beginner_1

will tranzmitters and recievers mix from brand to brand ?

MrMulligan

My Feedback: (314)

As long as they are on the same frequency and "shift" they can. Hitec and Futaba are negative shift. JR, Airtronics and Multiplex are positive shift. Hitec sells receivers that can be ordered for any brand. I have them for Multiplex, Airtronics and Hitec.

DBCherry

My Feedback: (4)

I was going to chime in, but it seems that Mr. Mulligan has answered your question very well.
Dennis-

Montague

Just one side note, not only do Hitech, FMA and a few others make receivers in either "shift", there are also receivers that are shift-selectable, or automatically detect the shift of the transmitter. And some companies such as Hitec and Polk make transmitters that are shift-selectable, so you can use them with any FM receiver you happen to have.

beginner_1

so can JR and Futaba work together and can diffrend brands of cristals work in diffrent recivers or tranzmitters. i dont no whick 1 is whick . as you can see iam a begginer

00000000000000

I use JR radios, the receiver I just got for my 2nd plane was a HiTec HFD-08RD and has a jumper to select what shift you want for what brand. I did have to buy a special HiTec Dual Conversion crystal for it though. The RX and 4 decent 425BB servos (RX with servos is called a Flight Pack) was only $79 from Tower, and the crystal was only $11 at my LHS (Tower was out of my channel), so it wasn't too bad all in all. I was worried the special crystal was going to be a $25 gold plated thing. I'm happy! On a side note. Don't buy different crystals for your radio unless you have to. They recommend sending a radio that has had it's crystals switched to a service center to get re-tuned. Just get Receiver crystals to match your radio instead. It doesn't matter as much if you are receiving a bit off channel, but if you're transmitting badly you will make your fellow fliers at the field very unhappy. - Joe

beginner_1

thx. man i dont no what i would do without this board.

DBCherry

My Feedback: (4)

You'd have to find a club and ask questions there. Which is also your best bet for learning to fly. I started eight years ago, and this type of "board" was not available on the interenet.

By the way, when Joelansing talks about sending in the radio when changing crystals, he's talking about the transmitter. In the US it's illegal (and unsafe) to change tarnsmitter crystals without having an authorized service tech tune it. (Don't know about Canada.)

To answer your later question, you can not use a JR receiver with a Futaba transmitter (or Futaba Rx with JR Tx.). The "shift" is different so they're not compatable.

Even though they may use the same shift, and you can use a Hitec Tx or Rx with Futaba Tx or Rx, you can not use a Hitec crystal in a Futaba Rx, or Futaba in Hitec. Transmitter crystals will not work in a Rx either.

Oh, one other thing. Futaba Receivers are also made in high and low "bands". In other words, if you're on channel 53 (as I am), you can not buy a receiver on channel 24, for example, and put a channel 53 crystal in it. (Well, you can, but it may not work properly.) Futaba is the only one that does this, and I can't for the life of me figure out why.

Good luck,
Dennis-

Montague

Some brands of RX crystals are interchangeable, buy many aren't, so it's safest to go with the crystal for the brand of RX you have. (Personally, I interchange FMA and Hitec crystals all the time, but I verfied with the FMA techs that they are, in fact, the same).

Some transmitters can have their frequency changed at the field, either by changing modules (not crystals), or though some sort of setting on the transmitter (Hitec and Polk are among the companies with transmitters that can change channels). However, as Dennis said, you shouldn't change the TX crystal. There are lots of cases of guys doing it to move a channel or two with no ill effects, but I still wouldn't do it.

gus

Your definitive answer for all things radio related is here:
http://www.torreypinesgulls.org/Radios.htm

This site was referenced a while ago, and although it took me a while to read, it is VERY informative, and you feel like an uber-geek when done. On the other hand, you learn a lot.

gus

aimmaintenance

I'm just curious. Does this then mean that If your flyin a Hitec on chan 24 that someone else can fly an Airtronics on chan 24 at the same time with no interferance?

nilo

[X(] I'm very surprised!
I knew the use of 72Mhz band for model aircraft was granted by FCC and therefore I thought that I could change the TX frequency whenever I want, as far as I stay within the allowed band (available crystals).
In fact, I thought this would be a common thing to do, like in the filed, when you see somebody else using your channel, you could simply change your crystal on both TX and RX and have fun.
I already bought a second crystal with this thought, tested on both RX and TX and worked fine, but didn't know I couldn't do it by law.
As far as the operational point of view, I don't see any problem on changing crystals. The system would work fine though but if it against the law, is againts the law!

