[R-390] R-390 Question

[Tim Shoppa]

>   0.2 ohm might be the resistance of the filament transformer, but
> when you take the reading, there are 4 series strings of tube
filaments with
> some series resistance in a couple of them in parallel with the
transformer.

The DC resistance of the filament transformer will dominate, of course.

> I think that's why the manual gives normal readings in the range of 6
to 9.5
> ohm.  Could be an error in the manual though.  That's not unknown.

Maybe there's an "assumed" step of 0: uncable the PS module? It is
almost impossible for there to be a solid short across the filament
transformer,
something would blow! (And not necessarily the fuse!)

> The reason I got into all of this is that the receiver lost
sensitivity and
> had no carrier level meter movement.  What is an expected carrier
level
> meter reading for the calibrator on say 15MHz?  I could just barely
hear 15
> MHz WWV while on my 75S-3 WWV was coming in way over S9 and I could
also
> hear WWVH.

On my 390A the calibrator will deflect the carrier level meter 3/4 of
the way on most bands. HAve no idea how relevant this is to your 390!

Tim.