Loaded folded dipole have a corner frequency below with the load is doing the work.? This
is related to the length like any dipole.? Also as you hit various resonances? ithe resistor
does some work.? Generally the losses are not horrific as sme may assume.? Some
bands its about par with a dipole.? The other effect is the antennas patter is less
subject to breaking into multiple lobes of unknown directionality (what NEC predicts
vs what the field installations does).
It would not be my first choice but it can be acceptable antenna for non-QRP operations.
It would be far down the list as you have o carefully roll it up and it requires substantial
height? at one end (if not both) to be useful.? They were popular for diplomatic missions
as they made fewer demands on the radio operators skills in the deploy phase.
A dipole fed with ladder line and a simple tuner is more efficient. and easier to install
and likely transport.? If the band is limited to one the dipole can be coax fed and the
whole thing fits in a plastic bag (25ft of RG174 and a 66ft 40M dipole).
The other popular antenna for portable work is the end fed half wave which can be
multiband LNR mades one the EF-QUAD for 40/02/15/10 that's 66ft long and also
a shorter 40ft EF-40/20/10.? I have experience with those and they work.? You can
make one or one of the many vendors sell them.? I know from use and also the
manual the EF-40/20/10 can use a wire cut for most any band between 5 and 30mhz
(468/f) and a handful of #22 wire is light.? Likely the easiest to deploy.
The random length wire (53ft and 125 ft) with a counterpoise fed with 1:9 transformer
and a tuner is also popular for field work.? The tuner is needed to insure the SWR is?
low as some radios are fussy.? ? Its easy to deploy like the end fed half wave antennas
as it can be Flat top, inverted V, L or sloping, even vertical depending on supports
My favorite terrible antenna:? 134ft or wire 41ft and 93ft with a 1:4 balun between them?
as an off center fed? wire about 1 ft (yes about 30cm) off the ground.? Its about
-10db antenna but fairly easy to tune with an antenna matcher from 160 through 20M.
If you like the B&K this is easier to install in a a flat area without any poles or structures.
Three rules for better signals:
1. Put the wire up higher where possible.
2. If not higher, use more wire longer wires, vertical arrays, or wire yagi beams
3. Any wire can be an antenna, and likely better than a bucket of wire in the shed.
The last one is most important, put something up!? Terrible antennas are still better than none at all.
With even a poor antenna anything can be better or at least you have something you can compare to.
Allison
