[ARC5] BC-455 cleaning (My experience)

[Bill Cromwell]

Hi Les,
.....Andrew,

I have a couple of radios in poor condition that are slated to return to 
active duty. I have five others that are "reasonably" clean. I'll be 
doing the soap and water approach on the very grimy ones. Along the way 
there will be some body work..automotive style bump, fill, and paint. I 
am most desperate for antennas at the moment and later this summer I'll 
get "into" three of my radios. I'll post more about it when id actually 
do it and others will have more to find in the archive.

I have operated around about eight of these on 90 volts from a series 
stack of ten 9-volt batteries with excellent results. Note that I do not 
use them to drive a speaker being a fan if high-Z cans. YMMV.

73,

Bill  KU8H


On 05/24/2015 07:25 PM, Leslie Smith wrote:
>    Hello Andrew,
>    I'm replying to your question from my EXPERIENCE with a single BC-453.
>    I got this set in poor condition; I bought it to 'rescue' the tuning
>    gang.
>    I decided to rescue the set - it was in a condition that could only
>    make the set better.
>    I based my method on the experience of those who reported putting a
>    "tube" set in a dish-washer.
>
>    I removed the 6 tubes, 3 IF transformers and the RF coil box.  That's
>    all.
>    My method involved hot soapy water, followed by washing in tap water,
>    followed by spraying with bathroom foam (Dot's Bath and Tile Cleaner).
>    The label said,  "contains quaternary ammonium compounds".  After this
>    used a clean paint-brush to work at the dirt under the chassis.
>    This means everything around the valve sockets.  Everything was foamy
>    white, and the Al. chassis has a few "cleaner" streaks where Dot's
>    mixture leaked out the various screw holes.
>
>    I followed this with more tap water (from a garden hose) and then a
>    50-50 mix of iso-propyl alcohol and water.
>    Finally, warm air + 2 days in the sun.
>
>    The result?  I can't tell, because my set has an intermittent fault
>    around the 12K8 local oscillator circuit.
>    When I turned my set on it didn't work.  I found the 12K8 wasn't
>    working.  The set worked after I replaced it.
>    BUT - I don't believe the 12K8 was faulty, because some time later the
>    set failed again.
>    Probing one L.O. pin (probably the anode) made the set work (for a few
>    days).  After that, the fault returned.
>
>    The well-informed (and very modest) D.S. gave me some good advice.
>    I loosened and re-tightened screws on the I.F. transformers (etc) and
>    put a small amount of good quality lubricant in the bearing of the
>    tuning capacitor.
>
>    My set has run for some months now.  I must add that I run my sets on
>    a 60V B+ line.
>    (If I was starting again I'd take that up to 90V; some advocate 135V,
>    other a higher voltage.)
>    I CAN'T say my method worked or failed, but you have my experience -
>    based on a sample of one.
>    However I suspect I got the set because it was faulty before I began
>    the cleaning process.
>
> If any-one has a dirty, non-working "junker" they want to donate to a
> scientific cleaning (using the afore-mentioned cleaner by "Dot")  I'll
> pay the cost of postage to get the set to my place for cleaning and
> de-bugging on my work-bench.  I want to try running a set on DC-DC
> voltage doubler, followed by a second doubler.  That should give me a
> 100V B+ supply, from the 24V filament supply.
>
>    I apologize for a longer posting.
>
>
>    73 de Les Smith
>    vk2bcu at operamail.com
>
>
>