N6BV report on K3 in SS
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With Dean's permission, I am posting to the Elecraft reflector the report by
Dean Straw, N6BV, regarding his use of the K3 at K6TA in SS CW. As you can see, he is a convert! 73, andy, ae6y >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> [Report by N6BV]: My primary motivation for operating SS CW for the last 10 years has been to contribute to the NCCC effort to get/retain the gavel for the Unlimited Club competition. This year I also wanted to give K6TA's new Elecraft K3 a real run for its money on CW, comparing it directly with a Yaesu FT1000MP. I had used a pair of FT1000MPs in SO2R for seven years operating at the K6TA station. RECEIVER SETUP I had used a K3 at the semi-serious CQWW Phone competition at N6RO's place at the end of October and I was very impressed with it (especially with the 1.8 kHz roofing filter -- SSB sounded very good even with this narrow bandwidth). But I consider the CW SS as a much higher stress test for any receiver, because of all the super-strong domestic signals crowding each and every kHz of any band that happens to be open. The K3 at K6TA had two roofing filters installed: a 2.8 kHz 8-pole filter and a 400 Hz 8-pole filter. The venerable FT1000MP had 500 and 250 Hz filters in both the 8 MHz and 455 kHz IFs. For both radios I set the AGC decay time constant to "fast." The AGC constants available in the setup configuration menu were left at factory defaults in the K3. I operated the K3 with the preamp "on," but on the FT1000MP I was forced to set the IPO to "off" (the equivalent of preamp off) to hold down overload. RECEIVER OVERLOAD During the CW SS, even on a clear frequency, the FT1000MP has always showed annoying low levels of what I call "diddley boops" -- more commonly referred to as "IMD products" -- created somewhere in the receiver chain. (I've been told that the IMD is better in FT1000MPs that have had the Inrad roofing filter modification installed, but this had not been done for the FT1000MP at K6TA.) In SSB operation and in casual CW operation, I've never been bothered by FT1000MP IMD. But the CW SS is a different sort of animal, as I said. By contrast, the K3 exhibited no IMD, even when I opened up the receive bandwidth to 2.8 kHz and discovered that I was surrounded by S9+30 dB signals. No "diddley boops" at all. Furthermore, the number of signals with objectionable key clicks was far less than I heard using the FT1000MP, especially when the rain static on Saturday night rose to S9+20 dB and I was forced to use the Noise Blanker on each radio to try to knock down the noise. The K3's Noise Blanker, used with non-aggressive settings for both hardware and DSP noise blanking, did help knock down rain static (to only S8 or so) while creating far less overload problems than did the 'MP's Noise Blanker. Interestingly, the K3's 400 Hz filter sounded somehow narrower than the 500 Hz filters in the 'MP, more than the nominal difference between the rated filter bandwidths. I used the 250-Hz filters in the 'MP when I used it for S&P in SO2R on the second band, while I kept the K3 bandwidth (both roofing and DSP) set to 400 Hz 95% of the time I used it as the CQ radio. And I didn 't find that I had to use the RIT very often with the 400 Hz filter, while I did have to use the RIT often when I had to narrow the DSP filtering down to 250 Hz while CQing. COPYING THE FULL EXCHANGE The quality of the K3's audio, the lack of overload and the action of the AGC seemed to make copying a full exchange much easier for me. I feel like I required less fills on the K3 than on the FT1000MP. (We'll see after log checking whether my UBN report is actually better.) Even when a QRP station faded considerably, the K3 had enough gain reserve and sensitivity so that the station didn't disappear altogether. In fact, the "presence" of signals on the K3 reminds me of the way my old Collins 75S3B used to work, with strong signals sounding stronger (without blasting your ears), while weak signals sounded weaker, but still copiable. I think Elecraft has gotten the "AGC slope" characteristics right in the K3. (That refers to the curve of output audio level versus input RF signal to the receiver.) I also like the way the K3's RF Gain control works like a conventional AGC system (the FT1000MP does also), with the S meter rising as the RF Gain control is backed off, in effect setting the AGC threshold level. (I dislike the way the RF Gain control works in my Orion I, but that's another story.) K3 TRANSMITTER K6TA is located relatively close to N6RO, and he was using two K3s in SO2R this SS CW. I tuned across Ken's S9+30 dB signal numerous times and marveled at his complete lack of key clicks. Elecraft got this right on the K3, for sure. I still heard far too many weaker signals ("only" S9) with really objectionable key clicks. Before the contest, K6TA marveled at how the Alpha 87 "enjoyed" the RF coming from the K3 -- with no leading-edge spikes in power that would occasionally shut off the amplifier while using the FT1000MP. Oh yes, this is the first SS I've used Win-Test. It is a pleasure to use, especially to someone who has used CT for more than 15 years. Win-Test made it easy to set up packet and worked perfectly without any crashes of any sort. The ability to point-and-click on unworked stations in the bandmaps was wonderful. Of course, the number of blown packet spots remains high enough that I don't think I'll get totally addicted to this kind of operation! I experimented with my sleep strategy, but I'm not convinced that helped my final score. And I'm not going to claim that using the K3 made Sunday afternoon actually fun during CW SS, but it made it more tolerable. I think my error rate went down compared to previous years. I thank Ken (K6TA) and Kay (K6KO) for their wonderful hospitality and for the use of their great station. They are fantastic hosts. 73, Dean, N6BV _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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I will ask here before calling Elecraft.
