[R-390] Dead R390A Need HELP

[Walter Wilson]

Tom,

You can inject 455 KHz (modulated) into either one of the IF deck
inputs and check the IF deck alone.  After that checks out OK, you can
start moving back through the RF deck one stage at a time, using the
RF deck test points to inject signals into to grid circuit of each
mixer.  Details are in any of the R-390A field depot manuals, many
available for free download.

If the PTO was disconnected from the front panel, the first thing I
would do is set it at 2455 KHz at 7+000 KC (that's 1 KC above 7 999
KC).  While at this position, check that all the camshaft pointers
line up with the black alignment marks on the front of the RF deck. 
The deck is so selective it won't receive any signals if the RF tuned
circuits are a little off.

Good luck.  I have lots of alignment information on my website, www.r-390a.us

Walter - KK4DF

On 9/22/05, Thomas Guest <Thomas.Guest at trw.com> wrote:
> Hi everyone,
>
> I am new to the R-390A but do antique radios. I may have bitten off more than I can chew at the moment but I hope that will change.
>
> I picked up this set from Fair Radio (used repairable) and powered it up and get almost nothing.
>
> I have replaced the killer cap in the IF, the 8 ufd audio section cap, and the electrolytic tests good at full rated voltages. Fuses are good. I have a short antenna 20' hooked up to the balanced input with the other half of the connector grounded to the chassis. The ballast tube is good. The brown beauty caps in the set have NOT been replaced! I see B+ of 285Vdc at the back panel fuse.
>
> I have a Hallicrafters R-42 speaker (600 ohm input) tied to the set and get only a faint scratching noise from turning the volume control.
> No signals across the board on this set. The carrier meter deflects about ½ way (my meters are not the factory ones) and I get no deflection on the line meter.
>
> Problems that I did find was the VFO was not connected to the front panel knob, & the rear terminal strip was loose and could have been shorting the RF gain jumpers to the chassis. After fixing these issues still have the same results.
>
> Any ideas on where to look next?
>
> Or is there a way I could inject signals into the set to prove out a section at a time?
>
> Thanks in advance.
> Tom Guest
>
>
>
>
>
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