Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

LF: <Tech> Variable Phase/BPSK circuits

To: [email protected]
Subject: LF: <Tech> Variable Phase/BPSK circuits
From: "James Moritz" <[email protected]>
Date: Thu, 26 Apr 2001 15:06:35 +0000
Organization: University of Hertfordshire
Reply-to: [email protected]
Sender: <[email protected]>
Dear LF Group,

I have put together some hopefully fairly accurate circuit diagrams of my variable phase modulator and linear BPSK generator experimental circuits. These are not meant to be fully worked out projects projects, but are complete functioning circuits which could serve as a useful basis for experiment.
There are 3 circuits:

Phase keying signal shaper, which takes a raw logic signal (eg. from a PC serial port) and converts it into one with approximately raised-cosine shaped transitions.
Linear BPSK modulator, which modulates a 137kHz carrier with the
shaped phase keying data to produce a few V pk-pk BPSK signal
with which to drive a linear PA.
Variable phase modulator, which produces a 137kHz carrier with a
phase shift proportional to the phase keying signal amplitude, and
with the shaping circuit produces "gradual" phase transitions as
discussed a little while ago.
The attached JPEG file shows the variable phase and BPSK
spectra generated by the circuits with 100ms and 50ms transitions.
If anyone is interested, I can send them the circuit diagrams as
JPEG files - they are a bit big for the reflector.
Cheers, Jim Moritz
73 de M0BMU
The following section of this message contains a file attachment
prepared for transmission using the Internet MIME message format.
If you are using Pegasus Mail, or any another MIME-compliant system,
you should be able to save it or view it from within your mailer.
If you cannot, please ask your system administrator for assistance.

   ---- File information -----------
     File:  vphase5.jpg
     Date:  26 Apr 2001, 14:29
     Size:  19000 bytes.
     Type:  JPEG-image

JPEG image

<Prev in Thread] Current Thread [Next in Thread>