On Jun 28, 7:42 am, "Sal M. Onella"
wrote:
wrote in message

ups.com...





Hi All,

Here's a challenge !

Having recently acquired a Yaesu FT-879 HF transceiver I'd like to use
it for portable operation from my camper van. Ideally to take
advantage of the improving HF conditions during my lunch hour at work.

So I originally thought about buying a Yaesu ATAS-120A, but then I
realised that I wasn't that interested in mobile operation. So I could
consider something a bit more efficient.

Suggestions for alternatives or best length of wire and transformer
ratio would be greatly appreciated.

UKM

See the Outbacker antennashttp://www.outbackerantennas.com/products.html.
Some appear to meet your requirments.

One of our club's hams used one at Field Day last year and this. (Outbacker
8, I think) He did as well as the guys who had much bigger antennas. He
merely clamped it to a chain-link fence at head-level and he was on the air.
The mass of your camper van might be OK if you can't park adjacent to a
suitable fence or other structure.

Downsides: Not cheap; band changes require your attendance at the antenna
unless you switch among many of them. (You are quite wealthy, right? :-)

There are also vehicle-mount products known as "screwdriver antennas" but I
am not prepared to address them.

73,
"Sal"
(really KD6VKW)- Hide quoted text -

- Show quoted text -

Hi Sal,

Thanks for this. I'm familiar with the outbacker range so I''l take a
look for some construction ideas.

In the meantime I've been doing further research and experimentation,
and have now found a good initial solution.

By using a vertical wire of a suitable magic length (7.2, 8.8 or
11.8m) supported by the fishing pole, I can get the LDG tuner to
provide a good match on all Amateur bands from 80m upto 6m as the
impedance presented to the tuner is just within it's (slightly
limited) matching range.

This has resulted in good signal strength reports on several bands,
even when using just 10watts ssb, so it's an excellent starting point
that I can work from.

The next stage is to improve the chassis bonding, play with some
impedance matching transformers and an optional counterpoise to try
and reduce the RF level inside the Van on 80m.

A linear loaded vertical possibly using multicore cable also shows
some promise. My initial measurements with an RF sweeper indicates
that it could add a useful secondary resonance at the low frequency
end, which may benefit the tuner.

A remote field strength meter is also in the plan, so that I can make
quantative measurements.

Once again thanks for the feedback.

UKM