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| TheMekon |
 Posted: Mon Aug 27, 2007 3:43 am |
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Not sure if this is the right forum but here goes....
I need to distribute off-air TV round a client's premises to about 20
outlets as RF
Easy, I get my friendly aerial man to do a distribution amplifier etc.
(I am in the UK and we are talking about PAL system I)
But...
Client also needs 6 channels of locally sourced video mixed in with the
distribution.
If it was 1 or 2 channels I would just get cheap modulators, choose a
couple of blank channels and mix it in with the off-air feed.
But doing 6 channels worries me.
Do I need to worry about the performance of cheap modulators?
Do I need to worry about intermodulation problems?
What else do I need to worry about?
Thanks! |
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| Marky P |
| Posted: Mon Aug 27, 2007 4:11 am |
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On Mon, 27 Aug 2007 09:43:59 +0100, TheMekon <No.Mail@please.com>
wrote:
Quote: Not sure if this is the right forum but here goes....
I need to distribute off-air TV round a client's premises to about 20
outlets as RF
Easy, I get my friendly aerial man to do a distribution amplifier etc.
(I am in the UK and we are talking about PAL system I)
But...
Client also needs 6 channels of locally sourced video mixed in with the
distribution.
If it was 1 or 2 channels I would just get cheap modulators, choose a
couple of blank channels and mix it in with the off-air feed.
But doing 6 channels worries me.
Do I need to worry about the performance of cheap modulators?
Do I need to worry about intermodulation problems?
What else do I need to worry about?
Thanks!
Hmmm. I'm not THE expert on here, but let's see... Where abouts in
the country will this installation be? You need to find out all the
frequencies used for analogue & digital TV that cover your clients
area THEN find out if there a six spare ones. It's possible, but
sounds like a bit of a sod.
Marky P. |
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| Dave Plowman (News) |
| Posted: Mon Aug 27, 2007 5:18 am |
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In article <---dnffH1LFOE0_bnZ2dnUVZ8q2dnZ2d@eclipse.net.uk>,
TheMekon <No.Mail@please.com> wrote:
Quote: Not sure if this is the right forum but here goes....
Quote: I need to distribute off-air TV round a client's premises to about 20
outlets as RF
Easy, I get my friendly aerial man to do a distribution amplifier etc.
(I am in the UK and we are talking about PAL system I)
But...
Client also needs 6 channels of locally sourced video mixed in with the
distribution.
If it was 1 or 2 channels I would just get cheap modulators, choose a
couple of blank channels and mix it in with the off-air feed.
But doing 6 channels worries me.
Do I need to worry about the performance of cheap modulators?
Do I need to worry about intermodulation problems?
What else do I need to worry about?
You Haven't a chance in hell of getting that number of channels to work
well. They'll work after a fashion, though.
--
*Why is 'abbreviation' such a long word?
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound. |
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| tony sayer |
| Posted: Mon Aug 27, 2007 5:53 am |
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In article <4f18e1e194dave@davenoise.co.uk>, Dave Plowman (News)
<dave@davenoise.co.uk> scribeth thus
Quote: In article <---dnffH1LFOE0_bnZ2dnUVZ8q2dnZ2d@eclipse.net.uk>,
TheMekon <No.Mail@please.com> wrote:
Not sure if this is the right forum but here goes....
I need to distribute off-air TV round a client's premises to about 20
outlets as RF
Easy, I get my friendly aerial man to do a distribution amplifier etc.
(I am in the UK and we are talking about PAL system I)
But...
Client also needs 6 channels of locally sourced video mixed in with the
distribution.
If it was 1 or 2 channels I would just get cheap modulators, choose a
couple of blank channels and mix it in with the off-air feed.
But doing 6 channels worries me.
Do I need to worry about the performance of cheap modulators?
Do I need to worry about intermodulation problems?
What else do I need to worry about?
You Haven't a chance in hell of getting that number of channels to work
well. They'll work after a fashion, though.
Yes it will work, you just need the right equipment.
Look up Taylor transmitters in Oldham they do this sort of stuff and
sell it everyday!. A combination of modulators and channel filters is
what's required.
Bill W could no doubt give you chapter and verse on this subject...
