Re: Multiswitches and Multisatellite Dishes

[Lewis Gardner <lgardner@xxxxxxxxxxxxxxxxxxxxxxxxxx>]

Ian Shef wrote:

> However, I haven't yet found a site that explains HOW a 4 input multiswitch
> can work with a Phase III DirecTV antenna.
>
> I guess that I could just accept it on faith that it works, but I would
> prefer to know the details.

So do I.

Apparently the Phase III uses "stacker" technology so I was thinking
"old tech" with the discrete LNB plan.

The Phase III LNB/switch works with 4 cables for 6 signals (3
satellites) because 2 of the signals (1 satellite) are in the Ka band.
Polarization is used on all signals but since Ka is a different
frequency than Ku both signals can exist on the same coax.

So (for illustration purposes ONLY) you end up with something like this:

coax1 14vdc = Ku1 RHCP + Ka RHCP
coax2 18vdc = Ku1 LHCP + Ka LHCP
coax3 14vdc+22Khz = Ku2 RHCP
coax4 18vdc+22Khz = Ku2 LHCP

Ku1, Ku2 and Ka are the three feedhorn/LNB assemblies. For DirecTV they
are pointed at 101/110/119 West Longitude for the Ku signals and
99.2/102.8 WL for the Ka signals. I believe you get 2 Ku and 1 Ka, which
ones depend on where you live.

Ku downlink at 11.7 to 12.2 Ghz is the traditional frequency for "small
dish" Direct Broadcast Satellite systems. Due to the exploding demand
for bandwidth (locals and HDTV) more is needed. Ka downlink at 18.3 to
18.8Ghz and 19.7 to 20.2 Ghz is one place where the DBS broadcasters are
"finding" additional bandwidth. Unfortunately the complexity of the
system goes up.

Ku signals are converted to 950 to 1450 Mhz by the LNB so the signal
loss on flexible coax is reasonable. Ka signals are converted to 250 to
750 Mhz for 18.3 to 18.8Ghz and 1650 to 2150 Mhz for 19.7 to 20.2Ghz for
the same reason.

Here are some links:

http://www.zcwc.com/zcwc/products/multi_switch/usermanuals/wb_68/WB68_Install_Guide.pdf
http://www.avsforum.com/avs-vb/showthread.php?t=716613&highlight=phase+III
http://www.highdefforum.com/showthread.php?t=2311

It looks like either the Zinwell WB68 or the Eagle Aspen DTV4X8 will do
what you need. You might want to get the WB68 in case you have future
need for even MORE satellites. Of course by then the tech may have
changed again and...

You might want to check solidsignal.com for your purchase. I have used
them before an have always had good results.


Good Luck!