Which radio's have the best range ?

[Plantation Bruce]

I use to have an Airtronics Vanguard 6ch FM Radio back in the early 90s that had good range as I could fly my 2 meter Spirit 2000ft high, right into clouds if I wanted and maybe a 1/4 mile down range without any issues. This was on 72 mhz.

Had a friend who had range issues with his Futaba 4ch AM Radio at those heights and it wasn't funny to watch him chase after his sailplane waving his radio above his head. It too was a 72mhz. transmitter but it was AM not FM which usually doesn't have as much noise as AM does.

I see the new radio trend nowadays is moving to 2.4 ghz. I'm no electronics guy but from what I know, the higher in freq you go in most cases you get less range.

So how high and how far have you flown your sailplane with your radio system ??

Bruce

[mlee8249]

Hi Bruce,

All of the 72-Mhz radios were limited by FCC rules to an output power of 750-mw, or 3/4 watt. Some manufacturers were a bit under that, but not significantly. The most probable reason your friend lost contact was due to the AM and not FM mode of transmission. AM is more prone to interference than FM. AM means amplitude modulation, and basically means it listens to how loud the signal strength is to interpret the commands. Now, that's waayyyy basic, so you electronic wizards out there don't need to panic at my statement. But anyhoo, being it is listening to the amplitude of the given command signal, at great distance, if the signal amplitude isn't strong enough, you lose command. If you get some static in the air and that fuzzes up the signal, you start to lose command. In FM, which is frequency modulation, this doesn't happen as easily. In FM, we are shifting the frequencies within the transmitted bandwidth to cause the servo commands. As long as the signal is heard by the receiver in either case, you will have command, but AM has a harder time being understood.

[Andy W]

Range is most significantly impacted by the receiver and antenna placement than anything else. All of the current transmitters (excluding the 'toy' models of course) work well beyond visual range, as demonstrated by some of the first-person videos posted in that forum - sometimes flying miles away. I personally fly with sailplane folks who put their large models about a mile out at times. Rock solid.
..a

[onethermal]

Hi Bruce
One thing you some times need to question is My transmitter working correctly.
always do your pre-flight range check and if there is a question of range then you need to look at your equipment (AM or FM), I gave up flying AM years ago and went to FM and I have not had a range question in years. mlee has given a good basic on radio transmissions.

Now back to the transmitter, for years I have run the impound for Soar Utah and one thing we do at our site is run a scanner on all transmitters coming to the event to see if they are on the channel that they should be on. out of the many radios that have come through our impound we have only found one radio that was having a frequency modulation issue. it was brodcasting on three diffrent channels right next to the one that it was to be on so needless to say that pilot decided to put it away and send the transmitter out for service. I never heard the end result on that radio but one thing you need to keep in mind is if there is a question check it out. and the only regret you will have is that you missed a day of flying not that you should have checked you equipment first.

Clarence

[lincoln]

The only radio I ever had a straight range problem with was a Kraft, and it was 10 years old. That was in 1984. The only problems I had with AM were due to the single conversion, not the AM. I had one or two dual conversion AM receivers that were just fine. I've also been almost shot down by someone on the same channel. Again, that was with the Kraft. And the guy who turned on after me without checking DID crash.

More recently, I've had excellent experiences with the old Airtronics receivers, with the Hitec 555, and with the FMA Extreme, all dual conversion but no longer available.

My EZ Glider had a range problem which seemed to be due to the proximity of the antenna and wiring. Don't recall what I did, but it fixed the problem. So I don't count that as just a range problem.

[aeajr]

The 2.4 GHz systems from Spektrum, JR, Futaba and Airtronics all have receivers that are rated for visual range. If you can see it you can fly it.

Spektrum, also offers very small, light weight receivers that are recommended for shorter distances. But Spektrum has long range receivers too.

Not really an issue with any of these.

Using a shorter range AR6100 receiver I have had an Easy Glider out and up about as far as I care to take it. I don't have a GPS on it but I would guess it was at least 2000 feet and perhaps more. With the AR6200, I would not hesitate to take it out to a dot.

[jtlsf5]

I did a real time ground range check about 15 years ago when I first acquired a rubber duck antenna for my Vision. I had a friend hold the plane as I drove away down a road with 3 miles line of sight back to the flying site. I move one control for authority, with the other controls for stability. We communicated by cell phone (the big, old clunky ones). I got to 1.1 mile on the ground before the plane lost both stability and authority. This road had power wires along it, so actual might have been higher.

When I got my Stylus in 1995, I repeated this test and got 1.25 miles. These were good enough for me and I have used the duck antennas for all flying activity (HL to XC) since with no TX-induced equipment problems.

JT