[Boatanchors] How much is too much?

[Carl]

The Navy used a large glow (oversize neon) tube built in that  protected 
receivers from 500W transmitters on a parallel long wire 50' or less away. 
Never had a burnout in the RBB/RBC or even the later submini tube SRR 
series. Also never saw a fried 390/390A when I was on tender assignment 
doing overhauls for the fleet.

Carl
KM1H


----- Original Message ----- 
From: "Glenn Little WB4UIV" <glennmaillist at bellsouth.net>
To: "Jack Antonio" <scr287 at att.net>; <boatanchors at mailman.qth.net>
Sent: Saturday, January 29, 2011 7:26 PM
Subject: Re: [Boatanchors] How much is too much?


> In Desert Storm the troops blew up the Harris solid state receivers
> right and left from sand static.
> The blowing sand charged the antenna past the point the front end
> could survive.
> Many years ago, I lived in Jamaica.
> I helped with the 6Y0A operation.
> We need a TR switch for the 160M rig.
> I was it.
> I had to move the antenna from the transmitter to the receiver and back.
> The 80M antenna ran parallel to the 160M antenna.
> I received a few RF burns from the coupling of the 80M antenna into
> the 160M antenna.
>
> I have seen many 3 MHz front end coils burned up in R-390 series 
> receivers.
> They almost always had a 3 MHz transmitter up and receivers tuned to
> other parts of the 3 MHz band.
>
> I have seen a neon tube placed across the antenna lead of receivers,
> possibly a NE-2 to reduce front end burn out from close transmitters.
>
> I would highly recommend that all receiver antenna connections be
> grounded when not in use.
>
> 73
> Glenn
> WB4UIV
>
>
>
> At 06:03 PM 1/29/2011, Jack Antonio wrote:
>>Subject is concerning power levels into a receiver, not
>>prices on eBay.
>>
>>I am looking at putting up multiple antennas at my QTH, for
>>multiple radio setups, and am wondering if RF into one
>>antenna may damage a receiver on another antenna.
>>
>>As a test, I hung an 80 meter inverted vee, with the centers
>>   separated by about 10 feet vertically and 3 feet horizontally
>>   from the regular station antenna. (these are eyeball measurements).
>>
>>100 watts into antenna A(+50 dbm) results in +34 dbm from
>>antenna B, as measured on a spectrum analyzer. Just slightly
>>over 2 watts.
>>
>>This seems like too much for a receiver to safely handle, but what
>>is a safe value?
>>
>>Thanks
>>
>>Jack Antonio WA7DIA/4
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