[Hammarlund] HX-50 Question

[Glen Zook]

The plate voltage to the 6DQ5 final amplifier tube is, according to the manual, 560 volts.  Now there are actually 5 taps on the high voltage winding of the transformer.  Between the taps and center tap there are 2 additional taps.  These additional taps feed a solid-state full wave rectifier.  On the schematic of my HX-50A (same power transformer) there is a notation of "300 volts".  This is after a 27 ohm and 220 ohm resister and is "under load".  The filter capacitor right after the full wave rectifier (NOT a "bridge") has a voltage rating of 450 volts.

Looking at the tube voltages on the voltage chart it shows 720 VAC on the plates of the 5R4 rectifier.  That would mean 720 volts on either side of the center tap.  However, there is no indication of the AC voltage into the full wave solid-state rectifiers.

Glen, K9STH

Website:  http://k9sth.com


--- On Fri, 3/4/11, Gary <xfrmrs at roadrunner.com> wrote:

I know this is a long shot, a very looooong shot but here goes. I received a power transformer for the HX-50 to be rewound. During the tear down process I came onto a very burnt up and I mean burnt, secondary hv winding. My problem is I could not get an accurate turns count between red/yellow, center tap and the red/black lead. If I only knew what the ac voltage was between these two leads I could figure the turns as I know what the volts per turn are. Again, this is a long shot but am hoping that someone has there HX-50 on the bench and could take that ac measurement for me.