[Hammarlund] HX-500 trials

[Jeff]

Oh -- and if anyone has a clean PDF of the manual, let me know.  I 
appreciate the one on BAMA from N9SOR, but the watermark he's put on it 
has washed out some of the text on the schematic and voltage/resistance 
tables.

I'd be glad to trade perfect quality PDFs of the original HQ-140X or the 
HXL-ONE manual, or Hammarlund HT-32 if you're interested.




On 4/24/2016 7:17 PM, Jeff wrote:
> 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
>
> ______________________________________________________________
> Hammarlund mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hammarlund
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Hammarlund at mailman.qth.net
>
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html