[Hallicrafters] Re: SX-71 Coils

[Philip Atchley]

> Phil -- could you have the coils mixed up?  I'm looking at the schematic
> from a manual I downloaded.

Barry
No, you're right about the Mixer coil.  I just referered to it as the RF amp
coil as it's in the Plate of the RF amp.  I should have made myself clearer
(I knew what I meant;-)

The coil that I think is bad is the antenna coil for band one.  Continuity
checks good.  However, connecting the antenna to the antenna connector has
only minimal effect on the lower end of the BCB, but if I connect it to the
grid of the RF amp (actually stator of the tuning cap) there is all kinds of
gain !  I think that coil was burnt when the AC line cap blew up (came in
that way), though, without removing the coil I can't see it really well.

73 de Phil  KO6BB


>
> The BCB RF coil does not show any resistor (T1), but the mixer coil DOES
> show the 100 ohm resistor across it.(T11) -- the only one of the five
mixer
> coils to have the resistor.
>
> If so, does that affect your diagnosis?  Also, without fully tracing the
> schematic lines -- eyes are tired here --  it doesn't appear that the
> "bottom" of the mixer coil is grounded directl, but rather through what
> looks like "C10-B" -- one half of a dual 4,000 pf ceramic cap.  The low
end
> of T1 (as well as T2 through T5) is directly grounded.  Which coil is
> apparently blackened -- the RF or Mixer?
>
> Barry
>
>
>


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.351 / Virus Database: 197 - Release Date: 4/19/02