Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[CERES]

 :-)Hello again,
If a Dual conversion crystal has a blue tab and a single crystal has a green tab, what are those crystals with neither which one seems to receive when buying on-line sometimes ??? .
Ceres.

[mattycoops43]

Lots of crystals don't have tabs, but they should have some way to identify freq. Usually etched onto the side somewhere.

[hmsantrim]

Hi ceres.
        Crystals have the frequency number printed the paper tab.  If the paper tab is missing or torn the frequency number will be     
         etched on the side of the crystal body if you peel back the remnants of the paper tab you will find it.
          The tab will also state letters TX to show the crystal if for the transmitter and RX to show the crystal is for the receiver 
            The coloured part of the tab is an "ease of use" frequency identification system and refers to the frequency number of the
             crystal.  This is done as its easier to avoid frequency clashes at the pond side by the use of colour coding the crystals rather
                than having to refer to a frequency number chart.

                 If you could let us know what frequency you equipment  27Mhz or 40 Mhz we could send you a frequency number chart
                  so you could identify the crystals by the number etched on them.
                             
             

             I have posted a pix of a pair of 27.195 tx and rx crystals. They are marked T for transmitter and R for receiver.

                27.195 refers to the colour coding for GREEN . these crystals are on E-bay and seem to have the full  set of ID markings
               apart from the colour coding.

           The crystals with no ID marked on them as you would get from giant cod are mini crystals which you may have bought         
            you are getting cheap crystals as they are not fully ID labled which are more expensive.
          You would have to make a note of what you bought and label them yourself as they do give the frequency number on the

              catalogue page        Single Conversion Rx Crystal 35.010mhz Ch61

   
 



                               cheers Frank

[CERES]

 :-)Frank,
Many thanks for your reply.

My transmitter is a Hi Tech 6 channel 40MHz dual conversion that came with a dual conversion receiver.

I understand that if I want to use the TX with a single receiver I only need to change the Chrystal in the receiver only.

The TX Chrystal is a CH52/ 40.685TF. Therefore based on the above, all I need is a single receiver Chrystal of the same frequency so that I can use the Transmitter with other models??

Your comments will be much appreciated.
Regards,
Ceres.

[barriew]

Yes - BUT if you buy another Dual Conversion Receiver, then you need a Dual Conversion crystal. HOWEVER you don't have to use a dual conversion receiver with that Tx and Tx crystal. You can buy a normal receiver and a single conversion 40.685 crystal. Its only the receiver that is Dual Conversion.

Hope this clarifies things.

Barrie

[CERES]

 :-)Last October I was trying to sort out what Single Conversion crystals to use with my Laser 6 TX.
Having purchased different frequencies to what I have, these also turned out to be nonoperational using that TX and my thanks again to Frank @ 'hmsantrim' and Barrie @ barriew for their views.

Checking web pages got me to the UK agency for the Hitec TX's and having spoken to their Service department the conclusion is as follows:-

The TX Crystal identification number must end in "TF" the receiver crystal does not as long as it is the corresponding number to the TX. Only this way will the Laser 6 function with a single conversion crystal.

Does any Forum member of of this reasoning.

Bernard.

[malcolmfrary]

The markings on transmitter crystals indicate the frequency transmitted to air.  That bit is simple enough.
The receivers work by generating a frequency that is offset from the required frequency, and need a crystal working at that offset frequency.  Single conversion requires one offset, double conversion (more selective, less chance of interference, costs more) uses a different offset.  Not long ago, they were marked with that frequency and channel information.  The trend now seems to be to mark them with the transmitted frequency that they are intended to receive and, hopefully, the fact that they are intended for receivers.  This is obviously easier for non-technical users and not a problem as long as all receivers work with the same offset, but a royal pain if a manufacturer decides that its a good idea to deviate from the norm without telling anybody else, usually in the hope of locking the purchaser into his brand.

[Rosenante]

 Hi all.

I've been battling with this for months.
Hitec Flash 5 Tx.    I can buy either mode of Rx with appropriate Xtal and it will work?

Ie.  D/c Rx with D/c xtals.
  and S/c Rx with S/c Xtals.
 But obviously no mixing.

  I've been fuming ,unable to match D/C Xtals. when S/c are available.
 Dumb Huh?

 Further, bought a 2nd Rx. Hitec. 36 Mhz (Aus) Dual conversion. Great, there is a God,
  Got it home, read the small print. This Q-PCM can only be used with a Q-PCM Tx.
 Never heard of it.
  "net tells me it is for helicopters.

  Read the fine print Ceres..Bas

[CERES]

  Thanks for your replies. Perhaps my message did not make it clear that by purchasing further sets of single control crystals they are all matching sets.      Not being an expert on the subject and at my age simplicity is the norm, I will just use the Laser 6 for the two models I have and if needed for another model just transfer the Rx crystal.
My alternative is ditch the Laser and by planet receivers for my Planet TX.

If I do get lucky I will pass on all info.
Thanks again.
bernard.