i took a couple of pics when i first bodged the only variable i had to hand in there to test the idea, after i proved it worked i soldered the variable in properly and used it like that for a couple of month, right now its stripped again while i fit regulators for the keying and biasing + power supply mods,
http://i5.photobucket.com/albums/y15...X/P1010306.jpg
http://i5.photobucket.com/albums/y15...X/P1010312.jpg
measure the dc voltage either on the wire loop of the bias choke or at the back of the input transformer, you will see on ssb there is no .6v untill you have sufficient drive on to turn the bias circuit on, fitting the variable as in the pic forms a potential divider feeding the base of the bias switching transistor which lets you set how much rf is needed to turn the bias supply on,
in stock form the keying transistor has to be turned on pretty hard before the bias is turned on which results in the relay pulling in way before the bias is switched on and that scratchy audio,
i only had a 10k variable handy so i tried it, i adjusted the bias untill it just turned off in rx then started at 100mw drive and increased it untill the relay pulled in at the same time watching the bias voltage to make sure it was comming on as the relay activated, i finally set it so the bias voltage starts comming up just before the relay activates,
as it pulls in the bias hits .69volts then starts backing down as drive is increased to just under .6v at full drive,
setup like that with no bias regulation its overbiased at very low drive levels and a little underbiased at full drive but it works and cures the ssb distortion,
a smaller value variable resistor will give better resolution of adjustment, just make sure you set it right so that the bias only turns on as the relay pulls over,
another thing worth checking that effects the bias level is supply voltage, i have 30.5v off load and 25.5v at 300w fm, the big drop in volts and ripple on the unregulated supply are not a good supply for an unregulated bias circuit,
if you have more than 30.5v offload i would be very carefull you dont have too much bias volts at very low drive levels, if you have higher beta transistors than me or higher supply volts you will need a 3 terminal regulator adding.
with the regulator i can set it so that its neither over biased nor underbiased across its input drive level range.
hope this helps... __________________
. I might have to buy a noise cancelling mic to use with it. The bad thing about it is... it is not practical to move the KLV away from me because It needs to be retuned whenever you change channels. 
