[MRCA] Field Exercises

[ersmar at comcast.net]

MRCA:

     One more e-mail then I'm going to bed.

     I found this URL:  http://www.vcars.org/tech/NVIS.html describing an amateur radio version of the AS-2259 NVIS antenna.  

     Good night, all!

73 de
Gene Smar  AD3F



> Rob et al:
> 
>      FWIW - Here's a URL for a Telex NVIS antenna (AS-2259/GR) that's apparently 
> available for military use from 2-30 MHz: 
> http://www.telex.com/Wireless/products.nsf/pages/1990!OpenDocument&c=files .  
> Click on 1990 Product Brochure and you'll get detailed specs; other places on 
> the web page will give you more info.
> 
>      From what I can see this is nothing more than a low (15 feet AGL) crossed 
> dipole array for 80M and 40M.  The mil rig's (e.g. PRC-47) internal tuner is 
> able to match either one of the dipoles sets over the entire HF range.  
> 
>      The key is this should be easy for us hams to duplicate for field use.  
> Replace the fancy coaxial support conduit with a simple PVC or aluminum system 
> and run real RG-8 or -8X up to the feedpoint.  Keep the far ends of the wires 
> off the ground and you should end up with a pretty useful NVIS antenna.
> 
>      Also check out http://www.pacificsites.com/~brooke/AS2259.shtml at the 
> bottom for other sources of NVIS info.  The most interesting (to me) sites are 
> those showing NVIS antennas on vehicles, especially those used by the Wehrmacht 
> during WWII.  The loops of tubing set atop their armored vehicles sort of remind 
> me of a loop of PVC containing #12 wire atop my YF's minivan.  Hmmmmm......  
> Don't tell her.
> 
> 73 de
> Gene Smar  AD3F
> 
> 
> 
> > Hi,
> > Adding VHF FM sounds great.  I would like to hear that, having none of the
> > gear myself.
> > 
> > As for NVIS on the HF exercise, I think that using period-correct antennas
> > should be encouraged, and we will learn something.  Maybe one station on
> > the mountain can run Vietnam-era gear and NVIS antenna, and the other(I am
> > nominating myself) can run WWII vertical style.  Hopefully we will have a
> > mix of eras back at the fairgrounds and can see how the different
> > configurations work out.  I think that in the absence of geological
> > obstacles NVIS offers little if any advantage at that kind of distance, but
> > I also thought it was improbable to hear a BC-611 at 15 miles under even
> > the best circumstances.  2 years ago, we had a mix of antennas, with the
> > home base running a dipole, which works well for contacting the outside
> > world via ionospheric modes, and most if not all of the portables running
> > verticals.  
> > 
> > It might be fun to have an amplified speaker to connect to the rigs at the
> > Fairground so visitors and our group members who aren't wearing the cans
> > can hear them.
> > 
> > If anyone else has infrared signalling gear, I am QRV.
> > 
> > Rob Flory
> > 
> > 
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