[Milsurplus] [ART-13_Transmitters] Working on my ART-13's

[Joe Munson]

Great ideas on the Caps.   I have been working on quite lot of SCR 274N 
equipment lately and have found that many of the caps, the oil filled cans, 
in the receivers, modulators, and in a couple of transmitters have failed or 
soon fail with power applied.  I always bring up the equipment with a 
variable current limited supply.  Of course pulling the brushes in the 
dynomonsters, and bring up the voltage slowly, watching the current, which 
should rise, and then fall.  After bringing up to voltage, run for at least 
6  or so hours.  Then touch the cans.  They usually are puking a greeinish 
yellow substance.  Upon taking them apart, it seems there is a chemical 
reaction taking place between the can and the oil. The resulting green goo 
is conductive.  So, the result, not only the cap leaks, the can leaks.  Much 
of this equipment was working fine business as late as 4 or 5 years ago.  I 
have a complete test setup for the units and have tested them and ran them 
quite often.  It appears that at that at the age of 65 to 70 years old, 
these caps are failing in large numbers.  At least I have found that to be 
true in the command sets.

BTW, I run all the equipment here from Dynamotours.  I have a BC 191 and ART 
13, BC 348 and BC 312 currently on the air on the AM nets.  Also a TCS is 
set up nearby on the Dynamotours.

WA4VAG
Joe Munson