150 ft tower

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mancow

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No pics of the tower but the antenna is a 4 bay vhf at the top of a 150 ft water tower.

The radios are in a waterproof box locked in the bottom feeding via Proscan and WIN500 linked by wifi. It's like having a 150 tower in your back yard and is amazing what can be received. Even distant 800 MHz systems are pulled in on this thing due to the altitude. It was setup as a test to see what is causing RFI at the spot but I'm hoping I can keep it there for a long while.
And, no the power transformer is not close at all. In that pic it looks nasty but is really about 25 feet away or more.



 
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Rt169Radio

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Cool! How exactly are you able to listen to the scanners? Live feed?
 

mancow

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It's a repeater site I was working on but it didn't work out. The coverage wasn't exactly what was wanted so I installed the radios there to try to get a better idea of exactly what was going on. The repeater input was up in the high 158 range and there is a pager tower at 158.1 nearby that I think is blasting it pretty hard. I'm hoping I can just keep there there until something is ever decided on the use of the site. So far, at this point I doesn't look like it will be used.
 

mancow

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Unfortunately, no I don't stream them here. I can't abide by the rules here so I don't bother, at least not for this receive site. There is no way I would constrain the feed to only main dispatch channels. That would defeat the purpose of such a prime site to sniff out all the secret squirrel stuff. However, I am contemplating streaming the regular sanctioned stuff from my home but haven't got around to it yet.

I might post the direct Proscan feed address though later on once I am sure things have stabilized at the site internet wise. I have had a few outages lately that I'm trying to figure out.
 
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If your terrain is as pancake-flat as the rest of Kansas a DB224 up at 150' AGL should give you multiple counties of solid coverage. Might be time to beg/borrow/steal a SiteMaster and see what's going on.
 

mancow

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I am thinking of doing the next reasonable thing with a funcube dongle but I'm afraid that antenna will blow the thing to bits. I thought about using the preselector section from a Vhf spectra to get things a bit under control for Vhf but that would kill everything else. As it is now though, with the spectrum sweeper functions in the existing radios it's pretty neat to set one to scan and one to sweep and just wait to see what lights up. I can pretty much sniff out everything that transmits in town the second it keys up. I'm even getting 900 Mhz baby monitors and other crap from who knows where. One evening I was hearing a ham repeater on Uhf in Southern Missouri or maybe Arkansas. Plus, I can even hear ground comms from the KCI airport. I recently lost my nice wifi link but am working out a plan to get into another network that will be rock solid. My house is 1/4 mile away across a park with only one house in between. I had planned on getting some hi power wifi stuff to beam a link there but if this other thing pans out I should be set. So, what other stuff should I try to put in there? I contemplated an RF sensing switch on the antenna so I could use a remote Vhf rig controlled by Ham Radio Deluxe so I can actually transmit without toasting the receivers but I'm not sure how reliable that would actually be.




If your terrain is as pancake-flat as the rest of Kansas a DB224 up at 150' AGL should give you multiple counties of solid coverage. Might be time to beg/borrow/steal a SiteMaster and see what's going on.
 
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kb0nly

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1/4 mile? You don't need anything high power for a reliable wifi link at that close distance. A couple dish antennas that average around 20-25dB or a couple simple yagi's would do it. I have setup wifi links over 1-2 miles with nothing more than a standard linksys WAP and outdoor antenna.
 

mancow

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What type of wifi devices are you using? Do you know what power level they are putting out? I have some Chinese supposedly high power thing that should arrive tomorrow but the other one ended up being back ordered and they refunded me my money. I also built a 15 element yagi from some plans on the internet. If you think two of these would work then I might build another and try lining them up.
 

Astro25

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If you can get a couple of Motorola canopy PTP links (900mhz or even some old 5.2/5.7 stuff if you can pull LOS) you'd be in business. Hit me up on AIM if you decide to go the canopy route...
 
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I can regularly get a 100 mile radius as it is now.
Sorry, should've clarified - what I meant was "you should get multiple counties of mobile coverage on a repeater." Also I just re-read your OP and saw the bit about the 158 MHz pager clobbering a 158 MHz input frequency. If the pager is at least 500 kHz up or down from your input you can still make a repeater work with additional pass/reject cans in line with the receiver - instead of tuning the reject to the repeater TX freq you tune it to the pager freq. But for that to work you'd need to know if it was actual overload/desense or if the overall noise floor was being elevated by the pager, which is where the comment about needing a SiteMaster came from.

Either way, what you're doing now is still neat. I'd be tempted to put up sticks in additional bands up top and feed everything into a triplexer.
 

jim202

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It's a repeater site I was working on but it didn't work out. The coverage wasn't exactly what was wanted so I installed the radios there to try to get a better idea of exactly what was going on. The repeater input was up in the high 158 range and there is a pager tower at 158.1 nearby that I think is blasting it pretty hard. I'm hoping I can just keep there there until something is ever decided on the use of the site. So far, at this point I doesn't look like it will be used.

Your never going to make that site work with a high powered pager transmitter operating that close. Sure you could put in suck out cavities, but they are also going to effect your input signal.

Best bet is to go find another site at least a couple of miles away from the paging transmitter. Then you might have a chance to be able to make it work. I bet if you put a diode in series with your antenna and connected a DC voltmeter, you would see an interesting meter reading.
 
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