All interested hams:
With many opinions about the B & W folded dipoles, one needs to understand
the design and actual tested operations of this antenna design.
It actually is quieter on receive, and the loss is only higher when the SWR
rises regardless any band or frequency operation.
Therefore, if the SWR is kept low, the transmitter efficiency of the
antenna is actually measured, the actual radiated power can be very high with
minimal power being actually lost through the resistor.
The higher the SWR, the less efficient the antenna and consequently more
power is lost through the resistor.
Regards,
Dr Joe Palsa
k3wry
No trees were destroyed in the sending of this message, however, a
significant number of electrons were terribly inconvenienced
In a message dated 4/21/2011 4:39:50 P.M. Eastern Daylight Time,
steve@karinya.net writes:
The military love them because they value frequency agility over
efficiency.
Cebik's analysis put the power in the terminating resistor at somewhere
between half and 90% of the applied power, depending on the band.
73,
Steve G3TXQ
On 21/04/2011 21:30, Grant Saviers wrote:
> I had one of these elevated resistors briefly in 1980. It was very very
> quiet at both ends.
>
> Might be ok for quick GOTA, emergency, or NVIS, that's what it seems the
> military wanted it for.
>
> Grant KZ1W
>
> On 4/21/2011 12:36 PM, David Gilbert wrote:
>> By all accounts I've read, the B&W folded dipole is indeed broadband.
>> Since it has a relatively small fixed "tuning network", that can only
>> mean it has significant loss relative to a normal dipole. Estimates
>> I've read vary between one and two S-units.
>>
>> By all accounts I've read, it is a "quiet" antenna on receive. Since
>> noise rejection can only come from pattern or polarity discrimination
>> and the B&W antenna has no more of either of those than does a standard
>> dipole, that again means it has significant loss. The antenna is
>> probably just as quiet on the other end as it is on yours.
>>
>> Dave AB7E
>>
>>
>>
>>> From: "Fred Serota"<fserota@msn.com>
>>> Sent: Thursday, April 21, 2011 1:30 PM
>>> To:<jim@audiosystemsgroup.com>;<towertalk@contesting.com>
>>> Subject: Re: [TowerTalk] Multi-band dipoles
>>>
>>>> Suggest trying Barker and Willamson's folded dipole. They have three
>>>> or 4 varieties, some made of stainless wire for very tough climates.
>>>> The longest is approximately 120' and fives a flat SWR under 2:1 for
>>>> 160-6 meters. Due to built in matching does not need a tuner. This
>>>> antenna has a special name, I have forgotten. Can be ordered direct or
>>>> I, thing, through HRO and AES.
>>>>
>>>> Mine is hung as an inverted V and works out very well.
>>>>
>>>> Fred, K3BHX
>> _______________________________________________
>>
>>
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