> The receivers will be worn under heavy coats with potentially > sweaty performers, so I'm not sure how much that will knock > the signal around A customer I'm trying to convince to use my units has been trying them out. He didn't believe me when I told him the signal is pretty pervasive. Get this - he put the receiver in a saucepan, inside the oven and he transmitted from inside his car. No problem. Now he believes me > I haven't seen the costumes close up yet, so not sure how easy > it will be to place a large aerial A piece of hook-up wire will probably do fine For a project I'm evaluating I might use a repeater. That would be to keep the user's aerials short, with the repeater having the long one. However, it would be possible to design a tuned system that doesn't rely simply on aerial length. That is the next step in my evaluation Joe * * ********** Quality PIC programmers http://www.embedinc.com/products/index.htm ----- Original Message -----=20 From: "David Duffy (AVD)" To: "Microcontroller discussion list - Public." Sent: Saturday, July 24, 2010 4:41 PM Subject: Re: [EE] Cheap & simple RF link > 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 >>> >> >> 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 >> > 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 > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist ---------------------------------------------------------------------------= ----- Internal Virus Database is out of date. Checked by AVG - www.avg.com Version: 8.5.439 / Virus Database: 271.1.1/3009 - Release Date: 07/16/10=20 06:35:00 --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .