Freeware PEP2TONE
download 3227 KB zip-file:

by Hans Jacobi, DJ7BA
is a precision two-tone modulation signal in .wav stereo audio format (like CDs) for PEP output (peak envelope power) measurement of SSB transmitters.

It was generated using Freeware Audacity.

Top, left chanel:
Mix of two sine waves of equal amplitude with 975 Hz and 1025 Hz.

Bottom, right chanel:
Square wave providing frequency difference of the tones for triggering.

Never was it easier to make exact PEP power measurements by Scope.

That's history now:

Two independant oscil- lators were used for two-tone generation. Specs had to be tough if you wanted stable scope displays. There is no difference frequency output for triggering.

In spite of the low drift you almost always had problems achieving stable scope displays.

RCN 205S
made by Neuwirth

No longer so. PEP2TONE got a trigger signal, is free, and needs no space to store. PEP2TONE makes the beautiful Neuwirth two-tone generator look obsolete. You connect your transmitter to a dummy load and modulate it directly from the sound card output. In case of ground loop problems you can copy the unzipped data to CD and use a battery operated CD player. The trigger signal provides stable display of the two-tone modulation and the modulated RF signals as shown on a Tektronix 453 Scope.

Modulation: Vertical: 0.5 Volt/cm. Horizontal: 2 msec/cm.

RF Output Signal: Vertical: 50 Volt/cm. Horizontal: 2 msec/cm.

You measure the peak half wave at the transmitter output.     On the right picture:     U peak = 110 Volts.

The PEP power is:

P PEP = U peak 2 / 2R

In the case shown the PEP power on a 50 Ohm Dummy Load is     P PEP = 121 Watts.

Download of (3227 kByte):

Copyright note:
PEP2TONE is Freeware for Radio Amateurs. The author provides no liability, whatsoever. PEP2TONE may be copied free of charge, but only unaltered and digitally, as analog copies would loose quality. The name „PEP2TONE by DJ7BA“ must be used on every copy.