[QRP] Usable, accessible portable antenna?

[Daniel Reynolds]

Hi Darrell,

How much space do you have to work with for an antenna? How high can you string
a wire? How long of a wire can you put up? If you can, try to get a four to one
balun that will tie into the back end of the radio, and then run 450 Ohm
twinlead to a long wire, an off center dipole, or a center fed dipole like a
G5RV.

I live in an apartment. What I've been trying lately is an 85 foot end fed long
wire with a 15 foot counterpoise attached directly to the balun which is hooked
up right to the output of my K2 (which has the tuner option included). If the
IC-703 tuner can handle most SWR's, the Balun will further improve its ability.
Most baluns can be had for around $30 or more. I've been using 22 gauge wire
for temporary antennas strung from my 2nd story balcony and tied off to a fence
85 feet away (the counterpoise just droops over the balcony).

If you get a chance to read eham.com, you might be able to find out what folks
say about the various antennas you've mentioned so far. A compromise antenna
might do a good job at 100 Watts, but that's because it is 20% efficient (80%
turns into heat) - so in effect, you have a signal that is still better than
QRP. If you run QRP into the same antenna, you are effectively operating QRPp
(1 Watt out with a 5 Watt signal into the antenna).

I use the Buddipole antenna most of the time since I try to operate away from
my apartment. It's a great antenna, and I am very fond of it. Compared to the
outbacker antennas, it is not quite as simple to configure. This is because you
can move any of the buddipole coil taps where ever you want on the coils. Also,
the coil taps can become loose, fall off, and dissappear in the grass (they
aren't much bigger than the fleshy end of my pinky finger which is under my
fingernail). If you knew you were going to always use the stock buddipole
antenna and Budd and company had a way to make their coil form with permanent
taps like the outbacker antennas, then it would be much easier to set up for
the various bands it can handle. However, you wouldn't have the flexibility of
design which would allow you to add more antenna arms, or use the new longer
shock-cord/section whips. This isn't a big issue for operation on most bands
like 20m and up since the stock Buddipole does a great job on those bands. On
the lower bands like 40m, you'll need to retune the coils or adjust the
telescoping whips if you change from the CW and Data portion of the 40m band to
the voice portion of the 40m band.

The key for compromise antennas like the Buddipole is to get a low SWR by
tuning the antenna, NOT by using an antenna tuner in your radio. The tuner in
the radio only makes the transmitter happy - it doesn't make the antenna more
efficient.

However, using the same tuner into a less-of-a-compromise antenna like a long
wire actually has a positive effect since it enables the radio to transfer more
power into a mismatched load (Although - I'm sure those who are more technical
will set me straight if I need correction).

Because you want to run QRP - you may want to also specify which bands are more
important to you, and what time of day you will be doing most of your
operating?

I understand your frustration about the outbacker. I recently set up a couple
slinkies with some aluminum tape in my radio room. The slinkies were stretched
out about 11 feet each, and the tape was another 5 feet added to the end of
each slinky. This antenna, which by all means appeared to be much grander than
any mobile 80m antenna (and also had a bandwidth of almost 200-300 kHz!!! - can
you say dummy load?), netted zero contacts in the half dozen times I tried to
use it. The last week I had it up, I tried to check into the Four States QRP
net - and the net control station couldn't hear my signal running through this
magnificently 'broadband' and efficient looking compromise antenna. The week
after the slinkies came down, I snuck out that 85 foot wire I mentioned
previously, and got a decent report from the net control station.

If you have a good idea of your surroundings, or if you have another ham who is
experienced with stealth antennas, you will hopefully be able to determine just
how high you can get a wire. The higher you can get it (for example, 30-40 feet
up), the better chance you will have of getting your QRP signal off the
continent on bands like 20-15m. If you run a random length wire along a wooden
fence line which is less than 10 feet tall - it may tune up on all the bands,
but your contacts will be relegated to primarily stateside contacts on bands
like 20-15m, and states in your region on 80-30m. That's because the closer
your wire is to the ground, the more of the signal that goes up (instead of out
ward and low to the horizon).

I hope this information helps. Setting up an apartment antenna can be pretty
tricky.

- Daniel/AA0NI
Oklahoma City