Starting to think I really ought to tidy up the coils of cable in the
wiring cupboard. Had a brief look around at multiswiches but don't
really know which are good or bad makes or even a decent place to buy
from.

The multiswitch needs to do DSAT (and if it outputs the relevant
voltages/tones for a quad LNB that is already installed and working
all the better), Be very convenient if it also distributed, Band II,
DAB (might get a signal with a loft aerial) and whats left of Band IV
and V for DTTV. There are 24 coax's in the cupboard but 7 of those
are DSAT and terrestial aerials. So a 16 output unit will be just
over full, but it's unlikely that all distribution drops will ever be
used at the same time, so 12 outputs will probably do.

Even though this isn't a "shared dwelling" I assume the hefty earth
bonding of the distribution cables is still a good idea. The plug-in
modules seem like a very neat solution and less time consuming than
the stand alone strips (and two less joints). Comments?

Would have tweakable input levels be an advantage bearing in mind any
test gear is just the signal level/quality indication of consumer
equipment. I do have a basic "adjust dish for maximum" satellite
meter.

The output drops probably vary from about 10 m to 25 m (ish) so I
don't think I really need to worry too much about variation of signal
level across drops.

Many thanks.
--
Cheers
Dave.

On 26/05/2017 15:40, Dave Liquorice wrote:
Starting to think I really ought to tidy up the coils of cable in the
wiring cupboard. Had a brief look around at multiswiches but don't
really know which are good or bad makes or even a decent place to buy
from.

I can't really advise you with any authority because I've been retired
years now and although Paul deals with such things we never seem to
discuss it.

OK hang on a minute...

He says he's happy to use Vision and Triax.


The multiswitch needs to do DSAT (and if it outputs the relevant
voltages/tones for a quad LNB that is already installed and working
all the better),


Hang on, one of his kids is screaming because he can't get Netflicks to
work.

Ahh...


You'll need to check on that yourself. It isn't a thing we would do.
Makes replacement of the switch a slight problem because usually they go
wrong at funny hours and you have to use what's in the van, and to only
stock that type would be limiting.

Be very convenient if it also distributed, Band II,
DAB (might get a signal with a loft aerial) and whats left of Band IV
and V for DTTV.

Oh yes you want that. They all do it. Some choice of input config but I
always used to use one-input ones and add my choice of
diplexers/filters/attenuators.

There are 24 coax's in the cupboard but 7 of those
are DSAT and terrestial aerials. So a 16 output unit will be just
over full, but it's unlikely that all distribution drops will ever be
used at the same time, so 12 outputs will probably do.

Oh get one that covers everything. It isn't worth giving yourself the
hassle of mucking about changing cables over (if they're labelled the
labels will all be wrong). And when switches go wrong, quite often it's
individual outputs that die so it's good to have spares.

Even though this isn't a "shared dwelling" I assume the hefty earth
bonding of the distribution cables is still a good idea.

I agree.


The plug-in
modules seem like a very neat solution and less time consuming than
the stand alone strips (and two less joints). Comments?

Either way really.


Would have tweakable input levels be an advantage bearing in mind any
test gear is just the signal level/quality indication of consumer
equipment. I do have a basic "adjust dish for maximum" satellite
meter.

Not really. You won't overload the switch with satellite signal. Lots of
head room. Just blast it with everything the LNB can give it.

For UHF and VHF use external attenuators (or pre-amps).


The output drops probably vary from about 10 m to 25 m (ish) so I
don't think I really need to worry too much about variation of signal
level across drops.

No, because normally everything is at a much higher level than the
receivers need.

However I have to say that doing this job without proper test equipment
is a bit hazardous. You're OK unless something oddball happens, then it
becomes a bit annoying.

Bill and Paul

On 26/05/2017 15:40, Dave Liquorice wrote:
Starting to think I really ought to tidy up the coils of cable in the
wiring cupboard. Had a brief look around at multiswiches but don't
really know which are good or bad makes or even a decent place to buy
from.

The multiswitch needs to do DSAT (and if it outputs the relevant
voltages/tones for a quad LNB that is already installed and working
all the better), Be very convenient if it also distributed, Band II,
DAB (might get a signal with a loft aerial) and whats left of Band IV
and V for DTTV. There are 24 coax's in the cupboard but 7 of those
are DSAT and terrestial aerials. So a 16 output unit will be just
over full, but it's unlikely that all distribution drops will ever be
used at the same time, so 12 outputs will probably do.

FWIW, last one I did was a Triax from CPC. Seemed to do a decent job. I
swapped the LNB for a quattro though.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Fri, 26 May 2017 22:00:16 +0100, Bill Wright wrote:

Had a brief look around at multiswiches but don't really know
which are good or bad makes or even a decent place to buy from.

I can't really advise you with any authority because I've been retired
years now and although Paul deals with such things we never seem to
discuss it.

Experience still counts, at least as far as what works physically and
which approaches give the better result.

He says he's happy to use Vision and Triax.

Thanks Paul.

The multiswitch needs to do DSAT (and if it outputs the relevant
voltages/tones for a quad LNB that is already installed and
working
all the better),

You'll need to check on that yourself. It isn't a thing we would do.

Makes replacement of the switch a slight problem because usually they go
wrong at funny hours and you have to use what's in the van, and to only
stock that type would be limiting.

