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Title: Range Of FM radio system Post by: rcforall on March 23, 2010, 01:48:08 PM Interesting discussion going on in RCG relating to FPV .
The range achieved with Corona and conventional receivers is interesting , so I thought I will link it here for benefit of all : http://www.rcgroups.com/forums/showthread.php?t=1214302#post14668409 I was told the same thing by Singa Hobbies when I asked their frank opinion 3 kms line of sight without obstruction ie gain altitude so that the aircraft is far above obstructions and Tx antenna is pointed towards Rx antenna :o Sai Title: Re: Range Of FM radio system Post by: izmile on March 23, 2010, 06:10:15 PM About a year before Sai and me tested the corona receiver's range (on ground). I was pretty much amazed by the range acheived. To be honest, we could not make the receiver to glitch even at ~1000 meters range. In fact, I returned back as it was way too far for a receiver range check. Impressive!
-Ismail Title: Re: Range Of FM radio system Post by: anwar on March 23, 2010, 06:48:11 PM Does it support a "reduced power" range test mode? And you got 1000meters with or without such reduction ?
Normally this question does not make sense, but with Corona receivers having said to have ranges up to 5km :o, it may not be a stupid question ! Title: Re: Range Of FM radio system Post by: izmile on March 23, 2010, 06:56:18 PM This is the "receiver" and I don't think there is a reduced power mode available. However, it is worth mentioning that the test was done using a standard futaba transmitter with its antenna pulled in. Note that we could not find the maximum range. The receiver kept on working without a glitch and we gave up. Truely, incredible receiver perfomance!
Title: Re: Range Of FM radio system Post by: anwar on March 23, 2010, 06:57:50 PM Yep, that is what I meant to ask, with the antenna pulled in the case of FM. Too much 2.4Ghz in my head :)
In any case, your response removes the ambiguity; and it does confirm that these provide great range. Title: Re: Range Of FM radio system Post by: rcforall on March 23, 2010, 07:20:07 PM Ismail ,
that time I knew it was good but I never imagined the range these guys are achieving :o . Mind you this range is got a catch " CLEAR LINE OF SIGHT ". I went 1.28 km on the easy glider and not a glitch :salute: One may be stupid question " why is range better at higher altitude " eg when my Easy glider pro went up to 400 m I could not see the plane but the Video transmission and Image quality improved drastically not a line on the screen but a 50 m there was some disturbance. sai Title: Re: Range Of FM radio system Post by: izmile on March 23, 2010, 07:41:32 PM Sai,
The disturbance is caused due to ground effect. There would be some reflection and absorbtion of the RF energy by the earth and this would result in loss/distortion of the received signals. When you are at a higher altitude there is more chance of a direct wave from the transmitter reaching the receiver but at lower altitude there would be more reflected waves reaching the receiver. Further, the direct wave would be also degraded. These reflections are NOT easy to measure or reproduce. That is why the range is quoted in line of sight. For a technical explainiation: http://en.wikipedia.org/wiki/Antenna_%28radio%29#Effect_of_ground Now, you are learning radio communications the practical way! -Ismail Title: Re: Range Of FM radio system Post by: ujjwaana on March 31, 2010, 03:18:28 PM Hey Sai, I just found something 'Very long range' 2.4G system (100KM!!)
http://www.rcgroups.com/forums/showthread.php?t=905915&highlight=futaba+receiver+antenna+modification http://www.webx.dk/rc/uhf-link3/uhf-link3.htm http://www.webx.dk/rc/uhf-link3/pa7w.htm Hope it helps! Looking fwd for your plane takeoff form Chennai and land in Bangalore :D Title: Re: Range Of FM radio system Post by: rcforall on March 31, 2010, 08:18:12 PM Hi Ujjwal ,
Thanks I am most likely going for this one : http://www.terranova.net/~winger/RCVideoStore/DragonLink/DragonLink.htm Thomas's system is also good . Thanks again Sai Title: Re: Range Of FM radio system Post by: FGFAPilot on February 28, 2012, 09:07:37 PM Hi guys I'm new in the forum and wanted to know how much range would i get with Tx-JR XF631 and Rx-R700 at 35mhz
I heard you could 1.5 km on standard 35mhz system, and is this frequency legal in india (I plan to build a fpv plane) Title: Re: Range Of FM radio system Post by: anwar on February 28, 2012, 09:20:20 PM Questions like is this frequency legal are easily solved in searches !
http://www.rcindia.org/search2?search=legal+frequency Why are people not searching before asking ! :) Title: Re: Range Of FM radio system Post by: FGFAPilot on February 29, 2012, 07:00:58 PM oh sorry didn't search it, will do for in future
thanks for the link by the way ;D |