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Hot Antennas

To: <towertalk@contesting.com>
Subject: Hot Antennas
From: wrt@eskimo.com (Bill Turner)
Date: Thu, 04 Jul 1996 01:08:16 GMT
On Wed, 3 Jul 1996 09:05:28 -0400 (EDT), you wrote:

>>Well, I have some problems with the premise that the KT34XA traps have that
>>much internal resistance that there is significant heating under rf load...
>
>It's really not that hard to understand. Let's boil down the math for a
>simple loss budget for a connection made with a ham-type UHF connector.
>
>Loss per connector = 0.05 dB (doesn't seem like much, eh?)
>
>Total loss = 0.10 dB (who even counts this stuff, right?)
>
>1500 W * 0.10 dB =
>1500 W * (1 - 10 ^ (.01)) =
>1500 W * .0233 =
>                                35 Watts!
>
>That's right. For every connector pair, you lose 35 watts.
---------------------------------------------
This can't be true.  If it were, every connector in my shack would be
too hot to touch when I'm running the legal limit.  In reality, even
on 10 meters running RTTY at 1500 watts, the UHF-type connectors are
barely warm after 4-5 minutes of transmitting.  I would estimate the
loss in each is perhaps one watt at the most, probably less than that.
Where did you get your figure of .05 dB?  And at what frequency?

73, Bill W7LZP
wrt@eskimo.com

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