[Heathkit] SB-200 issues.

[Kenneth G. Gordon]

On 3 Jun 2007 at 21:10, Ian wrote:

> Ken,
> 
> It sounds like it's time to get out the ohmmeter and start tracing the
> entire circuit.  ???????

Well, I found one problem that is fairly interesting: RFC-3, the RFC 
which is across the antenna connection for safety, appears to be MUCH 
larger than 1.1 mH. It looks a lot like a 2.5 mH or larger choke. When I 
disconnected that so that I could check to see if the bandswitch was 
adding the extra loading cap on 80, now the rig loads properly. At the 
bottom end of 80, the loading cap is still open a bit.

I wonder what else I will find?

> 
> Otherwise it would seem that you are in for a long series of finding
> the problem only to have another pop up down the stream.

Thanks, Ian. However I have gone pretty much completely through the 
circuit. It IS pretty simple, after all.

It appears that one tube, the one that wasn't lighting, is not drawing the 
proper current. All grid resistors seem to be OK. I am wondering if one 
of those little 200 pfd mica grid bypass caps is open.

And the difference in filament brightness still bothers me...one tube is 
considerably brighter than the other.

Ken Gordon W7EKB

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