For the past two weeks, I have been noticing a burning smell coming from
my rig http://schmidling.com/radio.htm when I buzzard.

I can not tell exactly which deck it is coming from but the power supply
has no hint of the smell. This leaves the RF deck and the mod deck. I
would have bet on the RF deck as it seems to come through the "window"
(hole) in the front panel of that deck but a careful inspection shows
not a hint of anything burning or even getting warm other than the tube.
There isn't much there to get warm other than the fil trans and the
little power trans for the bias supply and they are both cool to the touch.

This brings me to the mod deck and the only thing hot there is the fil
trans. I have left the filaments burning for several hours and the
smell never happens and the trans only gets moderately warm when not
transmitting.

The mod deck is a pair of 813's, zero bias as triodes. The centertap of
the fil trans is grounded through the meter.

The question is, what effect does the mod current have on the heat
carrying capacity of the filament transformer? Are all 10v 10A trans
equal? Does talking create heat in it and could this be the source of
the smell?

Lacking a better choice, I bought it from Antique Ele for $54 incl
shipping. Seems like a junky little thing compared to the one in the RF
deck. It's a Hammond T167S10.

Any thoughts?

js
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