Watsco 'Cappy' E2 - UK Vintage Radio Repair and Restoration Discussion Forum

agardiner · 30th May 2023, 1:23 pm

Hi,

Just picked up this interesting little vintage gadget, the 'Cappy' E2.

Looks like a simple capacitor leakage detector originally intended for a 'go / no-go' tester perhaps in the field.

Anyone got one of these? And if so, does anyone know how to take it apart? I would like to see the circuit and also check it over before trying it out.

Thanks,

stevehertz · 30th May 2023, 2:23 pm

Very interesting, nice find. I take it you've thoroughly googled it?

chriswood1900 · 30th May 2023, 2:29 pm

I think it is a US product used as a go no-go tester in the HVAC industry for motor and air con unit caps.

agardiner · 30th May 2023, 3:53 pm

Yes I have researched it. Doesn't seem to be much information at all on it.

It came with the original instructions, and can test all types of cap including electrolytic. I imagine that it will be a simple rectifier, limiting resistors selected by the switch and it uses a neon indicator bulb to show leakage. That's my best guess, but as said, want to tear it down and have a look!

agardiner · 30th May 2023, 5:37 pm

OK, looks like I won't be able to get it apart without destroying it. The 2 halves of the plastic case have been welded together. So.....

Decided to power it up, connecting the output to my scope. This proved my theory of a simple rectifier, as it was a half way output. I connected up a high voltage capacitor and the voltage across it quickly rose to 375V DC. Releasing the power switch instantly discharges the cap.

Running a batch of tests proves the unit is working fine and is actually quite useful. Assuming a 33uF HV cap, you put the main switch in position A and hold the non-latching power button. This results in a brief flash of the neon indicator as it charges; the neon goes out as the charge on the cap reaches approx 200V. You then switch to position B, and then C. If the neon lamp glows or flickers, it indicates a leakage current; approx 5 - 10mA in position B and around 300uA in position C. Low value caps can be tested just on position C.

Tested several new caps, and they all behaved as expected, without any kind of glow even on the C position. Tested a known leaky electrolytic, and it glowed on position B, indicating failure. Tried a couple of electrolytics in a Bush DAC90A and DAC10 (usually good), and there was no glow on the B position, and a small flicker on C, indicating low leakage, good caps. Tried a couple of waxies on C and the neon just glowed brightly.

What a great little gadget. Would love to know the actual schematic!

DMcMahon · 30th May 2023, 9:52 pm

Back in 2020 it was referenced in this antique radios forum link -

https://www.antiqueradios.com/forums...p?f=8&t=384003

Then there were a couple of images of the manual taken from eBay listing but the images now are no longer viewable.

David

Diabolical Artificer · 31st May 2023, 9:06 am

Sounds like this circuit, see attached.

Andy.

agardiner · 31st May 2023, 9:41 am

Oh, that's great, thank you. Any chance of you sending me the entire article?

Regards,

Buzby123 · 31st May 2023, 8:35 pm

Full article here ....

http://www.vmarsmanuals.co.uk/newsle...s/big_bang.pdf

30th May 2023, 1:23 pm	#1
agardiner Octode Join Date: Sep 2020 Location: Thetford, Norfolk, UK. Posts: 1,530	Watsco 'Cappy' E2 Hi, Just picked up this interesting little vintage gadget, the 'Cappy' E2. Looks like a simple capacitor leakage detector originally intended for a 'go / no-go' tester perhaps in the field. Anyone got one of these? And if so, does anyone know how to take it apart? I would like to see the circuit and also check it over before trying it out. Thanks, Attached Thumbnails __________________ Adrian. www.radiorestoration.co.uk Last edited by agardiner; 30th May 2023 at 1:23 pm. Reason: Add photo

30th May 2023, 2:23 pm	#2
stevehertz Dekatron Join Date: Sep 2011 Location: Rugeley, Staffordshire, UK. Posts: 8,530	Re: Watsco 'Cappy' E2 Very interesting, nice find. I take it you've thoroughly googled it? __________________ A digital radio is the latest thing, but a vintage wireless is forever..

30th May 2023, 2:29 pm	#3
chriswood1900 Octode Join Date: Jan 2007 Location: Dorridge, West Midlands, UK. Posts: 1,424	Re: Watsco 'Cappy' E2 I think it is a US product used as a go no-go tester in the HVAC industry for motor and air con unit caps. __________________ Chris Wood BVWS Member

30th May 2023, 3:53 pm	#4
agardiner Octode Join Date: Sep 2020 Location: Thetford, Norfolk, UK. Posts: 1,530	Re: Watsco 'Cappy' E2 Yes I have researched it. Doesn't seem to be much information at all on it. It came with the original instructions, and can test all types of cap including electrolytic. I imagine that it will be a simple rectifier, limiting resistors selected by the switch and it uses a neon indicator bulb to show leakage. That's my best guess, but as said, want to tear it down and have a look! __________________ Adrian. www.radiorestoration.co.uk

30th May 2023, 5:37 pm	#5
agardiner Octode Join Date: Sep 2020 Location: Thetford, Norfolk, UK. Posts: 1,530	Re: Watsco 'Cappy' E2 OK, looks like I won't be able to get it apart without destroying it. The 2 halves of the plastic case have been welded together. So..... Decided to power it up, connecting the output to my scope. This proved my theory of a simple rectifier, as it was a half way output. I connected up a high voltage capacitor and the voltage across it quickly rose to 375V DC. Releasing the power switch instantly discharges the cap. Running a batch of tests proves the unit is working fine and is actually quite useful. Assuming a 33uF HV cap, you put the main switch in position A and hold the non-latching power button. This results in a brief flash of the neon indicator as it charges; the neon goes out as the charge on the cap reaches approx 200V. You then switch to position B, and then C. If the neon lamp glows or flickers, it indicates a leakage current; approx 5 - 10mA in position B and around 300uA in position C. Low value caps can be tested just on position C. Tested several new caps, and they all behaved as expected, without any kind of glow even on the C position. Tested a known leaky electrolytic, and it glowed on position B, indicating failure. Tried a couple of electrolytics in a Bush DAC90A and DAC10 (usually good), and there was no glow on the B position, and a small flicker on C, indicating low leakage, good caps. Tried a couple of waxies on C and the neon just glowed brightly. What a great little gadget. Would love to know the actual schematic! __________________ Adrian. www.radiorestoration.co.uk

30th May 2023, 9:52 pm	#6
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 6,259	Re: Watsco 'Cappy' E2 Back in 2020 it was referenced in this antique radios forum link - https://www.antiqueradios.com/forums...p?f=8&t=384003 Then there were a couple of images of the manual taken from eBay listing but the images now are no longer viewable. David

31st May 2023, 9:06 am	#7
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,250	Re: Watsco 'Cappy' E2 Sounds like this circuit, see attached. Andy. Attached Thumbnails __________________ Curiosity hasn't killed this cat...so far.

31st May 2023, 9:41 am	#8
agardiner Octode Join Date: Sep 2020 Location: Thetford, Norfolk, UK. Posts: 1,530	Re: Watsco 'Cappy' E2 Oh, that's great, thank you. Any chance of you sending me the entire article? Regards, __________________ Adrian. www.radiorestoration.co.uk

31st May 2023, 8:35 pm	#9
Buzby123 Heptode Join Date: Oct 2011 Location: Culcheth, Cheshire, UK. Posts: 580	Re: Watsco 'Cappy' E2 Full article here .... http://www.vmarsmanuals.co.uk/newsle...s/big_bang.pdf