[NSRCA-discussion] RX choices

[Bob Richards]

Most of what I use PPM receivers for are sport models or small electrics. Even then, I have decided to stay away from the single conversion RXs, even on the ultralight foamies. I've had too many glitches with the cheesy single conversion sets.
   
  Having said that, there are advantages to some of the PPM receivers. With proper filtering, it is possible for a PPM RX to continue operating with certain interference that would render PCM inoperable. Not very likely, but possible. I do know of one case where PCM radios were having problems going into failsafe, but people flying PPM were not having problems.  At one time (years ago) I was told that PCM did not work well on planes with ignition engines. I never disputed it, though I never have seen proof of it.
   
  With PCM, you may not know that interference is present until it goes into failsafe, then it may be too late. With PPM, you may get glitches, but usually at least some control gets through.
   
  I use the PCM RXs in my high-dollar planes, and have my failsafe set to kill the engine.  For most planes, I leave all the other controls at the last good signal position.
   
  Bob R.
  

Wayne <Whinkle1024 at msn.com> wrote:
  I have a question guys.

I see in lots of posts guys using FM (PPM) RX's. Why is this?

In today's market there are so many choices of good PCM RX's I can't 
understand why someone would actually choose to run FM. Back in the days 
when I started RC there was no PCM and we had the choice of AM or FM. I was 
taught that my model was too important to me not to run the best link 
possible, at the time FM was it.

When PCM came in the price was much higher and I can see a reason to not use 
it. Today however both Futaba and JR have PCM RX's that are good for under 
$99, JR now even has one that PLL Synth. So why use FM?

It is my understanding with today's PCM that noise rejection is so much 
better with PCM that it seems along with its F/S properties both model and 
people are better protected. I can see the reasoning among average modeler 
its price why else do MPI, FMA and so on make such a profit on off brand 
leads and servos that are in my opinion very sub par. I felt that in the 
pattern community with available models shrinking, and the cost of models 
hitting larger prices that guys would trust their baby to better equipment. 
I mean a basic pattern model that is on the cheap is going to be $1000 to 
$1500 all up. The difference in a 127 Futaba RX and say a Futaba 138DP PCM 
or JR 790 PCM version is about $40

What am I missing?

Wayne 

_______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20060914/1cc3632d/attachment.html