daubs8 Posted September 22, 2008 Share Posted September 22, 2008 This may or may not surprise a few but I have encountered a major problem with the latest Wireless Redwall transmitters and receivers. Over the past 12 months or so I have fitted dozens of the things and found them much better than the previous versions. However, I had a site a 3 or 4 weeks ago which has approx 16 redwall wireless detectors on it which suddenly encountered an 'RF Jam' fault on the receiver and constant flashing lights. Optex technical weren't much help and said they hadn't encountered it before. To fix the problem I replaced the receiver and 3 expanders and so far all is well. Last week the same fault occurred at another site. I got Optex technical out to site who proceeded to scan the area with a meter. The outcome was that 2 x large transmitters on a nearby football ground were causing the jam. I don't know when the transmitters were erected or whether the frequency's had been changed but the site had been fine since install at Christmas. When asked what could be done to fix the problem the tech said the detectors had to be hard wired as there was no way of altering the frequency of the Redwall equipment. Brilliant!! Had we been able to use wired in the first place then we would. The investigation is in it's early stages but I will certainly be pursuing it! In the meantime I will not be using the Redwall wireless transmitters/receivers (wf100 eu and cu) ever again and would urge others not to either (just an opinion). It is only 2 sites but too much of a co-incidence that the same fault has occurred exactly 8 months after install? I am expecting a report from Optex and will post the outcome. Be careful if specifying these! Link to comment Share on other sites More sharing options...
luggsey Posted September 22, 2008 Share Posted September 22, 2008 This may or may not surprise a few but I have encountered a major problem with the latest Wireless Redwall transmitters and receivers. Over the past 12 months or so I have fitted dozens of the things and found them much better than the previous versions. However, I had a site a 3 or 4 weeks ago which has approx 16 redwall wireless detectors on it which suddenly encountered an 'RF Jam' fault on the receiver and constant flashing lights. Optex technical weren't much help and said they hadn't encountered it before. To fix the problem I replaced the receiver and 3 expanders and so far all is well. Last week the same fault occurred at another site. I got Optex technical out to site who proceeded to scan the area with a meter. The outcome was that 2 x large transmitters on a nearby football ground were causing the jam. I don't know when the transmitters were erected or whether the frequency's had been changed but the site had been fine since install at Christmas. When asked what could be done to fix the problem the tech said the detectors had to be hard wired as there was no way of altering the frequency of the Redwall equipment. Brilliant!! Had we been able to use wired in the first place then we would. The investigation is in it's early stages but I will certainly be pursuing it! In the meantime I will not be using the Redwall wireless transmitters/receivers (wf100 eu and cu) ever again and would urge others not to either (just an opinion). It is only 2 sites but too much of a co-incidence that the same fault has occurred exactly 8 months after install? I am expecting a report from Optex and will post the outcome. Be careful if specifying these! What frequency are they on? The new 900MHz frequencies are close to mobile phone frequencies so RF field strength near a comms mast will block them out. With the amount of comms masts springing up on buildings now there is going to be more of this! Ask Optex to increase the RF shielding and improve the RF front end rejection or declare the product unfit for purpose. ----------------------------------------------------------------------------------------------------------------------------------- Life is like a box of chocolates, some bugger always gets the nice ones! My Amateur Radio Forum Link to comment Share on other sites More sharing options...
james.wilson Posted September 22, 2008 Share Posted September 22, 2008 Any wireless system is succeptable to this. If something goes up in the area then you may have issues. to be fair any wireless device with jamming detect will have this problem. We had a site near sutton coldfields tranmitter, after the on-digital switch on we had issues with some old scanny 4600. Had to use the high powered tx, with direction aerials (should have given us 3km) just to get 40m. Still going strong now and been in well 5 yrs before the ondigital switch on lol securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount. Link to comment Share on other sites More sharing options...
