I was hoping that there was a bit more in the line out and what not. I've also noticed that the bottom EQ band does absolutely nothing but I'd kinda hoped that was part of the 470uF caps in the speaker out lines...
I also noticed that there were 10uF caps on the line out but being that most of whats going to be plugged in there is going to be relatively high impedance that's probably ok... Yes actually I was just hearing about almost 30 discrete value changes on the main DSP board... I've also been told that Elecraft can exchange your older boards out... You pay 50 bucks and they ship a new board to you. Then if you ship back your old one you don't get charged full price for the new board. ~Brett -----Original Message----- From: Paul Christensen [mailto:w...@arrl.net] Sent: Tuesday, July 07, 2009 9:40 AM To: Brett Howard Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 Turn on Pop(WAS K3 Audio) > Hrm. Oh well. I do think that the audio section would benefit from a > rejiggering of quite a few of those caps for more LF. On the Rx side, there's not much left to consider after the DAC --at least what I can see on the schematic. The circuit path is pretty darn simple. However, the cap fix we've been discussing is really only part of the cure toward establishing a flat low-end receive response to 100 Hz or a bit below. I still see the same effect as measured by Alexander in his link below: http://forum.cqham.ru/download.php?id=44172 There's additional low-end roll-off not attributed to the coupling C after the DAC (again, based on what I see on the schematic). So, the question is "what is causing the remaining roll-off starting around 400 Hz?" To compensate for what Alexander and I are measuring, I need to boost the Rx EQ Band 2 by about +10 dB to get something remotely close to flat between 100-200 Hz. Also, I do not see where Band 1 (50Hz) changes the receive audio response. It's almost as if it's deactivated or something in the analog and/or digital path is causing a sharp HP effect above 50Hz. No amount of cut or boost on Band 1 brings about change on my K3. On the TX side, there are additional C values (or if you prefer, R values), that can be scaled to your liking. I've discussed some of those component size changes on the N1EU website. Also, I believe the newer main K3 DSP Boards may now have re-scaled R values along parts of the affected Tx path. Paul, W9AC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
