Taylor 45 Valve Tester

[Andy - G8MNM]

Hi Guys n Gals!

I have a problem with my Taylor valve tester and it seems to be a resistor at fault.
I cannot make out the value from the indistinct bands on the resistor.
It is R12 on the circuit diagram, unfortunately Taylor in their infinite wisdom chose/omitted to list component values on the basic circuit diagram in the user manual.
Just wondered if anyone else out there with a Taylor valve tester may know the value of the resistor?
The resistor is located on the test selector switch at the front, it connects to PB2 (which is the 'GAS' test button on the RHS of the front panel at the bottom.
I have spent all day chasing my tail with this. Months ago I repaired the 'B' selector switch which had jammed, but didn't test the unit afterwards. I assumed today that when I came to use it that it would be issues with this switch, that doesn't seem to be the case though.

Regards

Andy

[John H.]

Hi Andy,
If your tester is a 45A, then according to some hand written notes with my cct diagram R12 is listed as being 2.2k ohms.
The diagram shows it connected at one end to the slider of the backing off potentiometer. Hope this helps, John.

[Andy - G8MNM]

Hi John,

Thanks for the info.
Mine is the 45C but I think the resistor value could be the same.
Mine also still has the original selenium rectifiers.
I imagine they are perhaps now past there best
if I change them for silicon then the out[put voltage will be higher than in the original design. Any idea of what the original voltage would have been?
I guess I need to play around with series resistor values for the full wave bridge.
As to the other 1/2 Wave ? rectifier who knows?

Andy

[WME_bill]

Taylor 45A valve tester. I attach a copy of the circuit diagram with values noted. Your R12 is 2.2k. The full manual is too large to post on this forum (2.2Mb), so send your email by private message if you want it. wme_bill