping on Amazon  which is fulfilled by Morrisons. Apparently it'll be picked and at my door in 1h 45m !!!

I'll be removing the 4052 later today and testing it again. In the information that Robert pointed me to, I discovered a photo of my board and it also has C19 cap missing, see attached photo, so that hopefully removes that niggling doubt that I removed it and never replaced it when recapping
 

[bd139]

It’s only used as a low pass filter on the current control knob so it will work without it.

[Specmaster]

Yep, but when the manual itself makes no reference to it other than in the schematic, not in the BOM or the variation table, it makes you begin to wonder.

Edit. 4052 removed, just about to power it up....

[tonyalbus]

When the seller said 'like new' .... Siglent SDG1010 ... i did not expect this.... 

i have seen some trick if you load in a csv it sould go to 50 Mhz... any of you know more tricks/hacks for it?   
@tautech or @rf-loop  .. do you have some magic firmware ?

[Specmaster]

Update, 4052 removed, powered on and the same result as last night, so I guess its back to leg lifting on the voltage control section?

[Specmaster]

When the seller said 'like new' .... Siglent SDG1010 ... i did not expect this.... 

i have seen some trick if you load in a csv it sould go to 50 Mhz... any of you know more tricks/hacks for it?   
@tautech or @rf-loop  .. do you have some magic firmware ?

Well, as long as it works like new, than the seller was not lieing was he  . The question is, did you get a real bargain or just the normal standard deal of getting what you pay for 

[bd139]

Update, 4052 removed, powered on and the same result as last night, so I guess its back to leg lifting on the voltage control section?

Damn! That proves that random part substitution doesn’t beat debugging at least.

I’d start poking around the OR gate section (where the two diodes meet between CC and CV sections)

[tonyalbus]

When the seller said 'like new' .... Siglent SDG1010 ... i did not expect this.... 

i have seen some trick if you load in a csv it sould go to 50 Mhz... any of you know more tricks/hacks for it?   
@tautech or @rf-loop  .. do you have some magic firmware ?

Well, as long as it works like new, than the seller was not lieing was he  . The question is, did you get a real bargain or just the normal standard deal of getting what you pay for 

Yes 135 + 9 shipping is very fair for a like new.... in my book

[Specmaster]

Update, 4052 removed, powered on and the same result as last night, so I guess its back to leg lifting on the voltage control section?

Damn! That proves that random part substitution doesn’t beat debugging at least.

I’d start poking around the OR gate section (where the two diodes meet between CC and CV sections)

OK will do, but I just measured the voltage on pins 2 and 3 IC7 and pin 2 was -19.3mV and pin 3 was -98.5mV but actual current using the Brymen at the terminals was 116mA with the controls maxed out.

Edit C18 still removed though.

[BravoV]

In the information that Robert pointed me to, I discovered a photo of my board and it also has C19 cap missing, see attached photo, so that hopefully removes that niggling doubt that I removed it and never replaced it when recapping

Mine does not have the C19 too.

[factory]

I accidentally bought that Beckman counter I was watching, as it went down to $30, shipping is still a killer on it though. 

What kind of display is this?

Until it arrives your guess is as good as mine, I couldn't find any info on it last time I posted about it when it was $50, I did find another (older?) version with neon number readout bulbs here; http://crasno.ca/articles/Beckman6148A.htm

David

Fleabay £1 selling fees again.

Not for me yet. I reckon they’re interlacing it every two weeks for different groups.

Have you checked on the eBay site itself? I never got the email but logging into eBay, it was there on the opening screen for me.

I've had the offer for the last three weeks, but not had offers any for a very long time before that, just not had the time to make use of these offers recently. 

David

[Specmaster]

In the information that Robert pointed me to, I discovered a photo of my board and it also has C19 cap missing, see attached photo, so that hopefully removes that niggling doubt that I removed it and never replaced it when recapping

Mine does not have the C19 too.

That is interesting as yours does not have the R51 main detection resistor or R60 which has been replaced by a diode (D26) and has more caps fitted and I cannot find any BOM for main control board that has that configuration 

[bd139]

R51 is mounted on the back of the board on later units.

[Specmaster]

Oh, and does D26 replace R60, 2.2K 2 watt resistor as well? I see that R61 2.2K 2.5watt one is still fitted.

Edit back on the power supply now, just washed the car and our wheelie bins using the new hose and pressure washer, so even if it splits now, I've had my moneys worth out of it, £10 min for car wash £4 a month bin washing 

[factory]

Got lucky on ebay. I snipped 3 substitution boxes for 20$   


The IET RCS-502 are really nice. They combine resistance (0.1%) and capacitance (1%) decades. The CDE CDB-3 is a lot older and only has only capacitance. Its also less accurate at 3%.

When received the CDB-3 was a bit inconsistent. I decided to open it up to clean the switches. The internal construction is somehow rustic with the piece of wood glued in the middle 


Also I never seen those capacitors before. Look like they are in ceramic. If radiomuseum.org is accurate, they were selling for 16.35 in 1965 (https://www.radiomuseum.org/r/cornel_dub_decade_capacitor_cdb3.html) In pretty good shape for it's age.

They look a lot like the paper/oil capacitors that often leak or fail in the "Shango066" radio or TV resurrection videos, hopefully I'm wrong and yours are a bit newer. 


I rescued a CDT 'tant' version a while ago. 

