Ian Jones Posted January 17, 2011 Share Posted January 17, 2011 The actual antennas on a 2.4 Rx are about 30mm long. On some RXs the antennas are exposed immediatly after the wires exit the RX case, very handy if there is nothing near to the Rx that affect the signal (metal, carbon fibre and items containing these). Some RXs have the antennas on longer leads, these amount to extensions to allow the actual exposed 30mm section at the end (i.e. the antennas) of the wires to be positioned away from anything that may affect the signal (metal, carbon fibre and items containing these). That may in some cases mean routing them to an external part of the aircraft. Holding the antennas in the required position can acheived by many methods and one is by placing tubes of a suitable bore at the required locations and inserting the antennas in them. The instructions that came with the RX should indicate the manner in which the antennas should be placed in relation to each other - often this is at 90 degrees but not always. Some, possibly yours by the sound of it should be parallel to each other at about the same distance apart as they are when they exit the Rx case. Quote Link to comment Share on other sites More sharing options...
Ian Jones Posted January 17, 2011 Share Posted January 17, 2011 Shaun, how about repeating your range check with the antennas mounted on one side of the aircraft and with that side of the aircraft facing the TX. Then do yet another range check with aircraft turned so that the fus masks the antenna from the TX? I don't know if there is any metal in silver solarfilm, your experience suggests there is, perhaps this test wil help to detimine that. Quote Link to comment Share on other sites More sharing options...
Shaun K Posted January 17, 2011 Share Posted January 17, 2011 Thanks Ian, I'll run a few tests as you suggest and report back in the next few days. Shaun. Quote Link to comment Share on other sites More sharing options...
Guest Posted January 17, 2011 Share Posted January 17, 2011 Silver paint sometimes consists of very fine metallic- aluminium - particals ( to give it the metal colour ) suspended in the paint coat. As solarfilm has a layer of silver paint on the film, then if the paint is made up as I suggest above, then shielding of the signal is probably taking place. Even if you poke the aerials outside the fus, you can still have the fus and/or the wings coming between the Rx and the Tx. Try a range check as Ian suggests ( Going way back, you could buy very fine aluminium or copper/brass particles to add to clear dope to get a metallic finish ) john Quote Link to comment Share on other sites More sharing options...
Keiran Arnold Posted January 17, 2011 Share Posted January 17, 2011 Geoff the only "thicky newby" question is the one that you don't ask. Radio st ups can be confusing to a beginner so better to ask than crash and find out the hard way Quote Link to comment Share on other sites More sharing options...
Geoff Smith 1 Posted January 17, 2011 Share Posted January 17, 2011 Posted by Keiran Arnold on 17/01/2011 18:12:50: Geoff the only "thicky newby" question is the one that you don't ask. Radio st ups can be confusing to a beginner so better to ask than crash and find out the hard way Thanks for this Keiran. Does it matter then that the antennas on my receiver are only 1" long? Now, the given range for this radio gear of mine is 200metres on the ground and 500 metres in the air, does the fact that the antennas are shorter than most contribute to the short range capability and is it therefore the receiver which governs the range. Could I buy another (proper) receiver and increase the range or does the transmitter have a restriction on it as well?. Cheers mate. Geoff Quote Link to comment Share on other sites More sharing options...
flytilbroke Posted January 17, 2011 Share Posted January 17, 2011 For 2.4 GHz your actual Antenna is NOT short. On the Receivers which appear to have a longer Antenna the little bit at the end is the actual Antenna. The rest is co-axial cable which has the correct impedance for the job. On your short range design the set-up of the Receive Antenna is more critical than some others. Quote Link to comment Share on other sites More sharing options...
Geoff Smith 1 Posted January 17, 2011 Share Posted January 17, 2011 Posted by flytilbroke on 17/01/2011 19:18:24: For 2.4 GHz your actual Antenna is NOT short. On the Receivers which appear to have a longer Antenna the little bit at the end is the actual Antenna. The rest is co-axial cable which has the correct impedance for the job. On your short range design the set-up of the Receive Antenna is more critical than some others. Thanks for this Flytilbroke. By 'setup' does that mean that I should be altering the receiver in any way? I haven't seen any instructions for this in the very sparse blurb you get with it. Cheers mate Geoff Quote Link to comment Share on other sites More sharing options...
Ian Jones Posted January 17, 2011 Share Posted January 17, 2011 Hi Geoff, You may be attaching too much importance to the range of your equipment. Unless I'm thinking of the wrong model your Cessna has wingspan of around 40" in which case you could run into a lot of difficulty flying it anything like 500 metres away. My Art-tech Typhoon is a little long in the tooth now but that came with a receiver with a range of just 350 metres and I had no problem at all. (I've changed the RX & TX now but for for unrelated reasons). Most 2.4 TX's can be switched to a range checking mode but the E-Fly ETB41-2 that came with my Typhoon does not so for peice of mind I tested the full range on the ground. 200 metres isn't a long walk so it may well put your mind at rest if you did the same. You mentioned that you are new to this sport which is great and I hope you get a great deal of pleasure from it. Quote Link to comment Share on other sites More sharing options...
