Very simple radio pager design needed

[Rob Storey]

Hi All,

Searches produce an overwhelming number of hits, and more complex than
I need. I'm hoping someone here has had experience in this area.

What's required is a simple building pager to alert someone anywhere
in the building to come to the rear door. So the transmitter location
is fixed, and only 1 bit of information needs to be sent.

The problem is that the building contains heavy concrete interior
walls, so range will be an issue. The building is fairly large,
requiring a range of about 75m.

Has anybody got some pointers to a design for a transmitter/receiver
combination that might do the job?
I'm hoping there are small hybrid TX/RX modules that would work, such
as these:-
http://store.yahoo.com/e-clec-tech/wirelessrc.html

Thanks in advance,
Rob Storey

 

[Joerg]

Hello Lewin,

It's not the concrete so much as the steel bars inside it that cause
problems...

Also aluminum backed fiber insulation in the walls. Lower frequencies
can help.

Regards, Joerg

http://www.analogconsultants.com

 

[Bob Monsen]

Rob Storey wrote:

Hi All,

Searches produce an overwhelming number of hits, and more complex than
I need. I'm hoping someone here has had experience in this area.

What's required is a simple building pager to alert someone anywhere
in the building to come to the rear door. So the transmitter location
is fixed, and only 1 bit of information needs to be sent.

The problem is that the building contains heavy concrete interior
walls, so range will be an issue. The building is fairly large,
requiring a range of about 75m.

Has anybody got some pointers to a design for a transmitter/receiver
combination that might do the job?
I'm hoping there are small hybrid TX/RX modules that would work, such
as these:-
http://store.yahoo.com/e-clec-tech/wirelessrc.html

Thanks in advance,
Rob Storey

Those might work, but you can get them far cheaper here:

http://www.futurlec.com/cgi-bin/search/search.cgi

How about a wired bell, or a loud horn?

--
Regards,
Bob Monsen

If a little knowledge is dangerous, where is the man who has
so much as to be out of danger?
Thomas Henry Huxley, 1877

 

[Joerg]

Hello Bob,

How about a wired bell, or a loud horn?

The "Trader Joe's" stores around here use real bells. They are loud and
have the benefit of being power outage proof.

Regards, Joerg

http://www.analogconsultants.com