3 position antenna switch
Welcome to Radioreference where there is no such thing as a stupid question. I noticed that your basic requirements are that you need at least three RF outputs & they must cover up to 870.0 MHz. The switch in your link does not specify it's usable frequency range, have you checked with Scanner World about that? Also any component in any communications system be it professional grade transceivers or consumer grade scanners needing to cover up to & past 800.0 MHz are configured differently then most economical communications products available. Most consumer grade coax switches only cover up to 800.0 MHz & utilize SO239 female sockets which are not really suitable for the best possible reception at those frequencies. Anything above the UHF range should be oufitted with N connectors exclusively however if cost & the possibility of having to compromise your system by using additional adapters between your antenna & scanner is a factor then get what you can afford. It's after 1:00AM here & I am whacked out however I did find two companies that have coax switches that may work for you, they are a little pricey but at least it's a start in pointing you in the right direction if you feel that these won't work for you.
www.alphadelta.com
Model: Delta-4B/N 4 position surge protected coax switch
RF coverage up to 1.3 GHz
N connectors (50 Ohm)
$99.95
Cables, Coaxial Cable, Cable Connectors, Adapters, Attenuators, Microwave Parts - Pasternack Enterprises
Model: PE7140 4 position surge protected coax switch
RF coverage up to 1.3 GHz
N connectors (50 Ohm)
$167.15
As I mentioned, they are a little pricey because they are targeted for the professional communications industry. Maybe another RR member will read this thread & come up with something a little more viable and/or affordable for you. Good luck.
FLRAILMAN