JR X378 PPM or PCM

[markyboy]

Hi i was going to buy a JR X378,was told by the shop to get ppm with it because i would not really need pcm with a heli.I just wanted to check if this was right or not.And does anyone know if the jr x378 is a good radio.Thanks

mark

[Stuart]

There are two trains of thought on PPM or PCM, personally I like PCM its a clearer stronger signal, it provides a more accurate servo positioning and also offers added saftey features with condition setting for lost signal. Plus if you ever move to digital servo's PCM is a must.

Your LHS is talking rubbish by saying that your won't need on a heli, I would say that 99% of the heli's at our club are PCM.

The only real disadvantage with PCM is that you get no warnings before a lock out, as soon as signal is locked then your at the mercy of PCM. While PPM will allow you to see any glitches and get a better opportunity of saving your heli.

This thread could go one for ever.....on the PCM v PPM issue.

The radio looks fine to me I had a look at the spec on the Macgregor website.

http://www.macgregor.co.uk/radio/378spec.htm

[markyboy]

hi stuart thanks for the reply im going to get the pcm thanks for your help.

mark

[Raptorite]

I also prefer PCM in helis, infact I was told once that PPM isnt really suitable for helis as there are far more working parts on them than there are on planks so a heli should use PCM whereas a plank can use either quite happily.

The other problem with using PPM on helis is that if you use a futaba gyro, either a GY401, GY502 or even a GY601 and you have more than 3 consecutive glitches on PPM the gyro will reset its central trim point in HH mode which normally means that it will at the very least swing the tail round 180 degrees and most often does that and also sets the trim to far left meaning you need to hold in almost full right rudder to keep it flying in a straight line.

I used to have this problem quite often on a raptor 30 with a GY502 and a PPM rx, when I changed it over to PCM I didnt ever have this problem again.

It is worth pointing out that this appears only to happen with futaba gyros, I havent heard of it with any other brands.

Cheers,

Pete.

[markyboy]

hi pete thanks for the reply you have both been a great help

mark

[Raptorite]

Hi Mark,

No problem, I hope you get youre raptor up and flying soon

Cheers,

Pete.