OLD Vintage Futaba Radio Systems Crystals and Modules

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SAVAGETITAN

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I've got several of these Transmitters and have been trying to get matching Receivers, Crystal sets, and Servo's. These are the FP-T 2F models that are metal cased and originally came with tan colored plastic cased receivers and servo's. Those servo's by the way were a square drive not a splined drive, making the chance of finding servo horns difficult. Being that these originated before I was born, and over time some of the channels that they were made to run on, have since been rendered illegal by the FCC. So hobby shops won't help me and have said they'd be forced to confiscate them if I brought them in, so did this one guy who mods old systems up to 2.4 Ghz, and charges full blown prices that would get you a modern high end system. So I need to understand how to identify crystals frequencies when some are interchangeable, some are not. There was 27 MHz, 72 Mhz, and 75 Mhz. Some if not all were AM. I don't think they used FM before the early 1980's. I could be very wrong. Futaba wouldn't help when I was trying to figure out the correct lengths of receiver antenna wire(s), as most of the used receivers I bought had their wires chopped. Any help would be appreciated. Thx
 
I've got several of these Transmitters and have been trying to get matching Receivers, Crystal sets, and Servo's. These are the FP-T 2F models that are metal cased and originally came with tan colored plastic cased receivers and servo's. Those servo's by the way were a square drive not a splined drive, making the chance of finding servo horns difficult. Being that these originated before I was born, and over time some of the channels that they were made to run on, have since been rendered illegal by the FCC. So hobby shops won't help me and have said they'd be forced to confiscate them if I brought them in, so did this one guy who mods old systems up to 2.4 Ghz, and charges full blown prices that would get you a modern high end system. So I need to understand how to identify crystals frequencies when some are interchangeable, some are not. There was 27 MHz, 72 Mhz, and 75 Mhz. Some if not all were AM. I don't think they used FM before the early 1980's. I could be very wrong. Futaba wouldn't help when I was trying to figure out the correct lengths of receiver antenna wire(s), as most of the used receivers I bought had their wires chopped. Any help would be appreciated. Thx

I will look in my pile ,might have something!...:cool:
 
Thx. I need some knowledge that others have or have since forgot. I believe that different matching sets of crystals on a different channel but on the same Mhz, can be changed so long as you stay on the same frequency, 27 to a different 27, 72 to a different 72, the only exception being the 75 Mhz band? I don't get the whole module thing, I guess they still had crystals? So why a module what did it do?
 
Thx. I need some knowledge that others have or have since forgot. I believe that different matching sets of crystals on a different channel but on the same Mhz, can be changed so long as you stay on the same frequency, 27 to a different 27, 72 to a different 72, the only exception being the 75 Mhz band? I don't get the whole module thing, I guess they still had crystals? So why a module what did it do?

Well I looked ,an it doesn't look good ,I have no 75's but one in the old rival trans.,the controller is intact an everything on it
is there with the 75 crystal which has the # of 78.
I found one receiver that is a 75 MHz airtronics that may have went with that radio ,but is in poor condition an has no crystal
an no antenna ,don't know anything about it ,nor do I know that it may work if a crystal & antenna was added.

I found a small box of crystals ,but most of are 27 MHz an are mixed matched on most of them.
I also have found a Futaba FP-R102GR AM 27 MHz receiver with out ant & crys. don't know if it will work!
An a hitec HP-2 RNB receiver ,its AM ,but don't know the MHz ,does have the red ant.
Also an unknown 27MHz receiver ,no cryst or ant.
Also have a traxxas 3 ch 27 with ant. cut off ,no cryst.
 
