Jim,
The "fan" dipole, and the bow tie are examples of broadbanding without loss,
assuming you are talking about the two wires being resonant on the same
band.
I've seen a fan dipole with one wire cute towards the low end of the band
(say 3650) and another cut toward the high end of the band (say 3850 or
3900), separated at the ends by a 5 foot plastic tube. This arrangement
covered 3.5 to 4.0 mHz at 2:1 or so VSWR, with a "double hump" type
response. There is no loss associated with the "fan". Bowtie's are similar,
except they are a continuous loop (no plastic spreader at the end...it's
spread, but conductively). I'm not sure which of the two produce the broader
response. In either case there are no additional losses (signficant) to
consider.
The last case is to have multi-band fan dipoles. In this case there isn't
any significant loss either, but tuning them can be a bit tedious, as
interaction is a problem if they are all in the same plane. Tuning is easier
if they are put up at right angles to each other in a "+" configuration. For
that matter, if you have the real estate, you can put the "fan" dipole up
that I described in the "+" configuation as well, but it takes more space.
Hope this helps. 73
..hasan, N0AN
I've
----- Original Message -----
From: "Jim Miller" <JimMiller@STL-OnLine.Net>
To: <towertalk@contesting.com>
Sent: Monday, January 30, 2006 10:57 AM
Subject: [TowerTalk] Broadbanding a dipole
> Speaking of broadbanding and the possibility/probability of increased loss
> as the actual cause, does this apply to the dipole cut to a specific band
> and then running several wires in a box (for instance) configuration
> separated by a foot or so with spreaders at the ends and all driven and
> connected together on each end? Does this add loss to the single wire
> dipole or does it simply make it more broadbanded without adding the loss?
> (realizing it will be a slight bit shorter than the single wire dipole).
>
> Tnx es 73, de Jim KG0KP
>
> ----- Original Message -----
> From: "ROBERT CARROLL" <w2wg@comcast.net>
> To: "'hasan schiers'" <schiers@netins.net>; <towertalk@contesting.com>
> Sent: Monday, January 30, 2006 10:40 AM
> Subject: Re: [TowerTalk] double bazooka vs full length dipole???
>
>
>> I see MFJ is selling Franklin 2 wavelength collinear wire antennas. Has
>> anyone had experience with this type of antenna?
>>
>> Bob W2WG
>>
>> -----Original Message-----
>> From: towertalk-bounces@contesting.com
>> [mailto:towertalk-bounces@contesting.com] On Behalf Of hasan schiers
>> Sent: Monday, January 30, 2006 9:36 AM
>> To: Alan Wilson; towertalk@contesting.com
>> Subject: Re: [TowerTalk] double bazooka vs full length dipole???
>>
>> Alan,
>>
>> The double bazooka (as conventionally described) is a waste of "weight".
> It
>> will not outperform an ordinary dipole in terms of gain (it has extra
> loss,
>> which is where the minor VSWR bandwidth improvement comes from).
>>
>> This antenna has be thoroughly analyzed by a wide variety of antenna
>> specialists, and the conclusion is unanimous: don't waste your
>> money/wire.
>> There are better ways (more efficient and less trouble) to broadband an
>> antenna, and there is no reason to drop your gain trying to get it.
>>
>> Check the archives of rec.radio.antenna newsgroup, as well as an article
> by
>> Belrose for the full story. In short, not worth the bother.
>>
>> (and yes, I've done it...my experience agrees with the "experts")
>>
>> 73,
>>
>> ...hasan, N0AN
>> ----- Original Message -----
>> From: "Alan Wilson" <ke4nu@ke4nu.myrf.net>
>> To: <towertalk@contesting.com>
>> Sent: Sunday, January 29, 2006 2:29 PM
>> Subject: [TowerTalk] double bazooka vs full length dipole???
>>
>>
>> > Ok guys, what is your opinion on which antenna is better overall. Of
>> > course the bazooka is more broadbanded, but does it have more gain? as
>> > compared to a simple dipole centerfed with coax thru a balun...73, Alan
>> > ps. Is the bazooka quieter?
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > _______________________________________________
>> >
>> >
>> >
>> > _______________________________________________
>> > TowerTalk mailing list
>> > TowerTalk@contesting.com
>> > http://lists.contesting.com/mailman/listinfo/towertalk
>> >
>>
>> _______________________________________________
>>
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