[BC] FM Exciters (Pic's)

[DHultsman5@aol.com]

In a message dated 2/25/06 11:16:12 A.M. Central Standard Time,  
harold at hallikainen.com writes:

The  Collins one, though, had a crystal
reference oscillator that was switched  into the FM detector something like
once per second. The output of the FM  detector used this crystal as its
reference, sort of clamping the output to  zero when the crystal was
driving the detector, then detecting the offset  when the FMO was driving
it. Clever (and complicated)  circuit!



This was the 310Z-2 (Later Continental 510-R) carrier generated at  
frequency, developed by Jack Sellmeyer.  The Z2 model was an upgrade from  the earlier 
Collins 310Z-1, which was a solid state version of the A-830   transistor/tube 
hybrid exciter.  The 310Z-1 did the modulation at 14 mHz.  and hetrodyned up 
to carrier so the crystal reference was 14 Mhz. below  carrier.  The major 
problem was it took two plug-in boards to do this and  bad card edge connectors.  
Sellmeyer's single modulated oscillator card  replaced all the boards except 
the final 20 Watt PA stage of the exciter. It  also featured very low 
distortion, IM and TIM.
 
Dave Hultsman