7,8125 khz is it right ?

[szukam]

hi!
I have done MD working on this freqency .But sometimes there are small problems obout this MD. If the freqency can be the reason ?
regards.

[Tony]

Re: 7,8125 khz is it right ?

No, the frequency is OK. May you share the problems here?

[szukam]

Re: 7,8125 khz is it right ?

I have ID meter in this MD.Sometimes old, very corroded nail gives ID like colour metal.
Md is not overload.
regards,

[Dave Emery]

Re: 7,8125 khz is it right ?

7.8125KHz is nothing special. The truth is that a cheap MPU crystal of 1.000MHz when divided by 128 outputs this frequency. A VLF detector should work very well at this frequency.
The same frequency can of course be obtained by dividing a 2MHz crystal by 256 or a 4MHz crystal by 512. A chip such as the 74HC4020 is perfect to divide a cheap crystal oscillator to provide a crystal controlled transmit frequency.