[Hammarlund] HX-500 trials

[Jeff]

Well, been playing on and off with this rig.  Finally reversed all the 
golden screwdriver "mods" to the rig and have all the specified 
component values in, including the Hammarlund power supply mods now done 
correctly.

Still, way high voltages on the meter.  Yes, I'm running a bucking 
transformer on the input, so I'm only putting about 109 VAC into it.

And... now it is drawing current like crazy in standby mode.  As it 
warms up, you can hear the power supply start to load then the left hand 
6146 will start to get red.  Reversing the tubes has no change, always 
the left one.  So, checked all the components in the power supply again, 
replaced all the components in the PA section (some drifted resistors, 
but not terribly off), checked wiring and grounds.  Still the one tube 
takes off.  Replaced parasitic choke resistors as the original carbon 
comps turned to dust in my hands when I started working them out of the 
choke.  Still the same. Removed the 12BY7 driver tube, no change.

Checked the bias supply -- right on the money with -90 and -50 volts 
where it should be.  I do however note that I have over 3 volts on pins 
4 & 6 of the 6146s, when the voltage chart in the manual says between 
point 6 and point 9.  About 250 volts at the junction of the screen 
resistors.

I am able to verify that the 1650 KC oscillators are working, so at 
least it appears that I'll be able to get some sections going.  It is 
also drawing a lot of current though on the LV power supply, and I 
haven't tracked that one down yet either.  Enough to burn up the two 
watt 15 ohm resistor in the LV supply.

I also notice now the meter is totally dead.

Anybody have any thoughts?  The PA current draw doesn't seem to be 
related to the driver section -- the tube's out of the rig...

And I thought my CE 100V was a bear to trace out...

Thanks for any thoughts --

Jeff
WB3JIH