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#1
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I am looking into setting up remote monitoring of a lab at my
company using 2.4 GHz wireless cameras. The monitoring location would be in a nearby building (a few hundred feet away across a small parking lot). I know the range of those cameras is not very far, so I'm wondering if anyone has any experience using any directional antennas (such as those used for WiFi or the LPY2 "log periodic Yagi" from Ramsey Electronics) to increase range on the receiver end. Assuming the stock transmitter antennas are pointed toward the monitoring location, is there any chance I could get this to work? Recommendations for specific antenna models are also appreciated. I am planning on using an AOR AR-8600MkII receiver with NTSC decoder board since the cameras are of different makes and the channels they use vary across manufacturers. TIA, Doug |
#2
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don't use those 2.4 gig wireless cameras. they will only end up
causing you grief. instead set up a standard WAP / wifi setup and transmit the pictures using the common ( and cheap on ebay ) remote web / net cameras. you can remote control those, access the cameras anywhere from your office or home network / router / or web , store the pics on your computer, and transmit the network long distances using standard , off the shelf , WAP / wifi equipment... available at best buy or good guys. with this more desirable approach , no one can sit in your parking lot and watch everything YOU are seeing , thereby compromising your security and activities ...plus you avoid the EXTREMELY irritating circumstance of buying the equipment , installing the equipment and suddenly finding out that any tom dick or harry with a common 2.4 gig spread spectrum cordless phone will wipe out your entire wireless video system, and render it useless every time they power up the phone. ( they will sweep the camera receiver freqs and tear your video sync signals and make your video stream useless. ) the bubble of a common WAP net ( range ) can be from a few square blocks to 20 miles ..depending upon what you buy to install. stuff to do all of this is VERY affordable on ebay. it's , simply put , a standard wireless office setup , using standard web cams ... ! also good for upgrading your office net too. k....................... On Thu, 18 Mar 2004 00:22:06 GMT, "DougSlug" wrote: I am looking into setting up remote monitoring of a lab at my company using 2.4 GHz wireless cameras. The monitoring location would be in a nearby building (a few hundred feet away across a small parking lot). I know the range of those cameras is not very far, so I'm wondering if anyone has any experience using any directional antennas (such as those used for WiFi or the LPY2 "log periodic Yagi" from Ramsey Electronics) to increase range on the receiver end. Assuming the stock transmitter antennas are pointed toward the monitoring location, is there any chance I could get this to work? Recommendations for specific antenna models are also appreciated. I am planning on using an AOR AR-8600MkII receiver with NTSC decoder board since the cameras are of different makes and the channels they use vary across manufacturers. TIA, Doug |
#3
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On Thu, 18 Mar 2004 00:22:06 GMT, "DougSlug"
wrote: I am looking into setting up remote monitoring of a lab at my company using 2.4 GHz wireless cameras. The monitoring location would be in a nearby building (a few hundred feet away across a small parking lot). I know the range of those cameras is not very far, so I'm wondering if anyone has any experience using any directional antennas (such as those used for WiFi or the LPY2 "log periodic Yagi" from Ramsey Electronics) to increase range on the receiver end. Don't mess with amateur toys if you are trying to do a real job. Go to a commercial supplier such as Tessco or Tecom and get antennas made for professional use. Assuming the stock transmitter antennas are pointed toward the monitoring location, is there any chance I could get this to work? If there is *nothing* between the antennas other than atmosphere, a few hundred feet is fine. Get a gain antenna for the receiver and point it at the transmitter to null out as much of the many many other signals you will find on the 2.4 ISM (Industrial, Scientific and Medical) band, aka the garbage dump. I am planning on using an AOR AR-8600MkII receiver with NTSC decoder board since the cameras are of different makes and the channels they use vary across manufacturers. This will give you soft video. The *make* of the camera doesn't matter. The frequency of the transmitters and receivers do, and if you are running more than one link you need a good bit of frequency separation. I recommend equip and antennas from www.microtekelectronics.com. They are reasonably honest with their specs, equip is about the best quality without going to government spec, and they have some decent antennas. Put the transmitter and receiver right at the antenna and run the video up and down from them. There is much less feedline loss at video freqs than the 2.4 gig RF freqs. A few feet of antenna feedline is about the max you can get away with. The Microtek stuff can withstand the elements. Mount everything in a piece of PVC pipe to weatherproof it. I'm not affiliated with Microtek in any way. You can buy Microtek from www.atvelectronics.com. Ask for Dan Potts. They sell to dealers or to competent self maintaining end users who will not need support. There are some wireless video articles in the White Papers section of our website which may be helpful. Don't buy consumer junk or stuff from spy shops or you will be wasting your money. Steve ************************************************** ******************* Steve Uhrig, SWS Security, Maryland (USA) Mfrs of electronic surveillance equip website http://www.swssec.com tel +1+410-879-4035, fax +1+410-836-1190 "In God we trust, all others we monitor" ************************************************** ******************* |
