ARLA/CLUSTER: Antena Diamond V-2000

[Carlos Pinheiro]

Caros colegas,

Estou a pensar adquirir uma V-2000, para cobrir os 50/144/432 Mhz, pois
tenho muito pouco espaço e apenas um mastro e esta antena até nem é muito
cara. Em principio é optima para um equipamento tipo TS-2000, ou IC-9100.

Acho que pelo que li na net, em 6m só funciona bem entre 52 e 54
Mhz(repetidores FM americanos) e mesmo assim, como só tem 1 radial para os
6m, não é nada omnidireccional.

Um colega espanhol fez-lhe uma modificação simples e barata e parece que
resultou em cheio(basicamente montou-lhe 3 radiais de 1,45m). Ver "link"
abaixo:

http://ea4eoz.ure.es/v2000.html

Um colega americano escreveu o seguinte, no "eham":

>>The bad news is that the antenna is really only usable in the topmost
section of the band. SWR goes up as frequency goes down; we hit 3:1 at 53MHz
and it climbs rapidly below that.<<

After posting this review, I realized I had improperly converted metric to
inches and thus the radials were slightly short.

After adjusting the radials to more than 1/4 wavelength at 6M, the usable
portion of the band shifted down somewhat. 3:1 VSWR now occurs at ~51.6 MHz
and drops smoothly above that, reaching around 1.2:1 at 54 MHz.

We also removed the factory 6M radial and reinstalled the third homemade
radial, lengthened to match the others. No change was noted.

With these mods, I consider this antenna to be adequate on 6M. It is
advertised as a 52-54 MHz antenna and it does cover that bandwidth, albeit
with a bit more VSWR mismatch than I'd like at the low end. 144 and 440 both
work very well. I'd almost describe it as a 2.5 band antenna, since it's
really only suitable for the upper portion of 6M.

I'm thus bumping up the rating a notch to 4. Technically it should get a "2"
since it definitely "needs help", but the mods aren't difficult once you
know what to do.

The remaining question is whether there are any other tribanders out there
that perform better in stock configuration than this one does. Anytime you
ask a single antenna to cover multiple bands there will be compromise, but
sometimes one product is better at that compromise than another.


Se alguém conhece esta antena, agradecia referências.

Obrigado,
73 de CT1PT
-- 
Carlos Pinheiro
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