[MRCA] NVIS on 40M - reprise

[ersmar at comcast.net]

Gents:

     I got to thinking a bit about that low resonant frequency that I measured for my 40M inverted V yesterday.  Today I actually took out a calculator and did the math: 468/70 feet = 6.69 MHz.  So in reality my measured low SWR freq for the V was right on the money for 70 feet of wire.  (Something's gotta be wrong.)  So I'll proceed to prune some length (70 feet - (468/7.25 MHz = 64.5 feet)) or about 5.5 feet total off the wires next time I erect it so the SWR will be lower in the SSB portion of the band.

     Also, today I added a foot of plastic chain (Home Despot again) between the ends of the wires and the nylon guy rope (HD, irridescent red.)  As I expected, the rope, chain and wires wrapped up nicely and neatly on the rope's original plastic spindle.  I have one half of the dipole/V on each spindle.  (I got this idea from ebay.  Someone was selling a special forces wire antenna kit from the Brits.  The kit clearly showed a plastic chain set in line between the guy rope and antenna wire.  Pretty slick.)  

     BTW - I used #14 stranded insulated house wire (HD) for the dipole.  I'll experiment with this stuff, and even use it in the demo next week.  Then I'll rebuild the dipole with some superflex #536 from The Wireman.  I believe it's not on his web pages, but he had some special made for another customer and I bought 300 feet of it.  It's very soft but relatively heavy gauge.  I believe it's #14, as well.  


73 de
Gene Smar  AD3F

P.S.  I'm also awaiting delivery of my second RT-70/AM-65 set.  Hopefully will have one of the two at Gilbert this year.