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THE AM BULLETIN BOARD => Technical Forum => Topic started by: N3DAN on January 14, 2005, 06:45:24 AM

Title: Johnson 500 softstart
Post by: N3DAN on January 14, 2005, 06:45:24 AM
Does anyone have info on HV softstart for the Johnson viking 500??  I seem to remember an article that came out awhile back but can't find it.  73.  Paul

Title: Heres What I Did
Post by: WA1HZK on January 16, 2005, 06:37:36 PM
I added a 25 amp relay that shorts out a 10 ohm 50 watt resistor. This is rigged in the primary feed of the plate transformer. I key a 28 volt DC supply that Keys the DC coil of the new relay on PTT. Rig a resistor in series with the DC to the coil and a fat cap. across the coil. When I key the rig I'm looking for a 1/2 second delay on the new relay shorting the 50 watt resistor that is in the primary of the plate transformer. Pick the RC to work with your relay. Also, 28 volts DC is a great keying voltage to have in the transmitter because all of your 110 VAC relays will work on 28 VDC also! This will also give you some release delay in the new relay  when unkeying but at that point there is no primary current flowing so it's not a problem.

Title: soft start
Post by: N3DAN on January 18, 2005, 10:00:37 AM
Keith - thanks for the info.  73  _Paul
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