[R-390] Mechanical Filter Issue

[Leigh Sedgwick]

Very sorry for my last post.  I had the trimmer numbers
cocked +90 degrees.  The Y2K manual, figure 3-6 is correct. 
My humble apologies to the list for my mistake!  Other data
in the post stands as is :-)

Sorry about that!

73 de Mike
K7PI

Leigh Sedgwick wrote:
> 
> Thanks all for the responses to my questions.  I appreciate
> the help.  A couple of finds today.
> 
> 1.  Either Figure 3-6, page 3-16 of the Y2K-R2 manual is
> wrong or my R-390A is wired differently than most.  All of
> the input trimmers shown in this figure are correct but the
> output trimmers are all incorrectly marked.  This is what I
> find:
> 
> FL502  2 khz filter - input C567/output C570
> FL503  4 khz filter - input C566/output C568
> FL504  8 khz filter - input C565/output C571
> FL505 16 khz filter - input C564/output C569
> 
> Can anyone confirm these findings?  If so, might be a
> candidate pickup for revision 3 of this fine manual (thanks
> to all for the hard work on this great resource).
> 
> 2.  Based on going through the 2 khz filter circuit, it
> appears the 2 khz filter is indeed bad and I am in the
> process of replacing it, ugh!
> 
> 3.  I looked at the slug racks in the RF deck, and they all
> appear to be identical (i.e., RF versus IF).  The RF slugs
> are all marked identically with both a white and red dot.
> The variable IF slugs have no markings.
> 
> Thanks again....
> 
> 73 de Mike
> K7PI
> 
> Leigh Sedgwick wrote:
> >
> > Hi Gang,
> >
> > On the a different subject.  My restoration R-390A project
> > is just about finished.  I rebuilt the RF deck and recapped
> > the IF deck and AF decks.  The smoke test was positive with
> > signals on all bands, although it is way out of alignment.
> > But I have a couple of issues.
> >
> > 1.  Three of the four mechanical filters appear to work
> > fine.  But, when I switch to the 0.1, 1, and 2 bandwidth
> > positions, there are no signals.  Is there any quick check I
> > can make to ensure it is the 2 khz mechanical filter and not
> > something else in the circuit?  It looks like a bit of work
> > to replace and I would hate to go through that effort only
> > to find out it is actually something else.
> >
> > 2.  I tore the RF deck apart with the idea I would get it
> > rebuilt within a week or 2.  No such luck...work issues
> > caused a significant delay of almost a year before I was
> > able to get back and finish it.  During that time, I lost
> > track of the ordering of the slug racks and was forced to go
> > with a "best fit" approach to reassembling them.  Other than
> > the fact that the alignment is totally hosed up, will I be
> > faced with any other issues, i.e., are they all identical or
> > are there differences I cannot see visually.  I saw
> > something on the FAQ page that some are different.  They all
> > looked the same to me.
> >
> > Thanks for any help.
> >
> > Happy New Year
> >
> > 73 de Mike
> > K7PI
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