During the mid 1970's, U.S. ARMY FIELD MANUAL 24-18, Appendix M and other
pubs referenced the Near Vertical Incident System antenna and its
development to meet a 0 to 500 mile skip-zone free communications
requirement in jungle and mountainous terrain. The antenna height
recommended was one-eighth wavelength or less including one tactical antenna
system consisting of a pair of 4 MHz and 7 MHz inverted Vee dipoles with
common coaxial feed guying a twenty foot pole. NVIS sky-wave path loss for
3-7 MHz should be 110 dB. Back in the mid-1980s I used a NVIS inverted Vee
(16 foot pole) all band doublet fed with 450 ohm line for a daily sked over
a 110 mile path either on 80 or 40 meters depending on absorption /
propagation. Never used more than 100W.
Best regards,
CSM(r) Gary Huber - AB9M
9679 Heron Bay Rd
Bloomington, IL 61705
(309-662-0604)
www.csm-gh.com
glhuber@msn.com
gary.huber@us.army.mil
-----Original Message-----
From: Steve Hunt
Sent: Friday, December 31, 2010 5:03 AM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] New and Improved Terminology
Jerry,
I seem to recall reading somewhere that the term NVIS dates from the
Vietnam war; I'll see if I can find a reference.
73,
Steve G3TXQ
On 31/12/2010 05:13, Dr. Gerald N. Johnson wrote:
80s sounds like when the name was invented. I recall commenting at a
radio club meeting when the topic of NVIS was announced that we'd been
doing that for eons, so what's new? The name I guess.
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|