Circuit for Intercom/Speakers/Phone

[Arg]

I want a intercom in my workshop which is at the end of the garden. Prior to
building it, I pulled 4 x cables through a piece of blue water pipe and
buried them underground.

The cables are 2 x Cat 5, and 2 x "burglar alarm" cable.

I think from memory that the burglar alarm wire consists of 4 x twisted
pair - all solid. The cat 5 is 6 x wires, all stranded.

Anyway, can anyone recommend a good wired intercom site? I had a look on the
ether and although I can see lots of schematics, does anyone know of a good
site which also includes a BOM from somewhere like Maplin/Farnell/RS? This
would speedme up, but I would welcome pointers to any good sites.

I would also like to have speakers driven from the house end, not very loud
so not much current, should I go with the stranded or with the solid core or
give up with that idea? Same question for a phone extension - stranded or
solid?

TIA

Arg

 

[Dr. Anton Squeegee]

In article <3f1fc76c$0$11384$4d4eb98e@read-nat.news.uk.uu.net>, Arg
says...

I want a intercom in my workshop which is at the end of the garden. Prior to
building it, I pulled 4 x cables through a piece of blue water pipe and
buried them underground.

<snip>

Suggestion: If you don't mind mounting one control unit in a
central location, and then using two pairs (one for a standard POTS
analog phone, another for a speaker) to each location, the Valcom V-
1109RTHF talkback intercom unit would be a great choice. They frequently
turn up on Ebay, as do the 45-ohm talkback speakers and the necessary
power supplies (-24V). Simply do a search for the word 'valcom.'

The way this works is: An intercom user picks up one of the phones
connected to the controller, and dials a single digit (it will accept
tone or rotary dial) representing one of nine outputs. The speaker at
the selected location will emit a single alert tone, and then a two-way
voice path is established. The person at the receiving end can talk
hands-free.

Another option to consider would be the "wireless" intercoms which
use the power wiring as their antennae (these are also referred to as
'carrier current' devices). The problem with these is that they are more
susceptible to interference than a hardwired solution.

I would also like to have speakers driven from the house end, not very loud
so not much current, should I go with the stranded or with the solid core or
give up with that idea? Same question for a phone extension - stranded or
solid?

The question of stranded or solid has little to do with the
ampacity of the wire involved. The choice between the two should be made
based on the physical conditions the wire will be exposed to.

Example: Network and telephone wiring home runs are usually done
with solid-core wire, since this type is most amenable to being pushed
into connecting block clips. However, solid wire is unsuitable for
things like network patch cords or telephone base cords because of the
flexing that is likely to occur. For this, one should use stranded wire.

Good hunting.


--
Dr. Anton Squeegee, Director, Dutch Surrealist Plumbing Institute
(Known to some as Bruce Lane, KC7GR)
kyrrin a/t bluefeathertech d-o=t c&o&m
"Quando Omni Flunkus Moritati" (Red Green)

 

[N. Thornton]

"Arg" <too_much_sp@m_so_email_disabled.> wrote in message news:<3f1fc76c$0$11384$4d4eb98e@read-nat.news.uk.uu.net>...

I want a intercom in my workshop which is at the end of the garden. Prior to

Anyway, can anyone recommend a good wired intercom site? I had a look on the
ether and although I can see lots of schematics, does anyone know of a good
site which also includes a BOM from somewhere like Maplin/Farnell/RS? This
would speedme up, but I would welcome pointers to any good sites.

Simplest intercom is 2x balanced armature telephone earpieces,
connected directly. End of story. For alert, glue a small coarse file
on the back of aech. Scrape a nail on the file and it croaks

I would also like to have speakers driven from the house end, not very loud
so not much current, should I go with the stranded or with the solid core or
give up with that idea? Same question for a phone extension - stranded or
solid?

Stranded is flexible, solid doesnt survive repeated flexing. Stranded
is more easily corroded.

So, for flex we use stranded, and for fixed installs we use 'solid'.

Regards, NT

 

[N. Thornton]

"Arg" <too_much_sp@m_so_email_disabled.> wrote in message news:<3f1fc76c$0$11384$4d4eb98e@read-nat.news.uk.uu.net>...

I want a intercom in my workshop which is at the end of the garden. Prior to

Anyway, can anyone recommend a good wired intercom site? I had a look on the
ether and although I can see lots of schematics, does anyone know of a good
site which also includes a BOM from somewhere like Maplin/Farnell/RS? This
would speedme up, but I would welcome pointers to any good sites.

Simplest intercom is 2x balanced armature telephone earpieces,
connected directly. End of story. For alert, glue a small coarse file
on the back of aech. Scrape a nail on the file and it croaks

I would also like to have speakers driven from the house end, not very loud
so not much current, should I go with the stranded or with the solid core or
give up with that idea? Same question for a phone extension - stranded or
solid?

Stranded is flexible, solid doesnt survive repeated flexing. Stranded
is more easily corroded.

So, for flex we use stranded, and for fixed installs we use 'solid'.

Regards, NT

 

[Terry Pinnell]

"Arg" <too_much_sp@m_so_email_disabled.> wrote:

I want a intercom in my workshop which is at the end of the garden. Prior to
building it, I pulled 4 x cables through a piece of blue water pipe and
buried them underground.

The cables are 2 x Cat 5, and 2 x "burglar alarm" cable.

I think from memory that the burglar alarm wire consists of 4 x twisted
pair - all solid. The cat 5 is 6 x wires, all stranded.

Anyway, can anyone recommend a good wired intercom site? I had a look on the
ether and although I can see lots of schematics, does anyone know of a good
site which also includes a BOM from somewhere like Maplin/Farnell/RS? This
would speedme up, but I would welcome pointers to any good sites.

I would also like to have speakers driven from the house end, not very loud
so not much current, should I go with the stranded or with the solid core or
give up with that idea? Same question for a phone extension - stranded or
solid?

TIA

Arg

If you're still interested I'll dig out the circuit I used for similar
project about 20 years ago.

--
Terry Pinnell
Hobbyist, West Sussex, UK