The AM Forum

..HI FROM TIM..BILL VE3LVL WAS ASKING ME ABOUT A STAND-ALONE,MORE STABLE VFO FOR HIS VIKING2. I THOUGHT I WOULD AS YOUR OPINIONS ON THE MATTER. IT WOULD BE NICE TO FIND SOMETHING LIKE A TMC VFO,BUT IN PLACE OF THAT,WHAT ARE YOUR THOUGHTS AS TO BILL USING HIS TS450,OR SOMETHING LIKE A DIGITAL SIGNAL GENERATOR?  ...TNX.. ..SK..

I've used a homebrewed DDS generator on my Viking2. I noticed however the signal wasn't perfect so I filtered the output of the DDS generator and all worked well.  Very nice stable signal with good output.  I wasn't happy with using a digitally generated signal with a boatanchor so I stablized a Heath VF-1 I picked up for nothing and use that when I'm not using a crystal. 

         I have a VF1 here that someone had solidstated using a mpf 102 ( I might have the FET letters mixed up). I did not use the voltage divider network or power from a rig but used an 18 volt wall wart ( transformer ) with extra filtering and it works great. Max drift about 50 cycles. The dope on this was in an old QST but I don't know what year.I'm going to do another one just for the fun of it. :) 73

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Write it up Roy. I have a lot of old VFO's that could use upgrades.
Keith
WA1HZK

One of these nights when a slop bucket ticks me off I plan to try my HP3325
as a VFO (in slow sweep mode) the HP8640B would make a great VFO and test generator. 250 t0 500 MHz cavity oscillator with ECL dividers to get ranges down to 455 KHz. Very clean source!

I did the same thing to one of the Heath LMO's, just shoved the FET leads right into the correct tube socket contacts, applied +12vdc to the B+ input on the LMO and it worked great! very stable!! (but no glow  ;D)