I am in the process of installing a new G-26 in my new Ultra Stick Lite 120. I was told by someone that I have to upgrade my receiver (currently using JR-700) to the PCM receiver or else I will have signal problems and glitches due to the Zenoah ignition ...Before I pull the trigger on a $160 receiver I was wondering if anybody has experience in this area and can validate that upgrade...Thanks...Matt

I'm sure others will chime who have actual experience with this, but here's my .02.

You do not need to run a PCM RX with a gas engine. By the way, be sure your radio is PCM capable if you decide to go that route.

PCM is rumored to be less susceptible to interference than PPM, but a properly set up gas engine installation will cause you no more trouble than a glow installation.

Then you get into the PCM v.s. PPM debate. The way I see it, PCM's advantage is that you set which way the control surfaces and engine speed will go if it loses a signal. I think the main advantage is that you can set the engine speed. Certain factors affect what the plane will do v.s. how you have the control surfaces programmed so that's a little iffy to me, but knowing your engine will go to idle (for instance) if you lose a signal, at least, assures you won't have as far to walk to pick up the pieces.

Thanks Mike, I am currently using a JR 8103 Aircraft FM, it might no be PCM compatible as you stated. I think what I'll do is press on with the JR-700 until I experience something that would warrant the change...Thanks again. P.S. your daughter's a peach!

I have run boy PPM and PCM receivers on a gas plane. Just make sure that the engine and ignition are properly grounded

Thanks, I'll be sure and ground them. BTW, do you know what upgrade I would have to make to get my Xmitter (JR 8103 FM) compatible with a PCM?..Just wondering, don't want to waste a thread..Thanks.

Ditto the above. Its a common misconception that you should only use PCM receivers with gas engines. Either PPM or PCM would be fine. If one is going to decide to go PCM vs PPM, it should be done on the actual merits of the technology along, and not old wives tales and incorrect information. So don't feel the need to switch because you are running a gas motor. It will only upset you when you start noticing all the airplanes on the flight line with gas engines and PPM receivers.

The JR8103 XMTR is ppm/pcm switchable.

While I am not a JR guy, in the parameters menu, you can configured the transmitter from PPM to PCM. So your transmitter is already capable. You just need to make sure that you have a PCM compatable receiver to receive the signal

Maybe I should not be flying my Zenoah powered, unshielded spark plug wired, giant scale planes with my 1972 Pro Line AM radio..Funny, it's been good all these years G62, G38, GT74...Soon a Phaeton 90 bipe powered by a G26....
"Experts" claim a bumblebee can't fly, either....

Thanks to all, I get the message, I'll stick with the FM receiver, for now. While I have your attention, does anybody know how to attach a sewer lid to the tail of an Ultra Stick Lite 120 because judging from what I'm feeling it's going to need it to balance out with this G-26 on the nose. Someone told me (here we go again) not to worry if it's nose heavy unless I plan on flying precision aerobatics. Should I blow him off or listen to him...PS, It's the same guy who told me to buy a PCM if I'm going to fly with a ignition type engine...Thanks again, you folks have been a great help.

On the smaller 60-size Ultra Stick people, including myself, have mounted the rudder and elevator servos in the tail to help with balance issues. Not sure how the 120 is layed out, but if the servos are supposed to be mounted in the fuse, start with mounting them in the tail. Good luck!

Draw a centerline down the center of the sewer lid. 1" away from the edge, and 2" away from the centerline, drill a 3/8" hole. That will leave you with two 3/8" holes, 4" apart, on opposite sides of the lid. Purchase a pair of 4" u bolts, with 4 large washers and 4 stop nuts. Use the U bolts, washers, and nuts to attach the lid to the bottom of the fuse. Take care not to over tighten the U bolts or you will crack the fuselage. If the only lid you have is 1" thick or larger, you will need to grind away the trailer edge enough for ground clearance. If you are ambitious, you can cut away the left and right trailing edges, and use them for auxiliary inboard elevators. You will need to glue the servos directly to the lid, or drill and top 4-40 holes for mounting. If you find the lid is too much tail weight, you can drill 1" lightening holes until you find the right balance for your flying style.

Good luck,and let us know how it turns out. Pictures would be appreciated for other Ultra Stick lite owners.

I will post pics of the building process and more importantly the engine installation. I'm a novice who has gone against the trend and switched to gas after 2 1/2 years of electrics. I guess spending $500 for a Hacker. speed control and batteries (not to mention the cost of the a/c) just to fly a 5 lb. plane for 8 mins got a tad expensive for my taste. Don't get me wrong I still fly electrics but found there is allot more bang for my buck in gas...Thanks all..Matt

Ralph, Grounded or Shielded????
It has got to be grounded, but shielding is an options!
.....but, you are the guru!

Have you tried it without a resistor spark plug?

Won't work without a resistor plug...My ignitions are inside the mount, so it's grounded that way, and the spark plug wire is only 5 inches long....A separate ignition box needs a ground, whether a shielded plug wire connected to the cylinder or a Bosch cap with the shield soldered to it....
The quote about pcm and ppm isn't mine, my only transmitters are either FM (old Airtronicss,) or AM, old Proline and Micro Pro...[8D]

I am flying two airplanes with Gas engines, one G-26 and one G-38. I have two PPM Futaba radios. Never had a problem with interference. Gas is good, Glo is bad.

Don't sweat the small stuff, just make sure all of it is grounded/shielded like God intended and you will do fine.

BTW, the G-26 is a real ripper. Should do a nice job on your Stik. Was looking at one the other day at the LHS, and fell in love with it. WILL be my next plane.
Have a very nice 25cc weedie engine just waiting for it to come along.


JimRoss

Hey bud I was told that as long as you have a resistor type spark plug and the rx, battery, and most servos are mounted in the back of the plane away from the engine things will work out.

That's great news. Thanks again to all. now off to the garage to finish putting this thing together. I'm sure I'll be getting back with you folks when I begin my engine installation, ie. grounding switch installation, carb adapter for throttle linkage hook up and such. Wish you all were here, IT"S FLYING SEASON!!

WOW-- I don't think I have ever read of somebody going to giant scale (and gas) because it is cheaper. Makes me feel a lot better.
PS-- you will love it.