H F Antenna - BWD-90 VS G5RV
Jim Lux wrote:
Bob D. wrote:
I'm still trying to decide on a ready-made HF antenna. I have a couple
more questions.
Can the Barker & Williamson's BWD-90 really be used without an antenna
tuner?
Does the G5RV really need an antenna tuner?
Wow, there's a 7:1 price difference here! Hope to be QSOing soon,
instead of emailing.
The B&W (and all of the essentially identical antennas which are a
folded dipole of some sort with a big resistor) are an interesting
solution to a system engineering problem. Sure, they're hideously
inefficient, but, they don't require a tuner, and if you're not power
limited, you can overcome the inefficiency by just turning up the amp.
It's no different than putting a 3dB pads on the ports of a mixer to
make them less sensitive to the match. You take a efficiency hit, but
you pick up overall system insensitivity to component variations, etc.
A terminated folded dipole and a broadband solid state amp is not a bad
system solution for someone who needs a broadband (2-30MHz) system that
is simple to deploy and has essentially instantaneous frequency change
ability. Hmmm.. folks with ALE or HF frequency hopping radios in a
tactical environment. And who buys these sorts of things: military and
diplomatic folks, who aren't power constrained, need fast frequency
changes and simple installation, and aren't concerned about saving every
penny. In that market, a few hundred dollars more or less makes almost
no difference.
Jim, that is an interesting - and correct - outlook on the folded
dipole. That's why it is a good solution for people who aren't
constrained in power.
For Hams, I would think it isn't a great solution, although if run at
full legal power it might be okay.
For Bob:
Don't be afraid of a tuner. Look at it as just another bit of circuitry.
Turning knobs is part of the fun of Ham radio.
That G5RV will need a tuner.
A suggestion for an antenna:
Get a ladder line fed dipole of 130 feet. I think AES sells them for
around 35 dollars or so. Use a tuner on it. If you want automation,
there are automatic tuners that will handle balanced line. MFJ makes one
for example. You'll have a nice all band antenna, if a little "lobey" on
the upper bands. And you won't have the loss of the Folded dipole.
- 73 de Mike KB3EIA -
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