Can I just change crystals to change channel on AM Futaba?

Can I just change crystals to change channel on AM Futaba?

Post by larryfu.. » Wed, 04 Oct 2000 04:00:00



I have a Futaba 4NBL Attack Transmitter that doesn't have a crystal, and
a receiver with a 54 crystal.  The transmitter apparently had a 54
crystal that has been taken out for some reason.  I have a pair of new
AM Futaba crystals on 40.  Can anyone tell me if I can just stick them
in and they'll work well, or does that unit need some kind of tuning to
change crystals that far away from the original frequency. Thanks,
Larry

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Can I just change crystals to change channel on AM Futaba?

Post by James D Jone » Wed, 04 Oct 2000 04:00:00


Check deja news for a very long thread on this subject.  Bottom line:
Some say yes, some say no.  According to Steve Kaluf, the AMA
Technical Director, doing so violates the AMA Safety Code and may
void your insurance.  That said, it will probably work just fine unless
your transmitter and receiver are out of tune.  If you try it, make sure
that you do a range check before flying.

Jim - AMA 501383

Quote:

> I have a Futaba 4NBL Attack Transmitter that doesn't have a crystal, and
> a receiver with a 54 crystal.  The transmitter apparently had a 54
> crystal that has been taken out for some reason.  I have a pair of new
> AM Futaba crystals on 40.  Can anyone tell me if I can just stick them
> in and they'll work well, or does that unit need some kind of tuning to
> change crystals that far away from the original frequency. Thanks,
> Larry

> Sent via Deja.com http://www.deja.com/
> Before you buy.


 
 
 

Can I just change crystals to change channel on AM Futaba?

Post by Paul Burk » Wed, 04 Oct 2000 04:00:00



Quote:

> I have a Futaba 4NBL Attack Transmitter that doesn't have a crystal,
and
> a receiver with a 54 crystal.  The transmitter apparently had a 54
> crystal that has been taken out for some reason.  I have a pair of new
> AM Futaba crystals on 40.  Can anyone tell me if I can just stick them
> in and they'll work well, or does that unit need some kind of tuning
to
> change crystals that far away from the original frequency. Thanks,
> Larry

> Sent via Deja.com http://www.deja.com/
> Before you buy.

It will work properly.
I change from ch 15 to ch 56 any number of times.
--
PJB's Seriously Aeronautical Stuff
http://www.networkone.net/~pjburke

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Can I just change crystals to change channel on AM Futaba?

Post by Yves McDonal » Thu, 05 Oct 2000 04:00:00


Yes, a radio tuning is required.  I know that R/C car drivers do it
regularly but they don't require much range and there are no risk to take
with an airplane.  Tuning involve adjusting some of the transmitter's
electronic components to match the crystal's own frequency.  The goal is to
get maximal power output 'on the air' (through the antenna).   An untuned
transmitter will have a poor range and some of its power will dissipate
inside the transmitter box as heat with the possibility of degrading some of
its active components (transistors).

I have this radio set too.  I like especially the receiver with its speed
controller and BEC circuits.  It works well with my electric trainer.  I
whish Futaba would make a new set like this one but in a smaller rec.
package and with a more efficient   high-rate speed controller.

I hope my techno-blahblah helps you.

YvesM

Quote:

> I have a Futaba 4NBL Attack Transmitter that doesn't have a crystal, and
> a receiver with a 54 crystal.  The transmitter apparently had a 54
> crystal that has been taken out for some reason.  I have a pair of new
> AM Futaba crystals on 40.  Can anyone tell me if I can just stick them
> in and they'll work well, or does that unit need some kind of tuning to
> change crystals that far away from the original frequency. Thanks,
> Larry

> Sent via Deja.com http://www.deja.com/
> Before you buy.

 
 
 

Can I just change crystals to change channel on AM Futaba?

Post by kras.. » Thu, 05 Oct 2000 04:00:00


 OK Guys, thanks for your input on this one.  I'm going to just stick on
54 and play it safe-purchase a new set of crystals  to replace the old.
 My only reason to change was that I haven't seen a cheap set of
crystals come on 54 on ebay, though I have seen many other freqencies
that I have been tempted to buy.

Quote:
> I have a Futaba 4NBL Attack Transmitter that doesn't have a crystal,
and
> a receiver with a 54 crystal.  The transmitter apparently had a 54
> crystal that has been taken out for some reason.  I have a pair of new
> AM Futaba crystals on 40.  Can anyone tell me if I can just stick them
> in and they'll work well, or does that unit need some kind of tuning
to
> change crystals that far away from the original frequency. Thanks,
> Larry

> Sent via Deja.com http://www.deja.com/
> Before you buy.

Sent via Deja.com http://www.deja.com/
Before you buy.
 
 
 

Can I just change crystals to change channel on AM Futaba?

Post by Mathew Kirsc » Thu, 05 Oct 2000 04:00:00


Quote:

> I have a Futaba 4NBL Attack Transmitter that doesn't have a crystal, and
> a receiver with a 54 crystal.  The transmitter apparently had a 54
> crystal that has been taken out for some reason.  I have a pair of new
> AM Futaba crystals on 40.  Can anyone tell me if I can just stick them
> in and they'll work well, or does that unit need some kind of tuning to
> change crystals that far away from the original frequency. Thanks,

You will get many many many many conflicting answers. Some will say yes,
some will say no. Others will say that it voids your AMA insurance, or
that the FCC shock troops will drag you away in the middle of the night
because you made modifications to a regulated radio frequency device.

The simple solution is this: You have the radio. You have the crystals.
Put the crystals in the radio and do a LONG range check. If you can get
75-100 feet away with the antenna down, go fly your airplane with it.
If you can't get a decent range check, have the radio retuned.