So you really got bit by the scanner bug and have several scanners to really keep tabs on the action. You really want to have a better antenna for them all but don’t want an antenna farm growing on your roof or your attic. What to do?
There are several good ways to share one antenna with 2 or more radios. There are also several bad ways. The bad ways might work good enough to hear some local stuff but that is about it.
The best way to share an antenna with multiple radios is by use of a Multicoupler. A Multicoupler has a connector for the antenna and 2, 4 8 or more ports for radios.Multicouplers allow signals from the antenna to pass thru it to multiple radios and prevents interference between them. “Active Multicouplers” have low power pre-amps in them to overcome the connector loss present whenever you put something between the radio and its antenna. “Passive Multicouplers” do not have the amplifier and will degrade the signal a bit.
Stridsberg makes several models of Multicouplers tailor made for scanners. Stridsberg is the most respected name in scanner multicouplers and ScannerMaster is proud to carry them. Up to 8 scanners can be connected to a single scanner antenna without loss. Check these out at https://www.scannermaster.com/Multicouplers_for_Police_Scanner_Radios_s/43.htm
If your needs are less stringent then you could use a splitter. Splitters are different in that they merely provide a way to share an antenna with two or more radios. These do not have the circuitry to reduce or overcome signal loss. Splitters can usually be used in the reverse way, to allow 2 antennas to feed a single radio, something that multicouplers usually cannot do.
One could just use coax “T” or “Y” adaptors but these provide no protection against interference or signal loss and are not recommended.
Regardless of the methods use there is no substitute for quality cables. Using high-quality coax, both for the downlink from the antenna and for the jumpers to the radios will reduce the loss and increase the signal strength. Don’t forget to use quality connectors if you make the patch cables yourself. Avoid the use of adapters as much as you can, everyone adds a little more loss to the line.