Riley County

[skatertj]

So,I'm trying to listen to Riley county fire department because I plan to volunteer with them. I live on Fort Riley so i should be receiving these frequencies with ease, but im not.... I have had my radio tuned to Ogden's tower which is 155.925. Everytime i would recieve a signal, it would come in with static. I currently have it tuned to the CT tone and have yet to see if it comes in with static cause they havent talked on it yet.

Background: I am running a pro-2055 with a radioshack antenna but it isnt the best. It looks just like this one Magnet-mount mobile scanner antenna - RadioShack.com but is older, i believe because it is full black and the screw on the base where the antenna mast and base meet has became rusted. I want to get a new antenna and am hoping it will give me better signal.

Heres my question. If i do join them, they will give me a handheld radio. Itll pick up signals on the military base and i know this because I know of a guy who was on base and got a call. Why is my scanner not picking this up? and when it does, why coming in really badly?

 

[n0lqt]

It could be a number of things wrong. A little detective work is needed. First, check the weather channels. Do you get a solid signal on that? If not, then there could be an issue with the radio itself. Next, do you still have the little telescoping antenna that came with the radio? Try putting that on and listen for a while. If you get a good signal, it might be that there is an issue with the antenna (broken center conductor on the feedline, shorted connections on the base due to rust or just general gunk, etc.) Next, move the existing mag-mount to a couple of different locations. You could have placed it in a “null” spot or there just isn’t enough of a ground plane for it to work against. Those mag-mounts were built to work against the metal ground plane of the roof or trunk of a vehicle and that would help create a “virtual dipole.” A way around the latter is to put a 18 inch square piece metal under the antenna.

When you do replace the antenna, get the best feedline you can afford. You won’t regret it ever. The feedline is normally the “weakest link” in almost all installations. The higher the frequency and the longer the run, the more loss you have. At 800 MHz., the loss can be more the 90% of the signal from the antenna...

 

[skatertj]

Feedline? You lost me there haha. I have been scanning for about 3-4 years now but that lost me. I just brought it into the house today and for tomorrow to see if the telescopic antenna does better. I usually get good signal on the weather unless im in a horrible area with alot of trees around.

Tonight, i also figured out the antenna was spray painted black so i took the old black paint off and sand it down to see if itll do better once its back on the car.
Thanks for the reply also!

 

[mancow]

Feedline as in a line (wire) that feeds a signal to the scanner. He's simply talking about the coax cable that leads from the antenna to your radio.

 

[skatertj]

Ok i understand now! Also, having the scanner in the house with the telescopic antenna is receiving MUCH better on two other frequencies that hardly EVER come in when the scanner is in my car and connected to the RS mag antenna. Any suggestions to help with in car? I thought about getting a Larsen Tri-band??? Good idea?

 

[mancow]

It could simply be that the antenna, cable, connectors or any portion of that system is bad. It might be worth investing in a new one. It sounds like you should be hearing it well in the car so I would suspect your antenna system is bad.

 

[skatertj]

Ok, so the only frequencies i care to listen to lie between 150 and 480. Would a 14th wave be ok? and whats the best cable to us? Not mount wise but cable type?

 

[n0lqt]

Sorry about that, Yep, "feedline" is "coaxial cable" but not all feedline is coaxial cable. I'm a Ham and I used some types of antenna lines that are not coaxial cable, ladder line, flat line and the like. For your purposes, coax is what you need though.

IF all you ever intend to listen to is VHF-Hi band from within Riley County then RG-58 or RG-8 minifoam will be fine. Losses at 150 MHZ in either one of those are fairly small, for shorter coax run length. You can even use RG-6SAT grade cable with the F Connectors cut off and the correct ends put on for distances of less than 30 feet. It is 75 ohm impedance (you would want 50 ohm normally), but the loss is so much lower at the higher frequencies even with the mismatch loss. The problem is going to be with more and more agencies switching to or needing to work with the 800 MHz bands. Kansas has the KSICS 800 MHz P-25 digital system mostly in place now. Pottawatomie County right next door to you has over 2 dozen coordinated talkgroups on KSICS now. Shawnee County in in the process of switching to it. Wabaunsee County is 800 MHz already. The buzz-word in Public Safety Communications for the last few years has been INTER-OPERABILITY.

For a home system, consider using a lower loss coax like a Belden 9913 or something similar. I used 1/2 Andrew heliax on my system, but I also have almost 100 feet of feedline length to deal with. (my "top" antenna is about 80 feet up the tower beside my house), so for me low-loss is a must. I’ve got over a thousand bucks tied up in various monitor radios and antennas, why skip on the feedline?

 

[skatertj]

Well i plan to only stay within 150 to 470. Right now, i dont have any 800mhz's programmed to the scanner. Would a rg-58 or rg8 be better? And is a 1/4th wave gonna do fine?