TM808 FREQUENCY CHANGE

[berreizeta]

I can not find 26370 xtal.
Does anyone know if these variations might work?



OR




Thkxall

[kt315]

you do not find out it just rare type. try the way -

1- simple pic or avr generator based on.
2 - something from 420 khz ceramic quartzs that used in tv remote control pults. plus divider on 4060.
420000/2/2/2/... = 26250

[berreizeta]

4060 its my second option 27mhz / 1024 = 26367Hz (nearly 26370)

26367 / 4 = 6591.75 Hz for coil its the same

[kt315]

i did not suggest mHz range - it wastes energy on every stage of divide.
you have to learn more electronics.
take a generator on TLS555. it is good way.

[berreizeta]

I'm going on the way to learn

thx kt315

[kt315]

[Skippy]

The 16 Volt power rail is something that you have to consider. 15 Volts is a common max quoted in datasheets for some 555 variants.

If you want alternative crystal / divider replacements, here's a couple:
4.194304 MHz divide by 32, divide by 5 = 26212 Hz ( 0.6% error)
4.433619 MHz divide by 8, divide by 7, divide by 3 = 26390 Hz (0.07% error)

Both these crystals are common and dirt cheap: (binary divider, & colour TV sub-carrier)

[kt315]

ask Eddy and he ll change a code for PIC on freq you need. http://smartelectronix.biz/publ/mini...telja/1-1-0-43

[kt315]

lay and hex http://smartelectronix.biz/load/0-0-0-35-20

[berreizeta]

Change xtal 26370Hz / 4 = F 6592,5Hz

xtal 24000Hz / 4 = 6000Hz (Coils TX: L=570uH C= 1.23uF ; RX: L=17.9mH C= 39,31nF )


¿ is need to change something more in the circuit ?

[kt315]

choice right r c values

[berreizeta]

Resonant Frequency Calculator :

http://www.1728.org/resfreq.htm

F: 6000Hz
L1: 570uH
L2: 17.9mH

correct?

[berreizeta]

Or R1, R2, C3, C4 in 4011 circuit ?

[kt315]

in THE generator on ne555 i did put above. you have to tune it on 26370.

[berreizeta]

I don't like the choice of 555, my question is:


¿Is not easier to change the xtal 26.37khz to 24kHz and adapt coils for 6000Hz ?




thx