That's what I was thinking....

Originally Posted by Daemon

Confusing video since there's no distance displayed or any indication of when it's actually in failsafe.

ian

Sorry comparing it to Chainlink. failsafe was at 3km away and 1500m high.

Funny it should failsafe when it did!

Originally Posted by Cir2kuk

Funny it should failsafe when it did!

Isn't that around the same location where it happened last time? Have you tried flying in the opposite direction? Just wondering if there's a powerful transmitter that direction.

Originally Posted by Daemon

Ok, well I'm just telling you, 12-15 seconds can be way too long to set the failsafe in the air,
which is how many of us do it. (trim for wings level, set appropriate throttle, little extra up trim,
maybe turn the camera pan slightly off center so can see when it jumps to failsafe.. etc, couple clicks
of rudder trim, and then set the failsafe). Problem is, failsafe trim is often the trim of
last resort and not how'd you'd normally fly so can't afford to wait 12-15 seconds for
it to record those positions while attempting to fly normally.

And then there's the random glitch after it records the positions, which could cause any
number of bad things to happen (imagine what a glitch looks like to any
rotor-craft).

ian

the mode button has other funtion for OSD, so the fs setting still need more than 5seconds.
so if i reduce it down to 5seconds, that would be ok?


Sid

Originally Posted by Cir2kuk

Not impressed! failsafes within 3km. failsafe at 6:42!

http://www.youtube.com/watch?v=iMbNk2YeB9g

maybe the antenna mismatch, if u still think the tx has an issue, just make the ground range test ,and email to me. you can send tx back to me for repair.


Sid

Originally Posted by sid.huang

the mode button has other funtion for OSD, so the fs setting still need more than 5seconds.
so if i reduce it down to 5seconds, that would be ok?

5 sec would be a definite improvement.

ian

While I no longer trust ground range test results as definitive (I've seen great variations
between ground tests, and in-air performance due to local Rf environment in the sky),
I still do them with all my control systems (both UHF and 2.4Ghz) as it does sometimes
weed out the under-performers.

Tonight I did a range test tonight with the transmitter set up on a tripod on a small hill (usual
spot), and Rangelink Tx module set at 400mW. Drove off with RL Rx antenna taped to
my windshield. Transmitter was cycling all the channels, and I had a servo with long
arm taped to the dash so I could watch it for glitches, although the blinking light on the Rx
is generally sufficient to see packet lossage. In addition to watching it while I drove, I
stopped and tested my 2nd RL Rx in my FPV Skywalker at 5 miles, 7, 10, 11, 14, and
topped out at 19.3 miles before driving behind a hill beyond which I would never regain LoS.

Still had a solid signal at 19.3 miles (31_km) as long as I had clear LoS to the Tx,
and even had it in 90% of all Rx antenna orientations (doesn't like pointing straight away).
It definitely helps to orient the ground plane (counterpoise) about 45 degrees away from
the coax feed line (should never let it run parallel to the feed line, although that's
the way it wants to sit given the way the antennas are built).
Powered up my Skywalker's ESC, ESC's BEC powering the RL Rx, plugged in couple
servos to cycle, and powered all FPV gear (1.3Ghz vid Tx, Camera, mic) as well as
testing with GoPro in close proximity, and other than a very slight degradation from the
GoPro when it was held against the antenna, it all worked fine together, all the way out
to 19.3 miles.

Back at 7 miles, I tested my Tricopter which has a brutally UHF noisy SN777 (aka VSN500)
camera, and it definitely killed the signal if the RC Rx antenna was anywhere within
about 8 inches of the camera. At 5 miles, could only get it to kill the signal if Rx antenna
was also pointed straight at Tx and pretty close to the camera. At 2 miles, totally solid in
all orientations even with camera less than 5 inches away from RL Rx antenna, which is
actually a pretty significant improvement over some of the other UHF systems I've
tested.

Because the Rangelink Rx has a SAW filter, I suspected it might be more resistant to
external Rfi, which is why I picked one up to test, and so far my tests have
supported that hypothesis. I need to get it in the air, and I need to
do some range testing in my usual high Rf noise environment (within
a few miles of the radio towers), but the results are positive so far.
Certainly won't hesitate to give it a try in the air, possibly as early as tomorrow.

Oh, here's a quick vid showing it operating out at the max range I tested.

19.3 miles (31km) Rangelink UHF range test (0 min 40 sec)

What you see at the start is GPS distance from Tx to Rx.

ian

Nice job Ian.
I tried a Non LOS range test and was impressed with how many houses it punched through before dropping out.
I left my transmitter inside my house on a table!

