++++++++++++++++++++ From: "giuliano" To: Date: Sat, 29 Mar 2003 01:37:00 +0100 Subject: [Elecraft] K1 mod. for USB and LSB reception Hi k1 gang, to the attached link the pdf document with description of Rx SSB mod. for K1. http://it.geocities.com/giulianoi0cg/k1ssbmod.pdf It is running fine on my #1523 K1 73 Giuliano I0CG +++++++++++++++++++++ From: "giuliano" To: Date: Fri, 4 Apr 2003 23:55:40 +0200 Subject: [Elecraft] USB and LSB reception on K1 Hi all, i have updated the K1 mod. for USB and LSB reception on K1. See this link: http://it.geocities.com/giulianoi0cg/k1ssbmod.pdf 73 Giuliano I0CG +++++++++++++++++++ From: "giuliano" To: Date: Wed, 23 Apr 2003 18:17:58 +0200 Subject: [Elecraft] K1 has become a CW / SSB transceiver Hi gang, i have finally modified my K1 transceiver #1523. Now it work very well also on SSB (reception and trasmission). A plug-in board can be inserted inside K1 at Noise blanker position. No mecanical changes are required. No wires necessary. No software is required. Restore the initial K1 status is very fast. Anyone can assemble it easy, if like. I have assembled it on a experiment board at all work fine! For any suggestion or clarifiation write to giulianori at libero.it . See documentation on my web page http://it.geocities.com/giulianoi0cg/k1_page.html 73 Giuliano I0CG ++++++++++++++++++ From: "Doug Person" To: "giuliano" , Subject: Re: [Elecraft] K1 has become a CW / SSB transceiver Date: Wed, 23 Apr 2003 13:01:35 -0400 Wow! I have to say I'd really like to see this become an add-on option for the K1. What a fantastic travel radio it would be then. BTW: Can't get to your website right now. It appears you've exceeded the maximum transfer rate. I guess a lot of people are anxious to see what you've done. 73, Doug -- K0DXV K2/100 #1920 K1/4 #1297 ++++++++++++++++++ Date: Wed, 23 Apr 2003 11:33:02 -0700 From: Wayne Burdick Organization: Elecraft To: giuliano Cc: elecraft at mailman.qth.net Subject: [Elecraft] K1 SSB? giuliano wrote: > i have finally modified my K1 transceiver #1523. > Now it work very well also on SSB (reception and trasmission). Hi Giuliano, I can't get to your site to look at your modifications, but it sounds interesting. Congratulations on your initial success with such a fundamental change to your K1. Modifying the K1 for SSB use while preserving performance and meeting FCC requiremenets would not be a small undertaking. It would almost certainly require modifications well beyond what I think you've mentioned so far. So I have a few questions, which may be answered already on your web page: - Did you linearize the final amplifier? It is biased class C, which cannot be used for SSB operation. It must be biased class AB or at least class B. The lower-level TX stages must be operating class A, or close to it, or they too will contribute to IMD. Performance should be verified using a spectrum analyzer. - What PEP power output level were you able to obtain? - How did you reverse the I.F. strip to provide SSB filtering on transmit? Or did you add a separate TX SSB crystal filter? If so, how are you accomodating USB and LSB operation, setting the BFO offset, etc.? What skirt selectivity were you able to obtain? (Generally a 7 or 8-pole filter is required for acceptible rejection of the opposite sideband.) - How did you handle the VFO range issue? We recommend an 80-kHz range, with an option for 150 kHz. But niether is adequate to cover both the CW and SSB segments of most bands. (The exception would be 40 meters, outside the U.S., where the phone segment starts much lower in the band.) In order to get coverage of the full band, you would presumably have to either accept much worse tuning resolution from the 10-turn pot (about 30-40 Hz), or add a switch on the left side of the case to select between two VFO ranges. - How did you handle the band-pass filter bandwidth issue? The K1 uses a premix design (as opposed to the K2, which generates an LO signal directly at the needed injection frequency). This extra mixer stage complicates elimination of close-in spurs. Because of this, it's of critical importance that both the premix and RF band-pass filters be as narrow-banded as possible, and this is facilitated by the small tuning range requirment (CW bands only). If you widen the band-pass filters to accomodate full-band tuning by the VFO, chances are that the harmonic content will be excessive on some or all bands. Looking forward to seeing how you approached these design challenges. 