I have 2 separate Lawmate 1.2 setups. I have two 3 axis gimbals and both have the identical 1.2 transmitter. I also have two Lawmate 1.2 receivers. Both setups do not work very well on channel 7 as they both have range issues. The signal just drops out completely and the range is not that great. Sometimes it works ok, sometimes they simple did not work very good at all. Sometimes I can get 500 meters of range out of it (not that I do thaht very often, sometimes I can't get 200 meters). Both setups work better on channel 1 but its illegal to use and even then I have inconsistent results. I have tried blue beam setups, stock antennas and even a high power 1.2 antenna. No antenna setup appears to be better than another. On both setups I use the low pass filter from here http://www.dpcav.com/xcart/Low-Pass-Antenna-Filter-for-1.2GHz-1.3GHz-TX.html on both setups. I've tried with and without the filters on both setups and I get no better results. I've tried it on 2 different monitors and the Zeiss glasses, same results. BTW: each setup uses different cameras, so its not a camera issue. Since I am experiencing the same isssues on both setups it basically eliminates any one bad component or wiring. I know many people have great results with this setup but I can't get it to work consistently. My Pilot 5.8 Iftron Extreme mondo setup works great for my and is very reliable but I need something for the camera feed. Is anyone running anything besides the Lawmate for the 1.2 setup? I'm using the same 1 watt transmitter from Quadrocopter, https://www.quadrocopter.com/Lawmate-12gHz-Transmitter_p_634.html and the same receiver https://www.quadrocopter.com/Lawmate-12gHz-Receiver-_p_635.html I got some big projects coming up that I need a reliable 1.2 feed. I would hate to have to remove the 5.8 system from the copter and use nothing as the pilot but the pilot needs a feed or I'm dead in the water.
Dave: do the problems happen regardless of where you are? Or just in one or two locations? I suspect there might be interference -- depending on which frequency you are on....and that could be something on the ground interfering with the reception of the 1.2Ghz. If you look at the Lawmate specifications at http://www.nghobbies.com/cart/datasheet/lawmate/TM-121800.pdf it would suggest that channels 3 and 7 are very close together. Also you can verify the frequencies and see which ones a legal. You can, if you want, also use a second 5.8 Ghz Iftron Extreme for your camera feed -- set that Tx and Rx to be at least two channels different to avoid cross-talk -- e.g. if one Tx is on channel 1, then use the other on channel 3 or higher. Andy.
HI Andy Correction: I meant to say Channel 8 (the channel its shipped on) doesn't work as well as channel 1. From all my research only channel 8 is legal to use which is why they ship it that way and glue the access to the channel selector.To answer your question I'm getting mixed results even at my house as I test so I don't think its interference issues. Interesting thought about using two iftron feeds. I'm going to be doing a little more testing on this setup.
Hello Dave, Am I correct to assume that you only have one 1.2gHz downlink on the kopter? You can run two 5.8gHz video feeds simultaneously as there is sub-frequency selections. However, this is not the case with the 1.2gHz set ups. Where do you position the antenna for the Tx feed on the kopter? Greetings, Adam
HI Adam Yes I have a 5.8 extreme mondo on the copter for me the pilot and I have a 1.2 lawmate on the 3 axis gimbal. I believe its a pretty standard setup on these copters. The Lawmate TX is on one of the landing gear legs of the gimbal and it points down away from the leg at an angle. I have two different 3 axis gimbals setup the exact same way. One has a 7D which uses the composite cable and the other gimbal uses a 760 with the lanc cable. Channel 1 1080 works better on both and more consistently than channel 8 however channel 1 is becoming more hit and miss as well as I don't have any faith in the consistency of the 1.2 system right now. What's weird is that the 1.2 system isn't working very good at my house where it was working fine before (on either gimbal).
I've pretty much eliminated both because I have 2 gimbals with the same type of transmitter and I also had a 3rd as a spare and tried that and that didn't improve anything. For the receivers I have 2 different ones. One that the cam op uses and one that I use so I can switch back and forth between feeds and I get the same thing on both receivers. I haven't tried my blue beam antenna's in a while, I'm going to give that a try.
Do you have WiFi in your house? That might be causing a problem as WiFi runs at 2.4Ghz, but 1.2Ghz is a subharmonic. Also, most houses have fairly "noisy" appliances, refrigerators, freezers, etc. Andy.
I got the system working better. I positioned the RX on the back of the radio where it's vertical that allows the antenna to be coming straight up. I bought a 5 lobe mushroom antenna from ReadymadeRC and it's working really good. http://www.readymaderc.com/store/in...duct_info&cPath=11_45_52_100&products_id=1029 the extension cable is thicker too and the construction of the lobe part is much stronger and durable. I good a solid 500 meters with it in all types of situations with the gimbal facing different directions.
Are you using a similarly shaped antenna on the Tx Dave? The 5-lobe is right-hand circularly polarized (RHCP) -- so the Tx antenna should be similarly polarized for best performance. I'd be interested to see some images of the Tx and Rx installation if you have time. Andy.
Also what is the power on your Lawmate? See the other track about 1.2 and it's affect on your GPS flight system and cellphone question.
Hi Andy Here's the pictures. The radio on the left is mine for the pilot (the one with the 5 lobe mushroom) and the one on the right is the one for the camera operator using Zeiss OLED's.
I'm using the standard 1 watt. In researching the 1.2 issues I watched the REadymadevideo that says they don't recommend anything over 300 mw for the 1.2 g band as it can affect GPS. Lots of great info on that site.
Dave the link you posted is for the Fan antenna. Is the photo of your TX not up to date with the fan?
I just realized I posted the wrong link http://www.readymaderc.com/store/index.php?main_page=product_info&cPath=165_108&products_id=1272
I just finished shooting 3 full days at a country club/golf course and both my 1.3 and 5.8 signals held up tremendously. ON a couple long holes where I can not start in the middle and fly back I had to fly it straight down from the t box up to 500 yards away and I got excellent signal. I contributing the major improvement to the 5 lobe mushroom antenna as well as placing the antenna higher as shown in the picture. I did this for my setup as well as the camera operators setup. The guy from Readymadevideo pointed out that placing the antenna even 8-10 inches higher can make a world of difference for some. The antenna orientation for the 5.8 works very well too as I can have at least one antenna mounted higher instead of both mounted about 10-12 inches lower. Can't argue with the results so its a keeper for me.