Cheers

hi mate, why do you need to do a failsafe setting in the air?
i do it on the ground while a mate holds the plane and i trigger the settings on the RC TX and RL TX (rth, throttle, up trim etc and push RL button)
i'm sure u have good reason, just curious as to what it is?
cheers
p

Originally Posted by Daemon

Ok, well I'm just telling you, 12-15 seconds can be way too long to set the failsafe in the air,
which is how many of us do it. (trim for wings level, set appropriate throttle, little extra up trim,
maybe turn the camera pan slightly off center so can see when it jumps to failsafe.. etc, couple clicks
of rudder trim, and then set the failsafe). Problem is, failsafe trim is often the trim of
last resort and not how'd you'd normally fly so can't afford to wait 12-15 seconds for
it to record those positions while attempting to fly normally.

And then there's the random glitch after it records the positions, which could cause any
number of bad things to happen (imagine what a glitch looks like to any
rotor-craft).

ian

Because with foam planes, it's not uncommon for their to be significant trim changes
required over time. The foam warps in the hot car while carrying it around or gets
mushed by other objects etc. You may also decide to set failsafe with or without
throttle, or differing amounts of throttle depending on which direction you're flying, or
local wind conditions.. etc. I sometimes set it on the ground as well, but rarely find
that once activated, that it provides the most stable flight, and usually have to redo it
in the air. A lot of folks never actually test their failsafe in the air, so just don't know.
For all they know, their failsafe could result in a death spiral straight into the ground.
I've certainly seen enough videos showing that.

ian

ok got it, that makes sense
thx
cheers
p

Originally Posted by Daemon

Because with foam planes, it's not uncommon for their to be significant trim changes
required over time. The foam warps in the hot car while carrying it around or gets
mushed by other objects etc. You may also decide to set failsafe with or without
throttle, or differing amounts of throttle depending on which direction you're flying, or
local wind conditions.. etc. I sometimes set it on the ground as well, but rarely find
that once activated, that it provides the most stable flight, and usually have to redo it
in the air. A lot of folks never actually test their failsafe in the air, so just don't know.
For all they know, their failsafe could result in a death spiral straight into the ground.
I've certainly seen enough videos showing that.

ian

Any of you Rangelink user's using DX8 care to PM me, i have a few questions about the system.

Originally Posted by Daemon

While I no longer trust ground range test results as definitive (I've seen great variations
between ground tests, and in-air performance due to local Rf environment in the sky),
I still do them with all my control systems (both UHF and 2.4Ghz) as it does sometimes
weed out the under-performers.

Tonight I did a range test tonight with the transmitter set up on a tripod on a small hill (usual
spot), and Rangelink Tx module set at 400mW. Drove off with RL Rx antenna taped to
my windshield. Transmitter was cycling all the channels, and I had a servo with long
arm taped to the dash so I could watch it for glitches, although the blinking light on the Rx
is generally sufficient to see packet lossage. In addition to watching it while I drove, I
stopped and tested my 2nd RL Rx in my FPV Skywalker at 5 miles, 7, 10, 11, 14, and
topped out at 19.3 miles before driving behind a hill beyond which I would never regain LoS.

Still had a solid signal at 19.3 miles (31_km) as long as I had clear LoS to the Tx,
and even had it in 90% of all Rx antenna orientations (doesn't like pointing straight away).
It definitely helps to orient the ground plane (counterpoise) about 45 degrees away from
the coax feed line (should never let it run parallel to the feed line, although that's
the way it wants to sit given the way the antennas are built).
Powered up my Skywalker's ESC, ESC's BEC powering the RL Rx, plugged in couple
servos to cycle, and powered all FPV gear (1.3Ghz vid Tx, Camera, mic) as well as
testing with GoPro in close proximity, and other than a very slight degradation from the
GoPro when it was held against the antenna, it all worked fine together, all the way out
to 19.3 miles.

Back at 7 miles, I tested my Tricopter which has a brutally UHF noisy SN777 (aka VSN500)
camera, and it definitely killed the signal if the RC Rx antenna was anywhere within
about 8 inches of the camera. At 5 miles, could only get it to kill the signal if Rx antenna
was also pointed straight at Tx and pretty close to the camera. At 2 miles, totally solid in
all orientations even with camera less than 5 inches away from RL Rx antenna, which is
actually a pretty significant improvement over some of the other UHF systems I've
tested.

Because the Rangelink Rx has a SAW filter, I suspected it might be more resistant to
external Rfi, which is why I picked one up to test, and so far my tests have
supported that hypothesis. I need to get it in the air, and I need to
do some range testing in my usual high Rf noise environment (within
a few miles of the radio towers), but the results are positive so far.
Certainly won't hesitate to give it a try in the air, possibly as early as tomorrow.

Oh, here's a quick vid showing it operating out at the max range I tested.
http://www.youtube.com/watch?v=OH-2ARF7Hu4
What you see at the start is GPS distance from Tx to Rx.

ian

Amazing result...

If my memory serves me correctly you have made this test for DL and Sherrer right? What is the difference in miles?

DL out to 12.3mi and TLRS to about 10mi but was my other test route, which likely has a higher noise floor. I still need to take RL that way. I've had the others on tonight's route testing in conjunction with other high noise components and I think RL compares favorably, which might give it the edge on the other route.

ian