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Q:
Will the folded dipoles operate the new 60 meter band?
Yes, the 65, 90 and 180 foot antennas will operate 60 meters with no
modifications.
Q:
What is the wire spread on the folded dipoles?
The wire spread is 18".
Q: What does the
folded dipole look like? Can I paint it?
The spreaders (6 of them) are white 1/2" PVC. The balun is housed in
2" white PVC, and the balancing network is in an off white fiberglass
housing. If painting, you must be careful to use a paint that will not
'melt' the plastic with volatiles. Test the paint on a scrap of PVC.
It must also be non-conductive. The balancing network may get very hot
with linear operation, so a thermal paint must be used here.
Q: What is the approx gain
on the BWD-90 as compared to a dipole in free space?
160 M -2 dB
80 M -1 dB
40 M 0 dB
20 M +1 dB
15 M +2 dB
10 M +3 dB
Please note that these numbers were measured on an antenna farm (ideal conditions). Site and installation are extremely
important at the lower freqs.
Q: What kind of coaxial
cable should I use? How do I check it properly?
It is essential to utilize a heavy (thick) coax for transmitting. If the cable
is too small (not enough copper surface area inside), then the losses will
increase and look like bad SWR from your antenna. Do
not use RG-58 or 8X. RG-58 is only suitable for transmitting a max of 10 - 20
watts with short runs. Utilize cables such as RG-213 or 9913.
To properly test your installation from radio to antenna feed point, do the
following. Disconnect your feed line from the antenna. Connect it to a dummy
load. In the shack, use a good quality SWR meter and check high, low, and
midpoints an all bands by transmitting at low power. If your match is not very
close to 1:1, you have a problem. That problem could be losses in cable, tuners,
switches, lightning protectors, splices, etc.
Check it out!
Remember, no antenna can radiate what never gets fed to it!
Q: Does the terminator
(balancing network) create losses?
No, it does not create losses. It dissipates losses from the ever present lack
of perfect antenna efficiency. No antenna is a perfect radiator. In transmit
mode, the terminator absorbs energy that did not get radiated out of the
antenna. In most antenna systems, this gets carried back to the rig where it can
do
serious damage. For a terminator to create losses, it would have to have a low
impedance. Our unit has a high impedance.
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