Curiousity Question...

[btritch]

I have a curiosity question....I can go about 50 miles from my hometown and I can still hear my hometown police and fire departments talking...however, when I am at home on my base or mobile antenna I cannot hear the places I am at when I can still hear my hometown. Could this be because of the difference between transmission power or something else that I'm doing wrong. I always thought that if I could hear us there I could hear them here.. That doesn't work, Can anyone tell me why, I'm just wondering...

Thanks!

 

[ka3jjz]

There's not enough information here to form a hypothesis. What scanner/antenna are you using mobile and at your home? Where are you (city/county/state will do fine)? What system or frequencies are you using (check the database and supply the URL)? With your home setup are you using an outdoor antenna? Which one? Coax type? The terrain can play a role, particularly in a hilly or mountainous area.

73s Mike

 

[Don_Burke]

I have a curiosity question....I can go about 50 miles from my hometown and I can still hear my hometown police and fire departments talking...however, when I am at home on my base or mobile antenna I cannot hear the places I am at when I can still hear my hometown. Could this be because of the difference between transmission power or something else that I'm doing wrong. I always thought that if I could hear us there I could hear them here.. That doesn't work, Can anyone tell me why, I'm just wondering...

Thanks!

There are several possibilities.

For whatever reason, your hometown police department is putting a useable signal 50 miles away. This could be a side effect of putting a good signal in every place they actually need it or it could be an overdesign of the system.

It is also possible that the place 50 miles away simply has a great signal path to your hometown's system.

Your base antenna may not have enough height to hit the out of town system.

 

[btritch]

More Info To Scanner Diagnosis Problem

Here is my home system.... http://www.radioreference.com/apps/db/?ctid=135 and I can hear them from here http://www.radioreference.com/apps/db/?ctid=175 and here http://www.radioreference.com/apps/db/?ctid=145 but I can't hear these two from my home system...I have two different Radio shack scanners, a mobile and a base and neither of them will pick them up from here but they will both pick us up from there... and I have just a regular mobile antenna like this: http://cgi.ebay.com/NEW-MINI-MOBILE...ryZ48692QQssPageNameZWDVWQQrdZ1QQcmdZViewItem and an older base antenna it's about 20 feet off the ground off the side of a tower.. Could it be the tower interference throwing it off. Here lately though I've just had it hooked to my antron CB antenna and it's about 60 feet up, it's picking more up but it's more of a direction toward memphis instead of west....
On The scanner antenna I'm just using regular RG58 Coax cable about 75 feet long that's split to two different rooms. It picks up locally great but not so great distantly...On the CB antenna I've got the biggest cable they make, Low noise reduction cable.. I'm in Paragould/Greene County Arkansas trying to hear Walnut Ridge/Lawrence County Arkansas and Cherokee Village/Sharp County Arkansas I can't do it from here but I can hear us from there.. Just to the west of town though are the Crowley's Ridge Hills, I thought that threw it off before but I can get us on the other side, if that were the case I wouldn't think this would be possible, I could be wrong, anyways, I have supplied all of the links I could find to help you with a diagnosis. Hope this helps! I look forward to hearing from you!

 

[hoser147]

are you using a PL tone what type of Radio Shack scanners?

 

[btritch]

I'm not even sure what a PL tone is unless it's the page tone but no, not that I'm aware of, Be a radio shack PRO 2051 for the base and just another basic pro for handheld. I'll let you know what kind if you need to know, I'll have to go out in the truck and look..

 

[btritch]

The hand held is a pro 82

Handheld = Pro 82
Base = 2051

and I'm not sure what PL is...I don't think I have it though.
What is it and I'll know..

 

[ka3jjz]

I see 3 issues right away - using a CB antenna to hear freqs in the VHF and UHF range is going to be highly inefficient. And using 75 foot of RG58 on VHF frequencies is a real issue - the loss is not so great as it is on 800, but still, you're needlessly sacrificing signal strength. Using the splitter on top of this mess is probably costing you another 2 or 3db worth of signal.

Time to consider improving the base situation - at a minimum, a ScanTenna fed with 9913 cable (with a 75 foot length, that's a tad too long for plain old RG6). There will likely be some interaction with the tower if it's too close, so you may end up having to put the antenna on the side which favors your desired direction. The splitter may be OK, but a distribution system, such as those sold by Electroline, is far preferable, since it has a small amplifier to overcome the loss when a signal is split n-ways.

