Re: Splitting antenna

On Fri, Nov 19, 2021 at 10:27 AM D'Arcy Cain <darcy@druid.net> wrote:

> I am using my FreeBSD box as my main ingress to my RV trailer.  We move
> around and sometimes use Ethernet, sometimes PPP directly on DSL and
> sometimes we connect to a local wifi hotspot.  To get the best connection
> I
> have mounted an external, multi-band antenna on the trailer and connect it
> to one of the antenna connections on the wifi card.
>
> My question is, can I split the antenna connection and use both antenna
> connectors on the wifi card (or three if I have that kind of card) or will
> that mess up the connection.  I know that each connection is for a
> different
> band.  Different camp grounds use different bands and sometimes I need to
> switch the antenna to get a better Internet connection.  It would be nice
> if
> I could just have both of then connected to the external antenna.
>
> Cheers.
>
> --
> D'Arcy J.M. Cain <darcy@druid.net>         |  Democracy is three wolves
> http://www.druid.net/darcy/                |  and a sheep voting on
> +1 416 788 2246     (DoD#0082)    (eNTP)   |  what's for dinner.
> IM: darcy@VybeNetworks.com, VoIP: sip:darcy@druid.net

Yes, you can split the signal, but the signal on each output will be a bit
less than half the strength of the input signal. Three-way splitters are
less common, but a 4-way means a quarter of the input. Make sure the
splitter matches the impedance of the antenna as do all of the cables. As
long as the S/N ratio is good enough, the split will work fine as it is in
the analog realm. Since signal strength will vary depending on location,
splitting may work in some places and not in others. A broadband amplifier
attached at or near the antenna will help a lot if the signal strength is
enough to work well before splitting. If you have a friend who is a ham
radio operator, they could help a lot.
--
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman@gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683