<<<SPAM>: Re: [R-390] First 390A Alignment prep and weak bands

[Tim Shoppa]

>     2-3 and 3-4 mc/s are deaf as stumps.  In particular, the core for
> L-217 is all the way at the bottom of its travel with no real peak. 
> Mechanical alignment is fine.
>           Looks like I need to pull T-203 again and have a look at the
> innards.  Any idea what I should be looking for?

If you've got a grid dip meter, you ought to see a peak at 4 or 5 MC
with the core removed, and you ought to see it somewhere between 2
and 4 MC with the core halfway in.

Take off the cover and look to see any physical evidence of burnt out
inductors.

If you don't have a grid dip meter, undo the minimum number of wires to
separate the L's from the C's, and check for conductivity in the L's and
lack of conductivity in the C's.

If you've got some sort of capacitance meter, check the capacitors, including
the variable ones under rotation.  Those postage-stamp micas have been known
to do some bizarre things, and I'm 99% sure there's two of them in the 2-4MC
cans.  IIRC there's also a small (<1 pF) ceramic cap in there.

Tim.