--
Tony Sayer |
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| charles |
| Posted: Mon Aug 27, 2007 1:04 pm |
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In article <4f18e1e194dave@davenoise.co.uk>,
Dave Plowman (News) <dave@davenoise.co.uk> wrote:
Quote: In article <---dnffH1LFOE0_bnZ2dnUVZ8q2dnZ2d@eclipse.net.uk>,
TheMekon <No.Mail@please.com> wrote:
Not sure if this is the right forum but here goes....
Quote: I need to distribute off-air TV round a client's premises to about 20
outlets as RF
Easy, I get my friendly aerial man to do a distribution amplifier etc.
(I am in the UK and we are talking about PAL system I)
But...
Client also needs 6 channels of locally sourced video mixed in with the
distribution.
If it was 1 or 2 channels I would just get cheap modulators, choose a
couple of blank channels and mix it in with the off-air feed.
But doing 6 channels worries me.
Do I need to worry about the performance of cheap modulators?
Do I need to worry about intermodulation problems?
What else do I need to worry about?
You Haven't a chance in hell of getting that number of channels to work
well. They'll work after a fashion, though.
I think you'll have to keep out all stray ones. That means using
channelised filters on the input. Then you should have reasonably clear
space to add your 6 new ones. Remember to avoid n+5 and n+9, although the
latter doesn't affect modern sets. ('n' being wanted channels)
--
From KT24 - in "Leafy Surrey"
Using a RISC OS computer running v5.11 |
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| Ivor Jones |
| Posted: Mon Aug 27, 2007 1:35 pm |
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"tony sayer" <tony@bancom.co.uk> wrote in message
news:si+YmcaT0q0GFwkx@bancom.co.uk
[snip]
: : Yes it will work, you just need the right equipment.
: :
: : Look up Taylor transmitters in Oldham they do this
: : sort of stuff and sell it everyday!. A combination of
: : modulators and channel filters is what's required.
: :
: : Bill W could no doubt give you chapter and verse on
: : this subject... --
: : Tony Sayer
I have 6 "extra" channels distributed around the house (2 x DVD recorders,
2 x VHS recorders, 2 Freeview boxes) and it works, but there's not a lot
of space between some of them..!
I'm in the Midlands and receive from Sutton Coldfield (Lichfield for Ch.5)
and the channel numbers used are as follows:
22 - Freeview 1
26 - Freeview 2
31 - VCR 1
37 - Ch 5
40 - BBC2
43 - ITV1
46 - BBC1
50 - Ch 4
60 - DVD 1
65 - DVD 2
68 - VCR 2
Ivor |
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| Dave Plowman (News) |
| Posted: Mon Aug 27, 2007 1:40 pm |
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In article <si+YmcaT0q0GFwkx@bancom.co.uk>,
tony sayer <tony@bancom.co.uk> wrote:
Quote: Client also needs 6 channels of locally sourced video mixed in with
the distribution. If it was 1 or 2 channels I would just get cheap
modulators, choose a couple of blank channels and mix it in with the
off-air feed. But doing 6 channels worries me. Do I need to worry
about the performance of cheap modulators? Do I need to worry about
intermodulation problems? What else do I need to worry about?
You Haven't a chance in hell of getting that number of channels to work
well. They'll work after a fashion, though.
Yes it will work, you just need the right equipment.
Look up Taylor transmitters in Oldham they do this sort of stuff and
sell it everyday!. A combination of modulators and channel filters is
what's required.
Bill W could no doubt give you chapter and verse on this subject...
I've yet to see one work what I'd consider perfectly. And I've seen plenty
of RF distribution systems in studio complexes. Where I assume cost
doesn't matter.
--
*Of course I'm against sin; I'm against anything that I'm too old to enjoy.
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound. |
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| Bill Wright |
| Posted: Mon Aug 27, 2007 1:49 pm |
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"TheMekon" <No.Mail@please.com> wrote in message
news:---dnffH1LFOE0_bnZ2dnUVZ8q2dnZ2d@eclipse.net.uk...
Quote: Not sure if this is the right forum but here goes....
I need to distribute off-air TV round a client's premises to about 20
outlets as RF
Easy, I get my friendly aerial man to do a distribution amplifier etc.
(I am in the UK and we are talking about PAL system I)
But...
Client also needs 6 channels of locally sourced video mixed in with the
distribution.
If it was 1 or 2 channels I would just get cheap modulators, choose a
couple of blank channels and mix it in with the off-air feed.
