[MRCA] NVIS on 40M - reprise

[ersmar at comcast.net]

Don et al:

     'UDE's page is at http://www.qsl.net/wb5ude/nvis/ .  Here are a few more:  http://webpages.charter.net/w9wis/NVIS.html http://www.w0ipl.com/ECom/NVIS/nvis.htm  http://www.co.missoula.mt.us/acs/documents/NVIS%20Class.doc  .  In the latter PDF, there appears a design for a three-band NVIS antenna: 80M V in one plane and a 40M and trapped 60M V's in the perpendicular plane.  This would be easy enough to try with my single-band 40M V.  I'll have to think about it a bit.

     But you're correct - the original AS-2259 and -2259 M (30 foot tall mast) are not resonant on any Amateur band.  The design shown in W9WIS's site is a copy of the AS-2259's dimensions (from what I recall of my encounter with one last fall at Gilbert.)  He advises that a tuner is required on all bands.  My guess is that the Spec Ops guys used this with their PRC-47's, etc. with an external tuner and put out whatever kind of signal they could manage.  The base camps were probably outfitted with hellacious antenna fields and super-performing RX's, so the field teams could be heard.  

     After next weekend's demo, I'll try my hand at duplicating the dimensions of the -2259 and report to you all.  I'm thinking that the greatest problem will be trying to get the autotuner in either my TS-570 or IC-746 to match whatever the impedances might be on the Ham bands.  I might be forced to live with QRP equivalent to the PRC-104 (20 W PEP).  

     Stay tuned.

73 de
Gene Smar  AD3F


 -------------- Original message ----------------------
From: "Rev. Don Sanders" <innatehealing at bigplanet.com>
> A couple years ago there was a listing on
> QRP-L  I believe showing a home brew
> version of the AS-2259 NVIS-I lost the
> URL in a disk crash but I have a printed
> copy.  His model is non resonant and
> requires a tuner. He references a web
> site by WB5UDE with a lot of info on
> the NVIS.
> Healthfully yours,
>                           DON W4BWS