Flexabilty of a Quattro LNB is understandable for a commercial
operation and multi occupancy dwelling. If the multiswitch goes pop
it has to be replaced to get all occupants back with service and a
Quattro LNB allows the use of either "type" of multiswitch. Not quite
the same for a self maintained single dwelling, if the multiswitch
goes pop with a Quattro LNB it's no (or restricted) telly untill a
new multiswitch is purchased, delivered and installed. A Quad LNB can
have up to four outlets with full DSAT by just connecting those drops
to the Quad LNB feeds, same for single FM, DAB and DTTV receivers.
Much reduces the domestic strife if down time is less than an hour,
rather than days...

Be very convenient if it also distributed, Band II, DAB (might get
a
signal with a loft aerial) and whats left of Band IV and V for
DTTV.

Oh yes you want that. They all do it.

That's handy. B-)

Some choice of input config but I always used to use one-input ones and
add my choice of diplexers/filters/attenuators.

Single input, own diplexers etc makes sense, unless a multi input one
has individual level tweaks I can see big signals in one band
possibly overloading the amp(s). Not that big signals is going to be
a problem here, at least not in band. The Air Traffic Control stuff
from 121 to 128 MHz is very strong from Great Dunn Fell, far stronger
than any broadcast signal.

So a 16 output unit will be just over full, but it's unlikely that
all
distribution drops will ever be used at the same time, so 12
outputs
will probably do.

Oh get one that covers everything. It isn't worth giving yourself the
hassle of mucking about changing cables over

I must admit I'm inclined to agree, I think the price difference 12
16 24 will be a big influence, Do unused outputs need to be
terminated?

(if they're labelled the labels will all be wrong).

I'll be labeling them, the labels will be right. B-)

And when switches go wrong, quite often it's individual outputs that
die so it's good to have spares.

Now that's a useful bit of inside info.

Even though this isn't a "shared dwelling" I assume the hefty
earth
bonding of the distribution cables is still a good idea.

I agree.

The plug-in
modules seem like a very neat solution and less time consuming
than
the stand alone strips (and two less joints). Comments?

Either way really.

Ok, neatness OCD is screaming have all the incoming cables terminated
along one edge of the mounting board, with enough slack such that any
cable can reach any port. The functional/easier side is saying just
lay neatly to each amp output and in the (unlikely) event of a drop
needing to moved if it doesn't reach a short jumper can bodge it
(ARGH!). B-)

The output drops probably vary from about 10 m to 25 m (ish) so I
don't think I really need to worry too much about variation of
signal
level across drops.

No, because normally everything is at a much higher level than the
receivers need.

Do you happen to know how these things work internally? Is it just a
single output amp, followed by say 30 dB attenuators to each output
port (giving 60 dB between ports), or individual amps per port? As
you say a single port can die that would indicate the latter as there
ain't much to go wrong with an attenuator.

However I have to say that doing this job without proper test equipment
is a bit hazardous. You're OK unless something oddball happens, then it
becomes a bit annoying.

I might be able to borrow a proper sattelite meter should there be
something weird a miss. I'm well used to fault finding temporary
installations right back to "unplug it all and start again from
power"

Thanks for the response (and Johns), given me a starting point and
that my thoughts are more or less on track. I'll have a look at what
CPC has to offer from Vision and/or Triax.

--
Cheers
Dave.

On 27/05/2017 13:24, Dave Liquorice wrote:

I must admit I'm inclined to agree, I think the price difference 12
16 24 will be a big influence, Do unused outputs need to be
terminated?

No


(if they're labelled the labels will all be wrong).

I'll be labeling them, the labels will be right. B-)

You might get in a muddle. I always did.


Do you happen to know how these things work internally? Is it just a
single output amp, followed by say 30 dB attenuators to each output
port (giving 60 dB between ports),

The one I took apart on a rainy day had stripline tap-off units on a
PCB. One long track with a lot of short tacks very close to it. The
little ones were grounded via a 75ohm resistor at one end and the other
end went to the output port.

or individual amps per port? As
you say a single port can die that would indicate the latter as there
ain't much to go wrong with an attenuator.

It's the switching between band and polarisations that goes wrong,
usually sticking on one permutation or sometimes two. Also you get bad
connections (hairlines) on the output sockets when they connect to the PCB.

When an amp goes down you lose one permutation on every port.

The commonest fault on multiswitches is the PSU. Luckily that's fixable.
They really don't like emp from lightning.

Bill

On Sat, 27 May 2017 21:46:37 +0100, Bill Wright wrote:

(if they're labelled the labels will all be wrong).

I'll be labeling them, the labels will be right. B-)

You might get in a muddle. I always did.

It'll be right... They are sort of identfied ATM up to five bands of
sticky tape one some, then flags and numbers. Pencil numbers on the
plaster above the sockets, OK until decoration takes place. B-)

It's the switching between band and polarisations that goes wrong,
usually sticking on one permutation or sometimes two. Also you get bad
connections (hairlines) on the output sockets when they connect to the
PCB.

When an amp goes down you lose one permutation on every port.

Usefull stuff again Bill.

The commonest fault on multiswitches is the PSU. Luckily that's fixable.
They really don't like emp from lightning.

Had a quick look at CPC last night, the Vision EV5-516 seems good
value for money. Comes with plug-in earthing bonding, switchable
input level adjustment, was probably going to go for line powered and
use a 12 18 DC-DC convertor as "the plan" is to have a decent sized
12 V supply and convert that for the various voltages the various
boxes will want. Requires a Quattro LNB AFAICT.

--
Cheers
Dave.