73, Wayne N6KR +++++++++++++++++ From: "giuliano" To: "Wayne Burdick" Cc: Date: Wed, 23 Apr 2003 22:59:53 +0200 Subject: [Elecraft] Re: K1 SSB? Answers on the text Thanks for your interest 73 Giuliano I0CG ----- Original Message ----- From: "Wayne Burdick" To: "giuliano" Cc: Sent: Wednesday, April 23, 2003 8:33 PM Subject: K1 SSB? > > giuliano wrote: > > > i have finally modified my K1 transceiver #1523. > > Now it work very well also on SSB (reception and trasmission). > > > Hi Giuliano, > > I can't get to your site to look at your modifications, but it sounds > interesting. Congratulations on your initial success with such a fundamental > change to your K1. > > Modifying the K1 for SSB use while preserving performance and meeting FCC > requiremenets would not be a small undertaking. It would almost certainly > require modifications well beyond what I think you've mentioned so far. So I > have a few questions, which may be answered already on your web page: > > - Did you linearize the final amplifier? It is biased class C, which cannot be > used for SSB operation. It must be biased class AB or at least class B. I have made a polarization network; i have about 150 ma IC current without modulation, i think that now the PA is running Class-AB The > lower-level TX stages must be operating class A, or close to it, or they too > will contribute to IMD. Performance should be verified using a spectrum analyzer. Seems that predriver Q6 is class-A via the R28-R29 polarization circuitry. I am making same measures with my Spectrum analyzer > - What PEP power output level were you able to obtain? About 6-7 W on SSB and 4-5 W on CW > > - How did you reverse the I.F. strip to provide SSB filtering on transmit? Or > did you add a separate TX SSB crystal filter? Yes i use two separate crystal filters . Reception filter with 6 crystal and TX with 4 crystal >If so, how are you accomodating > USB and LSB operation, setting the BFO offset, etc.? What skirt selectivity were > you able to obtain? (Generally a 7 or 8-pole filter is required for acceptible > rejection of the opposite sideband.) In the next day I insert on my WEB page plot of RX and TX filters. I change the BFO frequencies auomatically when i switch on the front panel FILTER1/2/3. For this i use two Cap. trimmer and one diode. > - How did you handle the VFO range issue? We recommend an 80-kHz range, with an > option for 150 kHz. But niether is adequate to cover both the CW and SSB > segments of most bands. (The exception would be 40 meters, outside the U.S., > where the phone segment starts much lower in the band.) In order to get coverage > of the full band, you would presumably have to either accept much worse tuning > resolution from the 10-turn pot (about 30-40 Hz), or add a switch on the left > side of the case to select between two VFO ranges. Now i have add a 68 NPO cap. on parallel to the 120 Cap. supplied. So the tuning range is about 250 KHz. It seems that stability and tuning are adeguate.Specially on Europe where on 40 m we use only 7000-7100 band . I am working, to solve better this problem, with a DDS AD9834 and a tuning encoder with 10/100/1000 Hz selectable tuning step. It is the next modification step. > - How did you handle the band-pass filter bandwidth issue? The K1 uses a premix > design (as opposed to the K2, which generates an LO signal directly at the > needed injection frequency). This extra mixer stage complicates elimination of > close-in spurs. Because of this, it's of critical importance that both the > premix and RF band-pass filters be as narrow-banded as possible, and this is > facilitated by the small tuning range requirment (CW bands only). If you widen > the band-pass filters to accomodate full-band tuning by the VFO, chances are > that the harmonic content will be excessive on some or all bands. I have measured the Filter selectivity, (see also my filter plot on my Web page) and seems that selectivity is adeguate to cover 350 KHz on 20 M and 150 KHz on 40 m. > > Looking forward to seeing how you approached these design challenges. > > 73, > Wayne > N6KR ++++++++++++++ From: Pieter Meiring Reply-To: pdm at shef.ac.uk To: elecraft at mailman.qth.net Date: Wed, 23 Apr 2003 22:48:48 +0100 Subject: [Elecraft] K1 SSB Mod documentation by Giuliano I0CG I have mirrored the Documentation that Giuliano has publishe don his web sir to allow more members of this mailing list to access it. It is accessible from: http://www.meiring.org.uk/K1 Best Wishes, Pieter G0BSX +++++++++++++++ From: "giuliano" To: Date: Sat, 26 Apr 2003 00:13:11 +0200 Subject: [Elecraft] K1 SSB performance test Hi gang, i am very surprised for the interest of my K1 SSB mod. (About 200 hits in the last two day). I am encouraged also from a very useful suggestions and comments of Eric and Wayne. So, i have decided to do ulteriors serious measuremts to see if all is running Ok (with limitation of my instrumentation). As first step i have made, this nigth (hi!), same measurements. I am working to do two tone IMD measurement to see if the TX is enough clean.(Eric suggestion) When ready i update the performance test file. The results are on a zipped file available on my web. http://it.geocities.com/giulianoi0cg/k1_page.html (150 Kb) mirrored to http://www.meiring.org.uk/K1 The name of file is "k1ssbperform_test.zip". I am studing PCB also so the mod. assembly become very easy. 73 to all Giuliano I0CG +++++++++++++++ From: "Bozidar Benc" To: Subject: RE: [Elecraft] My first QSO Europe- USA with K1 modified for SSB Date: Sat, 26 Apr 2003 23:47:53 +0200 Congratulations! I guess that was SSB QSO on 20 m. 73, Bole, 9A3RR K1 #1499 > This evening at 22.30 Local time i have had my first K1 QSO > Europe-USA with > WJ2DX Terry. > My K1 #1523, modified for SSB, is running with 5 W PeP into a 3 el. > yagi. > > 73 to all K1/k2 gang > Giuliano I0CG +++++++++++++++ From: "giuliano" To: Date: Wed, 14 May 2003 19:28:16 +0200 Subject: [Elecraft] SSB mod. for K1 Project status Hi all, on my web page http://it.geocities.com/giulianoi0cg/k1_page.html the photo of prototype PCB for the K1 SSB mod. Kit available soon 73 Giuliano I0CG +++++++++++++++ From: "giuliano" To: Cc: "Wayne Burdick" Date: Mon, 2 Jun 2003 23:38:11 +0200 Subject: [Elecraft] K1 SSB project Status: searching beta-tester Hi all, i am searching anyone, if possible on Europe, to test the K1 SSB modification (hardware and documentation). If anyone is available to do this test I send a complete KIT at only the component cost (only a little number of kits are available). The PCB is made double face, with metalized hole, silk mask and solder resist. This mesage is with the Elecraft approval( Wayne Burdick ) See this web page for documentation http://www.meiring.org.uk/i0cg/ Documents available: K1.avi : This is a movie showing the SSB board from all angles. k1ssbmod_PCB.zip : kit documentation. Kits are available within two or tree weeks. Thanks on advace for your help Giuliano I0CG ++++++++++++++++ From: "giuliano" To: Cc: "Wayne Burdick" Date: Wed, 4 Jun 2003 22:44:20 +0200 Subject: [Elecraft] Re: Elecraft digest, Vol 4 #191 - 66 msgs Julian, i sumarize here same measures: -RX/TX band coverage is about 250 KHz. (14000 -14250 Khz and 7000-7250 Khz) This coverage is possible adding a 68 pF ( NP0 cap.) parallel to C2, so the total cap. is 168 pF. With this mod i have this frequency drift: after 5 minuts warm-up: initial measurement , after 1/2 hour: -130 Hz after 1 hour: -260 Hz I have only a 2 band filter board (40/20 m) so i have made measures only for these band. Coverage on TX is, for all 250 KHz: 4-6 Watts The mod. isn't yet Elcraft approved because Wayne, in this moment, is very busy with others new projects and suggest me to make more tests with others HAM; so I am serching for betatester. Wayne tell me that can test the mod. on the Elecraft laboratory later on July or August. 73 Giuliano I0CG "Julian, G4ILO" wrote: > I wondered about that, too. What band coverage does a K1 have? It doesn't > appear to be listed in the data sheet. > > What's the "official" Elecraft view on this mod? I can't find any info or > links to it on the Elecraft site. A K1/SSB would be what I hoped the FT-817 > would be, but I'd really prefer to see a fully Elecraft approved version of > this mod. > > 73, > -- > Julian, G4ILO. (RSGB, ARRL, G-QRP, K2 #392) > G4ILO's Shack: http://www.qsl.net/g4ilo > > "Martin AC6RM" wrote: > > Say, does anyone have any data on the frequency stability of the K1? With > I0CG's mod, I was thinking it'd make a cool dedicated data radio ... > 73, Martin AC6RM k2/100 #3021 > > ++++++++++++++++++