Delta Mike

My Feedback: (18)

After 25 perfect flights in a UltraStik 120 using the new Spectrum module in my 5 year old 10X,I installed the AR9000 reciever in the EuroSport. Using all 3 recievers in the Euro which I am running 6x8611 servos 2x331 and a 8700g. Running 2x1950ma NiMH 4.8 packs. Today 4 perfect flights with a rock solid link in the EuroSport. I plan on putting in about 15 flights a week over the next month flying at different fields. I'll keep you posted.....

Blue Skies...

DM ;-)

CFII1974

My Feedback: (5)

Glad to hear it is working for you Dennis. (how are those landings?)

Sorry you missed the fly in Wellington is was a lot of Fun.

Talk to you ..

Dave

KC36330

an 8700g is a PCM Only servo, might wanna ask JR tech a bit about its use with the spectrum system and long term effects that might arise.

kc

seanreit

My Feedback: (60)

KC, spit out how you know this................. As this is the first I'm hearing of that servo, or this issue.

Thanks,

Ehab

My Feedback: (44)

The 8700 servo is for a Gyro and PCM use only. It says it right on the box of the servo and on the JR website... It is a very high speed tight servo for heli tail control.

quist

My Feedback: (198)

How does the servo know it is PCM? Since the skeptrum rx doesn't send bad signals like PPM fm rx that it wouldn't be a problem.

Delta Mike

My Feedback: (18)

Ya, I originally had that servo set up when I was using it on 72. It is my nose gear steering servo. I just realized that it is a PCM only servo. I'll check with JR to see whats up with that.

You guys are so observant!

DM

KC36330

As mentioned by the others it says so in HUGE letters on the box the servo came in, I've got 4 of them all on JR G5000T Extreme lock gyros on my helis. if memory serves me the reason for PCM only is the frame rate at which the servo updates, a PPM can't deliver the signal fast enough. it also was supposed to be used with the gyro only at one time but I'm not sure if that has changed or not.

kc

EDIT: added pics

Delta Mike

My Feedback: (18)

Hey Dave, The base was way to rough for the Euro. I flew at the Torks field in Columbus. That field is perfect for jets..... Landings were better but we had a 12mph direct crosswind so I stuck it 4 times no problem. I want to start flying at Chandler untill I get comfortable. I should be home on Friday. How did the F18 maiden go? Dennis

Delta Mike

My Feedback: (18)

KC, Danny Snider gave the 8700G thumbs up using 2.4... I guess the super sonic frame rate of the Spectrum makes it possible.....DM

quist

My Feedback: (198)

I think the ppm frame rate is faster then pcm.

mr_matt

My Feedback: (10)

It is on their site:

http://www.spektrumrc.com/Products/F...D=JRPS537#faq5

cairoman

Gentlemen,

I received a Spektrum set from Dreamworks last week and I installed it in my JL-F15. All was fine, range checked at 85 paces, Graupner G-Booster running.....wow!! except for channel 8. As soon as I hit the slider for the brakes, all controls jitter like crazy. Tried to switch with another function, same results, channel 8 always jitters.

Question: would this be a problem related to the receiver? Anyone has experienced similar situations?

Regards,
Chris

c/f

My Feedback: (1)

PCM is the slowest digitized format of processing, Its only benefit was failsafe protection of unwanted signals thru FM modulation, but seems its not so good with JR and the recent Bandit crash. So......

PPM is the fastest, FM modulation.

For PCM to work it takes the PPM and digitizes it to a coded pulse which takes time. NO mystery why do you think its the same module for 20 years. IT's nothing but FM modualtion or PPM.

Consider the DX6 used an existing PPM JR TX and Spectrumized prior to transmitting to RX, it took FIRST PRIZE in being the slowest latency or TX delay to servos in the market and was unaccetable for most hardcore 3D heli work

Then comes the DX7 which no longer processes PPM and is straight thru digitized thus ALMOST the fastest latency but Airtronics PPM still is faster.(unbiased third party testing)

Then comes Spectrum modules, WHICH ONCE again digitizes the PPM, BUT on Spectrums own website they say that they can digitize the PPM and transmit FASTER than JR can digitize and send it PCM, so its an inbetween Hybrid faster than JR's own PCM digitizing capabilities, Which is still faster than hand/eye/muscle coordination IMHO.

A Heli pilot on Runryder has created a unique apples to apples elecronic test bed for ALL BRANDS TX Latency testing, unbiased of brand, creating a database spreadsheet, (PEOPLE send him HIGH dollar TX's for testing,) I can post link latter if interested, or just search TX latency.....