STG

My Feedback: (26)

Thanks for your response. Although the JR receiver may be better, the Futaba PCM that I have is range checking very well --200+ feet motor off or on not sure what the limit is---stopped at about 220 feet.

I have experienced the loss of enjoyment and frustration the last 2 trips to the field. I put the plane together abiding by the RF 101 rules so I would not have to worry about any RF problems and have that loss of enjoyment and frustration. I guess I would feel more comfortable flying it if the PPM range check with the motor running was not so terribly bad--just seems that there is something blatantly wrong with only a 30-40 foot range.

Jeff Boyd 2

Yes, I know what you mean with the PPM range check.

I couldn't walk 5 paces with the Electric Katana before it glitched like mad. It was unflyable.

I fitted the PCM Dual Conversion receiver and the range check/preflight tests were all good, so that was all I needed to know. Flying has been rock solid with no glitches of any kind, and I don't just fly around using the occasional imput for directional control either. If I aint flying a maneuver of some kind, I get bored :-) I fly 3D and Pattern and that's it, and I would've noticed the receiver 'masking' glitches and felt the dead spots in control (I am pretty sure that's what happens??), especially with the electric, that glitched so bad that I would have hardly had normal control, and I am sure that I would have had that much "signal hold" from the PCM that it would have probably crashed.

I am happy to just keep fitting the PCM receivers, and it seems odd that we would need to fit a single conversion PPM first then fit the PCM when ready to fly. What I DO though . . is make sure that I constantly move the sticks as I slowly walk back looking for hesitations in the deflections. This can be really noticeable if you are using twin Elevator servos mixed on seperate channels NOT a Y-lead (like in the YAK), as they will start to move unevenly if you are losing it.

Anyway, I go flying and glitches are a thing of the past, and I never once worry about radio while at a competition . . NEVER.

Jeff

Zeeb

My Feedback: (41)

Could be a problem, I too use the nytube for models where they have crossing pull pull cable setups. That doesn't explain two models doing the same thing unless they are both setup that way, but I still think it's a stretch. While I've not had to fight an RF problem so far and I use throttle/choke servos mounted on the engine box of my Edge, there are no metal to metal contacts anywhere and I use metal control rods for the engine with the DuBro HD ball ends for the isolation.

I've seen/heard guys say the metal to metal will/has caused problems so that's maybe the first place to verify. What about your sparkplug? Is it the one that came with the engine? My ZDZ's come with (I've forgotten exactly what they call them) a resistor type plug that was originaly designed to eliminate radio noise in automotive type applications. There have been some guys find out buying the wrong sparkplug will cause RF. What about the sparkplug/wiring shielding, is that all intact? Servo extensions, are they all new and HD type? I saw one guy fight this type problem only to find the used elevator servo extensions he'd installed on the model had a problem and changing them out fixed it.

If none of that works, try disconnecting the servos from the rx except for one and see if it does it. If not, add one servo at a time and try again to isolate the possible problem.

Sorry you're having so much trouble, but you've got lots of us scratching our heads trying to help you figure it out...

One other thought; are the rx's you're using single or dual conversion? Are you using crystals made by the rx manufacturer in them i.e. Futaba crystal in the Futaba rx? I've seen folks post that you can interchange a Hitec crystal into a Futaba and vice versa, but I've seen folks say that caused them problems too. My stuff except for the foamies is all dual conversion and except for my Blade CP (Horizon won't say who makes the rx but it is negative shift) I have the like branded crystals in the rx's. Just another thought/question.

burnin1st

Ok Everyone on the receiver tx issue. Here is the answer, it's not working right don't use it. as far as compatability Hitec and Futaba are all -shift and do not have issuses with any of the non HITEC QPCM rxs. Now for the 2.4 do some research. 2.4 radios have a 1/75 chance of radio interfearance on every signal sent which is alot of signals per min, compounded exponentaially per radio in use at the same time. 72 is far less prone with a 1/some odd thousands.

burnin1st

sorry missed one more aspect on 2.4 radios, candy for thought. How many of you have a giga rated cordless phone? And how many of you get static from time to time. Granted it's not all but a large number. Now lets go to 9th grade physical science and remember the sections on radio waves and their ability to penetrate substances based on density, now tie in the ecology fact that the atmosphere is becomming more and more poluted(denser air). The lower the frequency the higher the penetration capability and vis versa. Hz can pentrate solid and some of the lower mHz. Most of the mHz cannot penetrate solids. None of the Gig range can penetrate more that a few meters of liquid. Yes Gig travels faster but when the signal can't penetrate who cares how fast it's moveing. So why are we so concerned with a speed differance that no human can register with out special equipment, when the very real fact of denser air that is getting worse can make a visibal differance for the worse? Just some food.

BobH

My Feedback: (2)

Um.. there's still a lot of room between molecules in the atmosphere for the radio waves to navigate through.

rmh

up here in the mountains, the molecules are so far apart we have to send the dog to fetch em -and herd them in so we have enough air to fly in
My DX2 stuff works extremely well in this environment
I understand tho - in death valley, they have to increase antenna length to poke thru that thick air
hope this helps

dirtybird

My Feedback: (5)

Now that's a classic. I really like that part about gig travelling faster.

xtraflyr

My Feedback: (11)

You guys that live out in East Bumble f#$% probably have alot less stuff to interfere with your equipment. Here in Jersey your lucky if you dont have a house within 2 miles that your flying from.. And if youve ever been to Jersey mostly everything in Dense!!HAHA.