AS for the 2 RCS-502 they are working fine excepted 1 resistor on the second decade. Decided to open it up to investigate and found this:



  Luckily those resistors are readily available on digikey.

Oooh, nice stripy tants. 

David

[bd139]

Random review: Amazon grocery deliveries are a shit show.

Missing 7 items from manifest and half destroyed. They have refunded the entire order of £68 and let me keep the stuff without question though. This ain’t Morrisons fault. Last mile delivery dude is the worst.

Now cleaning up milk and mess. 

[factory]

Anybody want a cheap nixie tube LC meter ? the seller just sent me an offer at 17.50$

https://www.ebay.com/itm/Systron-Donner-9400-Meter/274527728404?hash=item3feb20b314:g:-0sAAOSwy2NfgQqG

Damn you, just sent an offer of $15 last night  , just noticed it's been accepted. 
Total price including shipping to the UK (no import fees as its' below £15) is £53.35.

Manual is over eight times the price of the LC meter. 
eBay auction: #273858476640

David

[Specmaster]

Random review: Amazon grocery deliveries are a shit show.

Missing 7 items from manifest and half destroyed. They have refunded the entire order of £68 and let me keep the stuff without question though. This ain’t Morrisons fault. Last mile delivery dude is the worst.

Now cleaning up milk and mess. 

Well, thats a mixed bag for you, delivery on time? I'm putting my money on that the order was correctly picked and packed but the last mile delivery dude had to slam his brakes on for whatever reason and loads of peoples orders went flying across the van in all sorts of directions so someone else has your missing items 

On the plus side, you did the order for free so anything you can salvage is a win and then pop round to Morrisons and replace the missing / damaged items and laugh all the way top the bank 

[factory]

British made 520MHz number readout bulb counter anyone?
eBay auction: #273858476640


David

[bd139]

Random review: Amazon grocery deliveries are a shit show.

Missing 7 items from manifest and half destroyed. They have refunded the entire order of £68 and let me keep the stuff without question though. This ain’t Morrisons fault. Last mile delivery dude is the worst.

Now cleaning up milk and mess. 

Well, thats a mixed bag for you, delivery on time? I'm putting my money on that the order was correctly picked and packed but the last mile delivery dude had to slam his brakes on for whatever reason and loads of peoples orders went flying across the van in all sorts of directions so someone else has your missing items 

On the plus side, you did the order for free so anything you can salvage is a win and then pop round to Morrisons and replace the missing / damaged items and laugh all the way top the bank 

Yeah picked and packed fine. There was one bag of 8 missing which explains it.

It is a mixed bag. However another fuming great big turd just landed. Sent my eldest off to the shops to grab the remaining bits and she comes back with extra kitchen roll, sausages, flora and bread. So I’m sitting there wondering how the fuck she came to that.

Well turns out Microsoft todo had a sync error and this was left over conflicted items from the other day which didn’t get ticked off when she was offline. Uninstalling it ffs. Total fucking nightmare

The cloud has brought a race to the bottom both on cost and technology quality.

[mnementh]

Finally got some workable endpieces for the PSU of Doom™, so spent some time making up connectors & adapters. I think the pix should be pretty self-explanatory in this space. Idiot light is RED for Fault, GREEN for Power Good. I omitted the Blue element for sanity's sake. Pix of various connectors are for the trade with another TEA member. 

Sound level is noticeably decreased with both endpieces... but I am still working on a new tailpiece design which is more similar in style to the nosepiece. Hopefully it will also be a bit mo quiet-ahh.

mnem
 

Interesting concept. But doesn't having only fixed +3.3V and +14.1V outputs limit it's usefulness?

Yes and no. These produce some pretty clean power for a switcher... and 14V/45A means you can run a fucking roomful of mobile radio with just one little brick stowed under/behind the bench.

For the advanced hacker, you can relatively easily float the DC side GND without without disabling the line-voltage side GND or hipot circuitry; so they can be series-stacked with some measure of safety. 28V/42V @ 45A... now that's a foundation for a decent bench supply with the addition of one or more of those cheap panel-mount CV/CC regulator modules. EDIT: And I bought 6 of 'em for $45 Canadian pesos... so that works out to ~$5.73 Dumbfuckistan dollars each. And a buttload of pain.

mnem
"...Shocked and amazed at the wonders of necroflesh? You're not alone. For a limited time only, you too can have this handsome epidermis for the eensy price of your soul and a buttload of pain.... ~The Violator - SPAWN

[Microdoser]

I think I have become addicted to test equipment. It started out small, just a handheld multimeter here and there but now I have a Rigol and I am considering binocular microscopes and bench multimeters, signal generators, higher frequency probes and other costly stuff.

I am planning a lab redesign to reduce EM interference on the testing side of the lab.

I don't know where this will end. I see a lot of capacitors in my future.

[mnementh]

   When the seller said 'like new' .... Siglent SDG1010 ... i did not expect this.... 

i have seen some trick if you load in a csv it sould go to 50 Mhz... any of you know more tricks/hacks for it?      @tautech or @rf-loop  .. do you have some magic firmware ?

Well, as long as it works like new, than the seller was not lieing was he  . The question is, did you get a real bargain or just the normal standard deal of getting what you pay for 

Yes 135 + 9 shipping is very fair for a like new.... in my book

I'm a bit jelly right now. 

mnem