2 scanners one antenna

[cowboymike1971]

I have a question. I was looking to see if I could run 2 of my scanners from my one outdoor antenna using a splitter. I don't really have the money right this second for a stridesburg multi-coupler. Al though I would eventually like one. Is it possible and ok to use a TV style splitter? Like a digitial type. i have seen them at Radio Shack before and Home Depot. The freq range on the back of some I have seen says something like 25-1300 or something similar. Are these ok and decent to use??? I hope so I really would like to get my BC 9000 up and running again. Thanks

 

[N4JNW]

Yes.

You can split your one antenna coax to run 2 seperate scanners. BUT, there is a catch..

If you split with a TV type splitter, that has more than 2 "outputs", say your splitter is a big one, with like 5 places to plug into.

You'll want to terminate the other open connectors to minimize signal loss. Granted, if you're going to be monitoring decently strong stuff, then you won't have to fool with terminating the open ones.

I have done this many times with my scantenna outside, with very acceptable results for me.

 

[iMONITOR]

This questions comes up a lot on RR, and it always turns into a big technical fiasco about loss, impedance, gain, etc.

The simplest, and most inexpensive solution will work. Something like this:

http://www.grove-ent.com/SPL2.html

There are much better solutions, and progressively cost more. But it doesn't hurt to try any of them. That's half the fun, is experimenting. Some users on RR have had remarkable results from concoctions that would make a communications engineering fall out of his chair laughing!

 

[N4JNW]

This questions comes up a lot on RR, and it always turns into a big technical fiasco about loss, impedance, gain, etc.

The simplest, and most inexpensive solution will work. Something like this:

http://www.grove-ent.com/SPL2.html

There are much better solutions, and progressively cost more. But it doesn't hurt to try any of them. That's half the fun, is experimenting. Some users on RR have had remarkable results from concoctions that would make a communications engineering fall out of his chair laughing!

You're right.. Scanning is a hobby where you don't have to go by the book..

Gain and Impedance and stuff when calculated correctly, might make for a somewhat better setup, but personally, I couldn't care less about it.

I'll worry about gain and fine tuning when it puts my scanner in harm.

Whatever happened to cramming a coat hanger in an RCA jack and "going with it"?

Understood, antenna technology has came a long way, and a good antenna set up is the key to monitoring, and in a transmitting situation.

I know someone will chime in... Being a ham, I should know this, but I'm a dummie and don't.. But there is a formula or something floating around that calculates how much power you need to transmit to increase the S-meter reading. Once the S-meter gets so high, I think you've got to multiply your power or something each time to get one more S-unit.

So 5 watts may give you S3, but in order to have S6, you'd have to transmit at 50 watts, and to get S9+ you have to transmit so much more power or something like that..

Probably fixing to eat crow again.. *ties bib*

 

[cowboymike1971]

RE: 1 antenna 2 scanners

I guess my local Radio Shack would have the connectors I need to go from the splitter to the BNC? Is it F connectors? I'm not up on all the connections.

 

[iMONITOR]

I guess my local Radio Shack would have the connectors I need to go from the splitter to the BNC? Is it F connectors? I'm not up on all the connections.

F connectors is what Grove sells, with BNC/F adapters. I have seen some splitters with BNC connectors on them, but the price starts to go up.

 

[tneff]

I am using a homebrew dipole( look in the wiki) a Pro-2055 , and a BCT8, I tested with a good quality splitter and without. Without being using a BNC T , I got a little better reception using the T. If I add anything else to the system I will have to boost the input, if your only using 2 scanners you may give this a try and see how it works for you. I monitor 450-460 , and 800-868 using this setup with very satisfactory results.

 

[cowboymike1971]

Re: 1 antenna 2 scanners

well i need some kind of adapter to turn the splitter connections into BNC style. because my antenna coax is BNC style. also where can i get two small sections of coax to go from the splitter to my scanners? both with BNC connections on them. Small runs, like 1-3 ft. My scanners are not at all far apart.

 

[tneff]

cowboymike1971 , if you want to try a BNC T setup. Shoot me an e-mail and I'll donate one a few connectors for the cause.

Here is a pic of the setup with a BNC T

 

[benjaminarthurt]

I am using just a regular wideband tv splitter (radioshack's should have freq range listed mine does) and a couple short rf cables.

local radio shack should have all the parts. If you like PM me I can give you the part numbers I am using.

I am using a 4way splitter (1 in 4 out) in to a 2 meter 1/4 wave ground plane antenna about 40 feet off the ground (3/4 wave on 440 how easy) I can hear radio systems 50 miles away in either of those ranges. It did even better when I had it on the discone.

As long as you don't mind spending 30 bucks on a few cables adapters and splitters then I would give it a try.

 

[kb2vxa]

Hi guys,

Better late than never I suppose so let's tie the ribbons on this thread.

"As long as you don't mind spending 30 bucks on a few cables adapters and splitters then I would give it a try."

WAY too much money for what he wants to do!

"...if you want to try a BNC T setup..."

A particularly sloppy way to do it. No isolation between scanners means one can easily interfere with the other.

"http://www.grove-ent.com/SPL2.html"

Take a closer look at the little thingy in the middle of the picture. It looks a lot like a TV splitter doesn't it? Now we get to the meat of the matter, a plane Jane splitter works as well as any other including those horribly over priced Stridesburg units, they all have the same little coil inside. The down side is it splits the signal quite literally, splits it in half so you have half the signal going to each scanner, a 3dB loss. There are 3dB gain active splitters that make up for it but you'll pay the price in dollars.

Errata;
"But there is a formula or something floating around that calculates how much power you need to transmit to increase the S-meter reading."

Consider me chimed in. The formula tweaks the mind of the not so technically inclined so the simple explanation is 3dB equals one half S unit. Since there is no such thing as a calibrated S meter it becomes irrelevant. What is important is the relationship between decibels and power and again the formula tweaks the mind, I suggest getting a chart or a calc program for the computer. The better ones calculate just about every measurement you'll encounter in radio communications.

A simple rule of thumb is doubling the power increases the signal by 3dB or one half S unit. In other words no matter what the power level in order to go up by that puny amount you have to double the power. By the time you get to a kilowatt things start getting ridiculous and you start wondering if that Ameritron AL811A is really worth spending all that money. Never mind paying the electrician to install the 230V line and running up the electric bill, you'll appreciate antenna gain a whole lot more.

 

[MarcTheHague]

If you are looking for a good solution, buy the RF-SYSTEMS SP-3.
It sets you back 100 Dollars, but it is worth the money.

With this toy you can connect 1 radioscanner to 2 antennas, or 2 radioscanners to 1 antenna.

http://www.rf-systems.nl/direct/N_frame.html?http://www.rf-systems.nl/direct/N_home.html

Marc, The Hague, The Netherlands !!!