Temp loss of control
10-26-2010 | 01:26 PM
#52
RE: Temp loss of control
ORIGINAL: Woketman
Dan, in all fairness to Mr. Malloy, formerly of MSFC, the Thiokol guy you speak of did NOT ''know there would be a failure''. He strongly suspected that the risk of a failure had risen to higher, perhaps unacceptable, levels. But he certainly did not KNOW there would be an SRB failure on ascent of STS-51L.
ORIGINAL: rcjetsaok
Very Intereeeessssting !!!!!!!! I believe it. You almost have to think these companies think they are the CIA or something !!!! All this cloak and daggar and smoke and mirrors crap !!! Some body at Spectrum knew this full and well and the was overridden by the powers at be saying it's not a problem or the probable failure rate was acceptable !!! Just like the the guy from Morton-Thiokol that knew there would be a failure and tried to stop the launch and was pushed away and they launched any way... And of course we all know what happened...... Makes you wonder !!!
Danno
Very Intereeeessssting !!!!!!!! I believe it. You almost have to think these companies think they are the CIA or something !!!! All this cloak and daggar and smoke and mirrors crap !!! Some body at Spectrum knew this full and well and the was overridden by the powers at be saying it's not a problem or the probable failure rate was acceptable !!! Just like the the guy from Morton-Thiokol that knew there would be a failure and tried to stop the launch and was pushed away and they launched any way... And of course we all know what happened...... Makes you wonder !!!
Danno
I stand corrected on my verbage... But I can't help but think these things go on in everday life with ordinary products and companies... I fly JR on 2.4 , and no one put a gun to my head and makes me do it... That being said, It is a choice. Red or Black... spin the wheel and see if you win or lose...
Danno
10-26-2010 | 02:22 PM
#53
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From: El Paso,
TX
RE: Temp loss of control
ORIGINAL: GrayUK
Where do you get this from?
We are on 100mw, what do you think the states are on?
Paul
ORIGINAL: bigplumbs
I am wondering if the fact that we transmit at 1/10th the signal strength has somthing to do with it.
Dennis
I am wondering if the fact that we transmit at 1/10th the signal strength has somthing to do with it.
Dennis
We are on 100mw, what do you think the states are on?
Paul
I know that the European and other (Non-US) units are operating at a lower power than US units, I thought it was 10 mw for Non-US, and 100 mw for US, or maybe 100 and 1000, not sure. It's on RCU here somewhere, maybe someone else can chime in.
10-26-2010 | 02:41 PM
#54
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From: HoddesdonHerts, UNITED KINGDOM
RE: Temp loss of control
ORIGINAL: Moerig
RF Noise from sources like electric motors and static buildup.
From the Device Datasheet:
Datasheet Document #: 38-16015 Rev. *I on page 23 refers to L/D pin recommendation changed to :
"PMU inductor/diode connection, when used. If not used, connect to GND.
From Cypress technical support:
If the L/D pin is left floating, the switching regulator inside the PMU will pick up noise which will in turn increase the radio noise and the noise on the board.
PMU refers to Power Management Unit. It is a feature to prevent brownouts. Spektrum did not implement this feature and this pin was left unconnected.
This is a cut and dried technical issue confirmed by die chip vendor. Not debatable, sorry
RF Noise from sources like electric motors and static buildup.
From the Device Datasheet:
Datasheet Document #: 38-16015 Rev. *I on page 23 refers to L/D pin recommendation changed to :
"PMU inductor/diode connection, when used. If not used, connect to GND.
From Cypress technical support:
If the L/D pin is left floating, the switching regulator inside the PMU will pick up noise which will in turn increase the radio noise and the noise on the board.
PMU refers to Power Management Unit. It is a feature to prevent brownouts. Spektrum did not implement this feature and this pin was left unconnected.
This is a cut and dried technical issue confirmed by die chip vendor. Not debatable, sorry
<br type="_moz" />
10-27-2010 | 03:39 AM
#55
RE: Temp loss of control
England/ Europe is 100 mw.
My info is that the FASST module in the USA is the same (100mw).
I hear rumours that the DSM system uses more in the USA but nobody has ever shown me evidence that this is so.
Paul
My info is that the FASST module in the USA is the same (100mw).
I hear rumours that the DSM system uses more in the USA but nobody has ever shown me evidence that this is so.
Paul
10-27-2010 | 03:52 AM
#56
RE: Temp loss of control
ORIGINAL: Kinky John Fowler
Increase the radio noise and noise on the board - How much? 1/100000 above normal levels or enough to actually be a problem? Is this actually a serious problem or a recommendation? What is Spektrums response to this?
<br type=''_moz'' />
ORIGINAL: Moerig
RF Noise from sources like electric motors and static buildup.
From the Device Datasheet:
Datasheet Document #: 38-16015 Rev. *I on page 23 refers to L/D pin recommendation changed to :
''PMU inductor/diode connection, when used. If not used, connect to GND.
From Cypress technical support:
If the L/D pin is left floating, the switching regulator inside the PMU will pick up noise which will in turn increase the radio noise and the noise on the board.
PMU refers to Power Management Unit. It is a feature to prevent brownouts. Spektrum did not implement this feature and this pin was left unconnected.
This is a cut and dried technical issue confirmed by die chip vendor. Not debatable, sorry
RF Noise from sources like electric motors and static buildup.
