[Amps] SB200 - RFC2 Replacement?

[Chris Allingham]

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