At 02:19 PM 9/3/2005, Aidehua@aol.com wrote:
>Interesting thread on the B&W....But one can one do if listening to multiple
>bands/freqs simultaneously through several receivers and a multicoupler??
>Or frequency hopping and/or ALE??
>
>Not many alternatives to this....
One might be able to make some sort of bicone or fan that has decent match
at many frequencies.
Or, an offcenter fed dipole with a 4:1 or 9:1 transformer might actually
have almost as good a match with less loss.
For ALE, you don't really need continuous coverage. You need each of your
bands. For instance, 4.5, 5.7, 9.1, 11.2, 15.1, and 17.5 MHz (one set of
bands used for ALE) might be covered by 3 or 4 parallel wires of different
lengths.
For totally omni/broadband you could always use a discone, but that's
vertically polarized, with all the hassles involved there.
However, the B&W is simple to erect (being symmetrical) and relatively
hassle free. Two parallel wires of the same length is easier to handle than
a ratsnest of different lengths.
Considered in a system context (just turn up the Tx power to compensate for
the low efficiency), it might just be the optimum solution.
B&W has been in business a long time (1932), they build stuff that's
reasonably rugged, and they've got the government procurement thing figured
out. For many situations, that's actually more important than whether it
actually works better. Many ham type manufacturers might not be willing to
go through the hoops for bidding on gov't procurement contracts. For
instance, the "gov't must receive the best price" regulation is a sticky
point for many vendors. Domestic content certification for the "Buy
American Act" is another.
(only recently, has it become much easier just to buy "catalog stuff" with
a gov't credit card)
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|