Mosley or Force 12 or Fritzel ??

F8BDU

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Oct 6, 1997, 3:00:00 AM10/6/97

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Looking for a 3 or more bander HF beam i will appreciate any comments from
anyone who knows about Mosley's TA-53-M or TA-34 or CL-33-M versus Force
12's C-4 or Fritzel's FB-DO-450.

Thanks in advance and 73's de F8BDU Oktay

Piotr Tomczak

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Oct 6, 1997, 3:00:00 AM10/6/97

to F8BDU

Hello Oktay.

I can not say much about comparision reagarding Mosley, Fritzel or
Force.

One friend of mine has Mosley and the other Force12 and it look like
both antennas working
very good, but I have just ordered a Force12 C3 for my location so we
will see.

Piotr LA9HFA

Jari Jokiniemi

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Oct 7, 1997, 3:00:00 AM10/7/97

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In article <01bcd256$f3d56440$a465...@hbar.club-internet.fr> "F8BDU" <hb...@mail.club-internet.fr> writes:
Looking for a 3 or more bander HF beam i will appreciate any comments from
anyone who knows about Mosley's TA-53-M or TA-34 or CL-33-M versus Force
12's C-4 or Fritzel's FB-DO-450.

I've had a Mosley TA-53M for some four or five years. I've measured
it's pattern with OH2BYS living some 10 kilometres from me. The
measurement instrument was a more or less calibrated IC-751, so you
should be prepared for an error margin. Furthermore, the measurements
were made on towers, not using a helicopter or anything like that, so
the truly three dimensional directional pattern is reduced somewhat
erroneously to be only a plane.

Overall the antenna performs just as one might expect for a multiband
beam with a boom of only 5 meters. It does have directivity, F/S is
usually around 17 to 20 dB or so. It is a compromise antenna.
FB is usually poor, between 8 to 16 dB depending on the band. The very
best property of TA-53M is the fact that the antenna is small and
yet you have five bands. This is important if you are restricted
to only one beam for a reason or another. (Don't we all dream of 6
over 6 monobanders.)

Now I have a Fritzel FB-53 (14/21/28) and a 2 element Fritzel WARC beam
(10/18/24). I've measured those antennas with OH2BYS, too. FB-53 has longer
boom than TA-53M and it shows (7,5 meters against 5 meters). The main
lobe is clearly sharper than that of TA-53M. Front to back is always
at least the same as TA-53M's best value, usually better. The 2
element WARC beam shows about similar performance as TA-53M on
the WARC bands.

Then I've operated a station having two fixed Force 12's four band yagis.
I have no idea what might be the model code for those antennas. As I
could not rotate the antennas I made no measurements. Switching
between EU and USA directions gave me the impression that
front to side was pretty similar than that of a typical three
band yagi with a 5 meter boom. I don't know about front to back.

Force 12 antennas are small mono banders and it should show in having less
losses than trap yagis. A calculation I saw about a three band 3
element yagi with a 5 meter boom gave the following approximate
results (I've posted the original numbers some months ago, these are
how I recall them): 28 MHz practically no losses at all, 21 MHz a little bit
less than 1 dB loss, 14 MHz 2 dB loss.

Then I've made some very unscientific measurements regarding the
effects of increasing the height of the antenna. Roughly I'd say that
going from 12 meters to 24 meters gained always between 5 to 15 dB,
usually more than 10 dB.

I'd really like to know how much one would gain on 14 MHz by going up
to 36 meters. Anyone tried and recorded the measurements out there?
--
Jari Jokiniemi, jari.jo...@tekla.fi, OH3BU, OH2MPO
Tekla Oy, Koronakatu 1, 02210 Espoo, +358-9-8879 474