I'm having grief with a wireless PA only system that is going in at the moment:

It's a 6 storie apartment block of concrete construction (five floors including ground plus a basement car park). There are 13 flats each to have a portable PA button. I'm using a 768r controller with two 769r expanders. These, in turn are signalling a Castle Euro-1 plus with a plugged on BluStu.

Now, it's a big site, so I put on a 1/2 wave antenna.

Here's the problem. At first, I sited the controls and antenna on the ground floor. This gave me good signal from the Txs on all floors up to and including the 2nd. Basically, floors 3 and 4 weren't having it. So, I re-sited the antenna to the 3rd floor. Still no joy on the 3rd and 4th, although all other floors were ok - even the basement. Re-sited to 4th, and even the roof, still the same situation.

It seems that I get good Tx/Rx in all areas except 3rd and 4th regardless of antenna position. In some cases - the 1/2 wave antenna won't pick up a PA pressed 5m away, but will get one 100m away.

Called Scantronic, who were as much use as a trapdoor in a canoe (and close for lunch now).

Went back with a 706 test meter (or whatever it's called). Good tx/rx in most locations (up to 9 bars) except floors 3 and 4, where I get around 3 or 4 bars. Turned it to background interference check - I regularly get 1 or 2 bars of interference, with it spiking up to 9 a couple of times per minute.

There's no indication what this might be, and I get it outside (outdoors) too.

Need help.

And "You shouldn't have used Scantronic because it's ****" is not help. I know all that.

what would happen if you put an expander high on floor two and low on floor five with there own arials

only used to risco radio so dont know if the arials fit direct to the expanders like it would on risco but just a thought

angus

Eggy

Please contact me when you can i will arrange for this to be sorted.

my number is on our website

www.coopersecurity.co.uk

Darren Cooper

Maybe ground based radar locally, especially given the fact you say the interference peeks a couple of times a minute.

Eggy

Please contact me when you can i will arrange for this to be sorted.

my number is on our website

www.coopersecurity.co.uk

Darren Cooper

why what do you obviously know that your not telling the public yet

Maybe ground based radar locally, especially given the fact you say the interference peeks a couple of times a minute.

Can never discount anything without physically checking but i doubt it is radar. 2 spikes a minute is very unlikely to be radar. If it was, you'd have it on all floors. Obviously some transmission or other is occuring and seems very directional. I'd be looking for comms dishes - light of sight transmission stuff.

why what do you obviously know that your not telling the public yet

Hmmm. Interesting point.