But doing 6 channels worries me.
Do I need to worry about the performance of cheap modulators?
Do I need to worry about intermodulation problems?
What else do I need to worry about?
This is what we do. It's our mainstream business.
See:
http://www.wrightsaerials.tv/SystemPlan.htm
http://www.wrightsaerials.tv/Main%20Services/System%20Planning/example%20of%20working%20drawing%202.pdf
http://www.wrightsaerials.tv/410boxesthreeandfour.htm
Contact me via the website if you think we can do business.
Bill |
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| charles |
| Posted: Mon Aug 27, 2007 1:55 pm |
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In article <4f190fc97bdave@davenoise.co.uk>,
Dave Plowman (News) <dave@davenoise.co.uk> wrote:
Quote: In article <si+YmcaT0q0GFwkx@bancom.co.uk>,
tony sayer <tony@bancom.co.uk> wrote:
Client also needs 6 channels of locally sourced video mixed in with
the distribution. If it was 1 or 2 channels I would just get cheap
modulators, choose a couple of blank channels and mix it in with the
off-air feed. But doing 6 channels worries me. Do I need to worry
about the performance of cheap modulators? Do I need to worry about
intermodulation problems? What else do I need to worry about?
You Haven't a chance in hell of getting that number of channels to work
well. They'll work after a fashion, though.
Yes it will work, you just need the right equipment.
Look up Taylor transmitters in Oldham they do this sort of stuff and
sell it everyday!. A combination of modulators and channel filters is
what's required.
Bill W could no doubt give you chapter and verse on this subject...
I've yet to see one work what I'd consider perfectly. And I've seen plenty
of RF distribution systems in studio complexes. Where I assume cost
doesn't matter.
but, if you've seen them in BBC studio complexes, consider how many Studio
Capital Projects people knew anything about RF. Mike Lyons did - in the
end.
--
From KT24 - in "Leafy Surrey"
Using a RISC OS computer running v5.11 |
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| Bill Wright |
| Posted: Mon Aug 27, 2007 2:13 pm |
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"charles" <charles@charleshope.demon.co.uk> wrote in message
news:4f19112beccharles@charleshope.demon.co.uk...
Quote: I've yet to see one work what I'd consider perfectly. And I've seen
plenty
of RF distribution systems in studio complexes. Where I assume cost
doesn't matter.
but, if you've seen them in BBC studio complexes, consider how many Studio
Capital Projects people knew anything about RF. Mike Lyons did - in the
end.
Some of the worst RF botchery I've ever seen was in studios and news centres
and such like places.
Bill |
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| Bill Wright |
| Posted: Mon Aug 27, 2007 2:23 pm |
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"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:4f190fc97bdave@davenoise.co.uk...
Quote: Bill W could no doubt give you chapter and verse on this subject...
I've yet to see one work what I'd consider perfectly. And I've seen plenty
of RF distribution systems in studio complexes. Where I assume cost
doesn't matter.
Well, I'm sorry, but you're wrong. There's no great difficulty in getting
excellent results from multichannel RF systems if you know what you're
doing. We do it every day. It isn't magic and it isn't rocket science.
We have customers who demand perfection, and they get it.
My own household/workshop system carries ten in-house channels, seven
off-air analogue and six off-air muxes and believe me I won't tolerate
anything less than perfect reception.
I know what's made you believe that it can't be done. You just never seen it
done properly so you've quite reasonably reached a (specious) general
conclusion.
Some of the worst systems I've seen have been in studio complexes. I could
name names . . .
Bill |
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| charles |
| Posted: Mon Aug 27, 2007 2:27 pm |
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In article <6_ydnSUa88jiv07bnZ2dnUVZ8vydnZ2d@pipex.net>, Bill Wright
<insertmybusinessname@f2s.com> wrote:
Quote: "charles" <charles@charleshope.demon.co.uk> wrote in message
news:4f19112beccharles@charleshope.demon.co.uk...
I've yet to see one work what I'd consider perfectly. And I've seen
plenty of RF distribution systems in studio complexes. Where I assume
cost doesn't matter.
but, if you've seen them in BBC studio complexes, consider how many
Studio Capital Projects people knew anything about RF. Mike Lyons did
- in the end.
Some of the worst RF botchery I've ever seen was in studios and news
centres and such like places.
