[Amps] adding second tube to AL1200

[Phil Clements]

> Kevin Adam wrote:
> > Wanted information on adding a second tube to AL 1200 has anyone done
> > this if so can you give the details as to what all is envoled what
> > parts you had to change if any please help
> 
> Off the top of my head, you would probably need an outboard power
> supply, since it's doubtful that a larger transformer would fit.  Then
> you'd need to change the input network components for half the
> impedance

A 2:1 unun transformer will work fine here; just like the ones Alpha
supplied with their 77DX to SX conversion kit.


> Ameritron is known for borderline tank
> inductors, so you might have to replace the coils with ones made of
> larger wire or tubing to handle the RF current.

That is an understatement! Under-sized wire compounded by small winding
diameter.


 > Why don't you just build a new one?

I learned a long time ago that selecting a single tube to meet your desired
specifications makes life much simpler. The initial cost may be higher, but
a proper tube with a lot of headroom will last a ham a lifetime. If I were
to mod an AL-1200, I would change to a single 1200Z7 and call it a day.

(((73)))
Phil Clements, K5PC