[Heathkit] SB-200 6m Mod

[Kenneth G. Gordon]

On 30 Jul 2007 at 13:26, kb0nly wrote:

> That's a possibility also!
> 
> I'm also looking at my options for building a 6m amp from scratch.  So
> if anyone knows of a good design with full construction details online
> let me know.

Well, there was a surplus amp, the AM-8(*)/TRC-1, originally designed 
to cover 70 to 100 Mhz, that with the simple addition of two door-knob 
capacitors in parallel with the plate tank tuning capacitor would be able 
to easily provide you with 600 watts output on 6 meters.

Since it is grid-driven, you would need very little drive.

However, you would need an external DC power supply.

The amp has a built in 110 VAC filament transformer, and all the 
necessary VR tube regulators for the screen voltage. Three, I think, 
with room for two more. VR-150s.

Final amp tubes are a pair of 4E27s in push-pull. Plate tank coil is a 
humongous sliver plated job. Built-in antenna changeover relay, and 
front panel mounted controls and meter, with three fancy pilot lights. 

Big, honking 110 VAC blower inside, which you don't really need unless 
you plan to operate it when it is still mounted in its combo wooden 
desk/carrying case. 

Feet pressed into the steel bottom plate inside of which is glued a large 
schematic. Top is hinged and has an interlock switch. Painted a nice 
Army green crinkle.

The 4E27 uses the same socket as the 5-125B/4E27A and the 813.

They were designed by Link and built in 1945 or so.

Fair Radio sold a bunch of them. I had 7 once. I think I have 2 
left...somewhere. Still NIB in the crate.

Now all I need is a 6 meter rig to drive one of them with...

Ken Gordon W7EKB