The story started about 4 days before the Desert Storm Jet Rally. I had just installed a new JetCat P200 in my 7 year old 98"; 53lb, Yellow F18. I went to Buttonwillow, a 4000' runway to make sure the new engine and old fuel system would not fail me at an inopportune time. If something went wrong, I would have plenty of runway to set my heavy "glider" back down.
Ironically it was not the engine that gave me problems, but the RF environment. On my third flight of the day I was starting to gain confidence in the motor and made a low, high speed pass down the runway. As the plane approached me from the right 2' off the deck and about 300' from show center the gear suddenly dropped indicating a failsafe. I pulled back pressure on the stick of my 10x and fortunately the RF reconnected and plane jerked skyward. I immediately dropped the gear (that had already gone back up in the wells) and landed the plane without incident.
A frequency check with a scanner proved that there was a significant interference problem on my channel (and only on 41?!). I grounded the plane for the day and drove home contemplating things, until it struck me..."what am I doing messing around with PCM when I have Spektrum available? I had converted my aerobatic planes to the DX7, and although this hornet was complex I figured I must find a way to make 7 channels work in this plane!
The next day I had 1 AR7000, 2 channel expanders and 1 matchbox in the nose of my hornet and I had all 11 functions of that airplane working with my little 7 channel radio. I had time for 1 quick test flight at the local field and everything worked out well with zero failsafes (the JetCat ECU gives you a count after each flight).
Off to Arizona I went to fly with the boys at Speedworld. It was amazing how many guys came up to me and commented upon seeing the Spektrum Rx in the nose of the big hornet. It was as if they were grateful that I was flying it and therefore re-assuring them that it was "good to go" for their "heavy metal". The weekend was full of great camaraderie, spectacular weather and the smell of Jet-A. The weekend culminated with 4 successful flights on the hornet and 11 successful flights on my spectrum equipped Harpoon - a total success. I made it through the entire weekend without a single failsafe registering on the ECU's.
On the ride home I phoned my Buddy Dave Presta, who had won best scale jet with his immaculate Tamjets F18E. He had gotten out of work early and blitzed it Thursday accumulating 20 flights in the two days before I got there. He did another 4 flights Saturday before heading back early Sunday. But when we talked about it, He (using a 10x) said he had seen a numerous failsafes on each flight with as many as 4 failsafes in a single flight (for a total of 2.6 seconds signal loss).
My next phone call during my 6 hour return drive revealed another fact. It so happened that during my flying at the Speedworld event and only 30 miles away at the "Cactus Classic" IMAC there were 57 pilots duking it out in precision aerobatics. One of the competitors informed me that over the course of the weekend two pilots had accidentally turned on and shot down fellow competitors on the 72 MHz band.
I settled into my seat and enjoyed the ride home feeling grateful and secure that Spektrum and its solid, impervious link is available for us here and now! Thanks Horizon!
This model is over 14yrs old and has recently been updated with the DSM system. It uses the R9000 receiver, plus flight Log, The transmitter is a JR10X with Spektrum Module. Caroline is known for her excellent soaring skills and has had many longs flights with her ASK using the reliable Spektrum DSM RF link.
Peter Goldsmith's large 40% Super Cub. Pete is often seen towing at the JR Aero tow with this monster. It has had 100s of flights and many 1000s of tows. In the last two years Peter has enjoyed the reliability of the Spektrum 2.4 system. Peter uses a 10X Transmitter with spectrum Module and the reliable SPMr9000 receiver. Pete commented he has had many hundreds of tows with the Super Cub and with the responsibility of towing expensive sailplanes he only trusts the DSM RF link for it's ultimate reliability.
Pete's 8.6m 29.6' ASH-25. This sailplane is one of the largest on the scale soaring circuit and is most elegant in flight. Pete uses a 10X radio with SPM Module and receiver. He uses the SPMr9000 and has enjoyed many long flights. Pete also uses the Flight Log in his Large scale sailplanes and has recorded great numbers, even flying for hours and over long distances.
First place finishes in events such as the 2007 National Aero Modeling Scale Championships do not come easy. Every flight every round must be a solid performance. The DX7 system in my Hanger 9 Electric Mustang has performed flawlessly every flight from the day it was installed. It is a great feeling having the confidence of a solid RF link every flight, any time, any place.
This radio is a prefect match for the Hawk. It has many outstanding features and setting up a new airplane like the Hawk is very easy and fast. The scrolling feature on the DX6i is great addition along with the 10 model memory and the helicopter capabilities. I plan on using the DX6i often on new model setups.....it is a winner!
