[R-390] [KA9EGW] progress

[ka9egw at britewerkz.com]

My parts washer has regular kerosene in it, think that'd hurt the RF deck?
I mean, all the gears will get cleaned separately from the deck, obviously,
I found a good tutorial or two disassembly/reassembly and mechanical
alignment on kk4df's site and another on militaryradio.com.  I'm loath to
mess with the guts of the rf deck beyond the geartrain...the 10-turn stop
may be out of sync but the cams all look lined up at 7+000. so I don't see
disassembly of hte slug racks as necessary...

This radio isn't showing any corrosion, just the effects of years in a shack
that shares space with a machine shop and the attendant oil mist in the
air...

-----Original Message-----
From: powool at gmail.com [mailto:powool at gmail.com]On Behalf Of Paul
Anderson
Sent: Monday, September 14, 2009 7:33 PM
To: ka9egw at britewerkz.com
Subject: Re: [R-390] [KA9EGW] progress


Setting the mechanical limits on the PTO is probably down the road a
bit - I'd do what Roger suggested and get it all cleaned up first.

If you're leery of washing in the dishwasher, here's what I've found:

one of several IF decks had water get into the BFO, but the others
appeared ok.  Given that experience, I might or might not do the IF
deck again that way (but boy does it get clean!).

one RF deck I washed in a car parts washer, I did it too long and the
caustic solvent ate some of the MFP off enough to munch one of the
decals.

The dishwasher detergent also tends to be caustic and abrasive, so
some moderation there is fine.

One thing you can consider doing is a wash in the dishwasher followed
by a rinse with a mild no-spot solution, then followed by distilled
water.  When I was patient enough to do that, it worked amazingly
well.

Paul

On Mon, Sep 14, 2009 at 6:38 PM,  <ka9egw at britewerkz.com> wrote:
> Well, I attacked what is [for me] the scariest thing first--pto endpoint
> adjustment.  Piece of cake.  I don't know if my rx is typical, it's a
> collins 8719-p-55 unit, but there's an original [anodized bore same as the
> rest of the chassis] hole in the exact right spot in the subchassis so if
> your screwdriver is the right length and diameter [it is now] nothing but
> the endpoint screw cover plug [missing on my radio anyway] need be
removed.
> I could make another one, or several, if I had the dimensions.  Well, it
> took about 20 minutes to get it within a couple-three hundred cps, such
that
> backlash is now the bigger linearity issue...good enough for now and lots
> better than the 5 kc it was off.  [it was 1000.5-kc-worth-of-turns for
1000
> kc when I started].
>
> Which creates a new problem.  I have exactly 1000.3 kc from a reading of
> x.002 mc to +x.002 mc.  The pto is doing close enough to 1000kc-in-10
turns
> for now, but it seems that the 'zero adjust slipper clutch' [dunno the
right
> name, it's the wave washer thingy the 'zero adjust' mechanism compresses]
> well anyway it quits slipping before i can get any closer than reading 2kc
> high across the band.  If I could get one end spot-on the other'd be
within
> a couple hundred cps and I'd be happy for now.  I can easily use the zero
> adjust to go to reading 20kc high across the band, then it runs out of
range
> in that direction too.
>
> It's almost like a gear slipped a couple teeth.  Next I will check that
the
> nominal 70kc of overrange is even split between the ends of the range.  If
> it isn't, what do you guys recommend?  Or should I not worry about it
> further at this preliminary pre-resto checkout?
>
> Gads, I hope I explained that right.
>
> 73,
> Brian KA9EGW
>
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