SEC Re: [LeArc] 75 meters for relaying weather information

Sun, 13 Apr 2003 05:15:31 -0500

Re: 75M use comments from Jay

  Suggest all stations using HF for emergency service consider use of a
low mounted horizontal dipole for the band. That takes advantage of a
Near Vertical Incidence Skywave (NVIS) method, which will help reduce or
eliminate the skip zone that plagues some in close communication. The
80/75M dipole in use here for a statewide ARES net easily gives coverage
out to 300 miles, and is about 12-15 feet off the ground. It uses
inexpensive RS antenna wire, a "budwig" coax adapter, and has about 50
feet of RG-8X min coax for a feed. This type of antenna is easy to
construct and field for emergencies, and recommend this highly. 

  This is not a DX antenna, where the goal is to get farther coverage and
lower angles of radiation by raising it much higher, and I much prefer
the higher antenna with a ladder line feed and a tuner for the DX side.

  Understand the difficulties with QRN during severe storm activity, but
an NVIS antenna can and does reduce noise (and QRM), and stations using
this type antenna will usually have very good signal reports for each
other, day or night.. Hope you can give it a try for your next test, and
make one for your "go-kit" for emergencies. 

  Keep up the fine business on relays, and hope to hear McDonough and
surrounding counties check in soon on the Illinois ARES HF Section Net on
3905 KHz held on the first and third Sundays of the month at 4:30 pm
local. After the roll call for Emergency Coordinators and Official
Emergency Stations, we welcome your participation and testing of
statewide communications, and signal reports are always welcome.

vy 73 de Pat Ryan KC6VVT
Illinois Section Emergency Coordinator, ARRL
P. O. Box 24
Tonica, IL 61370-0024   
[email protected]

On Sat, 12 Apr 2003 15:48:52 +0000 Jay Hainline <[email protected]>
writes:
> I monitored 3990.5 khz for W0BXR this morning to see how well 75 meters
> would work for weather spotting. The band was quiet and W0BXR was good
and
> strong to me. However I heard others checking in from the Mt. Pleasant,
IA
> and Freeport, IL area and W0BXR was not having very good luck in 
hearing
> those stations. I had to relay to him the check ins. I'm not sure how
good
> this will work for weather spotting. Propagation during the day on 
> 75 meters is mediocre at best. It would improve in the evening hours.
However 
> if there are thunderstorms around, there would be an awful lot of
lightning 
> static that could overwhelm any increased in signal strength from the 
> better propagation conditions.
> 
> Just my observations. 
> 
> 73 Jay
> 
> Jay Hainline  KA9CFD  EN40om
> Colchester, IL
> [email protected]
> http://www.qsl.net/learc 

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