Love seeing everyone's shack pictures, but I have a question about antenna's. Lot's of scanners going, but just what do you do for antenna's? Can you use a splitter to add on more than 1 scanner to one antenna? I use a Discone but have 4 scanners and want my 2 base's on one antenna. Will it workout ok?
What lep said is good info. Touching on what jeatock said, good multicouplers do have low gain amps built into them to overcome the mini splitters (mini versions of a cable tv splitter but designed for 50 ohms) inside the MCA204 lep mentioned from Stridsberg.
I live in a very high RF environment and use multiple Stridsberg multicouplers. I've never had an issue caused by them from overload. If I do, that issue is also present without the stridsberg multicoupler. Another words, the Stridsberg multicoupers do not make the problem worse for me.
I actually have two of their MCA208M's which have 8 outputs each.
And as jeatock said, yes, they are not cheap! It's the proper way to do multiple scanners if you cannot dedicate an antenna to each scanner however. I wish I could but I'm in an apartment and they did give me a key for the roof hatch so I can work on my antennas but I don't push my luck and keep my scanner antennas to just two. One multiband and a 12 element Yagi beam on a rotor for 800 MHz. The setup works very well but GRE scanners do not play nice with all the very near VHF paging signals here on top of all the hospitals. The paging signals cause the GRE's to go into desense mode and thereby reduce the front ends sensitivity to the point I can't hear other VHF signals in many cases. I must use a PAR 152 MHz paging filter to correct that.
My Uniden's are not bothered by the VHF paging signals so they don't really need the PAR filters but I place the PAR filter at the input to the MCA208 so it's little amplifier is not affected by the paging signals also.
I removed the PAR filter the other day when a new statewide VHF site came online here so I could hear it. Our state is using several frequencies that fall in the 152 MHz paging band. With the PAR filter, I can't hear the sites that are not right here. So far, the GRE's are handling that sites signals without the PAR filter OK but there has been no voice traffic yet.
I may end up needing a 2nd VHF antenna hooked to another multicoupler for or state's new VHF system and let that feed just the Uniden's with no PAR paging filter. Then use the GRE's with a PAR filter but do not use them for the statewide sites that the PAR filter will reduce the signal strength on. It's going to be a bit of a challenge for me getting everything where I need it with multicouplers and PAR filters only for the GRE made radios. Then a new coax run and antenna and yet another Stridsberg multicoupler to feed the radios I dedicate for the state system.
It may be cheaper for me to purchase a PAR filter for each GRE made radio and place them at the mutlicouplers output jacks that feed the GRE's.
The PAR filters drop the signal levels within their designed range by about -35 dB and then that tapers off quickly as you move away from the designed filter range so they don't also attenuate other frequencies like say the 155 MHz range.
I've never tried placing individual PAR filters on the outputs from the multicoupler that feed the GRE's. In theory, it should work as the ports are isolated from one another so the PAR filters should still work as designed.
edit: to add, many have used simple splitters made for TV. While they may work for strong signals, they will reduce the signal levels as jeatock pointed out plus they often do not have good port to port isolation that a true multicoupler will have. Add that to the fact that you would also need adapters for each connection which can also cause a small amount of loss, It's been said that an adapter or simple connector can each add about 0.5 dB of loss. Get enough of them inline and you may end up doubling your loss which is not good if you are after distant signals that are already weak levels. Many also use Cable TV drop amps. Some of those work but many are a cheap design and have high noise figures that will wipe out any chance of decoding a digital control channel. They also do not pass any signals below 54 MHz so you would lose VHF Low Band if you are into that.
