[Elecraft] K3

Fri Jul 17 13:44:07 EDT 2009

Hi Paul and All,

I would suggest you take a look at the tripod/mast combination that Vern 
Wright, W6MMA sells.  I used this several times now to erect the portable 
beam Vern also sells.  The tripod is quite stable, but still one set of guys 
is almost a must, since any amount of wind will play havoc with an 
installation like this.  With an inverted vee attached, you probably 
wouldn't need guys, but again it's better to have some way of stabilizing 
everything.

Last winter, at the Quartzsite, AZ hamfest, Vern and I both had an 
installation set up like the one you see in the picture in the link I have 
given you below.  I think you know Vern, and if you do, you know he is 
"famous" for fabricating some really neat, quality stuff.  The tripod/mast 
combination is no exception.  It is far superior to the similar combination 
sold by the Buddipole folks.  The tripod is actually intended to be used 
with heavy lighting equipment, so it is really stout.  Vern mated this with 
a mast arrangement he has modified to get to the 20 foot plus height.  It 
all erects quickly, and attaching guy lines is a breeze using a simple "O" 
ring.  See the link below.

http://www.superantennas.com/html/21_foot_mast.html

For inverted vee setups in a portable situation, I still like the Wonderpole 
the best of all the collapsible poles (www.wonderpole.com).  I have used one 
of these for several years now, and I think it is a great thing to have. 
The pricetag ($250) scares a lot of people off, but this is a 40 ft. pole 
with a lot of substance.  A couple of friends of mine here locally ordered 
one immediately after they saw mine, and saw how solid it is.  The top 
section is still 3/4 inch in diameter, but everything collapses down to an 8 
ft. package.  I have several of the fishing/kite poles, and they work O.K. 
too, but they are very skimpy at the top.  The best of those types is the 
one sold by Jackite, as it has a much more substantive top section, although 
it's nowhere close to the Wonderpole.  These go up to just over 30 feet, but 
with the all of these have, you are only getting about 25 feet up at best. 
The Wonderpole has some flex too, but not nearly as severe, and it can 
easily be stabilized with 3 string guys to preserve it's height.  Getting 
the extra 10 or 15 feet may seem expensive, but the Wonderpole is extremely 
solid, and will probably last forever.  It's really tough!

I guess while I'm at it, I will describe one other option.  At Dayton a 
couple of years back, there was a guy selling collapsible aluminum flagpoles 
out in the swap area.  One of them extends to 25 feet.  This uses pushbutton 
locks for each section, and is very solid.  I picked mine up for $200, and 
it gives me a lot of options.  Both this pole, and my Wonderpole, fit nicely 
into a gadget I picked up at one of the RV shows, which slides into my 
trailer hitch.  That really provides all the support I need for it, 
depending on what I put on top.  This pole is an excellent alternative to 
Vern's tripod/mast combo.  The beam mounts nicely on top, and everything is 
pretty stable just that easily.  I've used small guys though, just as 
additional caution.

With this combination of masts, I can put up beams for HF, VHF, etc., and a 
good dipole or inverted vee using the Wonderpole.  The flagpole and trailer 
hitch support makes a perfect tool for VHF roving if you are into that kind 
of thing.  I can probably send you pictures of any, or all, of this stuff if 
you are really interested.

Dave W7AQK

----- Original Message ----- 
From: "Paul Christensen" <w9ac at arrl.net>
To: "'Elecraft_List'" <elecraft at mailman.qth.net>
Sent: Friday, July 17, 2009 8:57 AM
Subject: Re: [Elecraft] K3

>> Can someone recommend a portable push up pole that I can use for the
>> center
>> insulator and then come down in an inverted V  Thanks Phil
>
> I have an interest in a well-designed telescoping pole as well, preferably
> 20-25 ft on a stable tripod.
>
> In thinking this through for a while, I've also decided on an inverted "V"
> for field use.  The Vee will be fed with 300-ohm ladder line and line 
> length
> will be adjusted pursuant to W5DXP's data to present a near 1:1 VSWR on 
> all
> bands from 40m-10m
>
> http://www.w5dxp.com/notuner.htm
>
> In doing so, I've decided to prepare pre-cut line lengths with banana plug
> connections in lengths of 16', 8', 4', 2', and 1'.   Changing line length
> does not change the 300-ohm VSWR, but it radically affects the end-of-line 
> Z
> and the 50-ohm VSWR.  And so, by manipulating these five plug-in line
> sections, a near 1:1 50-ohm VSWR is possible without a tuner and system
> losses are minimized.  A 1:1 current balun will form the transition 
> between
> the switched ladder line sections and coax.
>
> I thought about using the Budidipole system or one of its variants, and
> finally decided that I could attain better 40m-10m efficiency in the field
> by (1) changing line length; and (2) using a trap-less half-wave antenna
> length on the lowest frequency -- and make simple "plug-in" changes on the
> ground rather than by changing taps up on a telescoping mast.  Moreover,
> since there's a need to tether a 20-25 ft. telescoping mast anyway, it 
> makes
> sense to use the Vee as two of the three guys.
>
> Paul, W9AC
>
>
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