Crawls Backward (When Alarmed)

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Panasonic RF-2200 Mini-Restoration, Pt. 2

With the front and back off the cabinet I can go to town on cleaning the switches and pots on the RF-2200.

These are the bandwidth and crystal calibrator switches.  If you remove the 5 screws on the cover, there is enough access to the switches to spray contact cleaner into them. 

Word of warning for other RF-2200 owners:  the screws were very tight, and putting a lot of pressure on them makes the subchassis flex, and you can't get a lot of torque on the screws as a result.  I found that I could put a finger underneath to help support it while I turned the screws helped a lot.

The on/off, light and BFO switches are easier.  There are four plastic tabs holding the assembly in (two of them indicated by arrows here).  Press down the tabs and the board comes out.  (I'm actually polishing the switches with Novus here).

I went though these once, and then wound up opening the radio again to respray the BFO switch after the radio started acting up again later.

The silver 'boxes' are the main bandswitch (right) and the SW bandswitch.  Here I am about to spray into the main bandswitch.

When I went back to do the BFO a second time, I decided to take the cover off the bandswitches and get the spray nozzle further into the bandswitches.  I'd recommend doing that in the first place instead of trying to aim through one of the small holes.

The tuning capacitor.  I dreaded spraying cleaner into this, but I also didn't want to take it off the radio.  I put a rag around it and covered as much of the PC board as possible.  Then I hosed the tuner.  It seems to have worked.  I don't have crackling when I tune the radio now.

Moment of truth.  Radio on AM band, speaker connected with test leads.  I plug it in.

IT WORKS!  Much better.

(Although, as I hinted above, I wound up making a second pass the next day.  I was listening to some nice Cuban music on Radio Habana on 6000 kc, when suddenly nothing.  Juggling the BFO and bandswitches brought it back intermittently.  So I did this all again.)
With the radio now working, I cleaned the cabinet with a weak solution of Simple Green and water.  I took the speaker out so I could clean the holes in the speaker grille.

Took about 10 Q-tips to get the dirt out of the little holes.

Soaked the knobs in the solution and then used a toothbrush to get dirt out of the crevices.

The contact cleaner twins.  I use Deoxit for contacts, and the Nu-Trol for pots.  Both work great.

After the cabinet is clean, and has dried overnight, I used Griot's Vinyl and Rubber Dressing to wipe it down with.  Just a small amount goes a long way, and it's not greasy and won't turn things brown like Armor-All.

Here it is all back together.  It has some nicks here and there but looks good overall.
Close up of the controls. 

After using it for a few days, I'd say that it is great on FM and SW.  But I think the BC band is a little lacking compared to what I expected and have read.  The calibration is also way off (about 400 kc) on all bands, so I will be doing an alignment on it soon.  I'm debating going through and replacing all the electrolytics also.  That will mean taking the dial drive out to get to the PC board.

This I will ponder.

 
 
 
 

Post a Comment 4 comments:

  • Anonymous said...
    February 24, 2013 at 3:17 PM
    I am having a similar problem with my old rf2200. the AM reception cuts out intermittently. Switching the bfo/wide-narrow band switches brings it back for a while. What should I use to correct this problem? I noticed you used 2 cleaners. Which one would solve my AM problem?
  • John Jarratt said...
    April 14, 2016 at 9:01 AM
    This comment has been removed by a blog administrator.
  • John Jarratt said...
    April 14, 2016 at 9:02 AM
    The switches can be a problem as documented here. I found something different on my radio for the audio going very low on all bands. I needed to reheat the solder connections for the capacitors connected to the audio power amp IC. The radio has been working fine ever since.
  • Bryan said...
    June 13, 2016 at 5:42 AM
    Thanks for posting this up. I have one of these and am contemplating doing this per your directions here.

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