#4
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![]() http://cgi.ebay.com/ws/eBayISAPI.dll...tegory=43 461 On Thu, 18 Mar 2004 03:05:18 GMT, krackula wrote: don't use those 2.4 gig wireless cameras. they will only end up causing you grief. instead set up a standard WAP / wifi setup and transmit the pictures using the common ( and cheap on ebay ) remote web / net cameras. you can remote control those, access the cameras anywhere from your office or home network / router / or web , store the pics on your computer, and transmit the network long distances using standard , off the shelf , WAP / wifi equipment... available at best buy or good guys. with this more desirable approach , no one can sit in your parking lot and watch everything YOU are seeing , thereby compromising your security and activities ...plus you avoid the EXTREMELY irritating circumstance of buying the equipment , installing the equipment and suddenly finding out that any tom dick or harry with a common 2.4 gig spread spectrum cordless phone will wipe out your entire wireless video system, and render it useless every time they power up the phone. ( they will sweep the camera receiver freqs and tear your video sync signals and make your video stream useless. ) the bubble of a common WAP net ( range ) can be from a few square blocks to 20 miles ..depending upon what you buy to install. stuff to do all of this is VERY affordable on ebay. it's , simply put , a standard wireless office setup , using standard web cams ... ! also good for upgrading your office net too. k....................... On Thu, 18 Mar 2004 00:22:06 GMT, "DougSlug" wrote: I am looking into setting up remote monitoring of a lab at my company using 2.4 GHz wireless cameras. The monitoring location would be in a nearby building (a few hundred feet away across a small parking lot). I know the range of those cameras is not very far, so I'm wondering if anyone has any experience using any directional antennas (such as those used for WiFi or the LPY2 "log periodic Yagi" from Ramsey Electronics) to increase range on the receiver end. Assuming the stock transmitter antennas are pointed toward the monitoring location, is there any chance I could get this to work? Recommendations for specific antenna models are also appreciated. I am planning on using an AOR AR-8600MkII receiver with NTSC decoder board since the cameras are of different makes and the channels they use vary across manufacturers. TIA, Doug |
#5
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Lots of great info so far, krackula and Steve--thanks! One question: what
do you mean by "soft video"? "Steve Uhrig" wrote in message ... ... SNIP ... This will give you soft video. |
#6
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![]() NP ....... I had a friend that owned an auto parts yard. he had 8 channels of professional , high powered, wireless 2.4 gig installed. he had it for only about 4 months and a lady down the road , a quarter of a mile, got a new ( $79 ) digital cordless phone for christmas and completely ruined the system. made his entire investment nearly useless. ( anytime her phone is plugged into the wall and not being used , it sends out a channel scanning signal that hops over a set of 50 different channels which acts as beacon for the handsets to help them know which channels are clear and ready to be used by the system . with-in these 50 channels are the same channels ALL 2.4 gig cameras use too . when this signal sweeps the video camera channels it causes the picture to destabilize momentarily and makes a loud " psssst " in the audio channels, every 3 or 4 seconds ) he offered to buy her a new 5 gig cordless phone with two cordless remotes if she would surrender her 2.4 gig model. she declined saying the 2.4 was a gift from her children and wouldn't part with it. he had numerous other interference problems , tho, and local teenagers started playing hide and seek games in his lots ( full of cars ) using those hand held video monitors ( like the icom ic-r3 ) and paintball guns. he could never catch them, because they always knew when he was coming ...... ha hahah h haha . ( parts thiefs would have had the same advantage ) k.......... On Thu, 18 Mar 2004 13:28:10 GMT, "DougSlug" wrote: Lots of great info so far, krackula and Steve--thanks! One question: what do you mean by "soft video"? "Steve Uhrig" wrote in message .. . ... SNIP ... This will give you soft video. |
#7
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On Thu, 18 Mar 2004 13:28:10 GMT, "DougSlug"
