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Back in the November 1996 issue, the article covering the Anttron®
305
base station antenna didn't include a real life test. It did however
include a specification sheet and rough sketch of the antenna. One thing
that sticks out comparing the old spec. sheet with the new one is the gain
of the antenna. The old sheet claims; Gain - 10.35 dBi/QWM (Same Test
Method For A-99). The new spec. sheet claims; Relative Gain - 12.3 dB. Not
knowing if the antenna has been upgraded or not, I really can't comment
about the change in the specification. But an inquiry is in process. An
update will be added as soon as the information arrives.
The Anttron® 305 was installed over the new shop at 10 Thorndike Street
in Everett, MA. The antenna performed better than expected. It did seem
very quiet with respect to atmospheric noise. The building was full of
construction equipment including gasoline powered generators and air
compressors. Also truck and equipment maintenance was all performed in the
building. This included arc welding on many occasions. The radio remained
relatively quiet. At first, concern grew about the possibility of poor
gain being the reason for the low noise level. This wasn't the case. I was
able to talk over 25 miles to a base station that wasn't running power and
wasn't at a high elevation. The station was giving me a "S" 7 on
the meter. The meter on this Tram D210 is upgraded with the D201a solid
state meter circuit and had just been calibrated shortly after the move to
new shop.
Surprisingly, these results were achieved in spite of ignoring the
manufacturer's recommendation against using 9913 type coax. Anttron®
had
experienced a static problem with this coax on their antenna. It didn't
happen here. In addition, the antenna couldn't be grounded. There wasn't
any open ground to run a ground rod other than by the electric meters.
This could have caused an RF interference problem throughout the building
or even the neighborhood.
The other factory claim was the new VSWR matching scheme was unaffected
by rain or snow. It is true, the match remained unchanged during heavy
rain and snow storms. I was quite impressed with the performance of this
antenna. It lasted the two years at this location without any problem. I
decided to move the shop a short distance away once the lease was up.
Parking became an increasing problem for customers and there was a vacancy
in the Boston Market Terminal at the time.
At the new location I had a Solarcon I-Max 2000 installed. This being
the new base antenna at the time, I opted see how it performed. The gain
is equal to or slightly better than the 305, but the location could be a
factor. I believe them to be the same elevation above sea level. But the
noise level has definitely increased. This too is non-scientific and could
be due to a higher noise level in the area. I've been considering a second
omni antenna at this location, and it will be a Anttron® 305 when and if I
decide on a second antenna. ©CBWI
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