Rick,
You found it. And yes, I do understand that it will be barely
functional at 60 M. It does give me 10, 15, and 20 M so that would be
nice break in the driving. The antenna only needs the coil for 60 m, 40
M, 30M and barely (1 turn) for 20M, I am going to think about your
suggestion for 40. But it is collapsible and I started with the
premise that if I am going to the TT Fleamarket, I should bring a radio.
I have the Argosy, and it works, I can find picnic benches between
here and there. This antenna seems like a reasonable compromise and the
Argosy dunna work so well without one.
As to radials, I was thinking about 12 radials about 15 ft long.
Attach 2 sets to each side of the base with a wing nut. Again, it isn't
ideal, but should work reasonably well. I was thinking about getting a
15 or so 40 or 60 d nails to use as anchors. Maybe 20d nails might be
better, or at least cheaper and easier to insert into the ground. I
could crimp large rings on the outer end of each radial and nail it
down, so to speak. At any rate, I do believe that 12 to 16 radials is
the minimum to make the antenna play nice.
At the very least,it is an interesting project.
John / WA1JG
On 4/4/2012 2:16 AM, Rick - DJ0IP / NJ0IP wrote:
John,
The link didn't work for me, so I googled it and found another page.
Dunno if it is the same, but I think it is.
http://ad5yu.wordpress.com/2007/01/07/ad5x-portable-vertical-antenna/
My comments are based on the risky assumption that this is the same antenna
you are thinking about!
It's a 10' whip with a center loading coil.
It's gonna work pretty well on the high bands, but it won't be so great on
the low bands.
For mobile we have a legal limit for the length (I think 10'), but why would
you want to limit the height of a portable antenna to just 10' and then add
a lossy coil?
Even on 20m the quarter wave is 16'.
Maybe I'm biased because most of my operations is on 40m and that antenna
just is not going to be a great 40m antenna.
I much prefer the telescoping fiberglass pole method. They go up and down
in less than one minute. You can have a full size 40m vertical (33')
without even having to guy it (if it is only temporary). Just have separate
quarter wave wires for each band you want to operate.
In fact for 40m, since daytime operation is more close in operations, run
your 33' of wire only half way up a pole, then slope it back towards the
ground as if it were one half of an inverted vee. Tie it to a ground stake
about 20' away. Now you will have a MUCH stronger signal for NVIS type of
work.
NOW for low bands, Phil has put forth some outstanding suggestions for
matching 43' verticals on 80 and 160. His suggestions here are some of the
best I've ever seen.
FINALLY, I started out in the early 1970's using home-brew mobile whips with
coils in the middle. Once I switched to the long fishing poles (now days,
there are much better purpose-made poles for ham radio), I never looked
back. There is a huge difference.
The old adage, make your wire higher and longer is still true (in general).
73
Rick, DJ0IP
-----Original Message-----
From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
On Behalf Of John
Sent: Wednesday, April 04, 2012 12:03 AM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Using an Argosy in the field
John,
My current plan is to build a vertical that can collapse into short
sections. It is a design by Phil Salas - AD5X and uses a 10 ft telescoping
whip at the top and covers 60-10 meters, without a tuner. I have had good
luck with verticals and even though this is a 1/4, with some radials I
think I will be in good shape I placed the address of the article at the
bottom of this note if you are curious.
Also planned is the acquisition of a light sealed battery probably about
7 ah. The Argosy can run from 5-50 watts so it gives me some play room.
And hopefully my choice of battery size will not be too limiting.
John / WA1JG
http://www.ad5x.com/images/Articles/VerticalRevH.pdf
On 4/3/2012 4:49 PM, John Peters wrote:
Sent from my iPhone
On Mar 28, 2012, at 5:21 AM, "Rick - DJ0IP / NJ0IP"<Rick@DJ0IP.de> wrote:
John,
The lynchpin to having a good signal when operating low power
portable, is a good antenna.
Some people take a great rig, run it at reduced power on a crappy
antenna (i.e., mobil whip mounted to a ground stake), and wonder why
they don't work anybody.
Wire can be a wonderful antenna, but you have to get it up high in the
air.
That's why I always took a telescoping fiberglass pole with me.
In the early days they were just 8m long.
Later there were some purpose-built poles for ham radio that were 10m
long.
Today you can get them in even stronger quality in lengths of 12m or 18m.
In fact they even come as long as 26m but that's a bit overkill for a
one-man expedition.
For Field Day I always ran a doublet, with each leg 13m long, and fed
with
300 Ohm Openwire.
I had a tiny little MFJ Matchbox (T-filter), with a built in Balun.
The Balun was great for 5w QRP or 20w, etc., but I burned it up
running 100w.
Had to re-build it, then never tried 100w with it again.
For my normal excursions I had a special lightweight 3-band dipole:
- made of thin Teflon-insulated stranded copper wire (I guess about
AWG 22 or so)
- cut for 20m, insulator, more wire for 40m
- 2x short jumpers for jumping the insulator between 20m and 40m
segments, for 40m operation
- 2x short stubs with alligator clips to extend the antenna for 15m
operation (6 inches on each end)
- fed with about 50' of RG-174 (YES, THE THIN STUFF).
- A ball of twine for tying off the ends
Twine was cheap and disposable if it got too tangled. Ends tied off
to trees, or if nothing else, simply to stakes in the ground.
The thin RG-174 is sufficient and loss is really not bad for short
runs at those frequencies. The loss is worse if you use heavier
coax, and then fail
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