+++++++++++++++++++++++ Note: Real Time Clock (RTC) entries moved to KAF2_RTC ++++++++++++++++++++++++ Date: Thu, 09 Aug 2001 12:45:52 -0700 From: Eric Swartz WA6HHQ - Elecraft Subject: [Elecraft] New Elecraft product: KAF2 Audio Filter & Real-time clock The KAF2 supplements the K2's crystal filters with effective, low-noise audio filtering. It also adds a real-time clock, allowing you to check the time or date with a tap of the K2's DISPLAY button (details below). Audio Filter The KAF2 includes a passive, balanced low-pass filter (LPF) that significantly attenuates splatter, carriers, and wideband I.F. noise above 3 kHz. It's especially useful on quiet bands, with the preamp off, or when using small, low-noise receiving antennas. It completely eliminates the hiss sometimes heard when using hi-fi headphones. The passband has very low ripple, so the filter has no impact on speech or data signals. Also included is an active, two-stage, narrow band-pass filter for CW or data use. It can be used in conjunction with the K2's variable-bandwidth CW filter, providing a significant improvement in skirt selectivity and in noise reduction. The center frequency is tunable over the K2's entire 400-800 Hz CW offset/sidetone range. The -3 dB bandwidth of the cascaded filter sections is about 80 Hz, ideal for digging weak signals out of QRN or QRM, and the Q of both stages is low enough to avoid excessive ringing. The AFIL switch on the K2 front panel turns the band-pass filter on or off. Real-Time Clock (RTC) The real-time clock displays 24-hour time, as well as both MM-DD-YY and DD-MM-YY date formats. Time and date can be easily set using the BAND+ and BAND- switches. The RTC is very convenient for field operation since it eliminates the need to bring a separate clock. The on-board lithium backup battery will power the clock for up to several years, and can be replaced by removing either the K2's top cover or left side panel. Price and Availability The KAF2 is priced at $69 and can be ordered now. The kit will be shipped beginning about Sept. 7th. Orders will be shipped in the order received. Note: K2 firmware revision 2.01b or later is required to use the clock feature. If your firmware is older, you'll receive a free upgrade with purchase of the KAF2. If possible, please order using our on line order form at http://www.elecraft.com (This will avoid overloading Lisa with telephone calls.) Of course please feel free to call us if you prefer to order that way or have questions about the KAF2. 73, Wayne (N6KR) and Eric (WA6HHQ) - -- http://www.elecraft.com - --- Date: Thu, 09 Aug 2001 12:49:07 -0700 From: Eric Swartz WA6HHQ - Elecraft Subject: [Elecraft] KAF2 Pictures I forgot to mention that we have pictures of the KAF2 on our web page at: http://www.elecraft.com/kaf2.htm 73, Eric WA6HHQ ++++++++++++++++++++++++++++ Date: Fri, 20 Jul 2001 07:43:28 -0700 From: Wayne Burdick Subject: [Elecraft] KAF2 Audio Filter and Real-Time clock: preliminary info Bill Coleman wrote: > What are the plans for the KAF2? Hi Bill, I completed the KAF2 PC board layout and should be getting boards back in less than two weeks. Our usual track record in getting things ready to ship is about 1 to 2 months from the time that the prototype is built, so you can extrapolate. Pricing has not been set. We chose to make the filter all analog so that it is extremely low-noise, using an LM837 quad op-amp. DSP or switched-capacitor filters would not have worked at this point in the circuit (between the product detector and the AF amp) without a lot of shielding and extra gain. You can, of course, add a DSP-based filter externally. I've been using a proto-board version of the filter for a few weeks now, and it's a really nice addition to the K2's receiver. With just the 2.5 kHz low-pass filter enabled, residual I.F. noise is greatly attenuated, to the point that I'm using the K2's RF preamp a lot less, even on the higher bands. The band-pass filter is great for picking really weak signals out of the noise or for rejecting nearby QRM, and can be used in any mode, with any setting of the K2's crystal filters (the audio filter is completely independent). The real-time clock has also turned out to be a great addition. It means that I don't need to bring a separate clock with me on field trips (I don't need one in the shack, either, for that matter!). Gives the K2 something to do when you're not operating. The text below is the first page of the KAF2 assembly/operation manual. This information is preliminary. Note that the KAF2 plugs into the Control board--no wiring. And no toroids :) 73, Wayne N6KR * * * ELECRAFT KAF2 AUDIO FILTER and REAL-TIME CLOCK Assembly and Operating Instructions Revision A, July 16, 2001. Copyright © 2001, Elecraft; All Rights Reserved Introduction The KAF2 option supplements the K2's crystal filters with effective, low-noise audio filtering. It also adds a real-time clock, allowing you to check the time with a tap of the K2's DISPLAY button. Audio Filter The KAF2 includes a low-pass filter (LPF) that is in-circuit at all times and provides roll-off of signals above 2.5 kHz. Passive components (L/C) are used, so the LPF contributes no noise of its own. It is situated at the output of the KAF2 so it eliminates even the very small amount of noise generated by the unit's own operational amplifiers. The LPF is particularly useful on quiet bands or with small antenna systems, where signals are of low amplitude and the audio gain is thus turned up higher than normal. It can also significantly reduce high-frequency splatter