Hi Will,
If you mean circulating the air trough inside the coils copper tubing,
this shall be not so efficient. Considering the diameter (small) of the
copper tubing used for the coils and its length, the pressure drop
shall be very high and the airflow very low. Using liquid instead
of air shall be a better approach in this case. Other way, the use
of low speed high volume airflow for cooling of the entire tank shall be ok.
When using the optional fan for some amps (Alpha, ACOM), this
may contribute not only for better cooling of the power transformer,
but for the output tank also, as the air from the PS is directed to the
RF compartment though the holes located near the output tank circuit.
I think that the location for the holes of the PS and RF compartments
separating wall was not chosen by aesthetics, but by technical reasons.
The Harris RF-110 output tank is placed above the pressurized cooling
air duct and their separating wall have some holes, so a part of the
cooling airflow is directed to the output tank. The coils are tunable,
by using tuning cores (rods) inside the coils ceramic former.
There are larger holes for circulating the air trough the entire tank,
but some smaller holes are placed just below the ceramic formers
of the lower freq bands coils, so a small airflow is directed inside the
coils, probably for cooling the coils and their tuning cores also.
I saw a Philips 10 kW transmitter (4CX15000A) for which the output
tank included a large variable inductance (variometer).
The first turn of the variometer has copper fins attached, like a heatsink
and the air exhausted by the final tube was directed to the variometer.
My thought was that the variometer coil shall heat enough indeed, as to
justify the use of the hot air exhausted by the power tube for cooling it!
And especially its first turn, probably more heated when tuned for
the higher freq range.
I took few pictures of it, if anyone interrested.
73,
Traian
Will Matney wrote:
> Another idea I thought of for tubular coils, to keep them super cool,
> would be to terminate one end through a hollow insulated standoff into a
> pressurized chassis. This would force air through the tubing itself and
> out the other end the same as the blower forcing air through the fins on
> a tube. Just a thought =)
>
> Will Matney
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