Splitter for running 2 scanners/one antenna

[cowboymike1971]

Hello, I now run 2 scanners side by side ( BC 780 and a BC 9000) from one ground plane antenna on a 20 ft mast. I am going to upgrade my cable this weekend and I wanted to upgrade my splitter as well. I believe I am losing signals due to its setup. Its a "Y" type splitter that splits off the main incoming cable then runs to the back of each scanner so both can run simultaneously. Is there a cable TV type splitter I can use. i believe I have seen them before. with one inlet and 2 or more outlets to run several scanners. Is there something I can get at HRO Ham radio outlet??? and any suggestions on a decent cable thats not gonna break the bank...

 

[LarrySC]

Use RG-6. Put PL to F adp on antenna. Put F to BNC on scanner or use twist on BNC. Use TV/VCR type splitter and you could also use AB or ABC switch if you need.
My complet antenna / coax / scanner set up is built on this idea and works perfect. I would consider an antenna that has elements cut for VHF/UHF/800 Works much better than just one vertical element. You need a twril type two blade stripper and a good crimp tool. Good Luck, Larry

 

[HabboX]

Larry's advice is good and in 99% of applications should work fine. Try it first.

On a technical level, installing a TV type splitter will reduce the signal by at least 3 dB (half). It is also possible that signals generated by one scanner (aka birdies) could travel through the coax to the other scanner and cause interference (this is rare).

There is a company called Stridsberg Engineering that makes multicouplers specifically for use with scanners and shortwave radios. They make a really good product, but unless you are going to connect 4 or more scanners, then go with Larry's suggestion.

www.stridsberg.com

 

[cowboymike1971]

There is also one I saw thru Grove Ent. that showed a couple of cables and a TV style splitter and some connectors for 9.95. Is this something I could do myself too? and the suggestion from Larry was good but I am not an expert so if you could break it down some for me it would be greatly appreciated. thank you.

 

[Voyager]

Hello, I now run 2 scanners side by side ( BC 780 and a BC 9000) from one ground plane antenna on a 20 ft mast. I am going to upgrade my cable this weekend and I wanted to upgrade my splitter as well. I believe I am losing signals due to its setup. Its a "Y" type splitter that splits off the main incoming cable then runs to the back of each scanner so both can run simultaneously. Is there a cable TV type splitter I can use. i believe I have seen them before. with one inlet and 2 or more outlets to run several scanners. Is there something I can get at HRO Ham radio outlet??? and any suggestions on a decent cable thats not gonna break the bank...

OK. Another multi-post topic.

Yes, there are three, four, five, or more way splitters. BUT, keep in mind that with each split you will lose half of the signal unless it employs a preamplifier as well. For example, a 1-in/2-out splitter will lose 3 dB on each output. A 1-in/4 out will lose 6 dB on each (it's split twice). A 1-in/3-out will typically lose 3 dB on 1 output and 6 dB on the other two since one of the splits is split again.

There are dedicated splitters with preamps made for scanners. Check here: http://www.stridsberg.com/mca204a.htm

There are also problems with standard splitters in that signals generated by one scanner can interfere with other scanners. The stridsberg units take care of that problem as well.

Joe M.

 

[LarrySC]

You may loose 3db of signal with a split, but in my area that is a good thing. Thats the beauty of this type installation. With splittes, AB or ABC switches you still dont notice any loss in a strong RF area. Standard scanner/antenna installations in a strong signal area cause people to complain about overload, intermod, and other strange things. In my case, my combinations of antennas and scanners result in NO intermod, overload, etc because I cut it down using splitters and switches. It all depends on location. If you were in South Mississippi then you would notice loss using a splitter. Good Luck, Larry

 

[Voyager]