Nilo

DadsToysBG

My Feedback: (35)

We ran a test at or field one day with several radio's and planes, this what we found. (1) JR radio (chan 17) hitec (17) both FM very minor trouble. (2) JR pcm Hitec FM no problem. This is not to say that it makes it OK to fly at the same time, but shows the built in safety factor. Also you may change trans. channels. JR can go frm low to high. Futaba must stay within a certin range, but you can still change. Myself, I carry six different channels when i go to fly-ins so i don't sit to long. I use a JR 10X.
Dennis

Woodsy

Ok i quoted these 2 for a reason, frequency shift is NOT a problem all around the world, in AUS we work on 36Mhz band and ALL TX's will work with ALL RX's and providing the corect crystals are used you can swap from one frequency to another, however our governing body (MAAA) has a rule where by all TX's must be certified that they are on 36.XXXMhz and a sticker atatched by an authorised tester, this is for insurance only at MAAA clubs. Due to this rule synthisized (multi chanel) TX's are not yet legal here but there being tested now.

MikeL

My Feedback: (3)

No, it just means that the radios encode the data on a different portion of the signal. The receivers are set to listen to that portion of the signal. That part of the signal is still present even when the data is encoded elsewhere.

One thing that hasn't been mentioned is PCM receivers. They aren't cross-compatible between brands. Each brand uses proprietary technology.

There are two methods of being able to change frequencies legally and safely in the field: synthesis or modules. They're found mostly on higher-end radios. Synthesis involves generating the signal without crystals. It's a newer technology that's been around for several years, but is only now becoming more common in the marketplace. Modules allow you to change crystals in your TX by containing not just the crystal, but the whole RF deck. Each module is tuned to its particular channel. The reason you're supposed to send lower-end radios in to have the crystal changed is that there are other components in the RF deck that need to be tuned to the channel as well.

What's all this mean to a true beginner? It means that prior to ordering your equipment you should contact the club you'll be joining, and ask for a frequency distribution chart. Most clubs will have that. All it is is a listing of the channel numbers and the number of club members using each channel. Buy gear that's on one of the channels with the least number of users. Some fields also have interference problems on certain channels, so contacting the club prior to purchase allows you to avoid such things.

Our radio gear is amazingly flexible in how it can all work together. Receivers are really one of the only things you need to be careful of anymore. I mix and match my radio equipment all the time, to make sure I have everything matched to where I need it most. On my heli I use a JR TX, a Hitec RX, servos from Hitec, Futaba, JR, and Tower, a Futaba gyro, and an FMA Co-Pilot. It all works great together!

fredscz

My Feedback: (47)

If you use an Airtronics RD series transmitter you can use JR,Futaba, or Hitec receivers as long as they are on the same channel/frequency. The RD series transmitters are shift selectable.
Fred B

DBCherry

My Feedback: (4)

Dad'sToys,
You MIGHT get away with changing transmitter channels within one or two channels, beyond that your risking your aircraft, and those of people around you.

And has been stated, it is illegal in the US to change transmitters channels without a service tech re-tuning it.

The FCC is constantly being asked to give our frequencies to commercial enterprises. Why give them a reason to consider doing it? Giving everyone the impression that you can freely go out and disregard the law could eventually cause us to lose what we have.
Dennis-

Rodney

The main reason that it is against the law in the USA to change transmitter crystals is because there are other authorized users (who pay for their use of the bandwidth) sandwiched in between our channels. Some of these are used in areas that ; if interferred with, could cause injury or even loss of life. If your transmitter would be a little out of band (and even apparently working for you) it could be causing interferance to these other paying users. When you swap crystals in your tranmitter, you could be slightly out of tune and cause problems to others. A sure way for all of us RCers to loose our free bandwidth is to cause interferance to these other users and have the government not allowe our recreational use of them. Please obey the law.