HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Oct 15, 2012, 09:43 AM
X-Ikarus
Reflex1's Avatar
United Kingdom, North York
Joined Feb 2003
1,679 Posts
I suspect, but can't prove. we have an intermittent RF interference issue

Full freq. systems always cope , but DSM2 occasionally has Both carriers
knocked out, no way to predict when

As I stated earlier I have hours of logs from our Spectrum analyzer
but never managed to catch and identify the source.
Reflex1 is offline Find More Posts by Reflex1
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 15, 2012, 09:44 AM
Stop scaring my donkey!
JohnathanSwift's Avatar
Greenland
Joined Mar 2012
8,141 Posts
"Suspicion," by definition, is not based on fact, and will not feed the bulldog.
JohnathanSwift is offline Find More Posts by JohnathanSwift
Reply With Quote
Old Oct 15, 2012, 09:55 AM
AndyKunz's Avatar
Illinois
Joined Sep 2001
23,401 Posts
Quote:
Originally Posted by Reflex1 View Post
I suspect, but can't prove. we have an intermittent RF interference issue

Full freq. systems always cope , but DSM2 occasionally has Both carriers
knocked out, no way to predict when

As I stated earlier I have hours of logs from our Spectrum analyzer
but never managed to catch and identify the source.
Sounds like a simple solution for your field - fly DSMX.

Andy
AndyKunz is online now Find More Posts by AndyKunz
Site Sponsor
Reply With Quote
Old Oct 15, 2012, 09:57 AM
Stop scaring my donkey!
JohnathanSwift's Avatar
Greenland
Joined Mar 2012
8,141 Posts
It is interesting how conditions and experiences vary: I fly 100 yards from a high-power NOAA weather radar dome and scores of 2.4 routers. I even use the "old" AR 6100's with sucess. But, my needs are modest as is my understanding....
JohnathanSwift is offline Find More Posts by JohnathanSwift
Reply With Quote
Old Oct 15, 2012, 09:59 AM
X-Ikarus
Reflex1's Avatar
United Kingdom, North York
Joined Feb 2003
1,679 Posts
Quote:
Originally Posted by AndyKunz View Post
Sounds like a simple solution for your field - fly DSMX.

