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Range Problems Futaba

Old 07-25-2009, 08:24 PM
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vh2q
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Default Range Problems Futaba

I can't get more than 30 feet of range, beyond that I get servo jitters. Antenna is fully extended, screwed tight. Both batteries have full charge. I have changed the RX battery. That helped a bit. RX antenna is not broken, I checked the resistance with a multimeter and got 2.5 ohm from tip of antenna to RX circuit board. I have tried with several TXs and get the same result. The only thing I can think of now is that the TX needs to be tuned to the ch 21 xtal I am using. The Tx was originally ch 56 but along the way the xtals got swapped out. Any other ideas, this is driving me nuts.
Old 07-25-2009, 09:25 PM
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tschuy
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Default RE: Range Problems Futaba

Going from range frequency to a lower range frequency may have had a negative result. Typically the transmitter and receivers are tuned for either high range frequencies (channels 36 to 60) you should stay in that range. You selected a low range frequency (channels 11 to 35) which the radio and receiver are not tuned for. My guess if you pick a different channel in the high range you'll see an improvement in range.
Old 07-25-2009, 09:47 PM
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w8ye
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Default RE: Range Problems Futaba

If you change your transmitter back to 56 it will work fine!

Otherwise you will need to send your transmitter in to have it tuned to channel 21
Old 07-25-2009, 11:35 PM
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huck1199
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Default RE: Range Problems Futaba

It is illegal to change TX freq if you are not a certified techician.
Old 07-26-2009, 12:44 AM
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vh2q
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Default RE: Range Problems Futaba

I guess that means I need TX crystals 52, 53, 56 for my 3 Futaba TXs. I have TX crystal 21 surplus. I also have a TX module 17 that doesn't fit any of my radios.

And RX need matching xtals 52, 53, 56. I have RX 21, 36 (2 ea), 23, 24 and 17 & 16 surplus.

I thought, wrongly, that only the RX had to be hi or lo band.
Old 07-26-2009, 12:52 AM
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Default RE: Range Problems Futaba

The transmitter has to be "ON original frequency" if it is crystal controlled. If you want to change the crystal controlled transmitter frequency, you must send it in and have the service man change it. A transmitter with a RF module you can change the modules around. Some modules are adjustable in frequency. To change the frequency of an existing module, you have to send it in to service to have it changed
Old 07-26-2009, 04:44 AM
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Default RE: Range Problems Futaba

Everyone here is correct......first off it is illeagle to change freqs on transmitters in the US. on your own.....and second some receivers are shift sensitive with the line between hi and lo at channel 36......good luck
Old 07-26-2009, 07:58 AM
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dignlivn
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Default RE: Range Problems Futaba



OP,


Have you thought about going to 2.4 ?

Bob
Old 07-26-2009, 08:09 AM
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jester_s1
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Default RE: Range Problems Futaba

I'm just glad he didn't try to fly and cause interference with someone else's equipment. OP- It's not a big investment to have Futaba change your frequency for you.
Old 07-26-2009, 08:22 AM
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DavidAgar
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Default RE: Range Problems Futaba

If you do get your transmitter changed to another frequency at a service center, you need to know not to try and change it to any other frequency once you get it back. If it gets tuned to 21, then it needs to stay on 21. You also need to get the proper crystals for your receivers. You do not mention what model transmitter it is, but it sounds like you need to get one that has model memory and then all your planes can be on the same frequency. Good Luck, Dave
Old 07-26-2009, 10:51 AM
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vh2q
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Default RE: Range Problems Futaba

I was aware you had to send HiTec's in for tuning but nothing in the Futaba manuals about that. These are all older FM Tx's that I bought with the planes, trying to sort out the planes to get them flying. There is a company on the net that advertises crystal exchange ... so obviously there is a lot of crystal swapping going on. If they didn't want you to change them, I am puzzled as to why they have plug in/our crystals so easily accessible. Good news I have my own private field; bad news nobody around to explain this stuff to me.

Anyway thanks for the input. I get the message.
Old 07-26-2009, 01:46 PM
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w8ye
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Default RE: Range Problems Futaba

Crystals for transmitters are not sold to the public unless it is more or less a black market situation..
Old 07-26-2009, 02:44 PM
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Default RE: Range Problems Futaba

Hi!
Over here in Europe you can change the Tx and Rx crystals yourself ...but that is on the 35, 40 and 27 mHz band.
Is 72 or 50mHz any different??
Old 07-26-2009, 03:03 PM
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w8ye
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Default RE: Range Problems Futaba

The 50 MHZ can only be operated by Ham radio guys and they can change their own legally but you still need to be able to retune the transmitter.

