ST-2 Antenna Orientation

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MesquiteWx

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Hey guys, I have a quick question. I have a 2 Antennacraft ST-2 antenna and I love them. Very good antennas. Anyways, I have them up on a mast that is about 25'ish up in the air. Last week we had a wind storm that caused the mast to fall over. No damage to the Antennas because of how it fell and the safety lines prevented it from hitting the ground. Anyways, they were down for about a week and while they were down the orientation of the antennas were horizontal instead of the normal vertical orientation. While they were in this horizontal orientation I was receiving this P25 P2 system the best I have every received it. Yesterday I fixed everything and put them back to their normal vertical orientation. Since I have done this the reception of that system as degraded tremendously and is very choppy.

So I am wondering would trying to remount these in a horizontal orientation allow me to get better reception of these signals than if it was vertical? Just curious since the reception of this one system was better in horizontal orientation than vertical. All my other systems work great in vertical with the exception of that one.

-Thanks
 

SkiBob

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I think you do whatever works. Another thing to consider is that antenna is very directional. Point it to the tower you are wishing to receive from. Evidently you hit a sweet spot. Is there a way to temporarily mount it to where you can move it around to experiment finding the sweet spots? If so I would suggest doing that. You may find things you hadn't discovered before.

The fun thing about this hobby is finding what works. Because of terrain, obstacles, elevation and so on, what works for you may not work for anybody else.

Good luck and have fun.
 

davenlr

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While they were in this horizontal orientation I was receiving this P25 P2 system the best I have every received it. Yesterday I fixed everything and put them back to their normal vertical orientation. Since I have done this the reception of that system as degraded tremendously and is very choppy.
Yep, same problem I have. Mount one ST2 almost on the ground (still vertical) and use that one on the P25 system. Choppiness (errors) are caused by to strong a signal. By having the antenna horizontal, you were losing 20db of signal plus the additional loss of having it lower to the ground.

I have one ST2 mounted up high for everything except our local P25 system, and one mounted lower for the P25 system. Luckily, I have two scanners, so I dont have to give up range on non-P25 systems.

For some reason that attenuator in the scanner doesnt seem to help the choppiness, but a crappy antenna install like my discone with half the elements missing, or the ST2 mounted on a pole on the ground seem to work great. As soon as I try to use the other ST2 up in the air (10' above roof on top of a hill), I can forget P25 reception.
 

MesquiteWx

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Well the problem for me is the 2 antennas feed 8 scanners. I don't have any problems with any other systems. P25 systems I am able to get crystal clear. It is just this one P25 Phase II system that has issues. There is even a P25 Phase I system that is about 10 Miles further that I get crystal clear. It was just strange when it was laid horizontal and lower about 10' high the Phase II system was crystal clear.

The ST-2 is suppose to be omni directional but it is weird that when you use it directional it picks up other systems better. So that does answer some questions about it being directional.

I am thinking about getting a Yagi Antenna in the 700 Mhz range for this system. Curious though if I can use two antennas for the same radio that way I don't sacrifice the other systems.
 

woody_46

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The ST-2 is somewhat directional even though it's listed as omni-directional . I too have had the same issues as Dave which is the antenna overloading the front end of the scanner. Lowering and aiming it resulted in a better signal for me too. I live in a high RF environment.
 

LIScanner101

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I think the ST-2 is directional only because of the way it is mounted with a large portion of the lower dipole section (and even a bit of the upper dipole) directly opposite and parallel with the mast. I bet using a nonconductive mast like PVC would make it much less directional.
 

MesquiteWx

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Yeah it is possible and something I have thought about. I am not sure how much of that comes into play though.

I wonder if pointing the broad side of the antenna towards the tower would improve it any? Just kicking around some ideas and getting some feedback. It probably won't be until this weekend before I can mess with it.
 

popnokick

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MesquiteWx- a Yagi may make your problem with that one P25 system worse. What the other posts here are trying to say is REDUCE your received signal on that system. It is likely due to simulcast distortion from having more than one tower in close range. If the multiple towers on the system lie along a path that is within the directional beamwidth of the Yagi, your distortion may actually increase.
 

davenlr

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I am thinking about getting a Yagi Antenna in the 700 Mhz range for this system. Curious though if I can use two antennas for the same radio that way I don't sacrifice the other systems.
If you are talking about a 0db omni and a high gain yagi plugged into the same scanner with a combiner, it will probably work, but you will lose some signal on the omni from the combiner loss. You might even be able to use a regular T, if the yagi signal is a lot stronger than that coming in from the omni.

It will take some experimenting with the cable lengths tho, as you might hit a spot where they null each other out or are out of phase.
 
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