On 2012-01-16, at 8:41 AM, Ken wrote:
> Actually this setup is covered in this month's QST "The Doctor Is In" column
> with a couple of references to older QST articles.
> A center fed dipole with open wire or ladder line is a very good multi band
> antenna if you have a tuner which will feed it. A half wave at the lowest
> frequency is the classic antenna and is covered in the Handbook and Antenna
> Book. Some people find that the high impedance of the full wave (e.g. 130'
> on 40m) is difficult for some tuners to handle and a 100' length is a popular
> size for 80m and up. Myself, I prefer not to give up that extra length on
> Antennas like this do not have to be precisely tuned. 135', 130', 125' all
> will give essentially the same performance. 100' will give a slightly
> reduced performance on 80m.
> And additional plus of an antenna like this is that it will work very well on
> the WARC bands like 60 and 30m.
> I'm currently using an antenna like this. 40' of feedline to a 4:1 balun
> outside the house, then coax directly to the Elecraft K3. The K3's internal
> tuner handles it perfectly on all the bands 80 through 6m.
Hi Ken et al,
I had mis-givings here about feeding my 160-meter half-wave inverted "V" dipole
(50' at the apex) with foam-type 300-ohm TV twin-lead---and using it on all
bands from 160- to 10-meters---but my cares have been quickly laid to rest...
That sort of a multi-band tuned dipole is wonderful---and it even has the added
bonus of some "long wire" gain on 80- through to 10-meters...this, despite the
fact that it has good, round-the-compass coverage, what with the smaller,
"fill-in" lobes radiated by the antenna, which increase in number the higher
the frequency band.
One thing to pay attention to, though, is the feeder length: I settled upon one
of the recommended lengths shown in my older small-sized ARRL ANTENNA HANDBOOK,
otherwise I simply could not tune the thing on some bands with my transmatch...
~73~ de Eddy VE3CUI - VE3XZ
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