My daughter, Melissa "Sparky" Taylor, 10 years young, soloed with the T-28 and DX-7 last December.
I am a pylon racer. While flying our 175 MPH racers at 20 to 30 feet of altitude, we need a very reliable connection from our thumbs to the airplanes. Spektrum does the job. We operate our radio gear in a severe environment. High vibration is probably our toughest test. With the 72MHz receivers, the weakest parts in them are crystals and crystal filters. With Spektrum, there are none. Normal vibration problems are gone. I mount my receivers with hook and loop on the side of the fuselage. With the solid state technology, it is not a problem for me.
When I first heard about Spektrum, I knew it was the wave of the future, and the future is here. The first Spektrum that I had was a DX6. I used it exclusively in my foamies and it worked flawlessly.
When the DX7 came out, I got one from the first production run. The programming was very familiar, as it was very similar to the JR8103. I immediately put it in a new racer and headed to the flying field for testing. Range checked well and it was time to fly it. That day I was convinced that the Spektrum was the radio of choice for racing. I was one of the very first to show up at a race with Spektrum. Now it is common place.
All of my racers had AR7000 seven channel receivers in them. They worked great. Last summer, the AR6200 full range 6-channel receiver came out. I replaced the AR7000 receivers in all of my Q40s and again headed for the flying field. Notice, that I have so much confidence in this new technology that I do not do my testing in an old airplane. (I don't have any.)
One of the main reasons I hear from modelers why they do not want to change is because they have so much of the older equipment to use up. A light comes on when I remind them that they can use all their servos, batteries and switches with their new Spektrum. Any of the other brands work with Spektrum.
One of my favorite features of the DSM2 Spektrum technology is ModelMatch. With ModelMatch, you no longer have to worry about being on the correct model before you take off. When you bind your airplane properly to the DSM2 transmitter, the radio will not work and the throttle will be set at low or off. No chance of crashing or being way out of trim because you forgot to change models in the transmitter when you went to a different model.
No need to think that you are being a "Guinea Pig" with Spektrum. This system was not only thoroughly tested before it came available, but now it is a proven technology by many users. I have not seen any problems with Spektrum. Don't be afraid to make the change. You will like it.
Reprinted with permission from the Huntsville RCRC club newsletter:
First of all let me add a word about your modest president. He was indeed at the SPA/BPA contest held in Orlando but he neglected to say that he won his category handily with some good flying. That said, let me get on to a topic I would like to discuss a bit; the technology revolution that we are seeing in our hobby. This time I would like to talk about the new SS 2.4 gig radio systems that are emerging.
As you may know our RC hobby has thrived on pioneering work done in the early days by guys like Walter Good. Walt was instrumental in persuading the FCC to give modelers the first frequency available for model use--27.255 meg. Up to then only ham bands were of any use. Obviously as modelers took advantage of this breakthrough it was quickly saturated and we needed more help. Walt was successful in the obtaining several more 27 meg. FREQs and this worked for a while until CB operations, a lot of it illegal made it unsafe. So back to the FCC went AMAs freq.committee and they gave us a few shared 72 meg FREQs. More improvement was needed so back they went and were granted the multitude of 72meg (for planes) and 75 meg for non flying models. This has worked pretty well for a long time although the AMA has had to beat off usurpers from time to time. This system does require caution in use of frequencies to avoid "shootdowns". These frequencies are also subject to interference from electronic "noise" in the aircraft and care must be exercised in setting up the equipment in the aircraft. Some difficulty has been seen from "spillover" of other users on adjacent frequencies.
Then along came the bright idea of using the Spread Spectrum concept and frequencies used for quite some time by cell phones and other remote control applications. This concept basically uses two technical approaches; the one used by Horizon Hobbies and now JR which basically locks onto two unused frequencies at startup. No other xmtr will grab these frequencies until they are released by xmtr shut off. Up to 40 xmtrs could be in use at the same time using this approach. To date this has proven very successful with a lot of flying around the country and at events.
The other system use Frequency "hopping" where it constantly looks for open freqs for data transmission.This concept also seems to work well for model control. At present Horizon (who owns Spektrum) and Jr are using the freq. grabbing technique. Futaba, Extreme Power Systems and now Airtronics use freq. hopping.
The Spektrum systems have been on the market for some time for non airplane applications. Since last year I have flown most of the Spektrum aircraft systems in ten different models. The first system, the DX6 which Horizon restricted to small aircraft has been flown extensively in larger aircraft with a "buddy" backup 72 meg system on board for safety. In many flights I had one control interrupt at great distance. I have flown the DX7, the module systems and now the JR 9303 2.4 in several aircraft. My experience with these systems convinces me that SS is here to stay and I have a lot of 72 meg stuff for sale.
