[Boatanchors] Clipperton L Update
infomet at embarqmail.com
Sat Nov 18 22:20:07 EST 2017
OK, I got some useful inputs.
As it seemed, there was a metering problem.
I love radio forensics and got to use them here.
I won't give the gory details, but the PO had put a 1K resistor in series with the meter.
It was not a factor reading B+, since the meter is fed from a 100K source.
It was a BIG factor reading plate current, however, which is done by reading the voltage across a 0.05 Ohm resistor.
Nominally that's 50mV at one amp and the 20 Ohm meter would need about 40 Ohms to bring it in.
So why the 1K? The PO was an accomplished engineer, experienced ham, etc, now SK, unfortunately, so I can't ask him.
I don't know what he did with the amp. Maybe it was hacked by someone else.
Anyhow, I now have idling current as reported by people here, but I have not applied any RF.
The tubes, likely original (Cetron), are likely fine, since Ip is about 100mA in CW and 140mA in SSB.
SO there you go. A dead stock Clipperton L in working condition.
Trouble is, I have other amps and don't want to work on this one and it seems silly not to replace the filter caps, and maybe even the diodes.
Of course the Harbach board does it all for $100.
I'll report when I try some drive.
Meanwhile, if anyone wants it and can pick it up in central NC, let me know.
More information about the Boatanchors