73s Mike

 

[btritch]

availability

Where are these things available at and about what costs?

see that's the thing, You're talking about the inefficiency of using a CB antenna. Well at this moment, it's better than the actual scanner antenna to give you an idea of how horrible it is..

 

[ka3jjz]

And you can, and should do better - take a look at this link (just click on it and you'll be taken to the article...)

http://wiki.radioreference.com/index.php/Scanner_Antennas

I see Antenna Warehouse is out of stock on the ST2 ScanTenna, but there may well be other suppliers. Just be careful here - some cheaper ones won't stand up to the wind if it really blows. There have been other threads on this topic in this forum, so I'll leave you to search for them. There is a pretty inexpensive fix for this problem that you can apply before you put it up. The Diamond D130J discone is a favorite of many, but it's more expensive than the Scantenna. You will probably read about a RS antenna that sort of resembles a bunch of dipoles strung together, but I hear it's better as an indoor antenna; it's not built well enough to take a beating outdoors.

Also on this article are coax suppliers and filters. The PRO-2051, being a GRE scanner, may well overload somewhat from nearby pagers and such, so some filtering may be necessary.

I have no idea about shipping costs, but the suppliers in this article should be able to quote you if you decide to make a purchase. I'm sure there are other suppliers not on this article, but it's a good start. Forget about adding drop amps, ect. for the time being and stick with getting the right antenna and coax first.

73s Mike

 

[mjthomas59]

This certainly is a strange situation. Your county isn't as high power as say Sharp County EMS (100 watts vs. 250watts) but by the same token Greene County Sheriffs office operates multiple repeaters which i would think would make it easier to monitor.

Radio design, antenna design, tower height and location, and terrain all play a huge role in what you can monitor and from where. And that goes just as much for your own personal/home setup as it does for the public safety system you are trying to monitor. Greene County, by running multiple repeaters, isn't designed for omnidirectional coverage as say Sharp County EMS which is running one tower which has to cover the county.(This is what i've gathered from a quick look at the fcc licenses). The single tower in Sharp County is most likely extremely high in the air and with a good high gain antenna. Your local area probably isn't as picky because they have multiple tower sights so getting the signal out 50 miles in every direction isn't a priority, and the coverage area of each tower they have is fairly limited in the grand scheme of things.

I'm sure there is a way to atleast get the elevation of a given tower site using the FCC listing and gps coordinates but i'm not that interested to figure it all out.

Hope that helps a little!

 

[mjthomas59]

Ok so i am a little interested and didn't realize how easy it is to find this information.

This is the listing for the tower in Sharp County for the EMS, site elevation 265 meters, tower height 55 meters.

http://wireless2.fcc.gov/UlsApp/Uls...=1223879&pageNumToReturn=1&archive=&x=12&y=11

Listing for sheriffs office in green county to their highest antenna/repeater

http://wireless2.fcc.gov/UlsApp/Uls...eNumToReturn=1&keyLoc=15387616&licKey=1264471

Elevation between these two with tower height is about 60 meters different(what i would call a pretty big deal), plus 150 watts more juice is coming from Sharp County which makes it logical as to why it could be monitored from most likely anywhere in the northeast part of the state.

Here is the tallest antenna for Lawrence county sheriff
http://wireless2.fcc.gov/UlsApp/Uls...=1262823&pageNumToReturn=1&archive=&x=17&y=12

Basically it would make perfect sense if you were having the opposite problem. butAfter re-reading your initial post i can say that there is absolutely no logical reason for your dilemma I'd go with the suggestions above and get a better base antenna and coax to go with it.

 

[btritch]

So, What you're saying is that since Greene County has more repeaters than Sharp county this would make greene county easier to pick up further out than Sharp county as opposed to the signal strength determining the distance. Right? Also, Why would the county need more than one repeater site, NOTE, Paragould Fire Department has one frequency however looking they have a tower site in Greene County and A tower site in Jonesboro and Craighead county. Why would They need one in jonesboro That's the question....But the reason I can hear Greene County Further than Sharp/Lawrence County is because of the multiple tower sites to which I have no idea why the do this but anyway, Thats the general idea? Right?

 

[btritch]

For Instance, This shows the tower locations, Why there is one in Craighead County I have no Idea, However, I can Pick them up further out than I can The County S.O. I guess this explains why: http://wireless2.fcc.gov/UlsApp/UlsSearch/licenseFreqSum.jsp?licKey=1190940
Any Other Suggestions...