[MRCA] ART-13 Power Supply Project - Update

[Ray Fantini]

Having less than full filament voltage may be more of a advantage than a disadvantage, considering the tubes and motors of the ART-13 are sixty or so years old running the voltage ten or fifteen percent under may be a wise thing. I try to run everything about ten percent under and it has never been a problem. For about twenty years now have been using a practice in broadcast transmitters where you reduce filament on the final to the point of where you start to see drop in gain and than raise it just slightly above that and this always results in longer tube life. The problem now is with the death of analog television and the state of the art in AM and FM broadcasting down to just one transmitter with a tube. Everything else is solid state.
Ray Fantini KA3EKH


________________________________________
From: mrca-bounces at mailman.qth.net [mrca-bounces at mailman.qth.net] On Behalf Of D. Platt [jeepp at comcast.net]
Sent: Saturday, September 04, 2010 8:08 PM
To: MRCA at mailman.qth.net
Subject: [MRCA] ART-13 Power Supply Project - Update

Well, the project is now complete and the new ART-13 is up and running
as of this weekend.  Everything worked out OK, in the end.  The only
bump in the road was the selected 28v transformer.  Despite published
specs and calculations, it yields 24.5v when all is said and done.  That
said, the voltage is within the spec margin and the power out of the
transmitter is about 120 watts.  Both the +400v and +1150v supplies came
out as calculated.  I've sent the article about this NIB ART-13 and the
power supply project off to ER for publication later this year,
according to Ray.  I'm sure anyone who might be interested will, of
course, get the necessary ER issue but, in the interim, I'd be happy to
help anyone in MRCA with the info on the power supply.

Regards

Jeep - K3HVG