ivp wrote:
>> I was thinking of 433MHz with a simple decoder chip, similar to
>> a garage door opener. The arena is enclosed with sheet iron
>> panelling, and the closest parking is probably 50 metres outside
>> which should limit interference from car remotes
>>    =20
>
> I use the 433MHz ZW3100 and ZW3102 modules, originally
> from Jaycar/Electus but now I get them in quantity from Taiwan
>
> A 12F629 is used at either end to handle Manchester encoding of
> a number unique to each pair. Time delay for this is about 200ms
>
> 200m line-of-sight is possible with a 1/4 wave (34cm) aerial in good
> conditions. 100m is very reliable outside, even in heavy rain through
> two wet buildings. Range is still OK with 1/16th, or even no aerial.
>
> I've not experienced any interference problems in several years
>  =20

The receivers will be worn under heavy coats with potentially sweaty=20
performers, so I'm not sure how much that will knock the signal around. =20
I haven't seen the costumes close up yet, so not sure how easy it will=20
be to place a large aerial.
David...

--=20
___________________________________________
David Duffy        Audio Visual Devices P/L
Unit 8, 10 Hook St, Capalaba 4157 Australia
Ph: +61 7 38235717      Fax: +61 7 38234717
Our Web Site: www.audiovisualdevices.com.au
___________________________________________

--=20
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