Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Hi all,

I am having a weird problem with my Diamond Dust with Jett 60LX. I have a Hitec Flash 5 Radio (72 Mhz Ch 44) and a Neutron 6 receiver. With the engine off, the plane's electronics operate normally. But when I start up the powerful engine (which turns a 8.8 x 9 APC D-1 pylon prop 18,000 RPM) , the throttle servo goes crazy (I have absolutely no control over it, it goes up to full throttle and back to mid-throttle and then back up to full throttle, cycling constantly)....I had to stop the engine by blocking the exhaust pipe. I don't remember if the elevon servos were going crazy also. What is weird is that this problem only occurs with the engine running....Is it some kind of radio interference or vibration issue created by the engine?

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

YES!

It could be:
a servo with a bad pot
a metal to metal connection that is making RF noise
a bad bearing in the motor
a bad receiver
a bad extension

Start eliminating items one at a time. Sooner or later you'll find it.

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

I know its not a gas engine but are you using a metal control rod on the throttle?

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Yes

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

metal control rods sometimes cause interference when used on an engine, you might want to try a different control rod if its easy to try.

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

The carb arm on the Jett is metal, right?

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Yep

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Change out the throttle push rod for one that has threads on end so you can put a plastic clevis or even better a plastic ball link to make the engine connection. The servo end is your option on how you connect to a plastic servo arm. A long wire (push rod) making a rattling contact with a large metal mass (engine) makes RFI, Radio Frequency Interference.

Normally, this is only barely noticeable with the transmitter in close vicinity, an out of control servo like you describe doesn't bode well for the Neutron 6 receiver's noise rejection .

Time to stock up on the old Electron 6 receivers because Hitec may have FUBAR-ed again?

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Actually there is a plastic clevis at the end of the metal threaded throttle push rod. I'm wondering if I should change to a different receiver (I have an Electron 6 and a Supreme IIS laying around)...

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Yep, I just looked at Hitec's receiver lineup and you couldn't make me fly with ANY of their current offerings...what a shame!!!!

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Use the Electron. I have a Supreme II, I cant tell you what I think about it on this forum, I'll get kicked for sure.

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Hehehe, thats funny! I usually ran the Electron 6, until I noticed that on one of my Diamond Dusts it would go crazy once the fuselage heated up on hot days (over 90 degrees) at the field. I believe it had a faulty component that was temperature sensistive. After that happened I switched to Neutrons, but maybe I should give the Supreme a try.....

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Try a new crystal, if not, you may be right. It's toast.

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Dude.....

Spektrum 5e for under a hundred bucks.

:D

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

That was my first thought (time to give up the 72 MHz and make the plunge into 2.4)!!! I didn't realize they had a beginners system for under $100

I wonder which system (FASST vs Specktrum) is less suspectible to RF interference.....

Maybe I could start a FASST vs Specktrum debate!!!!!.....:eek:[X(]:):D

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Time to read up young man. :)

2.4G gets NO RF interference. [sm=thumbup.gif]

Choose your weapon: FASST, FHSS, DSM, etc

BTW, the DX5e is a 'full' radio, not just a parkie like the very first DX6. That means the DX5e can be used in anything. Yer not gonna take a 150mph plane out to a speck anyway, right? [sm=omg_smile.gif]

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Oh yeah, Hobby People has the Airtronics RD8000 2.4G radio on sale right now with a Rx for $140.

http://www.hobbypeople.net/gallery/751700.asp

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

I guess I'm waiting for this new-fangled 2.4 GHz stuff to catch on....:)

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

Thanks for all your help guys!

RE: Weird Radio Problem with my Diamond Dust with Jett 60LX
 

On a crystal type receiver, the vibration/rpm/frequency can cause the RX to go nuts. Seen it more than once on a QM40 or Q-500 where I didnt have the RX properly packed in foam and isolated from the airframe. (usually because I had not flown the plane in a while, and the RX snuck out of the foam padding, or the foam crushed unti the RX hit the airframe).

It happens just like fuel foaming........ and for the same reasons. Ensure that the RX is padded well with good packing foam and that is not touching the fuel tank or airframe structure.

On a lot of todays ARF installations (and some top end kits too), the instructions have you install a RX with some tape and a few tie wraps. Makes me cringe when ever I see that !!

The switch is another thing to check too. Some cheaper switches will fall apart with higher energy levels going through the airframe - but it is more obvious to see what is wrong there..... everything stops working