Very simple radio pager design needed

Does this have to be legal? If so, you might be better off with a powerline based solution.

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

Radio Shack has a system that may meet your needs - 1.4mile range, 1000 receivers...

kevin

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:-

Thanks in advance, Rob Storey

Hello Lewin,

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

Regards, Joerg

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

How about a wired bell, or a loud horn?

Hello Bob,

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

Regards, Joerg

Yes, I've actually bought some there ages ago, but couldn't find their page with a picture (there is one), so I used the other link for my question. (haven't tried them yet, didn't think they'd do this job)

The building is a cinema, so horns & bells are ruled out.

Cheers, Rob Storey

Looks good, though not carried by Tandy in AU. I'll pass that on to the enquirer.

Thanks to all who replied.

Rob Storey