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Joined: 5/29/2003 Last Login: 5/22/2013 From: Moreno Valley,
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Update on my range check issue, I have a SD10G that has range checked poorly with the FHSS 1 receiver at the field and at my home, The last time I performed a range check was after the rf update I had the plane in my garage and I could get to about the middle of the street and it would loose contact with the model I dont have a large yard from my garage door to the street is less than two car lenghts. Today I was at the field and my friend who also has the same radio and receiver said he had got a good range check eariler in the day I had my plane with FHSS 1 receiver so I desided to try a range check also and to my surprise we both got double the range we had got months eariler I would say over 50 ft I will say this you cant have your body between the transmitter and your model that will kill the range will quick. I dont know what changed between now and almost a year ago the only thing we can think of maybe it has something to do with the rf noise level at the field who knows.
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Joined: 6/19/2005 Last Login: 5/22/2013 From: Omaha,
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We finally got a chance to do some additional testing:
I uploaded the video we shot basically unedited. It's almost 15 minutes worth, but a pretty clear pattern develops during the video.
A) Two of the three SD-10g transmitters show a much weaker link to both receivers during testing than the RDS8000 or the third SD-10g. Harry's SD-10g performs so poorly during range testing with the RX500 receiver that we thought he might be overcontrolling the servos. You can visibly see the stronger range testing of the RDS8000 and the third SD-10g, the receiver LEDs are solidly lit up throughout the range tests and even turning to block direct line-of-sight between TX and RX from 100' away results in a lot less signal loss on the "good" transmitter tests.
B) The two SD-10g radios that performed poorly during range checks appeared to pass a basic range test from 100 feet away, but both lost control of the aircraft on the bench while testing from as close as 30 to 60 feet away. A basic range check where testing is simply performed from 100 feet away may not indicate the problem. More thorough testing, along with comparisons to signal strength from other transmitters in the exact same conditions, make the problem more apparent.
We shot all of the video within a 45 minute time span, pausing only to rebind the receivers to various transmitters and whatnot. As promised, the RF environment, test location, servos, batteries, receivers, antenna placement, airframe, weather, and every other thing we could think of was identical for all tests. The only thing that changed from test to test was which transmitter to which we were bound.
It has been said that failing a range test may not guarantee that there will be a problem while flying at full broadcast power. Harry Perkon's radio, the first tested in the video with both the RX600 and the RX500, suffered lockouts while flying at full signal strength. Harry almost lost his new GP Escapade .61 ARF, but got back control and was able to land. These tests show Harry's SD-10g failing range tests after coming back from Airtronics service and being given a clean bill of health.
Harry won't fly with his SD-10g, and based on our testing results I have to commend his decision. I have no idea why his SD-10g range tests so much more poorly than mine, even after he sent it in for the RF deck update. You can point to batteries, servos, RF noise floor, sun spots, a gypsy curse, or whatever else you think might affect the range test, but the "good" SD-10g and the RDS8000 transmitters were subject to all of the same incidental influences that the two SD-10g transmitters that performed poorly were.
Nathan King, our original poster for this thread, wasn't able to make it out to test his new SD-10g with which Airtronics supplied him. His old SD-10g, now back in stock at our local Hobbytown USA, showed the same poor range checking that Eric and Harry's SD-10g transmitters exhibit. A Hobbytown employee told us that Nathan's old radio came back into the store with a note that said "No problem found" and it is on the shelf for sale.
We have a lot of Airtronics 2.4Ghz radios in our club, and they've been very reliable. I have talked dozens of RC pilots into trying Airtronics FHSS radio systems. Our batting average for SD-10g radio systems, however is only 25% good with one remaining untested. I have no problems recommending SD-6g, SD-5g, or RDS8000 radio systems to club members, but I can't comfortably recommend the SD-10g right now. I'm the only person that I personally know of who owns one that works correctly.
I hope this extra information helps Airtronics identify the issue we've been experiencing so they can develop a fix. I'd like to feel comfortable showing off my radio system to potential Airtronics customers once again.
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Joined: 3/18/2004 Last Login: 5/21/2013 From: College Park,
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Thanks for the video.
I just checked FCC about the transmitter output of FHSS-1 and FHSS-3.
It looks like, SD10 and M11X got the same 2.4GHz module. Output power seams to be the highest on the market for any FHSS system available. Higher than Futaba, Hitec & Co. The RDS8000 has a lower output power than the SD10 and is on the line of Futaba and the like. SD5 and SD6 are close to the SD10. Of course, I talk about full power mode.
