[Elecraft] Advice on First HF Antenna

[Don Wilhelm]

Craig,

For the home station, your first consideration is build or buy.  It is 
quite easy to build a pair of dipoles, one for 40 and one for 20 if 
those are your most desirable bands.  Get some wire, and some good coax 
and a good common mode choke for each antenna and use the ARRL handbook 
section on dipoles to build your own - it is not difficult.
Look at what you have for antenna supports - the higher the better, but 
for 40 meters, 50 feet is a suggested minimum for good performance.
If you have only one support that high, an inverted Vee works nicely.
Use resonant dipoles center fed and feed with 50 ohm coax.  Low loss 
RG8X is almost as low loss as RG8 but not as heavy.  If you are going to 
run power, use the RG-8 or RG-213 right from the start.

With a single tall support, for an inverted Vee configuration, position 
a 40 meter radiator at right angles with a 20 meter radiator and feed 
both with a single feedline.  Being placed at right angles to each 
other, there is little if any interaction.  Get the  ends of the 
inverted Vee radiators up as high as possible - if you can get the ends 
up to the same height as the center, that is great - you will have a 
pair of dipoles, so much the better.
Put the dipoles up, cut a bit long from what the "formula" tells you, 
and then trim it a bit at a time for the lowest SWR or for a reactance 
of zero should you have access to an antenna analyzer at the midpoint of 
your operating frequency.

If you have room for another dipole, consider adding a multiband antenna 
such as a G5RV so you can explore bands other than 40 and 20.

Use a good common mode choke at the antenna feedpoint (for the G5RV at 
the junction of the parallel feedline and the coax).  You will need a 
tuner for a G5RV or most any other multiband antennas.

If your horizontal space is limited, try a vertical.  I can recommend 
the GAP Titan, being a halfwave vertical, it needs no radials.  Mount 
the base 10 feet off the ground so the loop for 40 meters is above head 
level and use a good common mode choke at the feedpoint.

This is just for starters on your antenna quest.  That quest is an 
ongoing exercise for most hams.
Do not strive for the "best" antenna for starters, just get something up 
in the air and start operating - with time you will be able to determine 
how you want to improve your antenna farm.

For portable QRP operation, take a look at the End Fed Halfwave antennas 
offered by LNR Precision - They work and they have a good "trail 
friendly" lightweight version.  An EFHW can be easily deployed with one 
end in a tree and the other end near the transmitter.
If your field operations are more of the picnic table variety than the 
backpacking type, then consider a 32 foot heavy duty telescoping pole to 
hold up the center of an inverted VEE antenna.  Tie the center of a 
dipole antenna to the top of the pole and push it up - anchor the pole 
to whatever vertical support is available with bungy cords.  Extend the 
radiator ends out to whatever bushes or other supports are available.

So my suggestion is to start simple with homebuilt dipoles or other wire 
antennas, then grow your antenna farm after you get on the air and 
determine what you really want, and that may be a 150 foot tower with 
stacked rotating beams sometime in the future.  If you have space and 
want "beam" antennas using wire, consider 4 130 foot wires spaced 45 
degrees apart (total of 180 degrees spread) and you will have V-beams 
that can be steered - a very effective beam on 20 meters, but does 
require some feedline switching to select the pair of radiators to 
properly direct the radiation (it is bi-directional).

73,
Don W3FPR


On 12/7/2015 5:13 PM, CRAIG SCHROEDER wrote:
> I am pretty new ham and a brand new KX3/PX3 owner excited to try my hand at DX'ing!  If you were buying your first HF base antenna, primarily looking for performance on 20 and 40 meters, what would you recommend?  Also, what do you suggest as a high performance field antenna for QRP?
>