The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: "Richard Hosking"
Subject: Re: Audio Phase meter cct wanted
Date: Mon, 18 Nov 2002 20:03:27 -0800
X-Newsreader: Microsoft Outlook Express 5.00.2615.200
We did a meter some years ago when working on SSB phasiung generators
As I recall we detected the zero crossing/positive transitions of the two
signals by using comparators to square them up
We then used a micro (PIC) and some logic to count a 20 MHz clock which was
gated by the transitions
Count 1 was time between the positive transitions of one of the signals (ie
Count 2 was the time between transition of signal 1 and transition of signal
Phase (degrees) = (count 2/count 1) *360
We used an LCD display to show results
This system correlated pretty well with the SSB suppression we got from our
eg 1 degree error = approx 40 dB suppression
0.1 degree = 60 dB etc
It gave usable resolution to 10 KHz
Jeff wrote in message
> I need a simple circuit to measure relative phase of audio tones, but more
> accurately than using scope patterns. Perhaps some sort of audio squarer
> with phase comparator and meter output. Has anyone seen such a circuit?
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup