Old Magnavox Home Security Console setup question.

[Steevo]

I have an old Magnavox home security system, in my archives.
HST-404, the fancy looking one, looks like an answering machine.
I got it out because I needed some alarms, until I can get something better.
I put the PIR in, and it set up it's zone. Worked fine.
I put a couple of door sensors in, no problem.
But the external powerhorn siren setup instructions don't seem right to me.
It says set house code, no problem, I did that.
Then it says to pick a high unit number that you are not using.
No problem, I picked 15 by setting the dial on the powerhorn to 15.

The instructions then say to press a unit number for the siren.
I guess that means set the slider to install sec and press 15 and it will know I mean siren?
I did that but I can't get any of the sirens to sound, either on the console or the remote one I set up.
I tried panic and I tried panic on the keyfobs, which I have set and are working.
There is something here that I don't understand.

[Brian H]

The Powerhorns will not sound with a simple X10 On command.
They need a constant one second On Off cycle to the X10 address they are set to.
Not familiar with the old system but if it has a address to flash some X10 lights. Try setting the Powerhorns to the same address as the security lights will be flashed with.

[Steevo]

I've given up on that, I found some defects in it likely caused by aging components.
I will be posting again on my new effort, again with old stuff from my archives.