[600MRG] Advice needed

NMF nmf.marshfield at verizon.net
Fri Jan 30 16:59:53 CST 2015


On 1/30/2015 5:11 PM, Dick Bingham wrote:
> Describe your 'loop' ! Tnx Dick/w7wkr and xsh-26

Too simple to sound true I guess:

Vertically polarized loop contains 600' of the following kind of wire:  
( 1000' come spring )

http://www.ebay.com/itm/14-AWG-Monster-Dog-Inground-Fence-Wire-45mil-LD-Polyethylene-Stranded-2-DBYConn-/261186769362?pt=LH_DefaultDomain_0&var=&hash=item3ccff1d1d2

The wire goes out of the shack via wall feed through, 70' up the closest 
pine tree, thence 250' horizontal to the SW to another tree, down 60', 
and back to the shack at about 8' above the ground...

Used compound bow to shoot over trees  ( 55 lbs pull )... Is very 
accurate... Shoot mono filament line from reel and pull wire back...

Now you have 2 wires looking as a simple loop with approx. 14,000 sq. 
ft. inside loop which in this case appears as about 18 ohms R and with 
about 350pf of series vacuum variable cap. resonates to J+/- 0 @ 475kc...
This cap alone makes the antenna tune from about 300kc. to 700kc...

The wire is very HV rated and I could not break it down with this set 
up, just some corona...  It is like the inner conductor of RG59 only 
much better dielectric...
The inner is 9 strands of copper for a #14 wire...

Use decade CAP box to tune it down to VLF 17-30 kc. about .12 uf... ( 
receive only ) and up through the beacon bands with less cap...

The two feed wires and the cap is all there is going to the bifilar 
Balun core with unbalanced output to the rig...
On the TX side it sees a 6 turn HV wire wrapped around the bottom of the 
variometer...

Its the best I could rig for MF and works outstanding on 
160-80m-40m-30m... WOW

Ground conductivity here is about .5 millimhos/meter ( poor ) but good 
for the loop to appear as more in free space...
Am sure that the trees load it down some...

Hope this helps...  Dave @ /17

* Is there someone out there who has a sample Part-5 app. all filled out 
that won a license?? Advice??







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