The USA FCC communications commision declares it illegal for someone without the FCC repair license to change the crystal in their R/C transmitter 27,72,75 mhx.
Old 07-27-2009, 09:32 PM
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ally2mail
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Default RE: Range Problems Futaba

why does horizon hobby sell JR tx crystals if they don't want us to change them?
Old 07-27-2009, 09:39 PM
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Default RE: Range Problems Futaba

That is a real good question? and as you can see here, they don't work unless maybe you just move over 1 channel
Old 07-27-2009, 10:03 PM
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Default RE: Range Problems Futaba

I wasn't aware they were selling TX crystals for 72MHz, but if they are, they shouldn't be doing that as it is irresponsible because they know peeps will change TX frequency, jack up their TX, and shoot others down, etc. Guess they don't care, and technically they aren't breaking any laws of that I'm aware. It is not illegal to sell, buy, or own crystals, it is just illegal for the consumer to service them in the TX of a 72MHz band et. al.. There really is no good reason to ever replace the TX crystal yourself. Any change to the tuning circuit, including replacement with the same freq crystal, should require a re-tune by qualified persons. Even if you fly alone in BFE, respect the RF band that we have as there are commercial freqs in between ours. Please don't give anyone a reason to take the 72 band away from us. Doesn't effect me directly as I've moved to 2.4, but indirectly I'd like all modelers to be good stewards of what we have, including the 72 band.
Old 07-28-2009, 12:37 AM
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Default RE: Range Problems Futaba

http://www3.towerhobbies.com/cgi-bin...I=LXH260**&P=0
tower does it as well.
Old 07-28-2009, 12:50 AM
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w8ye
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Default RE: Range Problems Futaba

They must be "dumping them"? They didn't used to sell the transmitter crystals except to the service people
Old 07-28-2009, 08:36 AM
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Default RE: Range Problems Futaba

Good morning: I have a couple of questions. 1. What is the difference between a Futaba R168DF recever, and Futaba FP-R127DF and Futaba 1024 FP-R129DP. Now i know that 1 of them are 8 channel, and one is 7 channel and 1 is a 9 channel is a Pulse code modulation system. Now is one better than the other. is there a difference in the receiving range.
Old 07-28-2009, 10:07 AM
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w8ye
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Default RE: Range Problems Futaba


ORIGINAL: DMSMITH

Good morning: I have a couple of questions. 1. What is the difference between a Futaba R168DF recever, and Futaba FP-R127DF and Futaba 1024 FP-R129DP. Now i know that 1 of them are 8 channel, and one is 7 channel and 1 is a 9 channel is a Pulse code modulation system. Now is one better than the other. is there a difference in the receiving range.
The 127 is the cheapest of the bunch is seven channel and a two layer board
The 129 is a later 9 ch PCM and is much more expensive than the other FM types
The 168 is the best of the 8 CH FM recievers

Old 07-28-2009, 12:30 PM
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Greg Wright
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Default RE: Range Problems Futaba

Why don't you just get into the 2.4 class of radio's and be done with it.
Old 07-28-2009, 01:28 PM
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Default RE: Range Problems Futaba


ORIGINAL: w8ye

They must be ''dumping them''? They didn't used to sell the transmitter crystals except to the service people

Tower is not "dumping" the Tx crystals. I just checked a 1999 Tower catalog and Futaba crystals were sold as a set, Tx and Rx , for $33.99 for dual conversion FM set. I know they sold them long before that but '99 is the oldest catalog I have at hand. Changing crystals has always been an issue in the Hobby and it's not really Tower or JR's or any other sellers responsibility to use them properly. It is the operators responsibility.
Old 07-28-2009, 02:37 PM
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Default RE: Range Problems Futaba

Crystal sets have been available for quite a number of years. That's because there ARE people fully-qualified to perform their own crystal changes and tuning of their R/C systems. However, if you cannot certify that your transmitter conforms to the FCC's requirements for output power, bandwidth, and spurious radiation, you are not qualified to change the crystal of your transmitter.
Old 07-29-2009, 05:45 PM
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ally2mail
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Default RE: Range Problems Futaba

well guys, I've been flying for a long time and I have been changing my tx crystals for at least 10 or more years. I have never had a problem. For the last several years I have had a JR 9303 that has a module in it which I changed the crystal in when I got it and it has never given me any problems. As for switching to 2.4, that really isn't an option for me as I have way to many 72 mhz planes to switch. My favorite of which is a 33% yak 54 with a 3W 80 on it.

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