Have A Guess

[UNG]

Was the 551 a 2 track / message dialler and the 550 was a single track / message dialler

 

[tazz]

Lets conclude this for the night.....It is an old 8 track tape....this is basically an auto-dialer....using an 8 track recorded message.
When a & fire or security alarm was activated, the system would dial 999 (not allowed these days ) with a recorded messaged. The 8 track tapes were only obtained by emergency service at the time

 

[tazz]

We were next door to the drum dude

He`s nice guy, the unit is packed with drum kits, very impressive....we have just revamped the place should finish just before Christmas.....you`l have to pop in for a coffee break..