Antenna(s) for multiple scanners -- how does it work?

[Airdorn]

Hi, Antenna-ers!

So I already have a Uniden scanner. I'm thinking of getting one of those snazzy Uniden SDS200 scanners to add to the mix.

I have a nice antenna on my roof. A couple, actually.

I have one that points at a certain very-active-but-kind-of-weak system. Can I get a BNC splitter and just split the antenna signal like that without a terrible loss?

Taken to its logical conclusion, if I add 8 more scanners (for a total of 10), can they all just feed off the same antenna? What's the limit before the signal degrades? Surely 100 scanners can't reasonably feed off a single antenna!

I'm mainly dealing with 400Mhz and 800Mhz signals.

Thanks!

 

[Enjoi19]

If you want to feed several scanners off one antenna, look into the Stridsberg multicouplers. Made just for this. Available in several configurations.

If it was just 2 and you were going off very good / strong signals, you can sometimes get away with things. But with that many, get the good stuff and be happy. Using cheaper stuff doesn’t seem to play well with weaker signals (I’ve just slapped a T adapter in before and found it to add interference and definitely take a hit).

You might even want 2 - a 4 port perhaps for your weaker signal one, then an 8 port to feed the rest when you have your 10 scanners

Multicouplers

Just two cents from someone who’s messed with a few of the cheap routes a bit now and knows he should be investing in the good stuff one day to keep signals at their optimal levels.

 

[jonwienke]

A multicoupler is definitely the way to go when using a single antenna to feed multiple scanners. I'm also using a Stridsberg.

 

[Ubbe]

Can I get a BNC splitter and just split the antenna signal like that without a terrible loss?

It depends of scanners and what frequency bands they are scanning. It could be a minimal loss or a very noticeable one depending of which frequency band the scanners are currently in.

A CATV splitter and a low noise amplifier together with some attenuation will in most cases improve weak signal reception and make it possible to split signals to several scanners.

Use of BNC splitters

/Ubbe

 

[buddrousa]

I have been the CHEAP way and when I did spend the money the difference is light and day.
CATV SPLITTER = WOOD WHEELS
MULTICOUPLER = MODERN RUBBER TIRES

 

[mr10pt]

I only need a 2 port multicoupler. Looking at the Stridsberg options there's a "passive" multicoupler that "splits" a signal, in phase, to the ports. They have one in the correct frequency range. Does not appear to need dc power. Will this work or is it a bad idea because of the word "split"? Stridsberg MC202 v/s MCA202M/N. I do have the N connector on my LMR400 cable.

 

[jonwienke]

A passive 2-port splitter has a loss of a little over 3dB. That's not too bad in most cases. But if you have more than 2 outputs, you likely want an amplifier to offset the splitter loss.

 

[bravo14]

Do they require a DC Outlet? I was looking into a 2 outputs. Looks like I need 2 of them 1 for vhf/uhf and 7/800

 

[jonwienke]

Amplified, yes, passive, no.

If you're splitting by band, a diplexer is what you want. The output is sorted by frequency range, but loss is less than 3dB.

 

[Ubbe]

Do they require a DC Outlet? I was looking into a 2 outputs. Looks like I need 2 of them 1 for vhf/uhf and 7/800

Those passive CATV 3dB splitters do not need power. They usually handle way below 25MHz up to more than 2GHz frequencies. 3dB equal to a half S value on a S meter and scanners usually has 5 or 6dB per segment in its signal strenght bars.

/Ubbe

 

[bravo14]

Will this work? 4 Port MCA204M VHF/UHF Receiver Multicoupler - 25 MHz to 1 GHz | Scanner Master

 

[lu81fitter]

If you use one radio for each band, you could use a diplexer. Feed from a multiband antenna can be split to 2 radios with minimal loss.
Try looking here.

Duplexers, Diplexers & Triplexers | The Antenna Farm

Of course, if you want to monitor all bands on each radio, then the multi-coupler would be a better choice.

 

[bravo14]

If you use one radio for each band, you could use a diplexer. Feed from a multiband antenna can be split to 2 radios with minimal loss.
Try looking here.

Duplexers, Diplexers & Triplexers | The Antenna Farm

Of course, if you want to monitor all bands on each radio, then the multi-coupler would be a better choice.

Cool Thanks.

 

[jonwienke]

Will this work? 4 Port MCA204M VHF/UHF Receiver Multicoupler - 25 MHz to 1 GHz | Scanner Master

That's the unit I use. It splits the output from a discone antenna to 4 scanners, each of which monitors multiple bands.

 

[bravo14]

That's the unit I use. It splits the output from a discone antenna to 4 scanners, each of which monitors multiple bands.

I notice it says 25mhz to 1ghz. I was looking at it months ago it was sold out. I have a base 1 handheld and 1 for dsdplus. Right now I have 2 antennas 1 is for dsdplus the other for base. I was looking at the ones that has the bnc connectors so I don't need bunch adapters........

 

[buddrousa]

I am running 3 eight ports and 2 four ports at my location.
All Stridsbergs

 

[mr10pt]

Thank you jonweinke, buddroussa and Ubbe. I take your advise as "golden". Guys that have been there, done that. Any newbie should pay attention to their advice. They won't steer you wrong. Reading between the lines I've decided to purchase a DC powered unit. One other question: I have LMR400 coming in, what should I use for a 4-6' patch or pigtail? Would RG6 work ok?

 

[buddrousa]

Just stick with 50 ohm jumpers

 

[jonwienke]

Thank you jonweinke, buddroussa and Ubbe. I take your advise as "golden". Guys that have been there, done that. Any newbie should pay attention to their advice. They won't steer you wrong. Reading between the lines I've decided to purchase a DC powered unit. One other question: I have LMR400 coming in, what should I use for a 4-6' patch or pigtail? Would RG6 work ok?

I wouldn't mix impedance for jumpers, there are plenty of 50-ohm options that will work just fine.

And you're welcome.

 

[lu81fitter]

Just for the record, I use 2 diplexers. One in the car that merges 2 antennas to one radio, and one in the house the merges an all band antenna to 2 radios. They work as advertised. I'm very happy with mine.