[Lowfer] Active whip antennas

[jrusgrove at comcast.net]

Yes ... performed that test here at the local small airport. Closest objects many 100's of feet 
away. Same results as Bill.

Jay


----- Original Message ----- 
From: "Bill Ashlock" <ashlockw at hotmail.com>
To: <lowfer at mailman.qth.net>
Sent: Sunday, December 19, 2010 7:32 PM
Subject: Re: [Lowfer] Active whip antennas


>
> "I wonder if anyone has tried that experiment at a more open site, perhaps hauling the antenna up 
> a wooden mast that wasn't a tree."
>
> John and all,
>
> You may remember an experiment quite a few years back where I set up my E-probe and potable SVM in 
> an open field where trees were at least 200 ft away. I raised the probe mounted on a insulated 
> pole in incremental distances and measured the signal output on the SVM from a constant signal 
> source many miles away. Turned out that the signal strength was very close to being proportional 
> to the height of the probe. I was careful to have plenty of coax laying on the ground at all probe 
> heights so that the capacity of the shield to ground did not vary in any significant degree and 
> was considered very large in comparison to the probe's input capacity to gnd.
>
> Bill
>
>
>
>> Date: Sun, 19 Dec 2010 18:43:45 -0500
>> From: w1tag at charter.net
>> To: lowfer at mailman.qth.net
>> Subject: Re: [Lowfer] Active whip antennas
>>
>> > No the output of the preamp will be higher due to the fact the antenna is
>> > higher up in the air and in the clear compared to being at ground  level
>> > and surrounded by lossy obstructions like vegetation and trees, plus  being
>> > further away from house wiring and AC noise. I have proved this myself by
>> > hoisting an active whip up into a high tree branch and observing the  change
>> > in the signal to noise ratio.
>>
>> I wonder if anyone has tried that experiment at a more open site,
>> perhaps hauling the antenna up a wooden mast that wasn't a tree.
>>
>> John A.
>> ______________________________________________________________
>> Lowfer mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/lowfer
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Lowfer at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> Lowfer mailing list
> Home: http://mailman.qth.net/mailman/listinfo/lowfer
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Lowfer at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html