Andy
Agreed Andy

Unfortunately most have lost faith in Spektrum
and have/are moving to other systems.
Reflex1 is offline Find More Posts by Reflex1
Reply With Quote
Old Oct 15, 2012, 10:14 AM
Registered User
pilotpete2's Avatar
The Northeast Kingdom, Vermont
Joined Jun 2004
5,202 Posts
When Spektrum updated DSM2 receivers to quick reconnect, they then setup another form of potential lockout. How so? with pre quick reconnect receivers, the receiver immediately goes into channel scan mode when power is applied. This was found to be unacceptable, since any momentary drop in voltage that rebooted the receiver resulted in a lockout of over 3 seconds. With the introduction of quick reconnect, the receiver reverts to the last two channels it was on before the brownout, this fixed the problem the brownout problem, but setup another problem. With quick reconnect having the receiver always power up the last two channels in use, creates a problem where when you turn on the Tx first as normal, then power up the receiver, the receiver is sitting there locked onto the last two channels in use, but the Tx is on two other channels now. How do we break the deadlock here? Simple, have a timeout, where if the receiver doesn't see the Tx for a pre determined period of time, it goes into channel scan to find the channels it should be on. This is the Achilles heel of DSM2. If a DSM2 receiver loses RF for longer than that timeout period, the receiver can and will go into scan mode and you have yourself a lockout while the receiver scans to find the two channels in use.
I did not come up with this myself. Some time back a Spektrum user on these forums whose opinions I respect, was discussing this behavior in response to another Spektrum users observation that when range checking, if he blocked the RF to induce a fail safe event, if the duration was a little too long, the receiver would then lock out for over 3 seconds after the Rf was restored, rather than immediately reconnect.
I've tried this myself at our field with a new DX6i and AR600 and AR500. Many times when I had a smaller electric model restrained safely, I forced the receiver into F/S (motor F/S was set to zero throttle, and the throttle was set to a low idle when the receiver was connected to the Tx) by having the Tx antennae pointed to the model, then hitting the range check switch triggering F/S, if the F/S event was too long, the receiver would then take a 3-5 seconds to reconnect, just like the old receivers did when they were browned out. It seems that quick reconnect traded brownouts for fade-outs. Without a software timeout in the receiver, a quick reconnect DSM2 receiver would never connect to the transmitter on normal start-up, unless the Tx just happened to be on the same two channels as the last time it was used.
No hatred for Spektrum, just a degree of disdain for some of the extreme apologists, AKA Spektrumistas
OK, I'm ready, fire away
Pete
pilotpete2 is offline Find More Posts by pilotpete2
Reply With Quote
Old Oct 15, 2012, 10:18 AM
Stop scaring my donkey!
JohnathanSwift's Avatar
Greenland
Joined Mar 2012
8,141 Posts
I'm not an "exterme apologist," nor am I an "apologist:" I've simply had but one "problem" in 5 years, and believe I was the author of the problem.
JohnathanSwift is offline Find More Posts by JohnathanSwift
Reply With Quote
Old Oct 15, 2012, 10:24 AM
Way to many airplanes!
Canada, QC
Joined Oct 2009
5,458 Posts
Quote:
Originally Posted by JohnathanSwift View Post
It is interesting how conditions and experiences vary: I fly 100 yards from a high-power NOAA weather radar dome and scores of 2.4 routers. I even use the "old" AR 6100's with sucess. But, my needs are modest as is my understanding....
Agreed... I'm using a AR600 in my small FPV rig which I regularly fly in fields surrounded by city houses. There's two communication towers in the field closest to my house. Here's a picture (taken out of a video) of me, having fun with a communication tower (on of those day, I'll likely hit the thing). 489 meter away from my DX7, with a 5.8ghz video transmitter literally sitting on top of the Spektrum receiver. (Again, it's my small FPV rig, so not much space for the electronic).
RealGambler is online now Find More Posts by RealGambler
Reply With Quote
Old Oct 15, 2012, 10:30 AM
Registered User
Joined Jul 2011
196 Posts
Quote:
Originally Posted by pilotpete2 View Post
When Spektrum updated DSM2 receivers to quick reconnect, they then setup another form of potential lockout. How so? with pre quick reconnect receivers, the receiver immediately goes into channel scan mode when power is applied. This was found to be unacceptable, since any momentary drop in voltage that rebooted the receiver resulted in a lockout of over 3 seconds. With the introduction of quick reconnect, the receiver reverts to the last two channels it was on before the brownout, this fixed the problem the brownout problem, but setup another problem. With quick reconnect having the receiver always power up the last two channels in use, creates a problem where when you turn on the Tx first as normal, then power up the receiver, the receiver is sitting there locked onto the last two channels in use, but the Tx is on two other channels now. How do we break the deadlock here? Simple, have a timeout, where if the receiver doesn't see the Tx for a pre determined period of time, it goes into channel scan to find the channels it should be on. This is the Achilles heel of DSM2. If a DSM2 receiver loses RF for longer than that timeout period, the receiver can and will go into scan mode and you have yourself a lockout while the receiver scans to find the two channels in use.
I did not come up with this myself. Some time back a Spektrum user on these forums whose opinions I respect, was discussing this behavior in response to another Spektrum users observation that when range checking, if he blocked the RF to induce a fail safe event, if the duration was a little too long, the receiver would then lock out for over 3 seconds after the Rf was restored, rather than immediately reconnect.
I've tried this myself at our field with a new DX6i and AR600 and AR500. Many times when I had a smaller electric model restrained safely, I forced the receiver into F/S (motor F/S was set to zero throttle, and the throttle was set to a low idle when the receiver was connected to the Tx) by having the Tx antennae pointed to the model, then hitting the range check switch triggering F/S, if the F/S event was too long, the receiver would then take a 3-5 seconds to reconnect, just like the old receivers did when they were browned out. It seems that quick reconnect traded brownouts for fade-outs. Without a software timeout in the receiver, a quick reconnect DSM2 receiver would never connect to the transmitter on normal start-up, unless the Tx just happened to be on the same two channels as the last time it was used.
No hatred for Spektrum, just a degree of disdain for some of the extreme apologists, AKA Spektrumistas
OK, I'm ready, fire away
Pete
Does this occur with DSMX (I know you said you tried w/ an AR600, but not sure what Tx you were using)?

How long is the timeout period?

Seeing as this issue should be reproducible, I for one will definitely attempt to verify it.
jsipprell is offline Find More Posts by jsipprell
Reply With Quote
Old Oct 15, 2012, 10:37 AM
Registered User
Joined Jul 2011
196 Posts
Quote:
Originally Posted by Reflex1 View Post
I suspect, but can't prove. we have an intermittent RF interference issue

Full freq. systems always cope , but DSM2 occasionally has Both carriers
knocked out, no way to predict when

