The AM Forum

OK...PICKED-UP A HEATHKIT MARAUDER ON THURSDAY..ASIDE FROM A LITTLE CLEANING,THE THING LOOKS NEW...BRIGHT CHROME KNOBS,FRONT PANEL,NO SCRATCHES,CABINET COULD USE REPAINTING. INSIDE,A LITTLE DUSTY,BUT IT'S ALL THERE. GOT COPIES OF ALL MANUALS,RAN IT UP ON THE VARIAC,AND IT HAS STABILIZED..A FEW TUBES NOT LIGHTING UP,BUT AFTER A GOOD CLEANING OF THE INSIDE,I WILL REPLACE THE TUBES,ES SEE IF SHE WORKS...MANUAL SAYS 25WATTS AM..COULD TRY RUNNING IT THRU THE SB200,OR BUILD A MODULATOR,AND PLATE MODULATE THE THING...THE PRICE FOR THIS GREEN BOX---FREE--- THE GUY JUST WANTED TO MAKE SURE IT FOUND A GOOD HOME...SEE YA...TIM...SK...

And Tim, who is the guy and where does he live???

Good deal, keep them warm

73

That rig can be made into quite a good low power AM tx if you don't mind making a few changes and losing ssb capability.
Same goes for any other ssb filter transmitter or transceiver.
Disconnect and bypass the I.F. filter with a .01 cap.
Disconnect any ALC loop.
Change values in the speech amp as you would in an AM TX.
Once you get it dialed in it will work as well as anyhting else out there.

Plate modulating the rig would be quite a bit of work as the final is now linear. After conversion to class C, the tank circuit would probably break down due to much higher peak Voltages with plate modulation. Just too much monkey business.

The Heathkit HX-20 mobile SSB rig I converted had a balanced input SSB filter.  I wound a trifilar toroid, 1:1, (ultimate ratio 2:1) then used small series capacitance on the output to ensure that the grid of the next stage wasn't overdriven.

It's **imperative** as Dave said that you disable the ALC, or you won't get decent peaks.

73 John