> Steve I forgot to add that the air the muffin fan is
> moving out of the amp is very warm during operating
> and cools down after I let it sit for several seconds.
> It does appear the muffin fan is pulling the hot air
> out of the amp pretty well. I am using the increased
> air flow out of the amp and the temperature changes to
> make that judgement.
>
> Thanks for your observations. Right on track as
> usual!!
>
[Steve Katz] Thanks. But what I do is use thermally sensitive
indicating strips installed on the critical components to see if I'm really
making any difference or not. Those are very inexpensive and work well. I
install them next to the anode cap on the tube envelope, between the
filament pins on the tube base, on filter capacitor cases, and anywhere I
think heat may be a problem. Then, I run with the "original" cooling
system, record all the measurements on paper, and make the modifications and
run with the modified cooling system, and record all those measurements. It
becomes pretty obvious if I'm cooling the "right stuff" with my boost
cooling, or not.
-WB2WIK/6
> 73,
> Bill
> --- Steve Katz <stevek@jmr.com> wrote:
> >
> >
> > > Well I reinstalled a muffin fan on the back of the
> > > Swan Mark 1. I fused it seperately from the amp
> > so I
> > > would not blow fuses in the amp.
> > >
> > > //A 10W fan (83mA at 120Vac) is going to blow
> > fuses in the amp??
> > >
> > > I checked the air
> > > flow out of the amp using only the internal fan,
> > then
> > > hooked up the muffin fan for a comparison. The
> > > addition of the muffin fan sucking hot air out of
> > the
> > > amp does move a lot more air than just the
> > internal
> > > fan alone. Maybe the hot air didn't do anything
> > to
> > > make the fan fail, I'll see with this new one.
> > >
> > > Not scientifc by any means as I didn't use a
> > > calibrated kleenex to check the air flow
> > differences!!
> > >
> > > //Interesting observation. Problem is, the test
> > doesn't mean much without
> > > measuring the difference in air flow around the
> > components you're actually
> > > trying to cool, like the 3-400Z's. Often, when
> > additional exhaust cooling
> > > is in place, the obvious extra air flow volume is
> > due to sucking air from
> > > places it needn't be. So, there's lots of extra
> > air exhausting, and the
> > > air will feel much cooler than the "original" air
> > exhaust, but that
> > > doesn't mean anything with relation to tube
> > envelope and pin seal
> > > temperatures, which are the only important ones.
> > >
> > > //-WB2WIK/6
> > >
> > >
> > > 73,
> > > Bill
> > >
> > > =====
> > > Bill Smith KO4NR
> > >
> > > __________________________________________________
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>
> =====
> Bill Smith KO4NR
>
> __________________________________________________
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> Yahoo! Health - Feel better, live better
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