At 11:18 AM 6/25/00 -0500, Phil Clements wrote:
>IMO, the heating was at the tap point, spreading out each way. Chances are
>the "black" area would have spread with time.
That's what I thought at fist, Phil, but forensic evidence suggests otherwise.
Clue 1: No problem with solder joint at tap. Conductor (also #12) attached
to tap point showed no signs of heating. The solder may indeed have gone
plastic (I was unable to poke at it under test), but since the wire
attached was cripmed hard to the tap point, it should not have made much
difference.
Clue 2: An attempt was made to see just how far the discoloration would
progress with sustained testing. It would not progress beyond the 1.5 turns
+/- the tap point.
Logic suggests your opinion would be correct, but yet......
>There has been mention on the reflector of directing cooling air on a coil
>to prevent "melt down." This does nothing about the losses due to under-
>engineering. RF is being converted into heat and does not reach the antenna.
>Heat can be eliminated by selecting the proper components for the job to
>be done. Hans and I are in agreement....there is a limit to how small you can
>make an RF deck.
Am I am in total agreement with both of you. The object of this particular
amplifier experiment was to try to put numbers on that limit. In other
words, see how close I can come to a Heathkit and not have a disaster. I
found how close.
>The same is true about band switches. One must take into consideration not
>only the voltage and current rating, but also the distance between contacts
>when selecting the proper component.
Switches are what make roller coils and/or monoband amps so attractive!
73,
Larry - W7IUV
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