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Author Topic: Viking Valiant II  (Read 1533 times)
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ka4koe
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It's alive. IT'S ALIVE!!!


« on: February 08, 2013, 08:00:29 AM »

I hope to pick up a Viking Valiant 2 at Orlando this weekend. Per the description, all the recommended MODS have been accomplished, and the rig is is nice shape. Are there any operational GOTCHAS I should be aware of, ie the kind that cause the magic blue smoke to be released, with all the attendent wailing and gnashing of teeth?

Tnx.

PHILIP
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I'm outta control, plain and simple. Now I have a broadcast transmitter.
WQ9E
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« Reply #1 on: February 08, 2013, 08:27:35 AM »

Philip,

If it still has mercury vapor rectifiers (instead of SS or Xenon) make sure the rig is operated filaments only (HV off) for about 10 minutes after you get it home.  This is standard procedure any time the MV rectifier tubes have been placed in a horizontal or upside down position-otherwise allow minimum 30 seconds warmup for normal use.

MV tubes do NOT like to see high voltage prior to filament warmup.  Make sure the plate switch is off and the PTT on the microphone is released before turning on the main power switch or the HV will come up instantly.

Although Johnson instructions allow you to switch the coarse loading control while the transmitter is producing RF this is a bad idea because it can lead to burnt switch contacts.  The HV can remain on but release the key or take control out of spot position (whichever you are using to generate RF) while switching coarse coupling positions.  It is perfectly OK to adjust the fine coupling control while RF is being generated but not the coarse coupling.  Normally you should have the coarse coupling position logged so for future tuneup on a given band you preset the coarse coupling to its correct value.

The fuse plug used by most Johnson (and also Heathkit gear of the era) has fuses in both sides of the line.  The problem with this is when the neutral fuse opens there are fault conditions which would cause the operator's body to become the neutral return.  One approach is to replace the original plug with a 3 wire plug and place the fuse in the "load" or "hot" side where it and the power switch belong.  Another approach is to mark the existing plug to clearly indicate which side is neutral, put a very large (20 or 25 amp) fuse in the neutral side, and make sure it is always plugged in correctly.  This way the load side fuse will blow before the neutral.  No matter what you decide to do, but especially if you keep the original plug, is follow the old amateur safety adage that ground should be the first connection you make when installing a piece of gear and the last connection removed when you are removing a piece of gear.

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Rodger WQ9E
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