Two Scanners.... One Antenna....

[N4JNW]

Ok, got a question about sharing an antenna between two scanners..

I have a RadioShack Pro-2055, and will be adding a Pro-2096 to the stack this Tuesday. I have a ScanTenna outside, with one coax coming in.

I want to share the scantenna between the two scanners.

I have in hand a couple of BNC "T" connectors. Would one of these do the trick, or would I need one of those multicouplers??

I figure I can plug the antenna into the BNC T, and then plug each scanner into the remaining openings, with some BNC jumpers..

You guys think this will hold water? I think it should, but I'd like some more opinions... Thanks!

 

[N_Jay]

A BNC "T" will cause an impedance mismatch (Minor problem),
will cause the cabling to be a "random" network, with random results,
and will allow any noise from one receiver (IF or MicroP leakage) a direct path to the other (Not good).

A multicoupler will fix #1 and #2, and greatly reduce #3

 

[N4JNW]

Ok, With a multicoupler, the one's I've seen have 4 or more outputs... If I connected two scanners to two outputs, what would I need to do with the other outputs? Just leave them open, or would I need to terminate them somehow to prevent RF leakage? Or would that even be a problem?

 

[SLWilson]

Bnc - T

N Jay is more than probably right. But, I've been running a Pro2096 and a Uniden BC780XLT with the T splitting the coax and going to both for quite some time. I haven't noticed any degrading of the RX on either scanner....

Our fire department has 5 scanners running off of a single antenna, but they did use a standard antenna spliter on the coax....

Steve/KB8FAR

 

[Junior08]

Get yourself a 4 port Stridsburg multicoupler. No need to do anything with the "open" ports. Be sure to get the ACTIVE one, not the PASSIVE one. They can be found here;
http://www.scannermaster.com/4_Port_Multicoupler_p/02-530557.htm

 

[N4JNW]

Have you noticed one scanner interfering with the other? Can you notice any difference when you use the T splitter and plugging one coax into the scanner while recieving something?

If the T will work good, I'd be money ahead to use it. I'm not planning on monitoring things a hundred miles away. In all honesty, the things I monitor can be pulled in with an indoor antenna. But the ScanTenna just gives me signal clarity... and I like clarity!

 

[SLWilson]

Nothing really...

Have you noticed one scanner interfering with the other? Can you notice any difference when you use the T splitter and plugging one coax into the scanner while recieving something?

If the T will work good, I'd be money ahead to use it. I'm not planning on monitoring things a hundred miles away. In all honesty, the things I monitor can be pulled in with an indoor antenna. But the ScanTenna just gives me signal clarity... and I like clarity!

I've not had any problems at all. I can't hear the unit that is "scanning" while the other one is stopped (interfering or "clicking" or anything) on a freq that is active/talking.

Like I said, I can't even hear the weather stuff on the 2096 (couldn't out of the box) but the Uniden hears everything fine. We're a good ways off from ANY of the weather freq sites (We're in Gallia County in SE Ohio. The closest weather broadcast is in Athens County. They even put in a 1,000 watt transmitter. Didn't help our county....I use the weather sites to judge how well a scanner hears (at least here in our town) and there is no difference WITH or WITHOUT the T in place....

Steve/KB8FAR :wink:

 

[N4JNW]

I'll probably try the T first, and see how my scanners like it, and if it don't work to my liking, I'll try to scrape up enough to buy a multicoupler.

My Pro-2055 shines on VHF and UHF. I'll be using the 2096 mostly for Trunked 800 stuff, and Kentucky State Police Digital. They're UHF, but they boom in on my Pro-96 like the transmitter is down the road here.

Time will tell. Thanks for the responses and help guys.

 

[w8jjr]

Ok, got a question about sharing an antenna between two scanners..

I have a RadioShack Pro-2055, and will be adding a Pro-2096 to the stack this Tuesday. I have a ScanTenna outside, with one coax coming in.

I want to share the scantenna between the two scanners.

I have in hand a couple of BNC "T" connectors. Would one of these do the trick, or would I need one of those multicouplers??

I figure I can plug the antenna into the BNC T, and then plug each scanner into the remaining openings, with some BNC jumpers..

You guys think this will hold water? I think it should, but I'd like some more opinions... Thanks!

