I am looking round to start a build(first one). Which radio is good quality for your money and that will work w/almost any other reciever? Also when they say the radion w/ (lets say 4 servos) does that mean a 4ch radio. Does the reciever come with the radio? Sorry for the questions, but I'm learning. Thanks.

When they say radio w/ 4 servos that means a complete system (most likely) that has at least 4 channel capabilities. It could have as many as 12 channels in the TX but only 4 servos included. You must read ALL of the specifications.

Example:
http://www2.towerhobbies.com/cgi-bin...&I=LXGAE9**&P=
This is a 7 channel Transmitter with 4 servos and since Futaba does not make a 7 channel RX they included their 8 channel RX. Also included are the batteries and switch harness and misc hardware.

You can see how closely you must read everything.

A radio transmitter can control 1 function per channel of control. More than one servo may be required for a single function, such as planes that require dual aileron servos. A typical sport plane may require a 4-channel radio with 5 servos, for example. When using a four channel radio with five servos, the two aileron servos would simply be connected with a Y-connector so both can be operated from a single receiver port.

Typical functions include:

Throttle
Elevator
Rudder
Aileron
Flaps
Retracts

When a radio system is purchased, it may be sold as transmitter only, transmitter and receiver only, or a full radio system with transmitter, receiver, servos, batteries, charger, and power switch. Some radio systems are sold with standard-sized receivers and servos, while others are sold with smaller "micro" gear for park flyers and small electric aircraft.

Some radios are sold as FM/PPM radio systems and include an FM receiver. Others are sold as PCM digital radio systems, and include a more expensive PCM class of receiver. PCM receivers are considered to be less succeptible to stray signals and interference compared to standard FM systems. PCM systems can also be set with failsafe programming so the vehicle will automatically assume a particular profile of settings if the signal from the transmitter is lost. Almost all PCM transmitters can also be operated as FM/PPM transmitters as well.

PCM radio receivers are somewhat proprietary in nature. They are not cross-compatible with different brands of equipment. You will need to use only specific recommended models of PCM receiver as listed by your transmitter's manufacturer. It is possible that a PCM receiver may not be compatible with your transmitter, even if they're both the same brand.

Some radio receivers are built around single conversion signal filtering technology. Other radio receivers are built around dual conversion signal filtering technology. Most single conversion receivers are designed to be inexpensive receivers for park flyers while most dual conversion receivers are better at blocking out signal interference and can operate at much longer ranges.

Transmitters in North America are normally designed to operate at 72Mhz and will either use positive or negative shift for carrying additional signal information. A transmitter must be matched to a receiver of like shift to operate properly, so a negative shift transmitter will require a negative shift receiver. Some transmitters are shift selectable, and can operate in either negative or positive shift mode. Some receivers are shift selectable, and will either auto-detect the shift of the transmitter or can be jumpered to a particular shift setting.

Within the 72Mhz frequency range, there are 50 seperate channels available for aircraft radio systems, numbered 11 through 60. Most transmitters and most receivers will require a frequency crystal so each operates on a specific frequency and both use the same frequency so they can communicate. Transmitter crystals are not user changable in the North American market, if you wish to change the channel of a transmitter, you're legal required to send it in for factory service so it can be recalibrated at the new frequency. Receivers can have their frequency changed by the user. You will need the specific model of crystal made by the receiver's manufacturer for that specific model of receiver.

Some transmitters and some receivers do not require crystals and their channels can be altered by the user simply by turning a dial or selecting a different channel on the radio menu. These are called synthesized radio systems and they lock into a specific frequency with a channel sythesizer system rather than with a fixed crystal.

In additon to 72Mhz FM (PPM)/PCM radio systems, there are now 2.4Ghz spread spectrum radio systems available. These radio systems are PCM only, and the specific transmitter only works with receivers designed for that particular model and/or brand of spread spectrum radio system.

In summation, you need to evaluate radio equipment by the following characteristics:

Transmitters
(72Mhz or 2.4Ghz)
(FM only or FM-PPM/PCM)
(mechanical or computer)
(fixed frequency or synthesized frequency)
(positive or negative shift or shift selectable)

Receivers
(positive or negative shift or shift selectable)
(single or dual conversion)
(fm/ppm or pcm)
(fixed frequency or synthesized frequency)

The list of variables involved in selected a transmitter and receiver is quite extensive. I haven't even begun considering standard versus digital servos or whether one should choose NiCd, NiMH, or LiPo batteries for one's receiver. If one studies these various terms and matches a transmitter to receiver based on these major characteristics, one should end up with a transmitter and a receiver that can talk to each other.

What radio do you guys think would be the best if I were to use it for a number of planes? Brand? Channels? Thanks.

G'day Mate,
Spektrum DX7. No other choice, IMHO.

Any radio that is comfortable in your hands and will fit your needs is all you need. Most of the computer radios now will hold multiple models.

I would suggest that if you are going to get help from an instructor, you should make sure that the radio you purchase is compatible with your instructor's radio.

New technologies are emerging, i.e. the Spectrum line. However, traditional radios will work well too. I personally fly with Futaba. I own a T6EXA, and a T4YF(buddy box for students). Again, a personal choice.

Suggestion, pick out a radio that you like, post the link, and then ask around if it will fit your needs. If you'd like, you can PM me and I will let you know what I think of your suggestion.

You don't necessarily need to get the most complicated radio on the market to learn to fly. Actually, I feel that the more basic, the better. That allows you to focus on your flying and less on playing with the radio.

Again, PM me if you'd like more personal information.

Thanks!

