Jim, Yes, you have the new DSP boards. I'm sure customer support will check out your audio as requested.
There will always be noise and hiss with no signal present and gain controls maximized, because the K3 has a lot of gain in the RX signal path, like any modern transceiver. But with AF gain, RF gain and preamp settings appropriately adjusted, even the noise from a very poor antenna will completely dominate any noise generated within the radio itself. If not, you have something set up incorrectly, or a hardware issue that CS will be able to identify. The new synths are not required just to produce clean audio. It should already be clean. 73, Wayne N6KR On Feb 24, 2015, at 10:50 AM, jim <jbol...@outlook.com> wrote: > Wayne, > > Thanks. > > My Serial Number is 04841. I was told the LPF was "most likely" in my > radio and I have not taken it apart to see if that is the case. > > DSP 1 and DSP 2 are at 02.83 > > MCU is at 04.86 > > As I stated in a mail I sent to the reflector, two days ago, I will be > sending in my K3 on RMA to have you review and update where necessary. I > will include a request to have Elecraft look at the audio spectra to make > sure it is **clean**. > > Are the new Synth's needed for better audio performance? The **noise and > hiss* is present with no signals present in the bandwidth of the 400 Hz > crystal filter (or for that matter, any of the filters choosen). > > Look forward to seeing the results of the repair/update and will post my > results. > > Jim > W6AIM > > > > -----Original Message----- > From: Wayne Burdick [mailto:n...@elecraft.com] > Sent: Tuesday, February 24, 2015 9:28 AM > To: jim > Cc: 'Wes (N7WS)'; elecraft@mailman.qth.net > Subject: Re: [Elecraft] Sherwood Engineering Tests > > Jim (et al), > > The K3's audio has improved due to three factors in the past couple of > years: > > - a low-noise, low-pass audio filter stage was added to the DSP board, > eliminating high-pitched CODEC artifacts > > - DSP firmware changes were made to correct AGC linearity and eliminate a > CODEC quantization problem > > - main MCU firmware was modified to allow the user to select the lower AF > cutoff in CW mode (100/200/300 Hz) by adjusting the lower edge of the > crystal filters > > With the above changes in place, we carefully measured the K3's audio > spectra and compared it to other radios with the same type of class-AB final > AF amplifier IC (most transceivers fall into this category). They are all > virtually identical. > > Rob, too, told us that the audio spectra he measured on a recent K3 (with > new synths and the latest DSP and MCU firmware) was significantly improved > from the K3 he measured several years ago. > > While it is possible to reduce audio IMD products even further, this > typically requires a class-A final audio output stage, which would add > perhaps 0.5 to 1.0 amps of additional receive-mode current drain (and an > associated heatsink). That is inconsistent with the K3's intended usage, > which includes excellent power efficiency for portable applications (Field > Day/DXpedition/travel). Also, most users would not notice such a subtle > change. > > 73, > Wayne > N6KR > > > On Feb 24, 2015, at 8:19 AM, jim <jbol...@outlook.com> wrote: > >> Wes, >> >> I agree, and if you look at a post I made a couple days ago, it states > that. >> Sherwood also states his list is sorted on one column and people shud >> take all factors into account when choosing a radio. >> >> I would NOT recommend a K3 for it's audio. >> >> Each person has their needs and should review them carefully. I would >> also not recommend a Drake R4-C, even though it is in the top quartile. >> >> I will send you a copy of an earlier post that I made. >> >> >> Jim >> W6AIM >> >> >> >> -----Original Message----- >> From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of >> Wes >> (N7WS) >> Sent: Tuesday, February 24, 2015 6:12 AM >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Sherwood Engineering Tests >> >> I'm sure there's a point here and I just fail to see what it is. >> >> Rob has stated many times (look for his videos) that one number does >> not a radio make. In fact, as best that I know, he doesn't own a K3. >> >> Wes N7WS >> >> On 2/23/2015 11:01 PM, jim wrote: >>> Guys, >>> >>> Further, pesky, facts on said Real Radio at >>> http://www.sherweng.com/table.html . >>> >>> Number two on the list. That is out of 116 receivers listed on the >>> Sherwood page. >>> >>> That puts said Real Radio in the top 3% of the radios Bob Sherwood >>> has tested for a critical receiver performance parameter. >>> >>> BTW, you will have to use the "Page Down" button, more than twice, to >>> even get a hint of the Kenwood 590. It is number 20 on the list, >>> putting it in the top 17% >>> >>> Also, important to note, is the Drake R4-C with the Sherwood roofing >>> mod, listed at number 28. The R4-C is *ONLY* >>> 45 (forty five) year old technology and that puts it in the top 23%. >>> Yep, FORTY FIVE year old technology. Yep, top 23 %. >>> >>> Just some further, pesky, facts......................... >>> >>> Rake >>> >>> P.S. BTW, I learned 45 years ago. This flies in the face of >>> someone's comment that I never learn. >>> >>> Ho Hum, another pesky fact............. >>> >>> >>> >>> >>> >>> >> >> ______________________________________________________________ >> 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 Message delivered to >> jbol...@outlook.com >> >> ______________________________________________________________ >> 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 Message delivered to >> n...@elecraft.com > > ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