So since I fly PCM esp. on my Gas burners and have 0 glitches,I would think PCM is perfectly safe to fly without doin a PPM test first..

Yea STG try getting those pull/pull to stop rubbing each other and see what happens. A Lot of us would like to know,and want to see you have a successfull flight..

Cya,
Frank

STG

My Feedback: (26)

Yesterday my Father let me fly his Lazer 3D and I ripped the wing off it doing a Deep inverted Snap Roll [:@] From the crash of that I acquired a Futaba FM reviever that might be compromised. I uncrossed the cables & tested with that in the driveway today and things were not very good even with the motor not running-- motor off about 50-70 feet-with motor running it was about 15 feet.

Knowing that things were not good with the receiver and possibly the environment, I still went ahead to see if I could learn something, as the range test was a lot worse with motor running. I first disconnected everything but the throttle and smart fly and results were the same. Then I disconnected the battery/switch and plugged a different battery directly into the receiver--same results. Then I plugged the switch/battery back in & moved the smart fly transmitter further away from the receiver & switch(up next to the throttle servo) and range with motor running increased to about 40-50 feet--almost as good as with the motor running (but still bad). I am going to change out the throttle servo to a 425 and try to get a better PPM receiver back in here and get back out to the field--not sure when I will get time again.

Thanks for all your help guys.

xtraflyr

My Feedback: (11)

OK sounds like your getting there.. Get that crashed Rx.out of there and try a better one. I think I'm almost more excited they you STG about how this is coming along...

STG

My Feedback: (26)

STG

My Feedback: (26)

I have a better receiver and have tried again. It is not Futaba it is a H.T. S8(with HT crystal) and I get about 200 feet with motor off and sometimes as much as 100 feet with motor running. This is in my driveway with trees and house not that far away. I say 100 feet sometimes with motor running because now it is about 10-60 seconds or so between quick glitches when I am as close as 20 feet away--this never happens with the motor off and used to be much more frequent.[&:]

I am going to pull it apart and look at it closely again and will now switch to the 425 servo. I think I am going to move the Smartfly receiver a bit further from the ignition module when it is apart and wire it so I can bypass it if I want for testing.

Why fly when you could have all this fun range testing!![&:]

strulag

My Feedback: (-1)

I would say...Put the PCM receiver in there and fly

xtraflyr

My Feedback: (11)

I agree fly the darn thing!! BUT... I can see if something happens (which Im pretty sure it's not goin to),your gonna rip us a new one!!

GO FOR IT!!!

STG

My Feedback: (26)

Ok, as you guys were saying from the get go, the problem did end up being something I should have first looked for closer. The shielding was starting to fray just where the plug wire exits the ignition module. I added a bead of silicone to that area and another ground strap, then changed over to a HT425 throttle servo. Now PPM with HT Super 8 and motor running is about 150 to 175 feet in my driveway. I still get a small glitch ~minute or so 100 feet or more out but never in closer.

I feel kind of foolish for not looking harder at what now seems to be more obvious. Thanks for guys for all your help.
----------

My father has a CH ignition on his with similar RFI problems. He complained that he thought his plug boot was not snug enough. I bet he may have a bad ground or something? He has not done any troubleshooting with his as he was hoping that I would find a simple solution that he could use to fix his RFI.

rcgood

I can't tell what exactly the 3rd picture is of.

rmh

even modern ignitions won't tolerate frayed shielding
th ignition you have -- is not one I have used -but the design is same -- a ht lead in a rubber cable housing --then a braid which MUST be complete over entire length of the cable .
back when--------- we looked ant and tried various cable -- a take off of th really $$$ good leads we used on our igh performance Chev engines -- EXACTLY same problem - you simply can't have an incomplete ground and poor shielding - especially if you have an ignition which will knock the balls of'n a pool table..
the result is a nice spark generator and radiated crap - -I would not fly any model with a bad shield or a patched shield - -I bet it could even knock out 2.4 gig.
You survived a really bad setup--which would have gotten worse. Cowl cuts are most typical failure points or those early on clamped NGMF plug caps which could --and did - simply fatigue and rip loose and bounce -which instantly sets up a huge field of electrical shi-t.

STG

My Feedback: (26)

Dick, are you saying that silicone I put on is only a quick patch and I should get it fixed?

The cable is fraying at bend to the bottom of the motor box as well--maybe the bend was too tight? I wrapped it with electrical tape and then with a rubber tube and then plastic ties. It sounds like I should get this fixed?

rmh

a complete - no loose ends wire enclosure is correct setup no taped up loose ends --
send the whole shebang off to CH ignitions . get a proper , new, shielded setup

rcgood

Would a very small break in the metal shielding (from the wire rubbing against a cowl edge) cause a lot of RF? My rudder servo (the only one doing it) was twitching pretty bad all of a sudden and I wonder if it's from the same thing. I also have a powerbox hooked up which is supposed to get rid of the glitches.

NM2K

My Feedback: (14)

Graphite is a conducter of electricity. Try switching the graphite out for plastic. Your problem should disappear.


Ed Cregger