From: "Lee Bahr" 
Subject: Fw: [drakelist] KA1FAN diode question


"Lee Bahr"  made an utterence to
the drakelist gang
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In my estimation, replacing 45 year old electrolytics and poor quality =
paper caps that are 45 years old is not doing shotgun or unreasonable =
restoration. On the contrary, it is the prudent way.  You are not being =
stupid, lazy, or ignorant.  You are being wise and smart.  In fact you =
have engaged in a lot of extra work up front.  I have found very few =
paper caps that old that don't leak.  Plus electrolytic manufacturers =
back then never designed their caps to last this long.  A leaky cap can =
introduce hum and if and when it shorts, it can take out a lot of =
components hard to come by today. (Look at a government issue R-390A =
receiver.  It's power supply electrolytics were plug in)!  I would =
rather take preventative measures and use modern fresh and better made =
components to protect my radio and the parts in it which are becoming =
ever so more scarce.  Maybe sometimes you can repair a radio without =
doing the above, but you sure have not restored it and you probably have =
set in motion a ticking time bomb.  Just have your bias supply fail by =
taking the cheap route and see what you think needed to be replaced as a =
precautionary measure once you have the failure.  We are taking about 45 =
year old equipment here.  You don't order parts from the factory anymore =
for these radios.  They are not 5 years old. We are not working, "on the =
clock",  and trying to figure out how to keep the repair charges down to =
$100 by putting in only $2.00 worth of parts into a repair that takes 5 =
minutes to accomplish.   Protect your radio by replacing problematic =
parts before you have a catastrophic failure.  These radios are already =
taking a pounding by having 123 volts pumped into their primaries rather =
then the designed 110 volts of yester year.  Todays caps are made much =
better, have MUCH better tolerence, are smaller and cost very little.  =
Diodes are made better with closer tolerances and of greater current =
capacity and give me much peace of mind knowing at least these parts =
won't let me down.  Even installing a relay circuit to switch on power =
from the small on-off switch thus taking the load off the switch makes =
sence today.  Try and find a new switch when this puppy fails!  While we =
are at it, don't forget to replace all the out of tolerance resistors =
too!  (Sometimes with a modern higher wattage unit of equal size).

I just had my auto's timing belt replaced at 60,000 miles per the mfg =
maintenance schedule.  The price was $400 but that was much cheaper then =
it would cost me to rebuild my engine if the old belt failed and  I =
neglected to replace it as specified in my manual.  Just think what the =
manufacturer would have in the manual if they knew I would be driving =
this car 45 years later to keep it running reliably!  To each his own, =
but the chief engineer at radio station w0vt plans to keep on taking =
preventative measures with this station's vintage equipment.  If you =
don't head this advice and your radio blows up, let me know, I'd be =
happy to buy your radio as a parts radio for a few pennies on the =
dollar.

Lee Bahr, w0vt
Houston



Finally, a voice of REASON rising out of the "cap" and "recap"
CRAP! I have replaced a lot of condensers and capacitors,
in over 50 years of repairing, designing and building electronic
equipment, but i've never replaced a "cap" in or "recapped" a
radio
If it is, replace it. IF IT AIN'T BROKE, DON'T FIX IT!
We used to call wholesale replacement of components the
"shotgun" servicing method, not looked upon as a favorable
procedure by a technically competent person.

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