UNIVERSAL FREQUENCY MARKER GENERATOR
(1998)

KLIK HIER VOOR DE NEDERLANDSE VERSIE


Too cold for Simple Technology?
Check your frequency with this simple device.

Barefoot technology
This is also real barefoot technology or simple, cheap and harmless technology. Although not so actual anymore due to the frequency counters and synthesizers we have nowadays, this marker generator is a very simple and cheap device to calibrate your frequency.

What is a marker generator
A marker generator generates signals at all multiples (harmonics) of a basic frequency. If the basic frequency is for example 50 kHz, at all harmonics of 50 kHz a signal is heard when connected to the input of your receiver. As almost all amateur frequency bands start and end at a multiple of 50 kHz, this could for example be a very simple device to check if you are within the band.
But if you take 10 kHz as the basic frequency, you can also calibrate the frequency scale of your QRP transceiver by marking the scale at each harmonic of the 10 kHz.
Another possibility is for skeds. If your frequency scale is not so accurate, choose your sked frequency near a marker signal so that you can tune exactly on the sked frequency.


Circuit diagram

How it works
The X-tal oscillator of 6.4 MHz (adjust it exactly to that frequency!) is divided to the desired basic frequency. As soon as the divider has reached the division value, selected with the matrix (wires connected to the pins as given in the schematic diagram, 2 wires for 20 kHz and 10 kHz marker signals) a sharp needle pulse is generated. The harmonics of this needle pulse are the marker frequencies.

Note:
Connect wires between the pins to set the desired basic frequency. There are 2 wire links needed for 10 and 20 kHz.
Add a potentiometer of 1k ohm between the marker generator and the receiver if you want to control the level of the marker signals.


Inside

Index PA2OHH