27 meg Crystals

[ph]

I all

Are 27 meg crystals interchangeable between TX & RX if not how do you tell
which is which, I have 3 sets Red, Brown and Orange and only one of the red
one's is marked RX.

Thanks for any help

Paul

[Justin Mahn]

Hopefully you didn't get bum sets, but each one should have a TX
(transmitting) and an RX (receiving) crystal. If they're not marked, then
plug em in. If they don't work, swap 'em around. If they still don't work,
it's a bum set. If you find out which is which, then take a permanent
marker and put a T and an R on the appropriate crystal for future reference.
And be sure to range check by having a friend walk the model as far away as
he can without the servos getting jittery or stop responding to transmiter
movements.

--
Justin Mahn
remove Panties to reply


"ph" <nobody@nowhere.com> wrote in message
news:tnxJa.2977$As5.22288571@news-text.cableinet.net...
> I all
>
> Are 27 meg crystals interchangeable between TX & RX if not how do you tell
> which is which, I have 3 sets Red, Brown and Orange and only one of the
red
> one's is marked RX.
>
> Thanks for any help
>
> Paul
>
>

[Rich]

"ph" <nobody@nowhere.com> wrote in message
news:tnxJa.2977$As5.22288571@news-text.cableinet.net...
> I all
>
> Are 27 meg crystals interchangeable between TX & RX if not how do you tell
> which is which, I have 3 sets Red, Brown and Orange and only one of the
red
> one's is marked RX.
>
> Thanks for any help
>
> Paul
>
> I can change my ones around and it doesn't make any difference,everything
works ok.

[JerryO]

Paul,

Each crystal should be marked for frequency. As I remember, the transmitter xtal is the one with the real frequency number on it. ie. Channel two is marked: 27.145 mh (under the colored tape). Since the IF frequency is standard at .455 mh, the receiver will differ by .455 mh. Futaba uses receiver crystals lower then the transmitter. a futaba receiver will use 26.690 mh. JR and Airtronics may use receiver crystals higher than the tranmitter. ie. 27.145mh plus .455 for a 27.600mh receiver crystal on channel two.

While not intended, interchangeing the transmitter and receiver crystals will probably still work as they will produce a .455mh beat for the 'IF' (intermeadiate frequency amplifier) in the receiver. Just as using futaba or airtronics receiver crystal in each others receivers may work. Just realize that only the actual brands in the correct products are designed and tested to work properly with full range.


JerryO

[ph]

"JerryO" <JerryO.pkkmg@rcgroups.com> wrote in message
news:JerryO.pkkmg@rcgroups.com...
>
> Paul,
>
> Each crystal should be marked for frequency. As I remember, the
> transmitter xtal is the one with the real frequency number on it. ie.
> Channel two is marked: 27.145 mh (under the colored tape). Since the IF
> frequency is standard at .455 mh, the receiver will differ by .455 mh.
> Futaba uses receiver crystals lower then the transmitter. a futaba
> receiver will use 26.690 mh. JR and Airtronics may use receiver
> crystals higher than the tranmitter. ie. 27.145mh plus .455 for a
> 27.600mh receiver crystal on channel two.
>
> While not intended, interchangeing the transmitter and receiver
> crystals will probably still work as they will produce a .455mh beat
> for the 'IF' (intermeadiate frequency amplifier) in the receiver. Just
> as using futaba or airtronics receiver crystal in each others receivers
> may work. Just realize that only the actual brands in the correct
> products are designed and tested to work properly with full range.
>
Thanks for the reply.

I have 3 set of crystals

1--Brown--both marked 26.995 mhz

2--Red--both marked 27.045 mhz

3--Orange--both marked 27.095 mhz

Am I correct in assuming that I have been sold 3 sets that consists only of
Transmitter crystals and no Receiver Crystals. or are some makes marked the
same to stop confusion.

Thanks

Paul

[JerryO]

"ph" <nobody@nowhere.com> wrote in message news:<GkIKa.7429$WN.52102382@news-text.cableinet.net>...
> "JerryO" <JerryO.pkkmg@rcgroups.com> wrote in message
> news:JerryO.pkkmg@rcgroups.com...
> >
> > Paul,
> >
> > Each crystal should be marked for frequency. As I remember, the
> > transmitter xtal is the one with the real frequency number on it. ie.
> > Channel two is marked: 27.145 mh (under the colored tape). Since the IF
> > frequency is standard at .455 mh, the receiver will differ by .455 mh.
> > Futaba uses receiver crystals lower then the transmitter. a futaba
> > receiver will use 26.690 mh. JR and Airtronics may use receiver
> > crystals higher than the tranmitter. ie. 27.145mh plus .455 for a
> > 27.600mh receiver crystal on channel two.
> >
> > While not intended, interchangeing the transmitter and receiver
> > crystals will probably still work as they will produce a .455mh beat
> > for the 'IF' (intermeadiate frequency amplifier) in the receiver. Just
> > as using futaba or airtronics receiver crystal in each others receivers
> > may work. Just realize that only the actual brands in the correct
> > products are designed and tested to work properly with full range.
> >
> Thanks for the reply.
>
> I have 3 set of crystals
>
> 1--Brown--both marked 26.995 mhz
>
> 2--Red--both marked 27.045 mhz
>
> 3--Orange--both marked 27.095 mhz
>
> Am I correct in assuming that I have been sold 3 sets that consists only of
> Transmitter crystals and no Receiver Crystals. or are some makes marked the
> same to stop confusion.
>
> Thanks
>
> Paul

My radios have crystals marked with the channel (ie transmitter)
frequency on the color tape that is placed on the crystal. ALSO, each
piece of tape has a rx or tx to indicate if it is for the transmitter
or the receiver.

HOWEVER, if I lift the colored tape, I can see the frequency of the
crystal itself. The tranmitter crystal will have the channel frequency
as above, BUT the receiver crystal will be offset by the IF frequency
(probably .455 megahertz).


JerryO