Can someone provide some information pertaining to PCM receivers in relation to the following for jets. I am interested in how they differ in their ability to block interference from outside sources first of all. Secondly, I would like to understand how the "S" modulation receivers differ from the "Z" modulation in relation to safety when used with turbine engines, such as placement in relation to fuel pumps which may create range problems created from using a"Z" modulation receiver, or fail safe shutdown safety in flight with the "Z" modulation receivers.
I have a J.R. PCM10 "Z" modulation receiver I would like to use but only if it is as good as the "S" modulation or at least very close. Thanks in advance for any help...Gary

i hope a jr rep replys ,
but i only fly jr and i thought the difference was just the coputer incoding as "S" or earlier "z" ????????????


either way great question

S is the better of the two.

Just for future reference, if you have questions like these you may want to search through the radio forum, and/or ask your question there. Chances are, the info is already there so that you don't have to wait for responses.

I just did a search on RCU for "s-pcm" in the radio forum, and got several hits. Here's one that may be of interest:

http://www.rcuniverse.com/showthread...highlight=spcm

ZPCM is an older generation of PCM from JR, and it is 512 resolution. SPCM is the newest generation of PCM from JR, and it is 1024 resolution. Both PPM and SPCM both have a stronger signal strength than ZPCM, eliminating the need for the amplifier in a Y harness.
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Z modulation is PCM 512. S modulation is PCM 1024. There is twice as much resolution with the S than the Z. On large control surfaces with large amounts of deflection the surface will look like it is moving in "steps" with Z modulation. If I'm not mistaken, all Z modulation RX's are single conversion. In my opinion, The "safest" setup is an S PCM 940/945 dual conversion receiver. These RX"s seem to be the most resistant to ECU/pump noise.
Your RX (Z PCM 910???) should be ok---you just won't have as much resolution. Whatever you do, perform a range check with any RX you choose.

I don't understand the quote in the previous post. PPM is FM. PCM is carried on an FM signal. I would imagine that the newer S PCM RX's are better overall besides just the improved resolution. I'm not a JR rep, so I don't know.

FWIW---a buddy of mine has flown his HotSpot with no problems using a Z PCM 910 RX. Kevin