FF9 changes from PPM to PCM by itself
07-18-2006, 03:39 PM
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FF9 changes from PPM to PCM by itself
Has anyone noticed this by Alex Whittaker on page 64 of the July 2006 edition of RCM&E: ". . . . the transmitter somehow had decided unilaterally to swap from PPM to PCM, but that's another story"
I 'phoned the magazine and was given the writer's email address, so I dropped him an email telling him my story (see below) adding that: "I would really like to hear what happened" in his case and that "I'd like to know what caused it to happen - and whether it was something I /we did wrong."
The reason for my interest in this article is that this exact same thing has happened to my new Futaba FF9 - twice! I know it sounds like a very unlikely story, but it's true and I'm really interested to find out exactly what happened in Alex's case, and what he did to fix the problem
But in the meantime, here's what happened in my own case: I was in my workshop when I switched-on my Tx and changed it to a new model's memory, ready to start setting-up the servos in my latest model's wing. The setting-up session went without problem and when I'd finished I changed the Tx back to the model settings it was originally set to, ready for the next day's flying session
A few days later and back in my workshop, I changed the Tx to my new model's settings again, this time in order to set-up the throttle, elevator and rudder servos - which all went-off without any problems. I turned the Rx and Tx off to make some adjustments to the servo horns and when I turned them back on again I found that the servos did not respond to the Tx. In fact they progressed to full deflection in "glitch-like" small movements, no matter what I did with the sticks
At this stage I turned-off the Rx in my new model and changed the Tx to a different model's settings (in fact to the model I had flown the previous day). Turning-on this model's Rx I discovered that these servos also refused to respond to my stick movements, instead they also "glitched" their way over to full defllection. At first I thought that I should change my new Tx's Xtal, but as it's the synthesised version it doesn't use Xtals! It was only then that I realised the Tx had changed itself from PPM to PCM! Manually re-setting the Tx back to PPM "cured" the problem, and I assumed that I must have done something wrong to cause the change-over . . . but what?
Over the next couple of days I went flying, using the older model's settings, without anything whatsoever going wrong. But a few days later the Tx again changed itself from PPM to PCM - in almost exactly the same circumstances as the previous time it happened
I really don't know how this can happen and I wondered if anyone else has experienced this strange and potentially dangerous phenomenon. To me it seemed on both occasions that the change-over occurred either when the Tx was turned-off, or as it was being turned-off or turned-on. But it certainly hasn't happened during actual use . . . . yet!
So, has anyone else had this happen with their Tx? Or maybe someone knows how I could have made the change-over in error? This is not my first computer Tx by the way, I also have an FF8 and a non-synthesised FF9, so I do know my way around the settings - apart from this particular problem of course
Tony
I 'phoned the magazine and was given the writer's email address, so I dropped him an email telling him my story (see below) adding that: "I would really like to hear what happened" in his case and that "I'd like to know what caused it to happen - and whether it was something I /we did wrong."
The reason for my interest in this article is that this exact same thing has happened to my new Futaba FF9 - twice! I know it sounds like a very unlikely story, but it's true and I'm really interested to find out exactly what happened in Alex's case, and what he did to fix the problem
But in the meantime, here's what happened in my own case: I was in my workshop when I switched-on my Tx and changed it to a new model's memory, ready to start setting-up the servos in my latest model's wing. The setting-up session went without problem and when I'd finished I changed the Tx back to the model settings it was originally set to, ready for the next day's flying session
A few days later and back in my workshop, I changed the Tx to my new model's settings again, this time in order to set-up the throttle, elevator and rudder servos - which all went-off without any problems. I turned the Rx and Tx off to make some adjustments to the servo horns and when I turned them back on again I found that the servos did not respond to the Tx. In fact they progressed to full deflection in "glitch-like" small movements, no matter what I did with the sticks
At this stage I turned-off the Rx in my new model and changed the Tx to a different model's settings (in fact to the model I had flown the previous day). Turning-on this model's Rx I discovered that these servos also refused to respond to my stick movements, instead they also "glitched" their way over to full defllection. At first I thought that I should change my new Tx's Xtal, but as it's the synthesised version it doesn't use Xtals! It was only then that I realised the Tx had changed itself from PPM to PCM! Manually re-setting the Tx back to PPM "cured" the problem, and I assumed that I must have done something wrong to cause the change-over . . . but what?
Over the next couple of days I went flying, using the older model's settings, without anything whatsoever going wrong. But a few days later the Tx again changed itself from PPM to PCM - in almost exactly the same circumstances as the previous time it happened
I really don't know how this can happen and I wondered if anyone else has experienced this strange and potentially dangerous phenomenon. To me it seemed on both occasions that the change-over occurred either when the Tx was turned-off, or as it was being turned-off or turned-on. But it certainly hasn't happened during actual use . . . . yet!
So, has anyone else had this happen with their Tx? Or maybe someone knows how I could have made the change-over in error? This is not my first computer Tx by the way, I also have an FF8 and a non-synthesised FF9, so I do know my way around the settings - apart from this particular problem of course
Tony
07-18-2006, 04:51 PM
#3
My Feedback: (11)
RE: FF9 changes from PPM to PCM by itself
It sounds like your transmitter has a bad memory chip. It should be sent to the service center for a full checkout.
Please note that this is the support forum for Futaba systems, and is not a discussion area. If you wish to create a discussion, please post in the general radios forum.
Thank you.
Please note that this is the support forum for Futaba systems, and is not a discussion area. If you wish to create a discussion, please post in the general radios forum.
Thank you.