From the Device Datasheet:
Datasheet Document #: 38-16015 Rev. *I on page 23 refers to L/D pin recommendation changed to :
''PMU inductor/diode connection, when used. If not used, connect to GND.
From Cypress technical support:
If the L/D pin is left floating, the switching regulator inside the PMU will pick up noise which will in turn increase the radio noise and the noise on the board.
PMU refers to Power Management Unit. It is a feature to prevent brownouts. Spektrum did not implement this feature and this pin was left unconnected.
This is a cut and dried technical issue confirmed by die chip vendor. Not debatable, sorry
<br type=''_moz'' />
I am sure the Spektrum response if any will be that it is not an issue. I am sure customers having lost models will disagree.
BTW this document update was published April 2, 2007. Good engineering practice and ISO certifications require design revisions where issues are revealed. Spektrum may just have an old datasheet and did not keep up to date with the errata that all products reveal after field use.
As I see it they either are aware of the issue, not aware of it, or dont think its an issue.
10-27-2010 | 02:09 PM
#57
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From: HoddesdonHerts, UNITED KINGDOM
RE: Temp loss of control
ORIGINAL: Moerig
I dont think Spektrum is aware of this because it is a cheap fix. It is serious enough to have warranted an update to the effect from the original documentation after designers encountered this issue. All known commercial designs using this chip I came across have addressed this issue. The effect can range from 0dB to 12dB in RX sensitivity. 3dB halves range. Unless you are an expert in ISM RF comms that have knowledge to the contrary from the chip vendor there is no point in trying to dilute this clear design issue.
I am sure the Spektrum response if any will be that it is not an issue. I am sure customers having lost models will disagree.
BTW this document update was published April 2, 2007. Good engineering practice and ISO certifications require design revisions where issues are revealed. Spektrum may just have an old datasheet and did not keep up to date with the errata that all products reveal after field use.
As I see it they either are aware of the issue, not aware of it, or dont think its an issue.
ORIGINAL: Kinky John Fowler
Increase the radio noise and noise on the board - How much? 1/100000 above normal levels or enough to actually be a problem? Is this actually a serious problem or a recommendation? What is Spektrums response to this?
<br type="" />
ORIGINAL: Moerig
RF Noise from sources like electric motors and static buildup.
From the Device Datasheet:
Datasheet Document #: 38-16015 Rev. *I on page 23 refers to L/D pin recommendation changed to :
''PMU inductor/diode connection, when used. If not used, connect to GND.
From Cypress technical support:
If the L/D pin is left floating, the switching regulator inside the PMU will pick up noise which will in turn increase the radio noise and the noise on the board.
PMU refers to Power Management Unit. It is a feature to prevent brownouts. Spektrum did not implement this feature and this pin was left unconnected.
This is a cut and dried technical issue confirmed by die chip vendor. Not debatable, sorry
RF Noise from sources like electric motors and static buildup.
From the Device Datasheet:
Datasheet Document #: 38-16015 Rev. *I on page 23 refers to L/D pin recommendation changed to :
''PMU inductor/diode connection, when used. If not used, connect to GND.
From Cypress technical support:
If the L/D pin is left floating, the switching regulator inside the PMU will pick up noise which will in turn increase the radio noise and the noise on the board.
PMU refers to Power Management Unit. It is a feature to prevent brownouts. Spektrum did not implement this feature and this pin was left unconnected.
This is a cut and dried technical issue confirmed by die chip vendor. Not debatable, sorry
<br type="" />
I am sure the Spektrum response if any will be that it is not an issue. I am sure customers having lost models will disagree.
BTW this document update was published April 2, 2007. Good engineering practice and ISO certifications require design revisions where issues are revealed. Spektrum may just have an old datasheet and did not keep up to date with the errata that all products reveal after field use.
As I see it they either are aware of the issue, not aware of it, or dont think its an issue.
Can you put a PDF from the Chip Datasheet on here so we can all see it? Or point us to one?
From the top of the chip which pin is 21? Can you post a photo. Which recievers have you checked and how old were they? Might take a look at mine.
How come rather than posting this on the forum you didnt tell spektrum?
Seems like a very serious issue.
<br type="_moz" />
10-27-2010 | 03:08 PM
#58
RE: Temp loss of control
Then here it is Paul. Extracted from the web site of of RC Japan.
DSMJ or DSM2 - Which should I choose?
Japanese / European Version DSMJ system
USA version DSM/ DSM2 system.
European Version DSM2
DSMJ system will only work DSMJ receiver and TX.
DSM/ DSM2 system will only work DSM/DSM2 receiver and TX.
So, This mean , DSMJ and DSM are different and are not compatible.
The reason why the regulation for 2.4Ghz different is each country has different law for 2.4Ghz.
USA version is too strong in Japan or Europe.
You can think of DSM2 USA and DSM2 Europe as brothers. Virtually the same, just the frequency is a little stronger in the USA.
Regards,
David.
10-28-2010 | 02:04 PM
#59
RE: Temp loss of control
Here is the link. The update mentioned was issued with revision "G"
http://www.cypress.com/?docID=17202
Remedy would be simple, short pin 37 and 36. 36 in a no connect that is connected to GND on the PCB. On all commercial variants of the modules like that used for the TX this is the case.
