CBWI July 2001 AnttronŽ 305 Revisited

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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 neighbourhood.

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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