hi Pete,
Well now things are getting interesting. The 220 outlet has the white
(nuetral) lead on the ground pin and a red and white on the other two. i
remember reading someplace that the neutral shouldnt be used at the outlet,
just the 2 hots and the ground to the ground on the outlet box. Perhaps
someone can shed some light on that...
Just for the heck of it I switched the two hots around on the outlet (the
filament winding runs runs off of one 120v leg) and now the filament voltage
is down to around 4.4 volts and it varies up and down enough to see the
brightness of the tube change (not transmitting for all tests). The voltage
from the filament winding with no tube is steady at 5.9 volts.
There is a bulkhead connector between the transformer and the rf deck that
uses what almost looks like treaded in bananna style plugs. Unfortunately
it will take some major disassembly just to measure the voltage from the
transformer itself.
Back to 120v to see what happens... It appears that the transformer has
been replaced and it is the correct part number.
Thanks again,
Kevin
----- Original Message -----
From: Peter Chadwick <Peter_Chadwick@mitel.com>
To: <amps@contesting.com>; 'Kevin Polchan' <kpevin@mediaone.net>
Sent: Monday, February 21, 2000 9:57 AM
Subject: RE: [AMPS] 3-500z going dead?
>
> Kevin says:
>
> > The brand new fluke showed only 4.6 volts. I then
> >liberated my old Simpson 260 from the garage and it alse reads
> 4.5-4.6
> >volts. Oddly enough if I rewire the amp back to 120vac it shows
> 4.9-5.0
> >volts on the filament. Each leg of the 220 line is exactly the
> same >voltage (117.5) so whats up with that?
>
> Dunno! But is the AC neutral tied to ground at all in the amp? If so, it's
> possible that you could have equal line to neutral voltages, but not
> necessarily line to ground. I'm not quite sure how these things get wired
> over there; our wiring regs make you keep neutral and ground separate, and
> they only join at the service entry to the property. Are the two primary
> windings of the transformer exactly the same? I assume that you have two
> primaries, in series for 220 and shunt for 117. I presume that you measure
> fil volts with the amp not transmitting - especially with the fluke.
> According to my DVM, my PA tubes have -200 on the screens when
transmitting,
> and +300 when not! Moving coil meters tell a different story..........
>
> GL
>
> 73
>
> Peter G3RZP
>
>
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