You may loose 3db of signal with a split, but in my area that is a good thing. Thats the beauty of this type installation. With splittes, AB or ABC switches you still dont notice any loss in a strong RF area. Standard scanner/antenna installations in a strong signal area cause people to complain about overload, intermod, and other strange things. In my case, my combinations of antennas and scanners result in NO intermod, overload, etc because I cut it down using splitters and switches. It all depends on location. If you were in South Mississippi then you would notice loss using a splitter. Good Luck, Larry

That may be true, but you will notice the difference on weak signals no matter where you are. Sure, if all you care about are signals that are 10 dB over quieting, 3dB loss will mean nothing. Most scanner users care about the weak signals, too. For that matter, if you only care about the strong signals, why spend the money on an outside antenna and splitters to start with? Use the supplied antenna. :wink:

With a switch, there should be NO LOSS because there is minimal loss in the contact of the switch and no other drains on the signal. You also still have to deal with signals from other receivers on the 'T' getting back into other units on the same 'T'. This can be worse in strong signal areas due to the higher potential of mixing within your receiving system. So, yes, the loss may not be a factor in areas such as yours, but you still need isolated outputs on a quality splitter or you are still introducing problems.

Joe M.

 

[HabboX]

For that matter, if you only care about the strong signals, why spend the money on an outside antenna and splitters to start with? Use the supplied antenna.

Because height of the antenna is more important than signal strength. An outdoor antenna mounted 20' AGL and attenuated 20dB is going to hear more than a rubber ducky inside with a preamp.

 

[nmfire10]

For that matter, if you only care about the strong signals, why spend the money on an outside antenna and splitters to start with? Use the supplied antenna.

Because height of the antenna is more important than signal strength. An outdoor antenna mounted 20' AGL and attenuated 20dB is going to hear more than a rubber ducky inside with a preamp.

That statement is a little flawed,

Signal strength is what you need. Height is the best way to find the strongest signal.

But there is a lot to concider when you start trying for height. If you use 100 feet of walmart RG-59 TV Coax with a stack of adaptors on both ends (all too common), then your rubber duck might just work better!

 

[HabboX]

If you use 100 feet of walmart RG-59 TV Coax with a stack of adaptors on both ends (all too common), then your rubber duck might just work better!

Well, I don't know why you would use more than one adapter on each end. In that scenario, I would rather have 100 ft of coax with a rubber duck at 20 feet AGL than to use a rubber duck at ground level.

 

[Voyager]

In that scenario, I would rather have 100 ft of coax with a rubber duck at 20 feet AGL than to use a rubber duck at ground level.

That's one way to prevent the signal from being too strong. :lol: 8)
(IOW: your argument works just as well for using a duck as for a splitter)

Joe M.

 

[INDY72]

OK the general rule is that if your using anything over 50' of coax, your losses outwiegh the gains anyway unless you use an preamp system.

 

[nmfire10]

OK the general rule is that if your using anything over 50' of coax, your losses outwiegh the gains anyway unless you use an preamp system.

What rule book is that coming from? Whoever fed you that is full of BS,

 

[Voyager]

OK the general rule is that if your using anything over 50' of coax, your losses outwiegh the gains anyway unless you use an preamp system.

What rule book is that coming from? Whoever fed you that is full of BS,

Ditto. It all depends on WHAT TYPE of feedline you are running and WHAT BAND you are operating on. With RG-58, that may be true on the higher bands, but certainly is not true for 7/8" Heliax. Conversely, RG-174 will not come close to matching the performance of RG-58.

Simply put, if your rule were true, you would not see any towers higher than 50 feet tall (unless the equipment were side mounted at the antennas).

Joe M.

 

[N_Jay]

OK the general rule is that if your using anything over 50' of coax, your losses outwiegh the gains anyway unless you use an preamp system.

What rule book is that coming from? Whoever fed you that is full of BS,

Ditto. It all depends on WHAT TYPE of feedline you are running and WHAT BAND you are operating on. With RG-58, that may be true on the higher bands, but certainly is not true for 7/8" Heliax. Conversely, RG-174 will not come close to matching the performance of RG-58.