I will do some diving. I may have a couple goodies for you. If you have any that are unmatched, please list what frequencies you have and if they are tx or rx. It will orb take me a bit to dig this stuff out so be patient. ;)
 
Thanks I'll try and look. A lot of my stuff was put into totes and into a storage unit, not all by me. I think mostly if I can get confirmation as to certain specifics: length of receiver antenna wire based on Mhz, whether or not channels can be changed between systems using the same Mhz, and why if not on the 75 Mhz band? Also is there a way if the paper tab was removed from a crystal, of identifying whether it is AM or FM? Can a radio system that was AM use crystals that were FM? I'm looking for the stuff that was Futaba G, as far as plugs go, I don't know if they made both AM and FM that used G type plugs. I'm also looking for the older tan colored plastic receivers and servos (Futaba). These items are more period correct to my future restorations of pre 1980 models, maybe even pre 1977. I don't know exactly when they changed over as Futaba doesn't want to be much help, and I wasn't born yet or was too young either way. As always any help would be appreciated. Thx
 
Thanks I'll try and look. A lot of my stuff was put into totes and into a storage unit, not all by me. I think mostly if I can get confirmation as to certain specifics: length of receiver antenna wire based on Mhz, whether or not channels can be changed between systems using the same Mhz, and why if not on the 75 Mhz band? Also is there a way if the paper tab was removed from a crystal, of identifying whether it is AM or FM? Can a radio system that was AM use crystals that were FM? I'm looking for the stuff that was Futaba G, as far as plugs go, I don't know if they made both AM and FM that used G type plugs. I'm also looking for the older tan colored plastic receivers and servos (Futaba). These items are more period correct to my future restorations of pre 1980 models, maybe even pre 1977. I don't know exactly when they changed over as Futaba doesn't want to be much help, and I wasn't born yet or was too young either way. As always any help would be appreciated. Thx

I have a lot of crystals with out tab ,however I seen the numbers very faint on them ,you will need a magnified glass
an a brite lite to see the number!

If the trans & receiver is an AM ,it should work with any AM matching crystal I believe ,so as long as the trans & receiver has
both matching crystal ,they should work.
As far as the antenna ,they should work at a certain point ,I think in distance!

I have some Ofna 27 MHz receivers with antennas ,they should be the same length in which
I can measure for you!...:cool:
 
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I am almost positive that you need to keep your frequencies within their band. In other words, 75 to 75 and yes, there are many frequencies within that band. As is with 27. However, due to the way radios are tuned, a 27 will not work with a 75. These bands are tuned so that the radio sends a signal over that frequency. Much the same way as a transistor radio works on a modulated frequency. The band is centered and the 'changes' are received. This 'commands' the receiver accordingly. Please forgive me as I am very rusty... It was in high school that I built a transistor radio and tuned it accordingly. My terminology is wrong but I am at a lack of proper... I do believe the principals to be correct.

Also, I believe that there was a length of wire based on those frequency that worked well... Attenuated as it were, I do have a couple 75 receivers... I will try and get a measurement for you.
 
I am so most positives that you need to keep your frequencies within their band. In other words, 75 to 75 and yes, there are many frequencies within that band. As is with 27. However, due to the way radios are tuned, a 27 will not work with a 75. These bands are tuned so that the radio sends a signal over that frequency. Much the same way as a transistor radio works on a modulated frequency. The band is centered and the 'changes' are received. This 'commands' the receiver accordingly. Please forgive me as I am very rusty... It was in high school that I built a transistor radio and tuned it accordingly. My terminology is wrong but I am at a lack of proper... I do believe the principals to be correct.

There maybe a band chart ,27 will not work with the 75 ,the numbers are too far away from each other ,I've
had a 37's work with 27 band withs.
Transmitters & receivers have adjustable diodes that can be tuned for the bands ,but ,radio gear is too cheap to mess with
that!
Back in the racing days ,people had to change the number crystals that they had if there was someone else on the same
Freq.
 
Yes, I remember well the numbered clothes pins hung on your antenna. GOD HELP YOU if you were at the track tuning without that pin!!! I believe what you're saying to be correct, that if the numbers were close it could work. Likely due to the cheap factor combined with the idea that you would need a somewhat loose setting to make all those frequency crystals work.
 
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