r-392 aligning bands

[NR5P]

I love my r-392 it works great.  However when I change some bands I zero beat and the frequency is significantly.  It's not so far off that I cannot zero with the dial so it's not really that big of a problem.  BTW I have went through a complete alignment of this radio as by the book.  Now I would like to be able to adjust each band to be as close as possible.  I realize that it's not going to be perfect on an old tube receiver but this thing is so stable from the time I 1st turn it on to when it is warmed up I think I can get very close.  Is there anyway to adjust this?  Thanks, Nathan

One more thing when aligning the rf stage slugs and capacitors at the very final adjustments I cannot peak the 3Mhz band.  I can tell it's very close to peaking if not peaking but there is not enough adjustment to see the "drop".  I aligned the cams.  Anything I'm missing here?

[WD8KDG]

On the 3MHz band: If the 392 is anything like the 390/A's, my money is on a bad cap in one of the RF cans in that octave. One clue is the slug adjustment is at one of the ends of adjustment, no more threads left to twist. Another clue is a day or two later that band/octave has lost sensitivity and needs tweeking again.

Replace the all the silver mica caps in that RF can.

Craig,

[NR5P]

Thanks Ill replace them.  I wasn't thinking about there being mica caps in there with the variable inductor and resistor.  Looks to be 15 and 430pf in that rf can.  This has an rf section from a later model r392 on this one.  I wish I knew where this thing has been in the past.

[N8ETQ]

Yo'


   I have encountered a set where those
little "triangular" plates were on the
wrong side of the bar that holds all 3.

   Since you say that you can't get the
3mcy band adjusted I think the Cam for
that 2 - 4 mcy band is outta synch.
Adjustment freq for that "Rack" is
2.2 mcy and 3.8 mcy. I assume you can't
get the slug far enough out of the coil
on 3.8 Mcy. Loosen that racks clamp and
adjust it at 3.8 and you'll be ok.

   I'm not saying it can't be a bad 500
volt slver mica, but if it lines up at
2.2 ok, I would think it unlikely.
especially on a 28 VDC rig.

   What happens if you lift the rack a
little bit with your finger. can you find
a peak with that?

GL and 73

/Dan

[NR5P]

My problem is I can't screw it in far enough.  I went through and aligned the cams with the dots.  It is only the 2-4Mhz can toward the front.  There are two slugs in that can on this r392 and one of them adjusts fine while the other slug won't go in far enough.  I will need to look at it again though it has been a while since I checked it. 

[WD8KDG]

One other item to try before fling'en hot solder. Put the slug adjustments in the middle of their adjustment range & start at square one. You might of passed by the sweet spot.

Craig,