It doesn't surprise me at all. In Manchester you could watch the output of
the continuity studio in the road outside on a tv set. Talk about 'leaky
feeders'.
--
From KT24 - in "Leafy Surrey"
Using a RISC OS computer running v5.11 |
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| Mike J |
| Posted: Mon Aug 27, 2007 2:36 pm |
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charles wrote:
Quote:
but, if you've seen them in BBC studio complexes, consider how many Studio
Capital Projects people knew anything about RF. Mike Lyons did - in the
end.
Ah a name to remember - re-built London Switching Centre as well!!
Mike |
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| Graham. |
| Posted: Mon Aug 27, 2007 3:08 pm |
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"charles" <charles@charleshope.demon.co.uk> wrote in message
news:4f19141718charles@charleshope.demon.co.uk...
Quote: In article <6_ydnSUa88jiv07bnZ2dnUVZ8vydnZ2d@pipex.net>, Bill Wright
insertmybusinessname@f2s.com> wrote:
"charles" <charles@charleshope.demon.co.uk> wrote in message
news:4f19112beccharles@charleshope.demon.co.uk...
I've yet to see one work what I'd consider perfectly. And I've seen
plenty of RF distribution systems in studio complexes. Where I assume
cost doesn't matter.
but, if you've seen them in BBC studio complexes, consider how many
Studio Capital Projects people knew anything about RF. Mike Lyons did
- in the end.
Some of the worst RF botchery I've ever seen was in studios and news
centres and such like places.
It doesn't surprise me at all. In Manchester you could watch the output
of
the continuity studio in the road outside on a tv set. Talk about 'leaky
feeders'.
The MDS was reasonably well engineered when it was first installed
(in-house) in the mid 80s
Before that there was a Top Rank twisted-pair system (vision carrier
a little higher than Redifusion IIRC) feeding 22in Doric monitors.
--
Graham.
%Profound_observation% |
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| Alan White |
| Posted: Mon Aug 27, 2007 3:17 pm |
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On Mon, 27 Aug 2007 20:36:25 +0100, Mike J <mikewj@tiscali.co.uk> wrote:
Quote: Ah a name to remember - re-built London Switching Centre as well!!
Mike was the Project Engineer for the video installation assisted by
Mike Turner and Keith Sudel. I was the Project Engineer for the audio,
comms and switching installation assisted by Dave Daborn and Graham (?).
I think it was the second time that we'd used a
modular system of desk construction, the first being in Belfast CTA in
the late 60s. Prior to that, every desk panel was custom made for its
application. This was expensive and inefficient in terms of
Engineer/Draughtsman time and effort. Another Engineer, Denis Noble,
who worked for me on the Belfast CTA project, and I decided to go for
a set of standard modules which could be fitted into a desk to fulfil
the operational requirement. We used ISEP frames and modules, decided
that BBC ED24 grey was not a good colour in subdued lighting so went
for a dark green (068 in BS2660?) with yellow engraving, round push
buttons for executive functions, square buttons for non-executive and
the cabling to every panel had to be long enough to allow that panel
to be positioned anywhere in the desk. Roger Jephcott, who was the
Ops. Manager(?) requested a rearrangement one week before the service
date which was very easily accomplished. That would have been
impossible using the old construction method.
I can't remember what we used for the audio matrix but it was probably
Type 25 miniature relays which were in widespread use by then and had
replaced the PO 3000 in most applications. The video matrix would have
been a DD effort. One anomaly, which we had to overcome everywhere
with a married audio/video matrix, was that DD, in their wisdom had
wired the control inputs to the video matrix in terms of the
destinations and our audio matrix was wired in terms of the sources.
This was sorted out on PO tag blocks with the control cables from the
audio matrix being wired to the column tags and the control wires to
the video matrix being wired to the row tags (or the other way round).
Dave Daborn did a brilliant job on this desk. I think it was the most
successful desk that we'd installed up to that time and, probably,
since. Certainly there was a great deal of discussion about the layout
and the fact that it was built virtually in situ helped a lot.
--
Alan White
Mozilla Firefox and Forte Agent.
Twenty-eight miles NW of Glasgow, overlooking Lochs Long and Goil in Argyll, Scotland.
Webcam and weather:- http://windycroft.gt-britain.co.uk/weather |
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