daubs8 Posted September 23, 2008 Author Share Posted September 23, 2008 What frequency are they on? The new 900MHz frequencies are close to mobile phone frequencies so RF field strength near a comms mast will block them out. With the amount of comms masts springing up on buildings now there is going to be more of this!Ask Optex to increase the RF shielding and improve the RF front end rejection or declare the product unfit for purpose. Thanks. I will do. Got a reply today but it merely states he tested it and found two transmitters nearby! I have asked for his expert opinion on why two sites have suddenly suffered this RF jam exactly 8 months after install. So luggsey, I need to word it exactly how you have stated "Optex to increase the RF shielding and improve the RF front end rejection" ? Is this something they could do at site or is it something major they need to do at production stage? Thanks. p.s. They operate at 868Mhz. Link to comment Share on other sites More sharing options...
Doktor Jon Posted September 23, 2008 Share Posted September 23, 2008 It's probably fair to say that Redwalls are not really my ball game, but it does occur to me that if the units are that prone to accidental jamming from spurious local signals, that doesn't say much for their use in a higher security situation, where deliberate jamming may be a potential risk. It will certainly be interesting to see if the design engineers can come back with a workable fix. Thanks for flagging this issue daubs8 Link to comment Share on other sites More sharing options...
Alarm Co Posted September 24, 2008 Share Posted September 24, 2008 are optex supplying equipment to do a site test before install ?? Link to comment Share on other sites More sharing options...
daubs8 Posted September 25, 2008 Author Share Posted September 25, 2008 are optex supplying equipment to do a site test before install ?? No but they will sell them to us! Thing is, you could conduct a site survey which will be clear of any interference then 6 months later a transmitter is erected nearby which can render the system useless! Link to comment Share on other sites More sharing options...
james.wilson Posted September 25, 2008 Share Posted September 25, 2008 But surly this can happen to any rf based system. Maybe the jam detection needs to be more intelligent rather than just looking for activity on a set freq? securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount. Link to comment Share on other sites More sharing options...
kensplace Posted September 25, 2008 Share Posted September 25, 2008 If its wireless (any make, not just restricted to optex) then you cant expect it to operate trouble free for ever, as if anyone, on puts up a more powerful transmitter that interferes, it will cause problems. There are not that many free frequencies available for manu's to legally use, and wireless equipment is getting more popular so the chances of interference cropping up is only going to get worse in the future. Using wireless is like using a wired system with your wires outside of the protected area, its open to someone coming along and interfering, accidentally, or not... Even if all the interference does is drown out your end, its enough to screw up your setup. Perhaps redwalls (and other product from other manu's) should use plug in tx and rx modules that offer a choice of frequencies so you can swap them out if problems occur. Link to comment Share on other sites More sharing options...
luggsey Posted September 25, 2008 Share Posted September 25, 2008 If its wireless (any make, not just restricted to optex) then you cant expect it to operate trouble free for ever, as if anyone, on puts up a more powerful transmitter that interferes, it will cause problems.There are not that many free frequencies available for manu's to legally use, and wireless equipment is getting more popular so the chances of interference cropping up is only going to get worse in the future. Using wireless is like using a wired system with your wires outside of the protected area, its open to someone coming along and interfering, accidentally, or not... Even if all the interference does is drown out your end, its enough to screw up your setup. Perhaps redwalls (and other product from other manu's) should use plug in tx and rx modules that offer a choice of frequencies so you can swap them out if problems occur. There is already kit that is way ahead of this, it's called broad spectrum frequency hopping, some of the 2.4GHz/5GHz already use it but it needs a wider frequency allocation which is not on VHF/UHF/SHF due to the small spectrum allowance. If any manufacturers kit is so easily disabled by a comms mast then it's unfit for purpose end of... ----------------------------------------------------------------------------------------------------------------------------------- Life is like a box of chocolates, some bugger always gets the nice ones! My Amateur Radio Forum Link to comment Share on other sites More sharing options...
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