and carrier leak-through generated by extremely strong stations a few kHz away. The KAF2 also includes a two-stage, narrow band-pass filter for CW or data use. The center frequency of the filter is tunable via two potentiometers. The first stage has a bandwidth of about 150-200 Hz, and the second stage about 80-100 Hz, although the builder can alter the bandwidths if desired with one or two resistor substitutions. As designed, the Q of both stages is low enough to avoid excessive ringing. The AFIL switch on the K2 front panel selects either OFF (LPF only), AF1 (first CW filter stage), or AF2 (both stages). After alignment, the operator can choose to treat both CW filter stages as a single setting (AF2) by installing jumper W1. Real-Time Clock The real-time clock displays 24-hour time, and is typically set to UTC (universal coordinated time). You'll find this convenient for field operation since it eliminates the need to bring a separate clock. Time can be easily set using the BAND+ and BAND- switches. The on-board lithium backup battery will power the clock for up to several years. ++++++++++++++++++++++++++++ Date: Sun, 5 Aug 2001 16:26:24 -0700 From: "Stephen E. Stuntz" Subject: [Elecraft] KAF2 demo Gang: Few days ago Wayne generously dropped by to give first-ever live demo of KAF2 in its final configuration. To these octogenarian ears this neat option will be a great enhancement - the sharp cutoff above 2.5 kHz practically eliminates distracting noise without affecting speech intelligibility. Since my preferred mode is SSB this is a significant gain - although it may elicit cries of disapprobation from proponents of wide-band hi-fi in the ham bands. Also KAF2 made a huge difference with CW, by cleaning up background audio noise remaining when XFIL alone is switched to narrowest bandwidth. - Almost enough to persuade me to break out the 60-year-old Vibroplex. Look out, World - and thanks, Wayne. Steve, K6FS, K2 0058 ++++++++++++++++++++++ Date: Sun, 26 Aug 2001 13:39:43 -0700 From: Vic Rosenthal Subject: [Elecraft] KAF2 vs. SCAF and DSP Wayne has given permission to share information on the KAF2 audio filter field test, so I thought this would be of general interest. I put together my field test KAF2 unit last night and have been playing with it today. I've been a/b comparing the KAF2 to a Timewave DSP59+ and an OHR SCAF. Objectively, the biggest difference is that the DSP and SCAF have much steeper skirts. This is very obvious when looking at the output with Spectrogram. Since the main purpose of the filter (at least, in my opinion) is not to eliminate QRM but to improve the s/n ratio on weak signals, this is not necessarily an advantage for the SCAF and DSP. Subjectively, the KAF2 appears to ring less than the other filters, probably a direct result of the more gentle slope of the selectivity curve. This makes it a bit easier to copy CW signals. The slight gain of the filter also seems to make the desired signal pop out of the noise, although the same effect could be achieved by turning up the audio gain control on the K2. None of these filters is of much help when my bloody neighbor turns on his broken a/c unit and causes QRN strong enough to activate the AGC (S8!). Only IF filtering is of any use here. However, the DSP seems to react the worst in this situation, with the KAF2 and the SCAF about the same. The DSP also introduces a certain amount of noise and distortion of its own. The SCAF hisses and is sensitive to RF at certain frequencies (despite a lot of effort on my part to bypass and filter it), and the KAF2 doesn't have these disadvantages. Of course the DSP is more versatile, providing bandpass filtering and auto-notching for SSB, but for a CW operator this is irrelevant. I will be selling the DSP and putting the SCAF on the shelf. 73, Vic, K2VCO Fresno CA +++++++++++++++++++++++ ate: Sun, 26 Aug 2001 19:49:05 -0700 From: lhlousek Subject: Re: [Elecraft] Re:My KAF2 Field Test Results. <<>> Hi John, Yes. You can. The left edge of the KAF2 (as viewed from the front of the K2) falls just to the right of the FCTR header so the FCTR probe can remain connected with the KAF2 in place. Lou W7DZN ++++++++++++++++++++ Date: Sun, 26 Aug 2001 21:41:25 -0700 From: "Stephen E. Stuntz" Subject: [Elecraft] Another KAF2 FTreport Everybody - KAF2 completed and installed today works perfectly. I DO like the sound of CW thru AF2, and the LPF sure cleans up the QRN on 40 SSB. Couple comments: I concur with recommendations for component-map of PCB, for KAF2 and all other kits. I further concur with suggestion that operation manuals for ALL Elecraft kits be available separately from assembly/instruction docs, whether in a single (loose-leaf?) publication, or separate unit-specific booklets. Re: KAF2 manual: as noted before, R11 and R12 belong on bottomside of PCB; manual sez TOP, profiles are on bottom. Erratum, anybody? X1 definitely should be mounted before C19 (33 pF); it's a lot easier to do, and there's less possibility of damage to the crystal's tiny wire leads. Kicker: I too was "gifted" with superfluous 47 pF cap! BUT - both inductors were 823's, although lettering on one could best be read by extended intuition... Not being in a rush to complete KAF2 kit, I didn't count hours and minutes. But it was a pleasant journey from outset to destination, thanks to Wayne's well-organized prose. This is going to be a really useful option at K6FS! And the clock upgrade turns out to be a winner, whether K2 0058 goes traveling or not. Thanks, guys. You "done good" - again. Steve, K6FS 88 and still