Simply put, if your rule were true, you would not see any towers higher than 50 feet tall (unless the equipment were side mounted at the antennas).

Joe M.

Oh, come on!

It's a "general rule", not a specific rule.

It's one of those things that simplifies life for people who don't care to know too much.

OK, no flames. Just being a bit sarcastic about one of my pet peeves.

 

[INDY72]

Dude when it comes to scanners,..

RG58C/U-
Freq - percentage of loss
At 50'- 50MHz - 33% At 100' - 53%
At 50'- 160MHz - 53% At 100'- 76%
At 50'- 460MHz - 74% At 100'- 93%
At 50'- 860MHz - 86% At 100'- 98%

RG8A/U-
19% and 33%
28% and 46%
45% and 69%
60% and 84%

9913-
11% and 18%
18% and 34%
31% and 46%
38% and 62%

Thats without a preamp.

 

[cowboymike1971]

Outcome/ Re: this topic

Well thanks to all those whom repl;ied with info. I didn't mean to start a brew Ha Ha.. LOL. I went to my local HRO Ham Radio outlet on Sat and purchased 50 ft of Cable Experts RG8/U (model # cxp008c50) I took in what i had been running and upgraded to this. Mine before was a type of belden Mini 8. Thin and soft. I upgraded to a hardline coax. Much thicker. I have noticed an improvment so far.. My next step will be to replace the splitter I am running with a Stridesburg Multicoupler.

 

[Voyager]

Re: Outcome/ Re: this topic

I went to my local HRO Ham Radio outlet on Sat and purchased 50 ft of Cable Experts RG8/U (model # cxp008c50) I took in what i had been running and upgraded to this. Mine before was a type of belden Mini 8. Thin and soft. I upgraded to a hardline coax.

For reference, RG8/U is not hardline. Maybe you didn't know, but 'hardline' is a term for a different kind of coaxial cable that is much more rigid than RG8/U. Hardline has a solid metal shield. There is also 'Heliax' that is a specialized kind of hardline - it has a spiral-ribbed shield as opposed to the smooth metal shield of hardline. RG8/U and it's relatives have a braided shield and have higher loss due to that fact. Going even higher up the chain is 'waveguide' that is used only at microwave frequencies and higher. It's similar to hardline, but has no center conductor. It is also typically elliptical (oval) in shape.

Superflex is a specialized form of Heliax that is much more easily bent. There is also Radiax that is, quite literally, very leaky Heliax - it's Heliax with slots cut in the shield. It's typically used in buildings where a conventional antenna won't cover all the floors. Radiax can be terminated in an antenna, or in some configurations, with a dummy load.

I think that covers the major types of coaxial cable. (although waveguide is not coaxial since there is no center conductor) 8)

Joe M.

 

[N_Jay]

Dude when it comes to scanners,..

RG58C/U-
Freq - percentage of loss
At 50'- 50MHz - 33% At 100' - 53%
At 50'- 160MHz - 53% At 100'- 76%
At 50'- 460MHz - 74% At 100'- 93%
At 50'- 860MHz - 86% At 100'- 98%

RG8A/U-
19% and 33%
28% and 46%
45% and 69%
60% and 84%

9913-
11% and 18%
18% and 34%
31% and 46%
38% and 62%

Thats without a preamp.

So how many dB does your "General Rule" cover?

 

[INDY72]

This is factual information using the 20dBS/N, and 12dBSINAD methods in a study years ago. This covers reception only not transmission. With a scanner you are not going to worry about transmitting. This is with no amplification of the signal. The longer the cable, the more signal will be lost. Thus the reason for amplification, high gain specialized antennas, and the like on professional grade equipment. THis whole thread was dealing with splitters and the like as pertaining to scanners. Coax has not changed much in the last ten years as far as a cable run for a scanner goes. You could get into a debate as to leaky coax and the like, but I do not hink you wil see too many scanner users running expensive leaky coax.