[Hammarlund] SP-600 RF illness

[James A. (Andy) Moorer]

Well, it depends on whether you mean getting at the sockets just to measure
the voltage, or whether you mean replacing some parts in the RF deck. If it
is just to measure some voltages, you just get a couple of these tube test
adaptors that go between the tube and the sock and have test points for all
the socket pins.

Otherwise, you will have to pull the RF deck to replace anything. On one
rare occasion, I managed to replace a resistor by just prying up one side of
the deck but not unsoldering it, but that is pretty uncommon. Most of the
parts are well inside and are thus not replaceable without lifting the desk.

It is worth checking the voltages first. If you lift the lid off T1 (to the
right of the RF deck), you can test all the voltages going into the RF deck.
Make sure they are reasonable before you yank the deck. It is not out of the
question that, for instance, the load resistor for the 0A2 regulator has
gone open and there is no more 150V.

One thing to be sure of: you MUST move the band select to halfway between
any two bands before removing or replacing the deck. This disengages the
coils in the turret from the RF deck. If you don't do this, especially when
replacing it, you will break those brittle contacts on the bottom of the RF
deck. Much cursing and gnashing of teeth will ensue.

James A. (Andy) Moorer
www.jamminpower.com


----- Original Message ----- 
> My question is, must I now
> pull the RF deck out completely to service this area or is there a
> simpler way to access the tubes' sockets?