Thank you Robert for your explanation how it came to the limited gain. Never mind we're all just human beings! You and all the others working on this SDR-project are doing a great job.
Martin DL5YEJ ----- Original Message ----- From: "Robert McGwier" <[EMAIL PROTECTED]> To: "Martin Hirsch" <[EMAIL PROTECTED]> Cc: <flexRadio@flex-radio.biz> Sent: Thursday, December 08, 2005 9:51 PM Subject: Re: [Flexradio] AGC an gain since V.1.4.5. prev 1 > Martin and all: > > The new agc is 3/4 implemented. The "fast attack" portion is just a > dummy calculation while I figure out why I cannot do what Phil says he > did. ;-). Since I put a dummy calculation in for my convenience when > coding, I was a real dummy for not being more careful. The dual track > (fast and slow track) agc computes the MINIMUM of the two possible > gains. This allows the fast to attack quickly and then get out of the > way and the slow agc takes over. I have been unable to get this to > work correctly (it sounds just awful). So in my infinite wisdom I set > the fast gain number to 3000. So the applied gain is the MINIMUM of 68 > dB or the correctly computed gain. Therefore, until the next release, > the maximum gain is 68 dB. > > For those of you with the code, in dttspagc.c, where the fast gain is > set to 3000, set it to 3,000,000,000,0000 so it will well and truly be > out of the way. > > My apologies for this stupid mistake. > > I am in Germany working on AMSAT issues for two weeks. I will get back > to the digital agc issue to try and achieve a complete and final > resolution immediately upon my return. > > > As a final remark, we all hope coming into this project that we can > learn something from it. I have watched Eric slowly gain very good > intuitive understanding for how things work. He was dogged in testing > this in my absence and discovered and fixed the bug. I was completely > befuddled until he figured it out. > > ;-) > > Bob > N4HY > > > > Martin Hirsch wrote: > > >Since Power SDR V1.4.5 prev. 1 I don't get full gain when in receive-mode > >even when I set the max-gain setting to 100dB. When no antenna is connected > >there should be no '''AGC-Voltage''' so the receiver should work with full > >gain. The audible noise floor should be the same when fixed-gain and agc > >max-gain are both set to the same value. This is the case for values up to > >70dB gain. AGC Max-gain-settings higher than 70dB have no influence on the > >gain (in fixed-gain-setting they have!). I'm not happy with this new agc > >because weak signals don't give same audio-out as stronger signals do > >(nearly same audio levels is the task of a good agc). This was classes > >better in Vesion 1.4.4 > > > >Martin DL5YEJ > > > > > >_______________________________________________ > >FlexRadio mailing list > >FlexRadio@flex-radio.biz > >http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > > > > > > > > > -- > Laziness is the number one inspiration for ingenuity. Guilty as charged! >
