[Cliffdwellers] Overview of antenna history at KD7BFX

Fri, 12 May 2000 21:44:58 -0800

Presently I have the best QTH, from an antenna point of view, that I
have had in 4 short years of hamming, and nearly 20 of "serious" SWL. My
main antenna for HF is a 66' inverted-V, 45' at the apex, with an
included angle of about 100 degrees, ends at 17.'  Needless to say, it
works quite well on all bands from 40-10, and when I tie the feeder
conductors together and use my artificial ground box, it does a credible
job on 80 as well. I work mostly CW.

Up until late last year, I had to deal with serious limitations on my
antennas, due to landlords, neighbors, or simply lack of space, even
where neighbors and landlords were willing.  Here is a short list of
*some* of the things I have tried which worked (reasonably) *well*:

*Random-wires, if they are at least 1/2 wavelength on the band of
interest. Quarter-wave "randoms" are a real mess without a serious
radial system (artificial ground devices don't work so well here), and
if you can install a good radial ground system, you probably don't have
to worry about stealth or space restrictions, anyway.

*Small transmitting loop antennas (also known as "magloops"). I have
used both the MFJ and AEA versions. The MFJ is the better of the two,
and it does work, but tuning is *very* sharp on 40, 30, and the bottom
of 20. Smallest antenna I have used, and the much hyped nulling and
noise-reducing characteristics of this antenna are real, and useful. I
homebrewed one, and it worked better than those commercially available,
for *much* less money ($75 vs. $350!). The real trick is finding (or
making, in my case) a suitable HV capacitor. Vacuum variables are ideal,
if you can afford them. I 'brewed a "trombone" variable, using copper
plumbing pipe and PTFE sheet insulation. I used a continuous piece of
5/8" copper refrigeration tubing, and welded the raditor to the cap,
which reduced the losses considerably. There are several excellent
design programs (DOS) available.

*Bent or 'articulated' dipoles. Simply, put up a dipole as big as you
can, where you can. I have had them from 20' to nearly 100, indoors and
out, high and low, straight and crooked, etc. As long as the included
angle between any two adjacent segments is not less than 90 degrees, the
antenna should work (or usually did for me). A tuner, the best you can
afford, is a very wise investment for the cliffdwelling ham. I have put
dipoles of this type under eaves, along ceilings, between a window and a
tree, etc.

*Mobile whips and other shortened, loaded verticals. One word:
counterpoise! There are a lot of mobile whips (I mean to include
screwdriver types here) and "restricted-space" shortened verticals on
the market. Some work better than others. I have had good results with
the "Hamstick" brand. On a second floor balcony, with one 'resonant'
radial hanging, I have routinely worked CW into G, DL, EA, VK, LU, JA,
and elsewhere, from Arizona using 50W or less. Results similar but
somewhat less on SSB.

I found being space restricted was a net, long term plus. I learned a
lot about antenna theory, about propagation (taking advantage of
optimums), and mostly about the importance and the difference that
quality in materials and workmanship makes. The best solder joints, the
best wire, etc. *will* make a big big difference when you have to use
less than ideal antennas. Filtering, shielding, and grounding are
important, more important than for the ham with 5 acres and no deed
restrictions and an unlimited budget. Without them, you *will* cause a
bunch of TVI and other RFI. It is almost inevitable with sub-subsized
antennas. This is especially important if you plan to run more than
100W. My present living arrangements are long term but not permanent, so
I may need to use and refine what I have thus far learned about
cliffdwelling. That's why I joined this reflector again. A compromise HF
antenna doesn't mean a compromise or weak or inferior HF station. I'm
not alone in using my own ingenuity, good advice, and careful, thorough,
hard work to squeeze the maximum out of my apartment antennas (and the
rest of my station) in order to work a good share of DX, even some rare
(the best operator with a pint-sized antenna will usually catch the
rarie before a poor operator with a KW and stacked beams), and good
reports. Don't treat it as second-best, it is really a challenge in the
best and oldest tradition of amateur radio.

73 de KD7BFX (Will) AR

Fernando Quinones wrote:

> Hello Allan.
> You are the first post I have read since
> I subscribed. My name is Fernando.
> I'm interested in how others get on the
> air from restricted conditions.
> Specifically, Stealth antenna solutions.
>
> enjoy
> --- allan egleston <[email protected]> wrote:
> >  My name is Allan Egleston. Call sign is kf6uxj. I
> > live on a small lot.
> > The only antenna I have now up is a j pole. 73's de
> > Allan kf6uxj
> > _______________________________________________
> > Cliffdwellers mailing list
> > [email protected]
> >
> http://mailman.qth.net/mailman/listinfo/cliffdwellers
>
> =====
> 73's Fernando NF6Q/NNN0JYM
> San Jose,CA.
> CCA #01187; K2 #2330 (in it's infancy)
> <http://www.geocities.com/nf6q>
>
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