Manual for Hunts CRB3 Capacitor Tester

[Excessive Leakage]

Hi Barry

No problem at all. Happy to help.

Apologies, I missed the small silver mica cap immediately to the right of the 6.8K resistor in picture 2. Do you have this installed, or should I take another look inside the CRB3?

Thanks

Adam

[Barry]

Hi Adam,
I do have the small silver mica cap next to the 6.8K resistor it does not have a value on it, I tried to test it but got no reading from it. I have also ordered a 2uf 250v cap, I have now replace(fitted) the 2x 01uf 400v and the 0.47uf 250v, replaced the Hunts 16uf+16uf can capacitor with a new one, and replaced some of the small resistors and now for the mains lead.

Thanks again
Barry

[JayBee]

Time to rake over this old coal.

I have just bought a CRB3 and was pointed to this website for a schematic so that I can get my one running.

Looking at the schematic, it looks very much incomplete.

None of the electrolytics are shown, just the rectifier.

The CRB3 has two potentiometers but only one is in the schematic.

None of the values for the components are given.

Does anyone have a correct schematic and component values?

Thank you.

[JayBee]

After having worked on the device, today, I realise that the electrolytics are in the schematic (C3 & C6) but they are just not displayed as such in the schematic.

[uslrs]

Hi Guys,
My first post is a thank you!  Have recently acquired a CRB3 to test caps in valve amps at their working voltage.  There were the usual problems with duff caps in the tester but having replaced them could get nothing from the magic eye.  When I checked the wiring I discovered the EM34 HT was connected to a 16uF cap but nothing else.  I was up against it without a schematic and after a lot of searching, found this thread with the manual - absolute god send!!  It's now up and running and a cracking piece of kit for checking those high voltage caps!  By the way of a thank you, I've scanned the schematic and added values (measured), so hope that might be of use to others lucky enough to lay hands on one of these.
It should be noted that there's an added 62k resistor in the EM34 HT feed - I was concerned that the voltage was significantly higher than is usual for this magic eye (390v versus 200-250v).  It has reduced the voltage to approx 250v, which will hopefully extend the life of the EM34.

Thanks again - pic of CRB3 and scan attached.

Les (newbie).

[Excessive Leakage]

Hi Les

That's a nice looking example!

I use a CRB3 on a regular basis and it has weeded out a fair few duff high voltage capacitors so far. A nice sturdy piece of kit  

Welcome to the forum BTW. A friendly bunch on here.

Cheers

Adam

[Alistair D]

The attached file is an improved(OCR) and extended version of the CRB3 manual. I certainly find it much more readable than the original but then I'm biased I compiled it.

Al

[JayBee]

Good work. Thank you.

The attached file is an improved(OCR) and extended version of the CRB3 manual. I certainly find it much more readable than the original but then I'm biased I compiled it.

Al

[Alistair D]

While searching for more information on the neon bulb I came across these. https://www.lampco.co.uk/collections/min...x52mm-neon They look to be a useable replacement for the original.

The voltage rating of 100-120 volts has been confirmed by reading the markings on both an Ediswan and a Philips device.

Al

[Freya]

Been thinking of modifying mine to only power the magic eye when needed (C & R), but the selector switch does not have any spare contacts sadly.
Unless someone else has any ideas.

Stephen