On 7/3/2025 7:37 AM, cqtestk4xs--- via TowerTalk wrote:
I'm no longer in a QTH where I can put up a tower, or for that matter, any
antenna. So I am planning on doing some operating when we camp out.
I'm looking at a multi-band vertical that can be attached to the tent camper tongue
framework (temporarily). I want the antenna to cover 40-10 mtrs, easily set up and
take dpown and can be collpsed to roughly 6 ft sections. The old 14 AVQ would be
pwerfect but is no longer made.
Any ideas?
Hi Bill,
I have a lot of experience with portable operation with all sorts of
ad-hoc antennas.
I know that you have serious vision issues, so launching wires into
trees with various methods would require help from others. If you so
have that help, there used to be a ham in the SF Bay area who built and
sold a pneumatic launcher for a tennis ball to which a lightweight
string was attached. Sherrill Tree service sells the "Big Shot," an
industrial-grade sling shot that tree climbers use to launch climbing
ropes; my climber uses one to get a rope up 100 ft or so into my
redwoods. My club back in Chicago had one that was loaned to members to
rig wires into much smaller trees and used on Field Day. For best
results, it's a two-person operation, with one person aiming and the
other pulling slingshot. Two local hams, one a neighbor and the other
NCCC member who was part of our CQP team for years, were very good at
launching small ropes with a weight attached over limbs in the 30-40 ft
range using their arms catapault-style. With all of these methods, you
get a very lightweight rope over a limb and use it to pull up a larger
one to hold the end of the antenna. If the wire is light enough, there's
not much tension on it, and you're only there for a day or two, the
lighter rope may be enough.
W4TV's suggestion of a fiberglass pole with a wire attached may be your
best bet. Over the years, I've seen several accessories at hamfests and
on the internet for holding these poles in position. Over the years,
I've rigged ad hoc setups in parks with such a pole, and a counterpoise
held slightly aloft by brush. Aloft is better than laying on the ground,
because there's less loss from the earth. Beefy wire is not required --
with setups like this, I've worked DX and even busted pileups during
Chicago QRP nights with our local club from a county park. That
counterpoise is critical to carry return currents. Could be the body of
your vehicle or camper.
From much experience, your major issue will be RX noise. I strongly
suggest trying to set up as far as possible from other human activity.
Mountaintop operation is like having a thousand foot tower. Among the
human activity to avoid are radio sites, like those for cell and 2-way
radio. Before leaving home, you'll need to chase noise sources that
you're carrying with you. Advice on that on my webpage,
k9yc.com/publish.htm Also, consider an LiFePO4 battery to run your rig
that's big enough that you don't need to charge it during operation.
Most PSU's that can be used to charge it are noisy. Genasun makes a
range of charge-regulators for various chemistries that are pretty
quiet. They're designed for use with solar panels, but can work with any
suitably rated PSU. I've used them for years with a 100 Ah LiFePO4
battery to run the K3s in my shack, with a second charger and SLA
battery to run the 12V accessories.
73, Jim K9YC
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