[Amps] sb200 fan question...

[Jim Thomson]

Date: Tue, 2 Feb 2016 19:08:05 -0800
From: jerome schatten <romers at shaw.ca>
To: amps at contesting.com
Subject: [Amps] sb200 fan question...

I have acquired a nicely refurbished SB200 and all works fine.  The  original fan has been replaced with and FM200 Harbach and the noise (partly mechanical and partly rushing air) is driving me nutz.  I?m using it only on CW, but mostly I listen. Is there good reason to keep the fan going over long periods of listening?  I was thinking to key up the fan only during TX, or if things must be cooled while the tubes are in cutoff, reducing the fan speed during RX. 

Any advice appreciated!
Thanks,
jerome - va7vv / ve7ass

##  Limit the fan speed on RX..with a single resistor in one leg of fan motor.   Then shunt out the resistor when on TX.
You cant run those tubes with no air on em in RX.   Use the key line to amp to activate the coil of a newly installed  spst  relay.
Which will be in addition to the oem tr relay. 

Jim  VE7RF