counting. First licensed 1937 as KA1US, Ft. Mills, Corregidor, Philippines ++++++++++++++++++++ Date: Thu, 30 Aug 2001 08:00:02 -0700 From: "Ed Juge/NM" Subject: [Elecraft] KAF2 beta test results Wayne asked that I post my impressions, as a beta tester, of the new KAF2 filter to the reflector. The kit went together in an hour or two. It installs with no cuts or jumpers... just the removal of two jumpers and installation of two sockets in existing holes in the control board. There is a switch on the PCB that switches the filter in or out of the circuit, mostly for test purposes. The KAF2's passive low-pass filter (on all the time otherwise) makes, to my ear, a small but noticeable difference in background hiss when the KAF2 is switched into the circuit. It's the narrow, active band-pass filter, for CW and data, (activated by a front panel switch) that is amazing. In the absence of nearby, strong, AGC-pumping signals, the KAF2 is usually good enough by itself when used with the widest crystal filter position. The reduction it offers in hiss and general background noise is better, to my ear, than a narrow crystal filter setting alone. Unless QSB takes a weak signal below the noise level, it just kind'a stands out by itself with virtually no hiss or noise. As long as a weak signal stayed slightly above the noise level, it was copyable with the KAF2, even when it was NOT copyable without it. Of course if a nearby strong signal is causing your AGC to pump, switching in more narrow crystal filters, along with the KAF2, works great. If you're a CW operator, this is as close to a "must have" accessory as you're likely to find. A friend of mine from Texas (who also owns an Icom 756PRO) was visiting yesterday and asked to run some comparisons between my K2 and my PRO on weak CW signals with the PRO set to a very tight CW filter setting. Although we didn't have much time, and we didn't adjust the PRO's passband settings, our initial impression was that the K2, with KAF2, heard a weak signal with somewhat less interference and hiss present. He was MOST impressed. I had, some time ago mentioned, to Wayne and Eric, the "Clear Speech" DSP audio filter as being the best noise-reducer I had found. On CW, they have it beat. Of course the CS works its magic on SSB where the KAF2 is not intended to do much more than cut some background hiss. And, the CS draws a LOT of current and costs more than twice as much as the KAF2. Ed, W5EJ - ------------------------------------------------------------------ Ed Juge Ruidoso, New Mexico Cellphone: 505-430-7209 Wireless (fastest way!) 8775992700 at airmessage.net Phone: 505-258-1721 +++++++++++++++++++++ Date: Thu, 30 Aug 2001 11:06:46 -0700 From: Eric Swartz WA6HHQ - Elecraft Subject: [Elecraft] KAF2 manual on Elecraft manual download page We have just added the KAF2 manual to our manual download page at http://www.elecraft.com We are still on schedule to begin shipping the KAF2 (and MH2) before the end of next week. 73, Eric ++++++++++++++++++++++ Date: Thu, 06 Sep 2001 14:44:32 -0700 From: Eric Swartz WA6HHQ - Elecraft Subject: [Elecraft] Shipping update (KAF2s, MH2s ship) KAF2 audio filters and MH2 microphones are now shipping as of Wednesday, Sept. 5th. (2 Days early!) It will take us about 3 weeks to ship all of the KAF2 backlog and 1 to 2 weeks to ship the MH2 backlog. We are also now including the KI6WX PSK31 changes with all KSB2s shipped after 9/5. (This only involves a couple of part value changes.) 73, Eric WA6HHQ - -- http://www.elecraft.com +++++++++++++++++++++++++ Date: Sat, 15 Sep 2001 13:02:55 -1000 From: John Buck Subject: [Elecraft] KAF2 comments and Test of CW Filter Rejection Mod. per KO0B/KI8WX Finished the KAF2. It tuned as advertised and really does a good job eliminating residual noise outside the desired passband. This filter is a must have for both CW and SSB modes. The listeners noise fatigue is greatly reduced. While I had the system open I decided to incorporate the KO0B/KI8WX shielding suggestions to improve the basic CW filter. K2 #1242 has all currently available options and significant mods, such as XFIL, Sine sidetone and PSK 31 installed. I made the best measurements I could using Spectrogram 6.2.3 The measurement system had a 70db below signal capability using the 90 db range. No Spectrogram or receiver setting changes (except for filter selection) were made during the modification and test process. I used a broadband noise generator as the signal source. Careful measurements were made three times: 1. Before modification; 2. After the crystal ground wires were modified by soldering to the side of the cans; 3. After the addition of the .1uf surface mount capacitors per KI6WX with the Gull Wing shield wires per KO0B. I printed the Display plots for each of the 3 measurements for each of the four filter settings. OP1, 700Hz, 400Hz and 100Hz. FL2, 3, and 4 are centered on 750Hz sidetone choice. When the plots were overlayed using a light box so I could see any differences, the following the conclusions were reached. A. There was no harm of any type due the the changes. I did not see any evidence of the slight broadening of the top of the filter response curve reported by one of the authors. In all cases, each sucessive plot coincided with or fit within the previous plot. B. As expected, the FL1 OP1 filter showed no significant changes. (KSB2 installed) C. The FL2 700 Hz filter shows 2 to 3 db improvement in the 1500 to 2000Hz area. Almost all of the improvement is from the crystal can grounding change. No effect from the gull wing