[Boatanchors] DX-100 RF delay

[L L bahr]

Bob,

You need to start at the beginning which is the VFO and/or the oscillator tube when using a crystal.  You say it does not put out any RF but is the crystal oscillator running right away as well as the VFO right away?  Does the rig put out power right away in VFO or crystal oscillator but not the other?  Your problem could be due to many things past the VFO or crystal oscillator too.  If the oscillator or vfo come on right away you could have buffer or driver problems which could be caused by a dirty switch, dirty tube socket, bad tube, bad ground bad wiring, changed resistor, or bad capacitor.  (You never fully described your problem.  If the oscillator does not come on using a crystal or VFO, you need to look there for your problem.  Without knowing more, one can really not help you much.  Are your voltages within spec?  What about voltages coming out of your power supplies?  (Can't really tell which power supply to check without knowing where the RF has stopped moving towards the 6146 grid circuit).

The bottom line is you need to start at the beginning and see where the RF stops along the way before the signal hits the 6146 grids. This will then tell you which section is giving you your problem.  If your VFO is at fault and not coming on right away, the first thing I would do is change tubes.  Use a 6AH6 rather then anothe 6AU6 as it is a better choice. Otherwise a dirty switch at the VFO, dirty VFO tube socket, or bad part.  That is why try it with a crystal.  If it works with a crystal then zero in on the VFO.  If it doesn't work with a crystal then most likely your VFO is OK.

Lee, w0vt 

----- Original Message -----
I recently purchased a DX-100 that is mostly stock except for the fact that someone has removed the coarse loading function and no I don't think it is a B model.I have it putting out about 140 watts after some cleaning and tube replacement. At this point the only thing that is a problem is that there is between a two and six second delay before it puts out any RF when the plate switch is thrown. I thought it might be the plate switch and I paralleled the switch with a good one but no luck.It also exhibits the same delay when switching from CW to phone. At times after the set has been off for a while and I turn it on again I will have to readjust the driver before it will produce RF,maybe this is related to the delay problem.. Does anyone have any thoughts on where the problem lies?

Thanks in advance
Bob W1GTH
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