The flickering light, if I remember correctly, shows the Rx switching from one antenna to the other. It also shows hits on the same frequency. But I might be wrong. ATX might help here. Close to my Wlan station at home, I can see the flickering light occasionally. But it would not affect servo movement whatsoever.
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Joined: 6/19/2005 Last Login: 5/22/2013 From: Omaha,
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I sent my SD-10g in for service in December. Mine didn't exhibit the range testing issues that we've seen in our club, but the wind blew it over while it was sitting on a starting table, and a couple of switches got bent when it hit the ground. I also managed to melt one of my RDS8000s again when my Quick Field Charger MKII failed to peak detect my 2200Mah NiMH Hi Energy transmitter battery. I know I should have removed it from the transmitter while quick charging it, but I got distracted.
Airtronics service fixed the bent switches, and also updated the RF Deck for the FHSS-1 service bulliten. I got the transmitter back and re-checked it for range testing issues. My SD-10g is still good as gold, and I'm no longer concerned that what we've experienced is directly attributable to the FHSS-1 RF upgrade. My RDS8000 was returned good-as-new once again, none the worse for having me melt it down a second time.
Harry and Eric still have their SD-10g transmitters at Global Hobby being checked out by Airtronics service. I'll continue to post updates as this inquiry continues.
< Message edited by bigedmustafa -- 1/20/2012 7:20 PM >
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Joined: 3/18/2004 Last Login: 5/21/2013 From: College Park,
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Some thought about the range check issue in low power mode and FHSS-1 modulation.
In Normal Mode, output power is more or less the same in FHSS-1 and FHSS-3 modulation.
Let us assume Low Power Mode reduces the power of the RF signal equally in FHSS-1 and FHSS-3.
The power reduction in Low Power Mode is calculated in order to make range tests easy in FHSS-3. The manual describes two ways to conduct the range check in FHSS-3. On in Low Power mode and one in Normal Mode.
Normal Mode:
"Also, conduct a range test at the area of operation to ensure that the radio control system has complete control of the model a the farthest reaches of the operational area."
That might be a lot of effort.
This is why we rather use Low Power Mode.
According to the manual, the servos should operate w/o any glitches at approximately 30 paces between the 10ch FHSS-3 Rx and the SD-10.
FHSS-3 has more range than FHSS-1 in Normal Mode. So, why do we think the range of both modulations should be the same in Low Power Mode?
Technically, that can not be the case.
The FHSS-1 full range is over a mile, and FHSS-3 is about 2 miles.
Simplified, if we have 30 paces in FHSS-3, 15 paces might be right in FHSS-1.
< Message edited by Pippin -- 1/21/2012 12:59 PM >
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Joined: 6/19/2005 Last Login: 5/22/2013 From: Omaha,
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We were comparing the range tests of an SD-10g that had suffered a lock-out while flying against the range testing characteristics of an SD-10g that hasn't ever exhibited a loss of signal over 18 solid months of flying.
We had initially compared some failed SD-10g range tests to the same test performed with an RDS8000 to validate the rest of the signal chain, but we realized we needed to directly compare to SD-10g transmitters. That's exactly what you see during the second half of the video, where we compare two SD-10g transmitters while range testing the same RX500 with the same servos, batteries, antenna placement, environmental conditions, etc.
I am happy to report that we have Harry's transmitter back from Airtronics service. They have replaced the RF PCB unit with a new one, and they saw about a 40% to 50% better range test with Harry's SD-10g, or an improvement from 30 or 35 paces to about 45 paces while in low power mode. We haven't had the opportunity to do any outdoor testing (Omaha had a foot of snow dumped on it last weekend) as of yet, but initial indoor range testing seems to indicate that Harry's SD-10g is now working perfectly well.
We still need to do some additional testing, of course, and Harry said it would take more than a couple of flights before he was comfortable once again with flying something other than an old sport plane with his radio. I'm fairly confident that Airtronics customer service has solved the issue, however, and I'm grateful to Mike Greenshields and to Craig K. for working with us so patiently while we tried to figure out the issue.
I'm looking forward to posting additional comments to confirm that Harry's radio passed additional tests with flying colors, and that he is once again enjoying his SD-10g.
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Now that we're back to enjoying beautiful spring weather here in the heartland, Harry finally got a chance to fly his SD-10g outside again last night.
Harry started out with an electric sport plane to test the waters, and he didn't have any radio problems. Feeling more confident about his new RF PCB, Harry then flew a glow-powered Mustang kit, and he got it quite high and quite a way out from the flight line without any glitches at all.
Harry is feeling much more confident now that his SD-10g is working as good as new, and I expect he'll be flying with it regularly as the season progresses.
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RE: SD-10G & RX700 Range Check - 