I have flown the Futaba FAAST 6 ch. and a Futaba module system a limited number of times--with success. I have flown the Xtreme system quite a bit also. I had some lockout difficulty with it until they modified the Xmtr antenna setup.
I am convinced that successful systems should have multiple rcvr antenni to lower the probability of the extremely short .antenna blockage by metallic objects and the fuel supply in model aircraft. The biggest concern by many was the difficulty of antenna function due to their very small size in a maneuvering aircraft.
Over the past several months I have witnessed two instances of shootdown due to carelessness in our operations with 72 meg. I have also seen several instances of range reduction due to EMI completely cured by a switch to SS Needless to say, that based on my own flying experiences and witnessing SS use at events and by others SS is here to stay. It sure is neat to simply turn on your xmtr anytime you want without the fear of harming someone else. SS also makes setting up and controlling ops at events so much easier.
I installed my 72MHz radio in my new F7F Tigercat, and I experienced severe R/F ignition interference while performing a range check with both engines running. I decided then and there to install the proven Spektrum 2.4GHz DSM2 module system with an extra remote receiver 24 inches from the SPMAR 9000 receiver. I performed another engine-on range check, which demonstrated that interference is a thing of the past using Spektrum. My revived JR XP9303 with the 2.4GHz DSM2 module system brings new meaning to safe radio control.
I set up the DX-7 for my F3A Pattern aircraft using the following setup steps. Some of the steps seem a bit out of order, but I set up the plane in very short order.
I like a single switch for all the control surface dual rates, so the first thing I did is got into the system menu (holding the select and scroll down button while turning the Tx on) and once on the "D/R SWITCH SEL" to "COM AILE" (I could have chosen to put them all on another switch like the flap, elevator, rudder DR switch).
To set up the wing (I have one servo for each aileron), Scroll to wing type, select flaperon on. Scroll down one more to input select. Select Aux 2: INH. TRIM: INH. Flap: INH, Flap TRIM:ACT. This gets everything working with the trims, takes the flap switch off, since normally I don't use any kind of flaps on my pattern plane.
Thats it- done with the system menu. There is one other neat function which you may consider called throttle recovery. If you beep the throttle trim down all the way to cut off the motor after a flight, if you beep once back up it goes to your pre-set position, ready to start the motor again.
Now, I went to Function mode (Turn off the Tx, push the select and up scroll while turning on the Tx)
Scroll to reversing SW and set up any servo reversing you need. (you get to this by holding select and down scroll and it gets you in to make the reversing).
I use two elevator servos. To set this up scroll down the P-MIX 6 and go elev to Aux 2 (plug in to your left elevator servo). Adjust rate to 100% (move elevator stick up and down to do this). Set SW: ON. Use P-MIX 6 for this because P-MIX 5 and 6 include trim. You want the elevator trim to move both elevator halves up and down.
Scroll up to travel adjust. Use a control throw meter and fine tune your travel up and down on ailerons and elevators. Remember you want to get them mechanically set as close as possible then use the travel adjust to get the throws perfect.
Scroll to D/R and Expo and set for elevator, ailerons and rudder. (remember it's positive expo for softer center). Suggest when you set up dual rates you use a proportionally higher expo with high rates, as compared to low rates. This will give you the same feel around center. For example, I use 20% expo on low rate (75% D/R) and 28% expo on high rate (100% D/R). This allows me to switch rates while I'm holding slight input- such as at the top of the loop switching to high rate for a snap roll avalanche maneuver.
For advanced precision trimming, I use the P-MIXES set to the following on my BRIO F3A Plane: I set P-MIX 5 to Throttle to Rudder. +1 high throttle, -1 low throttle. Offset 0 I set P-MIX 4 to Rudder to Aileron. I have a few percent in for right rudder to give opposite aileron. Offset 0. I set P-MIX 3 to Throttle to Aileron. (I don't use that but set it up in case needed) Offset -75% I set P-MIX 2 to Throttle to Elevator. 0 at high throttle, -17% at low throttle; Offset -75% I set P-MIX 1 to Rudder to Elevator. I have a few percent in for left rudder to up elevator. Offset 0.
The reason I use P-MIX 2 and 3 is used when doing throttle to elevator or aileron because these don't tie the throttle trim to the mix. So the down-line mixes will not be effected by throttle trim adjustments. This is similar to the ORIG on the JR 10X.
Done! Don't forget to re-bind with throttle stick at low before flying. This will make sure the throttle fail safe is set at low throttle.