Antenna question for trx-2

[mandcaff]

Just got my trx-2, my first trunking scanner, and still in the learning mode, and there seems to be alot to learn. I have ez-scan installed and the scanner up and running, so no issues there. I had been using the telescope antenna that came with the rig, and i realize they are not the greatest. when i tried listening to a local p25 channel it was broaken and garbled, even fully collapsed. so i had an old rubber duckie lieing around and put that on, and the trunking channels come in great with that, so my question is, would it be feasable to use multiple length antennas using a series of connector couplers with tee's on them for the differnt antennas? Hope this makes sense, and any thoughts on this would be greatful.

 

[krokus]

Just got my trx-2, my first trunking scanner, and still in the learning mode, and there seems to be alot to learn. I have ez-scan installed and the scanner up and running, so no issues there. I had been using the telescope antenna that came with the rig, and i realize they are not the greatest. when i tried listening to a local p25 channel it was broaken and garbled, even fully collapsed. so i had an old rubber duckie lieing around and put that on, and the trunking channels come in great with that, so my question is, would it be feasable to use multiple length antennas using a series of connector couplers with tee's on them for the differnt antennas? Hope this makes sense, and any thoughts on this would be greatful.

Feasible? Sure. Good idea? Not really. Paralleling antennas like that affects the impedences in circuit, and opens the door to strange results.

If you want to use multiple antenna, use band separators, as combiners. The small amount of signal loss from the combiner can be made up for, by more efficient antennas.

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[Ubbe]

would it be feasable to use multiple length antennas using a series of connector couplers with tee's on them for the differnt antennas?

Yes, absolutly. There is nothing right or wrong when it comes to scanner antennas. Experiment until you find something that works for you.

Connecting several antennas to one point are how they make some of the multiband scanner antennas. Some say the ST2 is the best scanner antenna made and that is made of several dipole antennas cut to different frequency bands connected together at one point. I include a picture of one table antenna sold as a multiband scanner antenna.

/Ubbe

 

[Blackswan73]

Yes, the ST2 is basically a fan dipole. However the different elements are specifically spaced to eliminate interaction

 

[Ubbe]

I wouldn't worry too much about spacing. Some say the DPD antenna works great and the three dipoles are connected at the same point.

/Ubbe

 

[krokus]

I wouldn't worry too much about spacing. Some say the DPD antenna works great and the three dipoles are connected at the same point.

/Ubbe

Once again, in calculated and tested manners. Not random connections by a neophyte.

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[Ubbe]

They state it is tuned 1/2 wave dipoles (tuned to the middle of its band) and by looking at it I can say that it is no more than that. They use a tube as the 300MHz dipole to make it cover a wider frequency range.

Wavelength: 1/2
Tuned: 225-400, 118-137 & 138-140 MHz
DPD Productions - Aviation Base & Mobile Antennas: Air Band, ADS-B, 1090 MHz, ATC, FBO Base, PCL, AWOS, ACARS

/Ubbe