Commissioning new Blackhill transmitter

"Petert" wrote in message
...
On Sun, 2 Jan 2011 14:41:08 -0000, "Woody"
wrote:



The transmitters are all combined at ground level and fed by
several cables to an aerial array

Cable or waveguide?

--
Cheers

Peter



6.25" co-ax - standard in TV transmission.

You don't use waveguide at these (relatively) near d.c.
frequencies.


--
Woody

harrogate three at ntlworld dot com

Woody wrote:
6.25" co-ax - standard in TV transmission.

You don't use waveguide at these (relatively) near d.c.
frequencies.


Though much of the feeder work is indeed solid 'piping' rather than 'cable'.

Onwards from 2 min in he-

http://www.youtube.com/watch?v=uRIwphu5TaI


--
Mark
Please replace invalid and invalid with gmx and net to reply.

www.paras.org.uk

On 3 Jan,
"Woody" wrote:

6.25" co-ax - standard in TV transmission.

You don't use waveguide at these (relatively) near d.c.
frequencies.

It wouldn't be particularly large for UHF. Provision was made at the planning
stage for using waveguide on at least one mast. I don't think it was ever
used though.

--
BD
Change lycos to yahoo to reply

On Mon, 03 Jan 2011 10:32:39 +0000, Mark Carver
wrote:

Woody wrote:
6.25" co-ax - standard in TV transmission.

You don't use waveguide at these (relatively) near d.c.
frequencies.


Though much of the feeder work is indeed solid 'piping' rather than 'cable'.

Onwards from 2 min in he-

http://www.youtube.com/watch?v=uRIwphu5TaI

Interesting. I can appreciate why my tour during a open day at Black
Hill did not include a trip to the top !

Mark Carver wrote:

much of the feeder work is indeed solid 'piping' rather than 'cable'.
Onwards from 2 min in he-

http://www.youtube.com/watch?v=uRIwphu5TaI

Handy URL parameter to jump to a specific time

http://youtu.be/uRIwphu5TaI#t=2m13s

wrote:
On 3 Jan,
"Woody" wrote:

6.25" co-ax - standard in TV transmission.

You don't use waveguide at these (relatively) near d.c.
frequencies.

It wouldn't be particularly large for UHF. Provision was made at the planning
stage for using waveguide on at least one mast. I don't think it was ever
used though.

Piccies from MB21 showing 'corrugated' coax/feeder being drawn up the
Stockland Hill mast for DSO

http://tx.mb21.co.uk/gallery/stocklandhill/dso/stockland_hill-mb-20071018-04.jpg

http://tx.mb21.co.uk/gallery/stocklandhill/dso/stockland_hill-20070705-bnl-010.jpg

And lots of nice gleaming copperwork at the bottom

http://tx.mb21.co.uk/gallery/stockla...dso/shdso3.php

On Monday, January 3rd, 2011 at 14:10:08h +0000, Andy Burns wrote:

And lots of nice gleaming copperwork at the bottom

In that condition, copper is a beautiful sight to behold.

However, how long will it stay in such a pristine condition
before succumbing to corrosion in the usually damp climate
of Devon?

J G Miller wrote:
On Monday, January 3rd, 2011 at 14:10:08h +0000, Andy Burns wrote:

And lots of nice gleaming copperwork at the bottom

In that condition, copper is a beautiful sight to behold.

However, how long will it stay in such a pristine condition
before succumbing to corrosion in the usually damp climate
of Devon?

There's tens of kilowatts surging through those feeders, and the exposed
copper sections are indoors, so I can't see damp being a major problem ?

--
Mark
Please replace invalid and invalid with gmx and net to reply.

www.paras.org.uk

On Monday, January 3rd, 2011 at 15:58:48 +0000, Mark Carver explained:

There's tens of kilowatts surging through those feeders, and the exposed
copper sections are indoors, so I can't see damp being a major problem ?

I did not mean damp being a problem to the delivery of the signal, but
merely the nice new copper work losing its shiny appearance.

"Scott" wrote in message
...
On Mon, 03 Jan 2011 10:32:39 +0000, Mark Carver
wrote:

Woody wrote:
6.25" co-ax - standard in TV transmission.

You don't use waveguide at these (relatively) near d.c.
frequencies.


Though much of the feeder work is indeed solid 'piping' rather
than 'cable'.

[snip]

You can't bend 6.25" very easily but it does else it would be
difficult to get it from horizontal ex the Tx hall to vertical
for the structure! It is however still technically cable.



--
Woody

harrogate three at ntlworld dot com