K1TTT
just wind a coil choke

Richard
What do you REALLY want?

There is a difference between a 12:1 and a 3:1 mismatch, especially in
a long coax run. What I want is a rough mid-of-the-range estimate of
where impedance in a 50'+50' squat inverted-V dipole across say
3-20MHz.

There is a gazillion description of such antennas fed via 450 ohm
ladder lines, and a few with 600 ohm lines:
- ready made 450 ohm plastic clad line is commercially available
- 600 ohm line can be made with commercially available spacers for
standard wire gauges.

Neither suggests that the corresponding impedance is a good midpoint.
The advantage of ladder lines is extremely low loss, allowing for
massive mismatches without much loss due to the exponentially-
decreasing but still substantial backwave.

Being forced to use a coax, I am looking for a ballpark match not
inspired by the current commercial availability of things I am not
going to include in the design.

The random dipole and the T2FD and related antennas ( like the
ubiquitous 3-wire damped dipole sold by many companies for
professional use) are operationally somewhat similar. All are
compromise antennas usable in a large spectrum, all are rather funny
in terms of losses, radiation efficiency, and radiation pattern.

The damping resistor is there exclusively to smooth the response over
the spectrum, at a cost. One could even argue that a balun+coax fed
tuned random dipole and an untuned T2FD of roughly similar size
exhibit similar losses, ^cept one heats the coax more (once the ATU is
peaked), and the other heats the resistor more, which should be handy
in determining deicing strategies. ;-)

There is plenty of literature, including some baseline simulations,
for the T2FD etc.. I haven't found the same for inverted-V random
dipoles. Any pointers? Have I been googling for the wrong things?