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PPM or PCM, single or dual Conversion ?

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Old 08-15-2003, 09:50 AM
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jarimi
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Default PPM or PCM, single or dual Conversion ?

I have receivers with glitch and blackout problems, my transmitter is an Futaba FF7 (PPM/PCM).

In my Multiplex TwinStar with 2xSP480, receiver ACT Micro6(PPM), I had short glitches 2-3 times in every flight without any BIG problems. Installing a FP-R139 GP(PCM) fixed the problem.

In my Multiplex Sky Cat with MEGA brush-less, receiver Jeti Rex-7(PPM), I had more glitches and total blackout when passing other Transmitters.

I'm thinking of buying a new Futaba receiver for my Sky Cat it has to be small of size and don't compromise range/quality.

Which receiver will solve my problems mentioned above(PPM or PCM ?, single/dual Conversion ?).

Thanks for your time
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Old 08-15-2003, 04:22 PM
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DMyer
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Default PPM or PCM, single or dual Conversion ?

I use a JR radio with both single conversion JR recievers and FMA Dual conversion micro recievers in my electric planes... never had a glich with either. I would check your electric motor/speed control systems to see if they are leaking interference. I assume you have good capacitors correctly soldered to you engines + - and case. Good luck

Dan
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Old 08-15-2003, 04:51 PM
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jarimi
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Default PPM or PCM, single or dual Conversion ?

PPM or PCM ? How much did you pay for your receivers?

Jan
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Old 08-15-2003, 04:57 PM
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transmission_dr
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Default PPM or PCM, single or dual Conversion ?

Hi,

I suspect that the PCM receiver has masked the problem rather than solved it. Do you have your fail safes set so that the motors go to idle? Setting fail safe that way allows you to know if the receiver is going into fail safe.

A PPM receiver will respond to short giltches and may move the servos wildy, while a PCM receiver will ignore short glitches and not move the servos, at the same time it is not responding to your inputs either. If the glitch persists then it will go into fail safe and move the servos to the fail safe position. With most radios, if you have not set up fail safe, the default choice is to leave the servos at the last good data position.

Suggest you do some investigating to see why your PPM receiver is glitching.

HTH

Jerry
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Old 08-15-2003, 05:01 PM
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DMyer
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Default PPM or PCM, single or dual Conversion ?

"PPM or PCM ? How much did you pay for your receivers?"

While my trusty old JR 388 transmits in all modes... I only use PPM. I second the previous coment about finding the source of the interference. Good luck.


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Old 08-15-2003, 07:08 PM
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jarimi
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Default PPM or PCM, single or dual Conversion ?

Thanks for your responses :-)

I think It's the XTAL in receivers or just poor quality receivers(bad selectivity), but i dont have the courage to experiment anymore and maybe heart someone.
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