As I stated earlier I have hours of logs from our Spectrum analyzer
but never managed to catch and identify the source.
You might want to look into harmonics in the 2.4 band. 1.24 ghz has a harmonic at 2.48 ghz for example.
jsipprell is offline Find More Posts by jsipprell
Reply With Quote
Old Oct 15, 2012, 10:40 AM
X-Ikarus
Reflex1's Avatar
United Kingdom, North York
Joined Feb 2003
1,679 Posts
Quote:
Originally Posted by pilotpete2 View Post
When Spektrum updated DSM2 receivers to quick reconnect, they then setup another form of potential lockout. How so? with pre quick reconnect receivers, the receiver immediately goes into channel scan mode when power is applied. This was found to be unacceptable, since any momentary drop in voltage that rebooted the receiver resulted in a lockout of over 3 seconds. With the introduction of quick reconnect, the receiver reverts to the last two channels it was on before the brownout, this fixed the problem the brownout problem, but setup another problem. With quick reconnect having the receiver always power up the last two channels in use, creates a problem where when you turn on the Tx first as normal, then power up the receiver, the receiver is sitting there locked onto the last two channels in use, but the Tx is on two other channels now. How do we break the deadlock here? Simple, have a timeout, where if the receiver doesn't see the Tx for a pre determined period of time, it goes into channel scan to find the channels it should be on. This is the Achilles heel of DSM2. If a DSM2 receiver loses RF for longer than that timeout period, the receiver can and will go into scan mode and you have yourself a lockout while the receiver scans to find the two channels in use.
I did not come up with this myself. Some time back a Spektrum user on these forums whose opinions I respect, was discussing this behavior in response to another Spektrum users observation that when range checking, if he blocked the RF to induce a fail safe event, if the duration was a little too long, the receiver would then lock out for over 3 seconds after the Rf was restored, rather than immediately reconnect.
I've tried this myself at our field with a new DX6i and AR600 and AR500. Many times when I had a smaller electric model restrained safely, I forced the receiver into F/S (motor F/S was set to zero throttle, and the throttle was set to a low idle when the receiver was connected to the Tx) by having the Tx antennae pointed to the model, then hitting the range check switch triggering F/S, if the F/S event was too long, the receiver would then take a 3-5 seconds to reconnect, just like the old receivers did when they were browned out. It seems that quick reconnect traded brownouts for fade-outs. Without a software timeout in the receiver, a quick reconnect DSM2 receiver would never connect to the transmitter on normal start-up, unless the Tx just happened to be on the same two channels as the last time it was used.
No hatred for Spektrum, just a degree of disdain for some of the extreme apologists, AKA Spektrumistas
OK, I'm ready, fire away
Pete
Now that is interesting.

So under an interference condition which killed both DSM2 carriers and triggered Failsafe

It will take "Length of time of interference" + 3-5 seconds to regain control

Andy can you confirm this ?
Reflex1 is offline Find More Posts by Reflex1
Reply With Quote
Old Oct 15, 2012, 10:44 AM
Registered User
pilotpete2's Avatar
The Northeast Kingdom, Vermont
Joined Jun 2004
5,202 Posts
No, not with DSMX, since it is a hopping system. DSMX, like other hoppers, connects immediately on initial power up, on recovery from a brownout, and when RF link is restored after a fadeout.
The AR600, like all current Spektrum receivers is capable of either running DSM2, or DSMX, depending on the transmitter being used, so only would be an issue if using a transmitter that wasn't DSMX. It seemed as though the timeout period on the receivers I was playing around with was about 1 second. This was not a scientifically conducted lab test, but a casual test that was repeatable on the ground.
Pete
pilotpete2 is offline Find More Posts by pilotpete2
Reply With Quote
Old Oct 15, 2012, 10:48 AM
Registered User
Kambalunga's Avatar
Deutschland, Hessen, LA
Joined Jan 2009
1,197 Posts
Quote:
Originally Posted by jsipprell View Post
Does this occur with DSMX (I know you said you tried w/ an AR600, but not sure what Tx you were using)?

How long is the timeout period?

Seeing as this issue should be reproducible, I for one will definitely attempt to verify it.
Only DSM2, 100mW, ground range test.

Reichweitentest Spektrum DX7 Clone vom HK (4 min 17 sec)
Kambalunga is offline Find More Posts by Kambalunga
Reply With Quote
Old Oct 15, 2012, 10:49 AM
X-Ikarus
Reflex1's Avatar
United Kingdom, North York
Joined Feb 2003
1,679 Posts
Quote:
Originally Posted by pilotpete2 View Post
No, not with DSMX, since it is a hopping system. DSMX, like other hoppers, connects immediately on initial power up, on recovery from a brownout, and when RF link is restored after a fadeout.
The AR600, like all current Spektrum receivers is capable of either running DSM2, or DSMX, depending on the transmitter being used, so only would be an issue if using a transmitter that wasn't DSMX. It seemed as though the timeout period on the receivers I was playing around with was about 1 second. This was not a scientifically conducted lab test, but a casual test that was repeatable on the ground.
Pete
But DSM2 ....... would cause this long timeout ?
Reflex1 is offline Find More Posts by Reflex1
Reply With Quote
Old Oct 15, 2012, 10:54 AM
Registered User
Kambalunga's Avatar
Deutschland, Hessen, LA
Joined Jan 2009
1,197 Posts
Maybe look first the Video and make no false assumption.
DSM2 reconect pretty fast.
Kambalunga is offline Find More Posts by Kambalunga
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Another reason why we hate lawyers dll932 Life, The Universe, and Politics 37 Jul 02, 2012 04:30 PM
Rant this is why i hate fee bay bethelflier8036 Other Websites 6 Apr 18, 2012 01:22 AM
Why do birds hate model planes ? Feodosia Flyer Electric Plane Talk 14 Jun 28, 2001 04:19 AM