178 miles...???

[kayn1n32008]

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I belive the guy is SOL, 178 miles is just too far with out enhanced propagation.

 

[902]

Guess no one's ever done any UHF weak signal work...

I give up - WAAAY too much involved! Thanks for all the great input though.

DON'T GIVE UP!

Here's the deal - I used to be able to hear Barnstable County ("Cape Cod") very reliably when I was in NJ and they were on VHF. They were on the same channel as one of the local police departments, so I couldn't help it on my old Bearcat 210. It was not an everyday occurrence but I didn't have to put up a thousand foot tower or fly lots of aluminum to do it.

There are certain conditions that allow you to hear it, and, much of the path is along the Long Island Sound from you, so there is a VERY GOOD CHANCE you will hear them several times a year, especially in spring and fall when the days are warm and evenings are cool or still cold.

Get an 800 yagi antenna. There are a lot of them around at hamfests or on auction sites, or even in the garbage from time to time. Does not have to be fancy.

Get some good coaxial cable that does not have a long run. Something like 25 feet of LMR400 should be fine. If you find a scrap of 1/2" or 7/8" hard-line with the connectors, that's better. It's not hard to find.

Point your antenna 68 degrees. That's about East-Northeast.

Program the system(s) in. Let your scanner go.

Under the right conditions, and if you're not overwhelmed by noise or other co-channel stations, you WILL hear them. Like I said, not every day, but it probably will work several times a year. It's not impossible. Here's a not too bad explanation of the theory of why this is possible. It is not the same mechanism as low band skip. Something like it, but this is atmospheric, not solar-terrestrial.

Remember, you are NOT relying on line of sight in this mode - none of the previous discussions about line of sight propagation are relevant! I've moved a few times since my NJ days, but I am near the ocean again. It's not uncommon for me to hear (and talk to) stations 300 miles over water on UHF with a modest yagi up about 35 feet and much less effective radiated power than they would be running.

 

[GTR8000]

You'd have a hard enough time pulling in an 800 MHz signal well enough to make out anything intelligible over the noise floor on an analog frequency at that distance...much less a signal strong and clear enough to decode a trunked system's digital control channel. Maybe once in a blue moon when the conditions are perfect and you're experiencing a ducting event, but certainly nothing sustained.

Remember also that 800 MHz trunked systems are often designed and constructed with semi-directional or directional antennas that radiate in a specific pattern and coverage area so as to minimize interference with co-channel users (including frequency re-use within the same system over a wide area, as is the case with the MSP system). They don't just erect huge high-gain omnis on 300' towers that blast out a strong signal in all directions. Keep in mind also that with a trunked system, you not only have to decode the control channel (the toughest part), but you have to hope that all of the voice channel repeaters are operating at maximum efficiency, otherwise you're not going to track the system properly.

It's cool for people to encourage you not to give up, and to have fun trying...but at a certain point you have to acknowledge the reality of the situation. 800 MHz trunked system at 178 miles is just not going to happen.

 

[kayn1n32008]

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You'd have a hard enough time pulling in an 800 MHz signal well enough to make out anything intelligible over the noise floor on an analog frequency at that distance...much less a signal strong and clear enough to decode a trunked system's digital control channel. Maybe once in a blue moon when the conditions are perfect and you're experiencing a ducting event, but certainly nothing sustained.

Remember also that 800 MHz trunked systems are often designed and constructed with semi-directional or directional antennas that radiate in a specific pattern and coverage area so as to minimize interference with co-channel users (including frequency re-use within the same system over a wide area, as is the case with the MSP system). They don't just erect huge high-gain omnis on 300' towers that blast out a strong signal in all directions. Keep in mind also that with a trunked system, you not only have to decode the control channel (the toughest part), but you have to hope that all of the voice channel repeaters are operating at maximum efficiency, otherwise you're not going to track the system properly.

It's cool for people to encourage you not to give up, and to have fun trying...but at a certain point you have to acknowledge the reality of the situation. 800 MHz trunked system at 178 miles is just not going to happen.

Agreed. He wants to try and listen to a trunk system from the better part of 300km away. Not gonna happen. Not on VHF never mind 800MHz with out ducting or some other enhanced propagation.

 

[VE3CRO]

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Reliably listening to a Vhf signal at 178miles is next to impossible, never mind 800MHz.

I, and many others, reliably listen to the space station on VHF and regularly talk to each other using the ISS VHF/UHF repeater and it is a bit more than 179 miles away.

 

[GTR8000]

I, and many others, reliably listen to the space station on VHF and regularly talk to each other using the ISS VHF/UHF repeater and it is a bit more than 179 miles away.

Please tell me you are joking or being sarcastic. I would hope that as a licensed amateur operator you would know the difference between what we are talking about here and the example you've given.

 

[VE3CRO]

Please tell me you are joking or being sarcastic. I would hope that as a licensed amateur operator you would know the difference between what we are talking about here and the example you've given.

