Sorry, but I wasn't confusing the two points at all. When I said
"efficient" I was referring to losses in the tuner. You can have a high
SWR on the line and still have low losses there, but if you have a poor
design for the tuner ... especially if the transmission line length
gives a really low impedance at the shack end ... you can easily lose a
LOT of power in the tuner. Any good piece of network software, such as
TLW that comes free with the ARRL Antenna Book, will show you that quite
clearly.
Dave AB7E
Trent and Lorraine wrote:
> I would suppose the efficiency (?) and having a low SWR on all bands are
> again confused. I still go by the theory that multibanders in general (G5RV
> and variations thereof) radiate equally poorly in all directions. BUT and
> it's a big BUT they do get you on air on a band that you normally may not
> have room to operate on due to zoning or other space restrictions, its why
> the hobbies is fun ... Getting all these different things to works as best
> you can..
>
>
> Trent Sampson
> [PO Box 1647 Toowoomba Qld 4350] VK4TI
>
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of David Gilbert
> Sent: Saturday, 20 January 2007 9:16 AM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] dipole length adjustment
>
>
>
> That's true to a point. I have used efficient homebrew antenna tuners my
> entire ham radio life and wouldn't be without one. But you can get some
> REALLY ugly radiation patterns from trying to use the same antenna
> on several bands. The antenna may tune fine and still not be putting
> your RF even close to where you want it to go. I always tried to stay
> reasonably close to a half wavelength ... for example, using a 50 foot
> dipole for both 20m and 40m still gives a fairly clean pattern on both
> bands.
>
> Dave AB7E
>
>
> Donald Chester wrote:
>
>> The best way to solve the problem once and for all is to feed the
>> dipole with open wire tuned feeders, using a balanced, link-coupled
>>
> antenna tuner.
>
>> That way you can instantly change the resonant frequency of the
>> antenna to any spot in the band from the comfort of the operating
>> position. And one dipole can cover multiple bands without traps or other
>>
> jury-rigging.
>
>> Don, k4kyv
>>
>> _______________________________________________________________
>>
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>
>
--
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