[Boatanchors] 8640 Options

[mrharisn at hughes.net]

Option 1:  Wide range audion oscillator, 20cps to 600Kc

Option 2:  Internal RF frequency doubler, to 1024Mc.  Not available 
with Opt.04

Option 3:  reverse power protection.  

Option 4:  Avionics version, with special audio characteristics.  It 
has flat AM modulation response, with minimum phase shift, from 30cps 
to 10Kc, and has  constant group delay from 9 to 11Kc.

Mike Harrison
KE0ZU