and capacitor additions is seen. D. The FL3 400 Hz filter also shows 2 to 3 db improvement in the 2000Hz area with noticable improvement starting in the 1000Hz region. The gull wing plot is almost identical to the grounding plot but there is a db or so in the 2000Hz area. E. The FL4 100 Hz filter shows about 5 db in the 1800/2000Hz region. About 2 db is due to the gull wing mod. About 1 db overall improvement starts as close as 1000 Hz. Was it worth it? Probably. My K2 now has even better close in rejection of strong signals than before. Knocking down a signal 400 Hz above the center of my filter by another db or two or a signal 1000 Hz higher by 5db could make a real difference. Then I can turn on the KAF2 audio filter for even more help! Who said that K2 does not have bells and whistles? I have .jpg files of the plots on my system if someone really wants to analyze my data. I did not make the .txt spreadsheet readable files however. I freshly downloaded Spectrogram for this effort and did not discover that feature until I was almost done. Aloha, John KH7T ++++++++++++++++++ Date: Sat, 15 Sep 2001 20:59:03 -0400 From: "David A. Belsley" Subject: Re: [Elecraft] KAF2 trouble John: Since you're getting nothing through the filter when it is switched "in", whether or not AF1 or AF2 are selected, there has got to be a problem in the basic LPF line. First check the voltages on U2, pin 7 (should be 6v) and pin 4 of U1 (should be 12). If ok, while switched "out", tune in a signal and then switch "in". Now check for AF signal on pins 2 and 3 of U1. If ok, trace the AF through the circuit: pin 1 of U1, pin 13 of U1, pin 14 of U1, etc. Use the schematic to see what to look at. I've picked points that are available from the top side of the KAF2 board, accessible while the board is mounted. At some point along this path, the AF signal should stop, and that should help you locate the point of trouble. (But always recall, there may be more than one point of trouble -- assume at first, however, there is only one). best of luck, dave belsley, w1euy - --On Saturday, September 15, 2001 2:58 PM -0700 N7SG K7FD wrote: > After building and installing the KAF2 I have no audio in the IN > position, only OUT. I have checked component placement and all is A-OK... > > ...and particular thing I should be looking for? I'm off to check > voltages... > > Thanks, > > John K7FD, K2/586 +++++++++++++++++ Date: Sat, 15 Sep 2001 18:23:49 -0700 From: "N7SG K7FD" Subject: [Elecraft] Unprogrammed PIC! KAF2... Thanks everybody...and particularly to Kevin WA6FWF for the heads up on the possible unprogrammed PIC causing 'vast nothingness' when the KAF2 was switched IN. Lucky for me, I had TWO KAF2 kits here (for K2/586 and K2/655) so finding a quick replacement was easy. As soon as I switched PIC's I had full functionality, including the RTC (which I love!)... First impressions on the KAF2 filtering is 'WOW!'. This option is worth its weight in gold...a hefty reduction in background noise/hiss/what-have-you! You won't be disappointed... Gotcha's: When setting the clock, I didn't power down 'long enough' before attempting to set date/time. Appeared as though it didn't want to step through min/hours or days/month/year. I powered it down again, left it off for 30 seconds, powered back up & then all worked as advertised. Another gotcha - no sidetone. Make sure you are at sidetone source setting 'U 6-25' if you are not using the KIO2. I somehow set this to 'U 8-4' along the way and scratched my head for about 10 minutes on this one... Overall, another great piece of Elecraft electronics for your K2! Once you get that AFIL button hot, they'll be no looking back, believe me... Thanks again to everyone who sent me their suggestions...especially Kevin! 73 John K7FD PS. We're getting enough K2 options now that I think it's high time for a 'Operating a K2 for Dummies' book...ONE source for all the commands; not all these manuals, addendums, sticky notes... ;) ++++++++++++ Date: Sun, 16 Sep 2001 11:39:44 -0700 From: "N7SG K7FD" Subject: [Elecraft] KAF2 Photos...just for fun! http://home.teleport.com/~cqdx/KAF2.htm If you are interested in some construction close-ups of the KAF2, feel free to click on the link above... 73 John K7FD, K2/586 ++++++++++++++++++= Date: Sun, 16 Sep 2001 19:45:06 -0400 From: "David A. Belsley" Subject: Re: [Elecraft] KAF2 w/ XFIL? Bill: I have my IF filters set for OPT1, 1.5KHz, .7KHz and .1KHz. I find that the AF provides the best compromise (between narrowing the audio and removing the effects of nearby stations) with the 1.5KHz IF filter. When there are strong near-by stations, switching to the .7KHz helps. I have so far found no need to use the .1KHz IF filter with the AF. I also find that the audio quality with the KAF2 is ok but nowhere near as pleasant as with just the IF filters. The sound quality with AF2 is ok, but it has a slight harshness. I also find that the use of AF1 is often just what is called for. For those of you who have installed the jumper to skip AF1, I would advise you to remove it for a while to see. best wishes, dave belsley, w1euy - --On Sunday, September 16, 2001 3:28 PM -0500 Bill Allen wrote: > Hey gang, > > For those who are couple steps ahead of me and have actually finished and > installed their KAF2, what has been your experiences in using the KAF2 in > conjuction with XFIL? Any caveats or procedural suggestiions? With CW? > With SSB? > > 72 es OO > Bill Allen, KC5ADF +++++++++++++++++++++++ Date: Sun, 16 Sep 2001 17:59:14 -0700 From: Eric Swartz WA6HHQ - Elecraft Subject: Re: [Elecraft] KAF2 w/ XFIL? Hi Dave, You should not be hearing any harshness with the KAF2 in line. Mine does not exhibit any change in audio quality beyond the effect of reduction of filter bandwidth. I actually find it more pleasant to listen to than a narrow crystal filter. If there is some harshness to your KAF2 audio (such as from audio clipping or other distortion) there may be a problem with it. You might want to double check the component values and soldering. Check with Gary Surrency (support at elecraft.com or gary at elecraft.com) if you still have a problem after checking it out. 73, Eric WA6HHQ (... now back in town and working on K2 Remote and the PA.. ++++++++++++++++++++++ Date: Mon, 17 Sep 2001 15:47:57 -0700 From: Eric Swartz WA6HHQ - Elecraft Subject: Re: [Elecraft] re dsp board and firmware We have shipped out a large number of 2.01 F/W versions with KAF2's. It is only shipped if your current F/W is earlier than 2.01. Our database is not perfect though, so let us know if you don't receive the 2.01 F/W and need it. 73, Eric WA6HHQ ==== kenneth m cubilo wrote: > hi, did anyone out there get the new version of firmware included with > the af filter board? when i placed my order last month i was told that > if needed the newer firmware was included with the kit. i expect my kit > to be shipped sometime this week > ken cubilo w8ob #1104 and still working beautifully ++++++++++++++++++ Date: Wed, 19 Sep 2001 12:04:44 -0700 From: "Douglas Westover" Subject: [Elecraft] Rev 2 Firmware and KFA2 Just finshed construction and installation of the KAF2 and the revision 2 firmware, both worthwhile additions to an already fine product. 1. The "8r hold" option in the new firmware is great..it makes it possible to drive my AL-80A amp without a lot of relay thrashing. (The K2 will drive the 3-500 to about 200 watts out). 2. I really like the ability to select tuning rates. Since I never used the 1 kHz rate, being able to do just the 10/50 Hz rates is most useful. 3. I've seen a number of comments regarding strange behavior when loading the keyer memories. I've done this several times and find nothing out of the ordinary...inputting to the memory seems normal and the output sounds okay to me..perhaps I'm just not as critcal as others on the list! 4. The KAF2 LPF really reduces the high frequency "hiss" which I really wasn't aware of. However listening is now much easier on the ears. 5. I really like the "AF1" filter...significantly reduces noise and close in signals. "AF2" is okay but just the first stage seems adequate without the additional ringing of AF2. All in all both the new firmware and the audio filter are very worthwhile additions to an already great product. Oh, as an aside, I really think it would be worthwhile to provide all the plugs/sockets for the planned options with the basic K2. It would be nice to not have to dismantle the radio just to remove some jumpers and install a couple of sockets. Especially any thing that requires removing the heat sink...what a pain! 73, Doug W6JD, K2 #1626 Anxiously awaiting the KPA100! +++++++++++++++ Date: Thu, 20 Sep 2001 16:15:17 -0500 From: "Tom Whiteside" Subject: [Elecraft] KAF2 Alignment I noticed ringing on my AF2 setting and decided to tweak the alignment a bit. After several attempts at trying to do this by ear, I went with Spectrogram. Line mode worked best for me and using the 400 Hz IF filter rather than my narrowest 100 Hz setting made it easier to see the little filter peaks move around. First step was using "Spot" to align the marker - maybe this is a bit of overkill but 501 Hz versus my 500 Hz marker landed the marker right on the "Spot" tone. Then turned "Spot" off and followed the procedure outlined in the manual to align AF1 and AF2. These are very narrow little peaks and this procedure got them right on top of each other and really reduced the ringing I was hearing on AF2 - being off just a tad acts to make the filter appear even more narrow and hence more ringing. Tom Whiteside N5TW Georgetown, TX +++++++++++++++++++ Date: Thu, 27 Sep 2001 07:02:51 -0400 From: "Mark J. Dulcey" Subject: Re: [Elecraft] KSB2 & KAF2 Edmund T. Wright wrote: > Thanks to all who gave advice. > > I have ordered the KSB2 & KAF2 modules. As suggested I have read through > the K2 manual and found that instructions for the KSB2 module modifications > are there. The KAF2, being new, is not described, but I am certain that > when I receive those modules that I will be able to figure out what to do to > facilitate installing that modules. The KAF2 is trickier. You can't just install the connectors like you do for the other options, because the bypass jumpers go in the same board locations as the connectors. You could put in the connectors, and then build something similar to my unmodules (http://mail.buttery.org/mark/unmodule/); you would need two connectors (3 and 5 pin) with jumpers connecting pins 1 and 2 of the two connectors together. (I'm planning to add KAF2 info to the article soon...) +++++++++++++++++++ Date: Fri, 28 Sep 2001 07:32:11 -0700 From: Wayne Burdick Subject: Re: [Elecraft] KAF2 Problem Ken Wagner wrote: > > My thought is that it is a bad resonator, but I'm a bit out of my league in > this area. Any thoughts would be appreciated. This is by far the most likely cause of what you described. Scott (copied on this) will happily send you a new one. 73, Wayne N6KR ----------- Date: Fri, 28 Sep 2001 09:19:47 -0500 From: "Bill Allen" Subject: Re: [Elecraft] KAF2 Problem Ken, You may have a non-programmed PIC or a damaged PIC or something