What kind of bandwidth do you get with your inverted L, 50 kHz?
Would I still be able to use a tuner in the shack if I want to bend
it for more coverage on 160?
Define bandwidth. Do you mean SWR bandwidth? Do you mean you can get
it to load?
A very good question. And it brings up a couple of points that are worth
mentioning.
If your antenna has a wide SWR bandwidth, it may seem like it works
really good, because it is so convenient. Operate the whole band without
making any adjustments as you go from top to bottom of the band. Very
convenient! Beware though that a wide low SWR bandwidth is often a sign
of inefficiency. How wide is the 1.5:1 SWR bandwidth of a Heathkit
Cantenna? Pretty wide. How much DX are you going to work with it? Not much.
A quarter wavelength vertical over an excellent ground counterpoise
system has an impedance of about 37 ohms. If you don't need a matching
device to get a 1:1 SWR at the resonant point, then it is likely you
have about 13 ohms of loss resistance (the kind that produces heat,
versus radiation resistance, the kind that produces a radiated signal)
that added to the 37 ohms of radiation resistance makes a perfect match
to your 50 ohm coax. Very convenient. Not very effective. What would you
rather have? A low SWR or a stronger signal? Many hams have chosen
(perhaps unwittingly) a low SWR.
A quarter wavelength that is folded over into an inverted L, instead of
going straight up, has an even lower radiation resistance. You will (or
at least you should) need a matching device to get the SWR down, unless
you have a lot of loss. You are likely to have high ground losses,
because your ground resistance is high and radial field is lacking. You
could have a low SWR, and a wide bandwidth. It could be very convenient.
Or you could reduce your ground losses and make your SWR worse. Not as
convenient, but much more effective as an antenna.
Yes there are antenna designs that have wide low SWR bandwidths, without
being outdoor dummy loads. Discones, biconical dipoles, log periodics,
etc. A fatter inverted vee "cage" will be an improvement, but you will
still want to do whatever you can to reduce your ground losses.
Have fun!
DE N6KB
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