[ARC5] Dynaverter noise
Clarence M. Owens
[email protected]
Fri, 5 Sep 2003 11:46:52 -0400
Hi All,
Acouple of points about difficulties with dynaverters:
Several years ago I bought a post war ARC VHF radio and companion
amplifier/whatever on a two receiver sized rack. The power for these units
was provided by a dynaverter. The units have tags indicating an
early1960's last repair/inspection date. The dynaverter rattled when I
shook it so I decided to open it up before trying to power it up. When I
tried to get it apart the case seemed to want to move a very little bit but
seemed to be glued in place by something inside, not around its edges.
Turned out after much careful prying that the gray potting compound for the
inverter transformer had turned quite soft and glue-like but would slowly
give up its grip when strong but patient pressure was applied. I tested it
for conductivity and it seems to be an OK insulator even in its
deteriorated condition.
The tantalum cap had leaked and left a lump of dried electrolyte which had
come loose from the case and was the source of the rattle. I cleaned up
the electrolyte, replaced the cap with a very similar tantalum unit from my
stock of NOS caps and reshaped the potting compound so it would go back
into the heat sink. For good measure I liberally coated the potting
compound with silicone grease. Hopefully it will come out again with less
effort than the first time.
I wonder whether these dynaverters were meant for use on LF or HF
receivers; it seems to me they would not create much if any RFI at VHF
frequencies since their switching freq. was in the audio range and they
were using relatively slow switching speed germanium power transistors.
Do any list members know from actual use experience that dynaverters were
used on LF or HF command receivers or their gray painted cousins?
73,
Clare Owens N2RJB
Kenneth Corwin
<[email protected]
t>
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09/05/2003 10:58
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Subject: Re: [ARC5] Dynaverter noise
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Hello, John -
I have a DV-10A that someone filled with silicone
jell. It doesn't make a sound. It can't be serviced,
either, because I can't get the heat sink off...
Good luck. Ken KF6NUR
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