also. 73, KC5ADF Bill Allen - ----- Original Message ----- From: "Ken Wagner" To: Sent: Friday, September 28, 2001 7:16 AM Subject: [Elecraft] KAF2 Problem > Good morning Elecrafters: > > The KAF2 arrived in the mail yesterday morning and by late afternoon, it > was finished, installed, and working.... sort of. The filter functions work > as advertised and with the push/hold would cycle through OFF, AF1, and AF2. > The filter IS working. However, the display showed "nStnot i" (some sort > of digital inversion of "not inSt", I guess) rather than "AF1" or "AF2." I > did some voltage checks around the PIC and all were normal except for pins > 15 and 16, which showed virtually zero(0) volts, rather than the "~3"(I'm > not sure whether that means approximately 3 volts, or 3 volts AC). Those > pins connect to the resonator. > > I re-melted the solder on the 3 resonator pins. The display then read > correctly, i.e., AF1/2... for about 3-4 minutes and it would then revert to > the "nStnot i." Momentarily reheating the resonator pins would "fix" the > problem... for 3-4 minutes. > > I let it (and me) cool over night and when I turned it on this morning, it > functioned properly... for 3-4 minutes and then displayed as above. > > My thought is that it is a bad resonator, but I'm a bit out of my league in > this area. Any thoughts would be appreciated. > > BTW... I like the way it sounds, even after only cursory alignment. > > Thanks & 73, > Ken Wagner, K3IU, K2 #920 ++++++++++++++++++ Date: Tue, 02 Oct 2001 14:38:56 -0400 From: Ken Wagner Subject: Fwd: Re: [Elecraft] KAF2 Problem Ooops... I just noticed that I didn't post this to the reflector. Ken K3IU ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >Date: Tue, 02 Oct 2001 14:08:02 -0400 >To: Wayne Burdick >From: Ken Wagner >Subject: Re: [Elecraft] KAF2 Problem >Cc: Gary Surrency , scott at elecraft.com >Bcc: UCCINC at aol.com,k3iu at arrl.net,aholesto at online.no > >SITREP THREE AND FINAL > >You guys are GOOD. Fix things by email. > >No... I had not removed any of the other auxbus devices(other than the >ATU/IO plug). So... removed the 160, NB, SSB, and ATU/IO cards/connectors. >Plugged in the AF card and it worked perfectly. I then plugged in each >card one at a time. Everything worked perfectly each time. I then began >adding back all of the devices, checking after each install, until >everything was reinstalled..... and everything is working perfectly, >including the AF. Still is after 30 minutes. > >Apparently, the simple act of removing/reinstalling the cards fixed the >problem. Perhaps in one of the connectors the auxbus pin was slightly >corroded(doubtful) or had a dog hair in it(very possible around here)... I >dunno... but everything works now as it should. Maybe one of these days, >I'll learn how that auxbus line works..... so much to learn. > >Thanks and 73, >Ken K3IU K2 #920(now happy again) >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >At 12:39 PM 10/2/01, Wayne Burdick wrote: >>Scott and Gary will continue to help you with this. Have you removed all >>other auxbus devices (option boards) to make sure there's no conflict? >> >>You could even have a flaky resistor or capacitor on the KAF2 board. >>There's a small resistor in series with the auxBus line, and a small >>bypass cap. >> >>Are any other auxBus messages affected, i.e. NB, ATU, SSB? >> >>tnx >>Wayne >> >> >>Ken Wagner wrote: >> > >> > Hi Wayne: >> > Replacement resonator arrived in the morning mail. Removed old, installed >> > new. Worked correctly on power up, however.....(don't you just hate >> > "howevers"!)... after a couple minutes it is doing the same thing as >> before >> > ("nStnot i" in display in lieu of AF1 or AF2). I'll do more voltage >> > checks later on this afternoon and continue troubleshooting. Any >> > suggestions would be appreciated. To repeat from first email, everything >> > about the AF filter seems to be working correctly, except for the display. >> > >> > Thanks & 73, >> > Ken Wagner, K3IU #920 +++++++++++++++++ From Steve Ray == sbralr at worldnet.att.net After installing the KAF2 and playing around with the filter setup, I lost the sidetone, needless to say I had the 2.0 firmware and not yet installed the KIO2. Well I wrote Elecraft and got the following reply back, the next day. Needless to say I should have reread the 2.0 firmware manual and would have caught it, maybe by showing this to others it might save them a day or so of grief. On a 2nd note, I highly recommend the KAF2 filter, I thought the K2 was good, but this makes it great. Here is the reply from Gary AB7MY to the loss of sidetone. Steve, Go into the Menu and Edit the "St L" entry. Then press the Display button until you see "U6-25", as it has probably defaulted to "U8-4", which is only used when the KIO2 is installed and the control board has been modified. Please refer to the K2 revision 2 firmware manual for more details. -- 73, Gary AB7MY +++++++++++++++++ Date: Wed, 3 Oct 2001 17:11:34 -0500 From: ke6d at juno.com Subject: Re: [Elecraft] Please Help - KAF2 doesn't work Thank you to all who responded to my distress call. Gary Surrency confirmed that it was probably an "unprogrammed PIC". A "programmed" PIC is on its way. 73, Dan KE6D On Wed, 3 Oct 2001 18:45:47 -0400 "Roger E. Marrotte" writes: > Sounds exactly like the problem I had with my KAF2. I had an > unprogramed > PIC chip (U2). They sent me a new one and it now works like a > charm. > > Roger, W1EM > > -----Original Message----- > From: owner-elecraft at qth.net [mailto:owner-elecraft at qth.net]On > Behalf Of > ke6d at juno.com > Sent: Wednesday, October 03, 2001 2:31 PM > To: elecraft at qth.net > Subject: [Elecraft] Please Help - KAF2 doesn't work > > > Hi > > I assembled and install the KAF2 into my K2 # 168 last night. But > the > filter doesn't seem to work. With the slider switch to the IN > position, > there was no audio (Well I actually heard the audio for about 2 > seconds > before it muted out.) The K2 firmware (v2.0? which came with the > KIO2) > complained that the KAF2 is not installed everytime I pushed the > AFIL > button. > +++++++++++++++++++ Date: Tue, 09 Oct 2001 09:24:38 -0700 From: Eric Swartz WA6HHQ - Elecraft Subject: Re: [Elecraft] KAF2 and firmware Correction. I mistyped in my last posting. I meant revision '2.01' firmware, not 2.1 We will ship the latest firmware with KAF2 orders if you have K2 firmware earlier than 2.01. 73, Eric WA6HHQ ===== Eric Swartz WA6HHQ - Elecraft wrote: > > Yes, if you have pre 2.1 firmware. We always ship new firmware if you need it to > run the new option and do not already have it. ==== > Mike Maiorana wrote: > > > > Does the KAF2 come with the new 2.x firmware? +++++++++++++++++++ Date: Tue, 09 Oct 2001 12:02:04 -0700 From: Wayne Burdick Subject: Re: [Elecraft] KAF2 firmware thought "Julian, G4ILO" wrote: > > As having the AFIL selected is somewhat disastrous to SSB reception, is it > possible that a future firmware revision could switch the audio filter out > when selecting a non-CW mode, but restore it (if previously selected) when > returning to CW? Julian, This would be fine except that some operators will want to use the audio filter in SSB mode for PSK31, etc. Also, some builders of the KAF2 have mentioned that--despite the narrow bandwidth--the AF1 setting is of use in reducing QRM during SSB reception. So we'd rather not reduce the flexibility of the unit by forcing it off in SSB mode. 73, Wayne N6KR +++++++++++++++++++ Date: Sat, 13 Oct 2001 14:10:24 -0400 From: "Ken Wagner" Subject: [Elecraft] KAF2 Problem - UPDATE | UPDATE | ======== | It turns out that it probably isn't a KAF2 Problem, but a SSB board problem. | | The AUXBUS gurus in Aptos have determined that the most probable cause of | the problem is a somewhat-off-frequency resonator on the SSB board that is | causing/allowing the SSB PIC to be naughty and speak when it is not being | spoken to, thus corrupting the data stream on the bus when the KAF2 is | talking. Gary said they have had similar problem in past with some ATUs; | and Wayne said that they are now using a resonator with a tighter frequency | tolerance. | | A replacement resonator was put in the mail to me right away. My thanks! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PROBLEM SOLVED The replacement resonator arrived and was installed on the SSB board. The problems no longer exists. All AUXBUS device functions are now completely normal. Many thanks to Wayne, Gary, & Scott for their quick help and repsonse. 73, Ken Wagner K3IU K2 #920 ++++++++++++++++ Date: Wed, 17 Oct 2001 22:00:11 +1300 From: zl1aih at ihug.co.nz Subject: [Elecraft] KAF2 The KAF2 was well worth waiting for -I thought the K2 was the best receiver I had ever used, but the KAF2 option is the icing on the cake. The set-up per the manual provided a marked improvement, but Spectrogram (after Tom, N0SS guided me - Tom, you are a tower of strength to those of us who are Windows- challenged - thanks again) showed just how good those K2 filters are. Tweaking the KAF2 pots using Spectrogram produced a series of textbook passband patterns. I made some notes to record the 6, 20 and 60 dB bandwidths but tested the K2 +KAF2 in last week-end's Oceania CW Contest just to make sure I was hearing what I was seeing. I wasn't disappointed. Wayne, Eric, Gary and Lisa for her timely E-mail, many thanks. 73, Ken ZL1AIH +++++++++++++++++++ Date: Wed, 24 Oct 2001 07:51:56 -0700 From: Wayne Burdick Subject: Re: [Elecraft] KAF2 and annunciators Ron Willcocks wrote: > Would it be possible to add some sort of annunciator to the display when the > KAF2 is activated?? Hi Ron, We tested various ways of indicating when different filters are selected, but in our judgement they all compromised normal operation. For example, you can switch to a different LCD format that shows filter selections (XFIL and AFIL) at the left end of the display, but this is at the sacrifice of frequency digits. Another possibility is flashing some odd combination of decimal points or annunciators. But all of there were either annoying or required too many other compromises. In the mean time, there is certainly acoustic feedback about what filter you have selected. The sound of the various crystal filter settings and the audio filter are all unique. In fact to make this even easier, you can turn off one or more crystal filter settings in each mode, independently. You can also query XFIL/AFIL status at any time by holding XFIL and AGC together. We have all of the items you mentioned on the wish-list for future product consideration. Thanks, Wayne N6KR ++++++++++++++++++++ Date: Tue, 30 Oct 2001 19:25:36 -0500 From: "Tom Dooley" Subject: [Elecraft] Audio filter happy note, was RTC discussion My comments regarding the need to tweak the real time clock (RTC) that several have expressed. It would be interesting if the "silent majority" seem to be happy with the clock accuracy??? Well, I understand that not all of the RTCs are equal, but I generally expect that if one can be defective/slow/fast/erratic, then I would have it! However, even with the dark cloud that follows me around, I