Geoff Smith 1 Posted January 17, 2011 Share Posted January 17, 2011 Thanks for this Ian. My Cessna is the bigger 500 series version with the 51" span. It's a bit rapid and could get away a bit quick, which is a bit worrying until I get me twiddle fingers back again. Ground range checked out with the help of my son, that was ok, that was the first thing I did. I'm not quite new to the sport, I am a returning angel. The last time I flew was 1992. Cheers mate. Geoff Quote Link to comment Share on other sites More sharing options...
Ian Jones Posted January 17, 2011 Share Posted January 17, 2011 Well welcome back Geoff, sorry if I seemed to be teaching you suck eggs. Quote Link to comment Share on other sites More sharing options...
Eck Posted January 17, 2011 Share Posted January 17, 2011 Posted by Geoff Smith 1 on 17/01/2011 19:22:38:Posted by flytilbroke on 17/01/2011 19:18:24: For 2.4 GHz your actual Antenna is NOT short. On the Receivers which appear to have a longer Antenna the little bit at the end is the actual Antenna. The rest is co-axial cable which has the correct impedance for the job. On your short range design the set-up of the Receive Antenna is more critical than some others. Thanks for this Flytilbroke. By 'setup' does that mean that I should be altering the receiver in any way? I haven't seen any instructions for this in the very sparse blurb you get with it. Cheers mate Geoff Re FTB's post, Geoff, I think he means the angle between the aerials is more critical than with full-range receivers. If the instructions say they should be parallel, as on the AR6100 series, they should be sticking out straight from the sides of the receiver, not bent to fit into the space available. Quote Link to comment Share on other sites More sharing options...
Shaun K Posted January 18, 2011 Share Posted January 18, 2011 Latest round of tests completed and early indicators are pointing to a failing flight pack. I removed the whole receiver from the plane and had the two antennas sticking up nice and high in clear air - no obstructions anywhere. Initial range tests were OK but within a couple of minutes I started losing comms again - much like the first flight a few days back! Since this is in my trainer with tricycle undercarriage, moving the rudder from side-to-side while the plane is sitting still puts a reasonable load on the servo driving the nosewheel steering and therefore a load on the flight pack. I was able to repeatedly lose comms in range check while loading up the battery with continual movement of the nosewheel steering. Stopping the movement for a bit let things recover and comms would return. Further evidence of the flight pack being on its way out - the flight pack (4.8V) was given a full charge prior to Sunday's flight, ending at around 5.9V. The flight lasted only about 5 minutes and with 10 minutes of testing today the pack was right back down to 4.81V already. I used to do 4 or 5 15 minute flights in a session and a recharge still came nowhere near the battery's capacity. I suspect that a new flight pack and better antenna placement my problems will disappear. Quote Link to comment Share on other sites More sharing options...
Geoff Smith 1 Posted January 18, 2011 Share Posted January 18, 2011 Posted by Ian Jones on 17/01/2011 20:37:12: Well welcome back Geoff, sorry if I seemed to be teaching you suck eggs. Hiya Ian, not at all mate, any help and encouragement is appreciated thanks. Cheers my friend Geoff Quote Link to comment Share on other sites More sharing options...
flytilbroke Posted January 18, 2011 Share Posted January 18, 2011 Eck got around to a decent reply before I did I do not know first hand many of the 2.4Ghz Receivers, I do know that Spektrum or some Spektrum Rx's are sensitive to a drop in voltage. Perhaps other makes are too. In the size of models I have Spektrum Rx's fitted to, I use 5 cell packs for that reason. Shaun, a 4 cell pack is a 4.8 volt pack, initial charge nearly always peaks above that and drops to the main voltage fairly soon, and even below that under a load. Many standard packs/cells also self discharge faster than we would like, although the newer "instants" and "eneloop" cells retain voltage/charge rather better. If in doubt always better to fit new packs, they are cheaper than ,,,,,, Quote Link to comment Share on other sites More sharing options...
Shaun K Posted January 24, 2011 Share Posted January 24, 2011 Hi folks, A follow up to my range testing problems of last week. A new flight pack has confirmed for me that the 2.4Ghz gear is fine and range testing with new 2000mAh flight pack resulted in unbroken communication up to around 25m away. Much different to the previous attempts with an aging flight pack. Thanks to all for your input. Best regards, Shaun. Quote Link to comment Share on other sites More sharing options...
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