Help required in understanding Crystals that I need to order

[Slats]

Guys take a look at the attached table from Schulze in Germany

http://www.schulze-elektronik-gmbh.de/index_uk.htm

I wish to order a set of Crystals for channel 85 which I know to be 40.875.

Note that Schulze has two lists for frequencies - one is titled "for transmit frequency" the other called "crystal frequency in MHZ"
For my example above the "for transmit frequency" is 40.875 and the "crystal frequency in MHZ" is 40.420. Both of which sit under the row of channel 85.

When ordering a TX and RX crystal am I actually requiring to order a slightly different freq crystal for the TX compared to the RX? I thought you needed exactly the same frequency for both TX and RX crystal...can someone walk me through this. If I had a TX that had a 40.875 crystal, what corresponding frequency RX crystal would I need to buy?

Thanks
John

[tsenecal]

direct link to crystal page:

http://www.schulze-elektronik-gmbh.de/alpqu-z.htm

there are no transmitter crystals on that page.

ignore column 3. act as if it doesn't exist.

column 2 is the TRANSMISSION not TRANSMITTER frequency. the chart is only for receiver crystals. you will have to buy crystals for the transmitter from the transmitter manufacturers site. I believe you stated you have a robbe transmitter.


long story short, the third column is the actual oscillation frequency of the raw crystal. it may or may not have anything to do with the TRANSMISSION frequency. It does re-enforce the statement that all radio manufacturers make, and that is that you CANNOT MIX CRYSTAL MANUFACTURERS. if you have a robbe transmitter, you must buy robbe crystals for it. you cannot buy schulze or Ace, or JR, or sanwa crystals for it. they will probably not work correctly, and may damage the radio.

i believe what you need for the transmitter is this:

http://at.robbe-online.net/rims_at.storefront/4e152c6d00696a23271b3e0dc146063e/Product/View/1&2DF103085

[Slats]

direct link to crystal page:

http://www.schulze-elektronik-gmbh.de/alpqu-z.htm

there are no transmitter crystals on that page.

ignore column 3. act as if it doesn't exist.

column 2 is the TRANSMISSION not TRANSMITTER frequency. the chart is only for receiver crystals. you will have to buy crystals for the transmitter from the transmitter manufacturers site. I believe you stated you have a robbe transmitter.


long story short, the third column is the actual oscillation frequency of the raw crystal. it may or may not have anything to do with the TRANSMISSION frequency. It does re-enforce the statement that all radio manufacturers make, and that is that you CANNOT MIX CRYSTAL MANUFACTURERS. if you have a robbe transmitter, you must buy robbe crystals for it. you cannot buy schulze or Ace, or JR, or sanwa crystals for it. they will probably not work correctly, and may damage the radio.

i believe what you need for the transmitter is this:
http://at.robbe-online.net/rims_at.s...ew/1&2DF103085

Thanks - that is a real help.
However on the mix of Crystals between manufacturers not being compatible, I don't think this is a given for ALL situations and I think needs clarification.
The Schulze RXs do require single conversion crystals as per Futaba. I have successfully used Futaba crystals in the Schulze RXs with no problems.
But nonetheless thanks, I appreciate it.

J

[Mankster]

I have used Schultze Rx a lot and they work fine with Futaba Crystals. Futaba crystals are the reccomended ones by all the shops that sell Schultze over here. They dont even import the Schultze crystals. Delving into the individual frequencies of the crystals and the differeance between Trasmission and RX crystals can be confusing - so just buy by Channel number instead - If you buy a Futaba RX crystal on Ch85, your Rx should work with any transmitter on Ch85
All my TX and Rx's are synthesised now - everything works on channels numbers. Tx and Rx are from different manufactures - Futaba, Robbe, Graupner, Multiplex etc - all work together.