[KL7AA] Pilot Station school club station

[David Heimke]

All good, but also Pilot Station is at the bottom of a hill and up against
some steep terrain.  Something to keep in mind.

-----Original Message-----
From: KL7AA [mailto:kl7aa-bounces at mailman.qth.net] On Behalf Of Jim Wiley
Sent: Friday, October 30, 2015 2:33 AM
To: w5gfr1 at gmail.com; kl7aa
Subject: [KL7AA] Pilot Station school club station

Gordon -

Hello from Anchorage.  It is encouraging to hear that you are taking on 
the project of assisting the students at the Pilot Station school.   I 
spent a fair amount of time in Western Alaska during the mid 60's, so
perhaps some of my experiences will be of use to you.

First off, Pilot Station (and most of Western Alaska) is part of an area
where communication between "there" and the south-central portion of Alaska
("here") is difficult at best.  There are radio clubs in Nome and Bethel,
both of which have a fair number of amateur radio operators.  It might be
advantageous for you to contact some of those operators so as to establish
some sort of "local area" communications net on the 75 or
40 meter bands.

For both 75 and 40 meters, low horizontal loop antennas will provide 
fairly reliable "local" HF communications.   It will perform well for 
contacts with stations within 300 to 500 miles from your location.

However, there are relatively few stations within this range, so contacts
may still be somewhat difficult to come by.  When I lived in the Cape
Romanzof area in the 60's, I actually had better luck with contacts with
Russian and Siberian stations than I had with USA stations, but then I
didn't have the advantage of knowing about the low horizontal loop concept.

Contacts to South-Central (Anchorage, Palmer-Wasilla, Fairbanks, Kenai
Peninsula),  on 75 and 40 meters, indeed any band,  will likely be difficult
because of distance, and may be limited to Winter months only.

Regular contacts using the 20 meter band, and 17 somewhat less dependable
contacts on the 17 meter band will be possible, even plentiful, with the US
West coast, Japan, and other Pacific Islands during most of the year.
Because of the declining solar cycle, contacts on the 15, 12, and 10 meter
bands will be difficult, and there may be 
times  when no stations will be heard.   I might even recommend that you 
put up a single-band (20 meters only) antenna.   Notice that I have not 
mentioned South Central Alaska for these bands.

You mentioned that the Pilot Station school has a vertical antenna that 
does not seem to work very well.   One absolutely essential point when 
using a vertical antenna is that it must have a good ground radial system
associated with the radiating element.  The absolute minimum ground radial
system would be at least 16 radials, 32 will be better, with each radial
being at least a quarter-wavelength long at the lowest band in use.  There
is no room for a compromise ground screen when using a 1/4 wave vertical
antenna.  Yes, some stations "get by" with much less, but they are typically
(1) located much closer to the equator, and
(2) much closer to other stations.  A station set up away from neighboring
communities or at an extreme northern latitude (or both) absolutely must
have a good quality grounding screen if they are to be successful.

One possible alternative would be to use a half-wave radiator, which will
ease the requirements for a radial system, but it will still not eliminate
the need for a first-class ground system.

Obviously, a half-wave radiator must be fed with a matching network, but 
that is fairly easy to accomplish.   Additionally, the half-wave 
configuration allows the use of elevated radials, and typically only 4 to 8
are needed.  The radials operate somewhat differently when used with a
half-wave radiator.  In this case, they are used to "decouple" 
the antenna from ground, as opposed to substituting for the missing half of
the driven element.

Next, using multiple vertical radiators gives you both "gain" over a
half-wave dipole and the option of instant pattern switching.  A 4-element
vertical antenna using the proven "4-square" configuration fed with
Wilkinson dividers is an excellent performer, often (but not
always) outpacing Yagi designs.  This configuration can be made very
resistant to adverse environmental conditions, which are a constant problem
in Western Alaska.  The use of a "pattern switch" allows instant changes of
direction and avoids the problems associated with a mechanical rotor.

Finally, keep in mind that a vertical antenna will  always be a low-angle
radiator.  That means that it will perform best with contacts that are 800
miles or more distant from your station. That means no Alaska contacts (most
of the time)  with a vertical.  Not that closer range contacts will be
impossible, just that signals may be weaker 
to_much _weaker the closer they are to your base of operations.   That 
is why I suggest the horizontal loop for contacts within Alaska.

I hope this has been helpful.

- Jim, KL7CC


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