Darrell, Certainly a meter could be devised to indicate the strength of the signals making it through the IF filter - you have the correct points in mind - all you have to do is tap in at the input of the IF amplifier and then amplify the signal(s) and drive whatever circuits you want (even a duplicate of the stock IF amp and AGC/S-meter circuit).
The biggest problem to solve is how to tap into that signal path without degrading the signal present in the receiver - that can be accomplished as long as you pay attention to the impedances. You may want to look into the Analog Devices AD8307 log amplifier rather than duplicating the IF amp, especially if you want to drive an external meter - the '8307 has a log function built in so you can have an S-meter log response with a linear meter. 73, Don W3FPR > -----Original Message----- > > As I typically leave the AF gain at maximum and use the RF gain > control to set > the listening level (Better signal to noise ratio.) the S-meter > is not too > useful. Also with the AGC turned off the S-meter is not operational. > > Anyone have any ideas for an AGC independent S-meter? > > I was thinking perhaps use some sort of high impedance RF voltage > detector > between D34 and T7 on the RF board. Then amplify the voltage to > the level and > range required at the S-meter voltage connection (pin RA1 of the > MCU), so the > existing meter could still be used. Of course the connection from > the MCU to > the AGC line would have to be disconnected. > > -- > Darrell Bellerive > Amateur Radio Stations VA7TO and VE7CLA > Grand Forks, British Columbia, Canada > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.446 / Virus Database: 268.18.8/718 - Release Date: > 3/11/2007 9:27 AM > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.446 / Virus Database: 268.18.8/718 - Release Date: 3/11/2007 9:27 AM _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