wrote: Lots of great info so far, krackula and Steve--thanks! One question: what do you mean by "soft video"? The receiver doesn't have the bandwidth for the extremely wide (relatively speaking) video signal of several megacycles. At a minimum you'd have to come off the I.F. and I still doubt you'd see decent performance. I don't know the receiver, but it needs to demodulate FM video to work at all. The various ICOM receivers with accessory video adapters stink, but without something better to compare them to you wouldn't know. 'Soft' means loss of the high frequency component at the band edges, which is contrast and sharp details. Take your TV, turn the control down from sharp to soft, and drop the contrast way back and you'll see. Colors, if you use color, will not be as crisp. If you use a decent high gain/very directional antenna on the receive end, you'll have a huge amount of fade margin and due to FM capture effect you are very unlikely to see interference from any Wi-Fi or cordless phone unless someone happened to be using the other device in the path (unlikely) and close enough to the receive antenna (also unlikely). Using the standard FCC Part 15 transmitter with very low TX power and making more system gain on the receive end where it's cheaper and legal, will go a long ways towards others intercepting the signal. It's not nearly as easy as the media likes to claim, or persons who haven't really done it. If someone is within maybe 150 feet with an average receiver they may get lucky. Anyone trying to intercept with purpose-built equipment could do better, but I rather doubt that's a concern. I've done just what I described a zillion times all over the world and had essentially no problems. I shot across the entire city of Seoul, over 20 miles airline from high rise rooftop on the receive end with a dish to a covert transmitter with patch antenna in another building with a facing window. Other than having some difficulty aligning the razor sharp patterned receive antenna with a compass and map it worked perfectly. You won't have an alignment problem because you can see the other end. The directional antenna (acceptable for use on receive end only) gives you a much stronger pattern in the direction in which it is pointing, and tends to reject signals from above and below, sides and rear. Depending on the size/gain of the antenna, your pattern might be 60 degrees down to 10 degrees or so. The more the better. Antennas at 2.4 are relatively small and lightweight and little wind loading. Read the antenna article in the White Papers section of our website for more info on antennas, gain, and why it matters. Steve ************************************************** ******************* Steve Uhrig, SWS Security, Maryland (USA) Mfrs of electronic surveillance equip website http://www.swssec.com tel +1+410-879-4035, fax +1+410-836-1190 "In God we trust, all others we monitor" ************************************************** ******************* |
#8
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On Thu, 18 Mar 2004 16:09:58 GMT, krackula wrote:
NP ....... I had a friend that owned an auto parts yard. he had 8 channels of professional , high powered, wireless 2.4 gig installed. he had it for only about 4 months and a lady down the road , a quarter of a mile, got a new ( $79 ) digital cordless phone for christmas and completely ruined the system Then the system was not professionally designed and installed. Very VERY few are. There's a lot more to this stuff than buying black boxes from a spy shop or dealer and hooking them up. There isn't enough space in the 2.4 ISM band to support 8 channels of video. 5 is the maximum, even with gain antennas to isolate. If there were 8 channels, they were spaced too closely, the receiver AFCs were fighting to decide between several channels and the effective sensitivity of the receiver would be reduced significantly. I will acknowledge you can get more separation by going to circularly polarized antennas instead of linear, and making each adjacent frequency the opposite polarization, but you're talking a lot more engineering than nearly anyone would be capable of. Anyone putting in a system in an auto parts yard is not going to be doing military grade work and spending a few hundred dollars each for sixteen antennas. The ready availability of wireless stuff has made every wannabee into a video and surveillance expert. If you don't believe they're an expert, ask them. They all think they are. The appropriate test equipment alone costs more than most of these companies will earn in a year. I train government law enforcement and see what it takes to bring competent experienced professionals up to speed on wireless video. It's nearly impossible to find a website or catalog with honest specs. 250 milliwatts at 2.4 is insanely high power and virtually never needed. All the work in wireless video is done in the antennas, not with raw insane transmit power. I've personally examined several alleged high power transmitters and not one was anywhere near rated spec. Jumping out the attenuator pads in the Wavecoms more often reduces ERP than increases it, because people screw up the impedance jumpering. You have to jumper with copper strap, not wire, and maintain the precise inductance as the SMD resistors you're replacing, or you lose signal instead of gaining it. Very easy to see on a spectrum analyzer. local teenagers started playing hide and seek games in his lots ( full of cars ) using those hand held video monitors ( like the icom ic-r3 ) and paintball guns. he could never catch them, because they always knew when he was coming Another indication the system was not professionally installed, if true. I owned an R3. Others have brought theirs over here too. My home and shop are next door to each other, on adjacent properties. I test between buildings. I keep a Part 15 2.4 