How To Cut Down On Interference Between Radio's...

[btritch]

I have two radios...A RS 2025 and a BC147XLT which are both analog scanners, However, I have one scantenna about 50 feet in the air and LMR 400 Cable Coming off it, Then I have it adapted down into RG 6 going into a cable splitter and then RG6 out from there to both radios...The BC 147XLT only has 16 channels so it just picks up locally here in town, However, the RS 2025 has 1000 channels and it picks up everything within about a 70 mile range pretty decent..Good enough to hear anyways, But with both radio's on at the same time in two different rooms with the BC147XLT being the farthest away from the splitter and the BC2025 being closest the BC147XLT will run all over the RS 2025, Interfence on all the channels, when someone local is talking on say 151.040 MHZ on the BC 147 XLT they will be coming in on like 158.990 MHZ etc... on the RS 2025. With one of them turned off though the other one will work like a top, not a problem or defect one that I have noticed, it only seems to happen with both of them on AND it only happens in that order.. The RS2025 has NEVER interfered with the BC 147XLT.. It will only happen in that particular order..Has it got to do with it being the farthest away and instead of splitting up the splitter it just goes straight into the other scanner or something? What will cause this and what can I do to fix it or at least fix the interference amongst the two anyway...I have tried numerous splitters and different types of splitters as well.. I've tried satellite splitters, cable splitters, radio shack splitters, I've tried different brand names, Different MHZ such as 900, 1000, 1200 etc...None of those seem to make much of a different at all in the way that the interference happens..Could it be the type of cable run etc. or is it just going to happen and something I'm going to have to get used to and live with, I've researched and tried tips and tried everything I could think of and basically ran out of options so my question is Does anyone have any ideas or suggestions on how to fix the interference problem or anything else? What could be causing it, that bad anyway? Does anyone have any ideas or tips, suggestions, etc. on what to do or try to do to solve this problem? Any help will be appreciated, Thanks!

 

[delta_p]

I approached a related problem by trying a Stridsberg active 4-port multicoupler which fixed it, sort of....http://www.radioreference.com/forums/showthread.php?t=102811

The main fix for the scanners chattering with each other is the electrical port-to-port isolation from that multicoupler. However, now the weak 2 meter signals come in with so much static they can't really be listened too. The passive coupler (a wilson 800 Mhz) does better for those. There's only one of those weak HAM freqs I ever listen to and now I am thinking of setting up the old passive coupler as a quick connect for just when I want to listen. Every other frequency band I listen, 2 meter included, is perfect.

I am now wondering if the second scanner loaded on the passive coupler helped the 330T in receiving which I just eliminated with port-to-port isolation?


It may be worth a separate scantenna and some LMR dedicated to each scanner. Probably a lot cheaper than the stridsberg just for it's port-to-port isolation.

PP

 

[zz0468]

I don't know what the mixing scheme is on either of the radios, but it may be possible that the RS 2025 is receiving an intermediate frequency of the BC 147. The likely path could be leakage out the antenna port of the BC 147, and into the antenna port of the RS 2025.

If this is the case, there are several things yoou could try... one would be to run separate antennas. In fact, you could try it temporarily and see what happens. Another possibility would be to use a splitter that provides more isolation between ports. Another possibility could be to add an amplifier between the splitter and the BC 147, then pad down the extra gain. This would have the affect of providing a very high degree of isolation of leakage coming out of the BC 147 antenna port.

Its very difficult to provide anything more than an educated guess given a fairly vague description of the problem. But based on what I'm understanding, the things above are where I would try first.

 

[btritch]

Or

Or since it's local and really doesn't require a whole lot to recieve on the 147 I COULD just use the original motorola plug antenna and just use the scantenna and dedicate it to the 2025 and do away with TWO problems, Long runs and a splitter... What do you think? Would that work ok? or better? or best?

 

[zz0468]

It's free to try it. So... try it.

 

[thewenk]

Or since it's local and really doesn't require a whole lot to recieve on the 147 I COULD just use the original motorola plug antenna and just use the scantenna and dedicate it to the 2025 and do away with TWO problems, Long runs and a splitter...

Sounds lik a winner to me.
Dave

 

[N4GKS]

Try plugging both units into different sockets. Also use ferrite beads on the ac cords.

 

[btritch]

Try plugging both units into different sockets. Also use ferrite beads on the ac cords.

Ferrite beads? Different Sockets? They're in two different rooms already on two different outlets and on two different coax's with a splitter in the middle that only has two sockets... I'm not quite sure what you mena by ferrite beads though...Can you explain?

 

[af5rn]

Ferrite beads? ... I'm not quite sure what you mena by ferrite beads though...Can you explain?

Sounds kinky to me.

Maybe you don't want to know!

 

[N4GKS]

Ferrite beads? Different Sockets? They're in two different rooms already on two different outlets and on two different coax's with a splitter in the middle that only has two sockets... I'm not quite sure what you mena by ferrite beads though...Can you explain?

http://en.wikipedia.org/wiki/Ferrite_bead

 

[Grog]

Sounds kinky to me.

Maybe you don't want to know!

I know what they are but I thought the same thing anyway :lol:

 

[btritch]

NOW I know what they are! I knew what they were I just didn't know what they were called...!!! I do now but I wouldn't know how to install them inline..

 

[N4GKS]

NOW I know what they are! I knew what they were I just didn't know what they were called...!!! I do now but I wouldn't know how to install them inline..

http://www.orbitcast.com/archives/xm-modifications-for-fcc-compliance.html