Topband: Protecting an Array Solutions K9AY Loop from Transmitted RF

[fmoeves at twc.com]

	I'm on a small lot way to many antennas here.

	I use the  _DXE-RG5000HD and _ _DXE-RG5000HD-PM_.

	Works great so far 1500 watts on 10 thru 160.

	Receiving antennas Beverage and K9AY Loop.

	No testing here installed transmitted power and we are good.

	Fred KB4QZH

	-----------------------------------------From: "K4SAV" 
To: topband at contesting.com
Cc: 
Sent: Friday October 11 2019 10:25:03AM
Subject: Re: Topband: Protecting an Array Solutions K9AY Loop from
Transmitted RF

It's likely you won't need any protection from the transmitter 
 (lightning protection may be another story). To verify this you can 
 either use an oscilloscope on the output of the K9AY or just build a 
 diode / cap detector and use a voltmeter.. Then ramp up the power to 
 see how much voltage is picked up. I was surprised when I did this. 
 None of my receiving antennas picked up enough signal to worry about.

 Check the pickup on all frequencies you operate. The gain of a K9AY
is 
 much higher on higher frequencies even though the pattern is very
poor 
 on higher frequencies. It's likely that on higher frequencies there 
 will be more voltage across the K9AY terminating resistor than at the

 output of the antenna.

 Simulation shows no problem at 60 ft separation on any frequency but 
 check it to be sure.

 If you decide to use a limiter, make sure there are no AM stations
close 
 enough to forward bias the limiter (even by the smallest amount). If 
 that happens all kinds of intermod products will show up on receive.

 Jerry, K4SAV
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