[Lowfer] Excellent VLF condx this morning! - pa0rdt in a tree

[Laurence KL7UK]

I found there was a small improvement at LF/MF and a "larger" one at VLF (Im being vague) hoisting the whole lot thru and above the Pecan tree canopy. The hanging coax is choked down about 15ft down using 7T thru large  77 material (I had to hand) - coax outer is bonded to a number of earth paralleled  Earth rods on the way to the shack. This apartment is RF wise transparent so I still get direct radiation from the house equipment and dont have the ability to bond to a rebar/building reinforcing acting as a Faraday cage.

The jpg shows how it worked but it was such a contraction and the gains were so small Ive going back to supporting the probe inside the tree canopy but away from the branches a few feet. Bit less of a target too. Im guessing as the Z of the probe isnt so high as say a portable VLF receiver with say 10Meg Z impedance we are getting less shunting. Certainly walking up the road with such a receiver (marveling at the Hum) tree "dumping" is noticeable within 30 or more feet with the much higher Z unit.

Laurence KL7UK/5

http://kl7uk.com/pecantreeprobe.jpg  

> From: jrusgrove at comcast.net
> To: lowfer at mailman.qth.net
> Date: Sun, 18 Sep 2011 14:41:42 -0400
> Subject: Re: [Lowfer] Excellent VLF condx this morning!
> 
> Dex
> 
> Are you talking VLF or LF/MF reception being affected ... or both? With the other receiving antennas 
> available here I rarely use the e probe for LF or MF work - just VLF. Not sure if the different 
> frequency ranges (VLF, LF, MF, HF) are affected differently by proximity to trees.
> 
> I don't think the PA0RDT mini whip operates like a  'normal' e probe antenna. The mini whip relies, 
> to a large extent, on signal pickup from the feedline. The tini tiny thingie attached to the gate 
> just doesn't gather much signal. Try mounting the antenna right down at ground level on a ground 
> screen sometime. Not sure if this has anything to do with what you've experienced or if we're even 
> comparing apples to apples.
> 
> Jay
> 
> 
> 
> 
> ----- Original Message ----- 
> From: "Dexter w4dex" <dexter.mc at gmail.com>
> To: "Discussion of the Lowfer (US, European, &amp;UK) and MedFer bands" <lowfer at mailman.qth.net>
> Sent: Sunday, September 18, 2011 11:34 AM
> Subject: Re: [Lowfer] Excellent VLF condx this morning!
> 
> 
> Jay,
> 
> I found my PAØRDT probe is a good tree detector.  It works great just
> ten feet above ground out in the open field in front of the house.  With
> large oak trees all around the house with it as much as 40 feet above
> ground the probe doesn't work near as well as a loop.  And that's with
> it about 40 feet away from the nearest trees that are about the same
> height as your trees.  I thought about mounting the probe at the top of
> my tower but it would have to be below the 6 meter J-pole lightning rod
> to survive.  My neighbor has a good view of my towers and he has seen
> many direct hits.  Molten balls of copper on the copper pipe cap top
> confirms the strikes.
> 
> I bought enough chain link fence top rail sections last year to attempt
> pushing the probe out the top of a pine tree about one hundred feet from
> the shack.  My idea was to attach a ten foot section of PVC pipe to the
> tree trunk as high as my twenty foot extension ladder would allow.  Then
> devise a rope and pulley hoisting contraption to raise the mast sections
> one by one up thought the PVC pipe.  The tree I selected has lots of
> branches near the top that I believe would keep the mast upright.  Guess
> I better do this while I can still run :)
> 
> Dex
> 
> jrusgrove at comcast.net wrote:
> > Dex
> >
> > Modified Amrad probe. What's interesting is that there are rows of tall trees (60 - 70') within 
> > 20'
> > of it to the west and south -it is mounted in the corner of an opening. Makes me wonder if having 
> > it
> > in the clear isn't an old wives tale. As they say, the results speak for themselves.
> >
> >
> 
> ______________________________________________________________
> 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