gig video transmitter running constantly with color bars modulating at the house, as a test source for receiver work at the shop. Antenna is a rubber duck about the size of a cigarette. Proper equipment with simple rubber duck antennas makes it fine between the buildings, which are wood frame and only a few hundred feet apart. No foil backed insulation, just paper. The R3 would not see the same transmitter through one adjacent wall in the next room, maybe fifteen feet airline. The professional receiver sees full quieting even in the pouring rain when you need a significant fade margin. Anyone expecting the R3 to receive wireless video is likely to be disappointed. Steve ************************************************** ******************* Steve Uhrig, SWS Security, Maryland (USA) Mfrs of electronic surveillance equip website http://www.swssec.com tel +1+410-879-4035, fax +1+410-836-1190 "In God we trust, all others we monitor" ************************************************** ******************* |
#9
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Can you connect the discriminator o/p of the aor ar 8200mk3 to the video in
of a scart cable and tune around 2.4G?? Xanax. "Steve Uhrig" wrote in message ... On Thu, 18 Mar 2004 13:28:10 GMT, "DougSlug" wrote: Lots of great info so far, krackula and Steve--thanks! One question: what do you mean by "soft video"? The receiver doesn't have the bandwidth for the extremely wide (relatively speaking) video signal of several megacycles. At a minimum you'd have to come off the I.F. and I still doubt you'd see decent performance. I don't know the receiver, but it needs to demodulate FM video to work at all. The various ICOM receivers with accessory video adapters stink, but without something better to compare them to you wouldn't know. 'Soft' means loss of the high frequency component at the band edges, which is contrast and sharp details. Take your TV, turn the control down from sharp to soft, and drop the contrast way back and you'll see. Colors, if you use color, will not be as crisp. If you use a decent high gain/very directional antenna on the receive end, you'll have a huge amount of fade margin and due to FM capture effect you are very unlikely to see interference from any Wi-Fi or cordless phone unless someone happened to be using the other device in the path (unlikely) and close enough to the receive antenna (also unlikely). Using the standard FCC Part 15 transmitter with very low TX power and making more system gain on the receive end where it's cheaper and legal, will go a long ways towards others intercepting the signal. It's not nearly as easy as the media likes to claim, or persons who haven't really done it. If someone is within maybe 150 feet with an average receiver they may get lucky. Anyone trying to intercept with purpose-built equipment could do better, but I rather doubt that's a concern. I've done just what I described a zillion times all over the world and had essentially no problems. I shot across the entire city of Seoul, over 20 miles airline from high rise rooftop on the receive end with a dish to a covert transmitter with patch antenna in another building with a facing window. Other than having some difficulty aligning the razor sharp patterned receive antenna with a compass and map it worked perfectly. You won't have an alignment problem because you can see the other end. The directional antenna (acceptable for use on receive end only) gives you a much stronger pattern in the direction in which it is pointing, and tends to reject signals from above and below, sides and rear. Depending on the size/gain of the antenna, your pattern might be 60 degrees down to 10 degrees or so. The more the better. Antennas at 2.4 are relatively small and lightweight and little wind loading. Read the antenna article in the White Papers section of our website for more info on antennas, gain, and why it matters. Steve ************************************************** ******************* Steve Uhrig, SWS Security, Maryland (USA) Mfrs of electronic surveillance equip website http://www.swssec.com tel +1+410-879-4035, fax +1+410-836-1190 "In God we trust, all others we monitor" ************************************************** ******************* --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.637 / Virus Database: 408 - Release Date: 20/03/2004 |
#10
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The R3 would not see the same transmitter through one adjacent wall in
the next room, maybe fifteen feet airline. The professional receiver sees full quieting even in the pouring rain when you need a significant fade margin. I'm not any expert, but that has been my experience, also. After failing to pick up any 2.4 GHZ video on my R3, I gave in and bought a wavecom tramsmitter/reciever pair. I transmitted from my bedroom, which was a very small room at the time. The r3 picked it up inside the room, but could not pick it up at all outside the bedroom (only about 3 feet away), while the Wavecom reciever picked up the same transmission from several rooms away. Anyone expecting the R3 to receive wireless video is likely to be disappointed And yes, I did expect the R3 to recieve wireless video (from all of the advertising hype about it), and yes, I was sisappointed with it as such. As I said, I'm not any expert on this stuff. So it's good to have experts like you in this newsgroup. so that I and others csn learrn about some of this stuff. |
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