I agree with vertigo, it's important to be able to buddy-box with sombody for a while. With that said JR, futaba, and hitec can all be connected to each other via adapter cables. The futaba 6exa flight kit is a good 6 channel computer radio with model memory for several planes and only costs about $200.00 with digital servos.

The Spektrum DX7 is a great radio system, but it's not without some downsides. At $310 minimum street price, it's not inexpensive. Because it's a 2.4Ghz spread spectrum system, the receivers and transmitter are all proprietary PCM in format. The transmitter can't broadcast in FM, and will only work with proprietary Spektrum 2.4Ghz receivers. Obviously a great deal of RC pilots have decided that this system is still well worth the cost, as the DX7 is a huge sales success.

Any of the available basic 6-channel computer radios would be a good choice to start out with. Airtronics, Hitec, Futaba, and JR all make computerized 6-channel air radios in the $160 price neighborhood that boast a nice selection of features and include a full flight pack.

One in particular, the JR Sport SX600 radio system, is worth a second look if you think there might be a DX7 in your future:

http://www.horizonhobby.com/Products...dID=JSP16000**

This particular 6-channel computer radio can be buddy boxed to a DX7, so it can still be useful down the road if you decide to go with a Spektrum system down the road.

I feel that $310 plus shipping and/or sales tax is simply too much to ask a brand new pilot to pay for a radio system, wonderful though the technology is. You could buy the JR Sport SX600, a World Models Sky Raider Mach I, and a Super Tigre GS-40 engine and have a complete trainer system with computer radio for less than a DX7. Having a bullet-proof radio system isn't really that helpful if you can't afford a plane to fly it with.

Jeez, I was looking at the "Joined" statement in everybody's name and I looks like I'm the forum veteran here, and I'm only 26.

vertigo72480, gee that sound slike a challenge!! Any way I am starting to look at those Spektrum radios myself. They do have I believe it is 20 model memory which is higher than the others except the Polk brand. [8D]

The Spektrum is 20 memories. Some of the Futaba's have plug-in CamPac memory modules which can greatly increase model memory.
http://www2.towerhobbies.com/cgi-bin...?&I=LXDKC8&P=7

If this is your first radio, and you don't have to 'worry' about getting rid of other or older receives, the DX7 is by far the best choice. The servo's from just about anybody will work, and it comes with four quality servo's. Receivers are going to cost you around 70 bucks no matter what you choose if you get the standard receiver (not including smaller electric model type mini or micro receivers with a limited range). The DX7 receiver costs a bit more, but you are getting more.

Read up on the systems, Horizon Hobby has the writeup on the DX7 and there are many posts here on RCU that discuss the DX7. I have one and prefer it to anything else I have. I am, in fact, in the process of replacing all of my RX's with the new DX7 receiver.

And, most hobby shops worth mentioning will sell it for $350.00. That's a reasonable price to pay for such a quality RC system.

Best of luck.

DS.

Yeah, you got me beat. Heh heh heh.

you might have a down side with the Spectrum if no one at your field has a JR that is compatible to buddy to right? It might be ok to look at what BigEd was saying and get a Hangar 9 product with a JR sport series so you have something to buddy to later. Do the other JR radios work? I myself am on the fence about the Spectrum, but not sure I want to drop that much at first, when I can get the RTF packages for around what just the radio costs. I haven't taken the final plunge into this addiction....er..Hobby yet and purchased a plane or radio system. I'm still reading and reading and reading to try to learn as much as I can and get other people perspectives. I did buy a sim and that was worth the bucks I will say.

Dave

I.Y.A.O.Y.A.S.

G'day Dick,
Too bloody right, the best thing since sliced bread, & if you come over here, the best price is $525.00 AUD, so $350.00 USD is a good deal. And the RX's are $125.00 AUD.

I love my DX7.

All of the JR's with the "Mono-pin" buddy box connector should work.

Futaba has its own issues too. Due to different buddy box connectors you need several different cords to cover all possible combinations.

I read up on the Spectrum and didn't know that the was Spectrum requires a dual reciever set up. One has to be mounted outside the fuselage if I am reading the facts right. If thats the case I would rather opt for the Polk radio which has snthethized tuning and you can pick your own channel and its futaba buddy box compatible. [8D]

The DX7 system has a one-piece dual RX set-up with both parts inside the plane. Of course you COULD put one or both outside if you wish (like on a profile) but I wouldn't. The most important part is to have the 2 antenna systems 90 degrees to each other to avoid blind spots as I understand it. In actuallity, unlike typical 72 MHz systems, NOTHING needs to show outside the plane with the possible exception of the on/off switch. No dangling antenna wires.
http://www.horizonhobby.com/Products...ProdID=SPM2710
above is the DX7 page from Horizon Hobby, lots of info pages.
And below is the COMPLETE AR7000 RX for the DX7 system
http://www.horizonhobby.com/Products...ProdID=SPM6070

Bruce is correct. The receivers do not have to be mounted outside of the fuselage. There are two antennas for the receiver and they must be mounted where they are aligned 90° to each other.

Ken

thankx for the info. [8D]

G'day Mate,
And even that, is not critical.

Nah, they just had some space on a page in the manual they needed to fill with something. Doesn't need to be EXACTLY 90 degrees but that is optimal.

Doesn't AMA still have the free trainer box option? If they do, get the JR/spectrum if you want and get the trainer box from AMA when you sign up. I think futaba trainer boxes might be a bit more common then jr, but if you get the trainer box with your membership, you don't have to worry at all.

I looked for the AMA offer the other day and couldn't find it. May have been my fault though. Could always call them.

[link=http://www.modelaircraft.org/promos/1/default.aspx]AMA Tx promo[/link]