A friend of mine has loaned me his SB200. If I can get it working again, I get
to use it (for a while anyway :=)
>From what he told me, and by inspecting the amp, it looks like RFC2 is burnt
>out. From what I've been able to gather from a schematic and partial manual
>found on the internet, cut-off bias voltage from the power supply bias circuit
>is applied through the coil of the T/R relay, a resitor, and RFC2 to the grids
>of the tubes (on RX). On TX, the Ant Relay jack grounds the grids of the
>tubes through RFC2 and a couple of resistors. (RFC2 is is parallel with a
>1Watt 3.3K resistor.)
The schematics show RFC2 = 28uH. How critical is this value? Can I just go
through my junk box and use any old choke that's close in value? Wind my own?
If not, does anyone have a suggestment for a replacement part (supplier, part
number, etc)?
Thanks in advance!
73,
Chris VE3FU / VO2AC
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