It is quite easy to physically connect one antenna to two scanners. There are a variety of T sockets and plugs on the market. However, if you try to connect two scanners in parallel to the same antenna, the results are nearly always disappointing. The reason lies in the tuned input filters found in most scanners. These are automatically tuned to the receiving frequency, and only on that frequency the input impedance of the scanner is 50 Ohms. If the inputs of two scanners are connected in parallel, the scanner which is tuned to for instance to a UHF frequency forms a short-circuit for the other scanner tuned to a VHF frequency. There is also another problem. Receivers have at least one internal oscillator, and there is always some leakage which appears at the antenna input of the scanner. Since the level of these signals is sometimes in the order of that of a strong radio station, these spurious signals (birdies) from scanner one are received by scanner two and vice versa. This leads to unwanted whistles, stops during scanning and can even cause blocking. The only way to correctly connect two scanners to one antenna is via a splitter. The received energy from the antenna is split in two. Although since each set notices a signal drop of 3 dB, in most cases this slight loss in signal strength is hardly noticeable. It is much more important that both scanners cannot "see" each other, so varying input impedances and oscillator signals cannot cause mutual interference and signal loss. This "isolation" between the scanners needs to be at least 20 dB. Most cheap "TV splitters" cannot be used with scanners They contain only 3 resistors which give to much loss and minimal isolation. Other types , labelled 0 - 1000 MHz, 22 dB isolation, contain a transformer but extensive research shows that the required isolation of 20 dB or more starts far above 100 MHz. Also the signal loss on frequencies in the UHF bands is high.

Try something like http://www.stridsberg.com/mca204a.htm

Unfortunately you won't find these at Radio Shack, however these are the splitters you are looking for. They protect each rig from the other(s) and come in passive and amplified models covering HF, VHF, UHF, and 800 MHz in different models.

 

[W4KRR]

For a much better solution to the BNC "T" connector, and a much cheaper alternative to the Stridsberg products, try the Electroline Multicouplers. They are made for the cable TV industry, and are rated up to 1000 MHz. They use type F connectors. A 4 port model can be had for around $70, and an 8 port model for around $80. You can find them on eBay, or from here:

http/www.cabletvamps.com/Products/EDA-UG2402.htm

I have an 8 port active model; that is, there is only enough built in amplification to overcome losses in the splitter network. I can't tell the difference between these and the Stridsberg models, and the Electrolines cost a lot less than the Stridsberg models.

 

[Caesar]

i use a T connector myself though i use both radios on 800mhz (trunking) I've never had any noticeable problems.I would try it and just save for a multicoupler so later down the rd if you want to add a couple more radios to the scanner you can with no problem (4port or 8port)

 

[K8PBX]

... a much cheaper alternative to the Stridsberg products, try the Electroline Multicouplers... I can't tell the difference between these and the Stridsberg models, and the Electrolines cost a lot less than the Stridsberg models.

I agree!

I've been using the Electroline EDA-UG2402 (4 port) and EDA-UG2802 (8 port) for some years now and remain pleased with their performance. Since I use RG-6QS for most all my receive antennas, the F connecors work out really well too. By being patient on eBay, I picked up mine for around $20 or less.

 

[LordJ]

I too have an electroline EDA-UG2402 (think I paid around $40 delivered) and I am very pleased with the results. I am running 4 radios off of it... I would suggest you try that and not the 't'

 

[mikeATtleccdotnet]

75 ohm stuff is not by any stretch of the imagination, 50 ohm two way LMR Equipment.

-Mike

 

[N_Jay]

75 ohm stuff is not by any stretch of the imagination, 50 ohm two way LMR Equipment.

-Mike

Hu????

 

[GrayWolfSA58]

Get yourself a 4 port Stridsburg multicoupler. No need to do anything with the "open" ports. Be sure to get the ACTIVE one, not the PASSIVE one. They can be found here;
http://www.scannermaster.com/4_Port_Multicoupler_p/02-530557.htm

Stridsburg multicoupler is the way to go..

 

[tonsoffun]

Stridsburg multicoupler is the way to go..

Save yourself some large dollars and go with the Electrolines as other in the post said. I've done numerous testing between both companies multicoupler and found no difference at all.
Take care

 

[bonus1331]

What type of connectors are on the Electrolines? I.e. BNC, N, etc.
Thanks

 

[tonsoffun]

What type of connectors are on the Electrolines? I.e. BNC, N, etc.
Thanks

Hi David,
The Electroline multicouplers use F-female connectors. There is a huge amount of adaptors available to match up for what you need.
Take care

 

[K8PBX]

Electroline units use F-connectors.

More info HERE.