The remark I responded to is quite clear and my response is accurate and germane in that context. Please explain the problem you have with it.

 

[GTR8000]

The remark I responded to is quite clear and my response is accurate and germane in that context. Please explain the problem you have with it.

The discussion in this thread is about ground wave propagation, line of site monitoring between stations on the surface of the planet, not line of site from ground to air/space. Apples to oranges.

 

[kayn1n32008]

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Reliably listening to a Vhf signal at 178miles is next to impossible, never mind 800MHz.

I, and many others, reliably listen to the space station on VHF and regularly talk to each other using the ISS VHF/UHF repeater and it is a bit more than 179 miles away.

Yea, LOS, with a station has has little more than some atmosphere between you and it... Not anywhere close to being relatable to this situation... The guy is talking about receiving a land based 800MHz trunk system from 178 miles away from it. How is that even similar to working ISS either directly or through the crossband repeater? Now how far is the farthest TERRESTRIAL signal you can here with out a band opening?????

 

[VE3CRO]

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Yea, LOS, with a station has has little more than some atmosphere between you and it... Not anywhere close to being relatable to this situation... The guy is talking about receiving a land based 800MHz trunk system from 178 miles away from it. How is that even similar to working ISS either directly or through the crossband repeater? Now how far is the farthest TERRESTRIAL signal you can here with out a band opening?????

Your point holds some value when the ISS is directly overhead but routine communications take place as soon as it rises above the horizon. I fail to see the difference between working a "ground station" with an antenna on a tower and the ISS on the horizon. If I am missing something please enlighten me. Thanks.

 

[kayn1n32008]

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Yea, LOS, with a station has has little more than some atmosphere between you and it... Not anywhere close to being relatable to this situation... The guy is talking about receiving a land based 800MHz trunk system from 178 miles away from it. How is that even similar to working ISS either directly or through the crossband repeater? Now how far is the farthest TERRESTRIAL signal you can here with out a band opening?????

Your point holds some value when the ISS is directly overhead but routine communications take place as soon as it rises above the horizon. I fail to see the difference between working a "ground station" with an antenna on a tower and the ISS on the horizon. If I am missing something please enlighten me. Thanks.

Exactly ISS needs to be above the horizon. Second you are talking a completely differend band that has significantly different propagation characteristics. Thirdly the OP wants to listen to a system that: 1 is below his horizon and 2 is probably not engineered to propagate outside its intended coverage area very far. So really to use talking to/through ISS is comparing apples to pineapple. Not in any way relatable at all.

 

[VE3CRO]

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Exactly ISS needs to be above the horizon. Second you are talking a completely differend band that has significantly different propagation characteristics. Thirdly the OP wants to listen to a system that: 1 is below his horizon and 2 is probably not engineered to propagate outside its intended coverage area very far. So really to use talking to/through ISS is comparing apples to pineapple. Not in any way relatable at all.

"Reliably listening to a Vhf signal at 178miles is next to impossible, never mind 800MHz."

Is the remark I was commenting on. Just that statement and no other. I supplied an example that contradicts the "VHF signal" part of that statement. If you see my remarks not related to that statement then there is nothing I can say to change your mind and there is no point in carrying on a discussion at cross purposes. Apples and Oranges. My point is that as long as there is line of sight, no matter how high the tower(s) needs to be to achieve it, communication is possible.

 

[LIScanner101]

Guys, guys - PLEASE! I don't mean to get everyone all riled up !
I MAY try this just for kicks, just gotta get hold of a few items...!

 

[kayn1n32008]

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Again, the OP is trying to listen to a system that is NOT LOS! If you are high enough anything IS possible, I stand by my (modified) comments, with out a band opening/ducting it is virtually impossible to listen to a terrestrial VHF/UHF/800MHz signal from a terrestrial location 178mi away.

 

[VE3CRO]

Guys, guys - PLEASE! I don't mean to get everyone all riled up !
I MAY try this just for kicks, just gotta get hold of a few items...!

LOL as the younger folk like to say.
I wasn't aware that we were getting riled up. Perhaps differing in opinion but it would be a boring world without that.

Once, a long time ago, I was involved with getting receiving antennas as high as possible with pibals (pilot balloons) filled with helium. It was rather amazing the distance from which we could receive signals at 500+ feet (it takes A LOT of helium to hoist wire that high) but really quite impractical. Experimenting is great fun. Let us know how you make out if you proceed.

 

[902]

Guys, guys - PLEASE! I don't mean to get everyone all riled up !
I MAY try this just for kicks, just gotta get hold of a few items...!

Nah, everybody is having fun! This is almost like rooting for your favorite sports team - some of us say no, some of the rest of us say yes. The "No" guys have a valid point - they have to qualify it with an "under normal conditions." They're right. Absolutely no way under normal conditions. But band openings are more common than you'd think.

Whatever you do, as long as you enjoy yourself and your hobby, it's all good.

 

[LIScanner101]

I WILL try it! I will!

I WILL