can honestly state that the clock works on time for me, even after over 4 weeks of operating time. I synched it with WWV once I installed it (built stock, as far as the RTC is concerned), and I just checked it and it is still within 1 second. I have spot checked it 10 times in the last month and it has always been between 0 and plus 2 seconds from WWV. Now, it appears that each clock is different, but YMMV! So I feel that the clock is a winner for me, but even without the clock, the audio filter is fabulous. The sound of it kicked in is impressive, even though I do tend to leave it off, just so I can hear the normal band noise. When the band noise is bad, this option really shines. I have been one of the low audio boys since the early days (K2 Serial #360). None of the recommended procedure seemed to bring my audio up to where I was happy. I felt that the rig was "as good as it could be made to operate (without audio amp add ons)". I purchased the option, on the reading of the ability to increase the audio gain. I followed the recommended change in the manual, and I am satisfied, at last, with the audio level. Still not the loudest K2 that I have heard, but enough for me. Don't want to adjust the clock? Double tap past the frequency display and see the voltage and current display. Single tap back to the frequency page. Voila, no RTC! The option, for me, is worth it without the RTC. Please keep in mind that this is just my opinion and is worth what you paid for it. Any flames are not really wanted, so please be nice! 72 de K4TJD Tom ++++++++++++++++ Date: Tue, 30 Oct 2001 16:57:54 -0800 From: Phil Wheeler Subject: Re: [Elecraft] Audio filter happy note, was RTC discussion Tom Dooley wrote: > The option, for me, is worth it without the RTC. > That's it in a nutshell: The filter, alone, makes KAF2 a great product. I'd rather glance at my watch than tap a button anyway. I'll wait for the WWV autosync option .. and I'd likley still use my watch :-; 73, Phil ++++++++++++++++++ Date: Tue, 30 Oct 2001 17:14:26 -0800 From: Wayne Burdick Subject: [Elecraft] Re: Audio filter happy note, was RTC discussion Tom Dooley wrote: > Don't want to adjust the clock? Double tap past the frequency display and > see the voltage and current display. Single tap back to the frequency page. > Voila, no RTC! The option, for me, is worth it without the RTC. You can also just turn the RTC off using its secondary menu entry (set RTC to OFF). The time will then not even come up when you tap DISPLAY. 73, Wayne N6KR +++++++++++++++++++++++ Date: 04 Nov 2001 21:16:44 -0500 From: Richard Mulvey Subject: Re: [Elecraft] KAF2 overly enthusiastic effect on filter response On 04 Nov 2001 15:47:01 -0500, Richard Mulvey wrote: > On 04 Nov 2001 14:44:36 -0600, Tom Hammond NØSS wrote: > > Rich: > > > > >I built and installed the KAF2 last week, and noticed that the passive > > >filter portion has quite an effect when using the USB filter - the > > >frequencies from about 1200hz to 2500hz are noticably suppressed. I > > >first noticed it when running PSK - the left hand side of the display > > >had a much higher gain than the right side. When the KAF2 is switched > > >out, they are much closer to being flat. Using Spectrogram, the filter > > >is down about 12dB at 1500Hz, as opposed to being down about 4dB with > > >the filter switched out. > > > > > >Guess I'm going to have to play with it a bit and see if I can even > > >things up a bit. > > > > Have you performed the SSB Snf XFIL mod yet? That can account for a > > 'tilted' SSB filter response... well, NOT performing the mod AND account > > for the tilt... the mod helps to FIX the tilt. > > > > Hi Tom: > > Yep - I installed the mod right after it came out. When the KAF2 > isn't switched in, the passband is as flat as I remember it being when I > did the mod. :-) > > I'll dump some plots from Spectrogram and pop them on my website so > that I can illustrate the issue. Darn, I'm embarassed. It looks like the excessive cut-off was actually a function of the PC sound card settings being used, and not the KAF2. I had just resurrected an old PC for use with Windows, and installed a new sound card, at the same time that I finished up the KAF2. Well, tonight, in the interest of reducing all the possible variables, I found that the Multimedia settings for the sound card had a slider for the sampling quality that ranged from "Good" to "Highest", and the setting was at "Good". When I changed the setting to "Highest", the passband image flattened right out, with the KAF2 both in and out of circuit, at every mode setting. Go on - someone ask me how much I dislike Windows. I dare you. :-) - - Rich ( Going back to his Linux machine ) +++++++++++++++++++++++++ Date: Fri, 16 Nov 2001 08:33:36 -0500 From: "ZOOM" Subject: Re: [Elecraft] KAF2 Firmware Question Yes just replace the old with the new but you will have to do some realignment especially the VFO. Does not take too long. Cheers, Robert VE3RPF - ----- Original Message ----- From: Jay & Jackie To: Sent: Friday, November 16, 2001 7:35 PM Subject: [Elecraft] KAF2 Firmware Question > I have just completed the KAF2 and am at the point where it says under > Control Board Preparation..."follow all instructions supplied with the > upgrade..." I don't see any instructions for installing the upgrade > Firmware. Do you just pull the chip from the K2 and replace it with the > new one (which I do have)? > > Thanks in advance for any advice. > > Jay, W6JDB #279 ++++++++++++++++++++++++++ See continued info in KAF2 Notes2 +++++++++++++++++++++++++++