First, I have the following filters installed on the main rcvr, all 8 pole: 6 Khz, 2.8kHz, 1.8 kHz, 400 Hz, 250 Hz. There are two issues: 1. When I turn my 250 Hz filter on in config, and then select that filter (which is FL5 here)I can hear noise coming through but no cw signals come through. I can see the signals on my PowerSDR/LP-PAN setup and CW Skimmer. Signal comes through all the rest of the filters O.K. Yes, I opened the radio, and all the filters are installed. 2. I run CW Skimmer with my K3. When I change filters, the CW offset signal shown on CW Skimmer changes. I thought the 8 pole filters had no offset. Is anyone else experiencing this? Any comment appreciated. Dave, W5UN _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Is it possible that your narrow filter has cut off the desired signal?
Make sure your CW pitch is reasonable and you've tuned a little bit for the signal with the narrow filter. If your CW pitch is different from where you're listening at a wider bandwidth, the signal can disappear when you tighten the bandwidth. I'd recommend tuning in a steady carrier with the CWT and/or spot buttons, and then narrow the bandwidth. If the CWT doesn't center at a comfortable pitch (this is a personal preference), adjust it by entering CW mode, HOLD the Pitch button (it's labeled "Spot" for its tap function) and rotate VFO A until you get a pitch you like. I prefer about 400 Hz, your preference may be different than this. Also make sure that the Filter Configuration has the filters enabled by mode. The K3 Utility's Crystal Configuration Dialog can be used to quickly view the filter configuration, it's available by clicking the "Edit Crystal Filters" button on the K3 Utility's Config menu. I understand that you may have tried all this... Dick, K6KR -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of W5UN Sent: Monday, November 17, 2008 9:23 AM To: [hidden email] Subject: [Elecraft] Filter questions I will ask here before calling Elecraft. First, I have the following filters installed on the main rcvr, all 8 pole: 6 Khz, 2.8kHz, 1.8 kHz, 400 Hz, 250 Hz. There are two issues: 1. When I turn my 250 Hz filter on in config, and then select that filter (which is FL5 here)I can hear noise coming through but no cw signals come through. I can see the signals on my PowerSDR/LP-PAN setup and CW Skimmer. Signal comes through all the rest of the filters O.K. Yes, I opened the radio, and all the filters are installed. 2. I run CW Skimmer with my K3. When I change filters, the CW offset signal shown on CW Skimmer changes. I thought the 8 pole filters had no offset. Is anyone else experiencing this? Any comment appreciated. Dave, W5UN _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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>I prefer about 400 Hz, your preference may be different than this. Dick, What process did you go through to arrive at 400 cycles? I ask because I'm relatively new to CW and have experimented with the available frequencies in the K3, and find that if the signal is down in the noise, that higher frequencies seem to jump out of the noise better. However if the signal is strong, I prefer lower frequencies such as 400. OTOH, being relatively new to CW, I am open minded and defer to experience and would like to hear what you and others have to say on this subject. 73, Paul _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Don't defer to anyone else's experience, use your own preferences!
Some of this depends on your personal aural frequency response curve. My high-end response is down because of my age (I'm nearing my 62nd birthday), and perhaps some questionable decisions I made in the past about music volume, operating mainframe chain printers with the cover open because it's quicker to change paper that way, radio contests with the headphone volume up way too high in an attempt to dig weak signals out of the noise, and some exposure to Naval gunfire. Some CW enthusiasts opt for relatively low frequencies because they are able to discern one signal from another more easily if the relative frequency difference is larger. Eric Scace, K3NA, is usually worth listening to (or reading) on a lot of topics; psychoacoustics seem to be of particular interest to Eric. He has an interesting post on the TopBand Forum on this topic: http://lists.contesting.com/_topband/2006-11/msg00205.html There's also a link to a hearing test to help you understand your own capabilities in that post. One of the most proficient pileup competitors I have ever encountered is Fred Laun, K3ZO. He regularly appears at the top at the Dayton Pileup Competition. Fred recalled that he used to hone his pileup skills when he was operating from Thailand. His was a rare DX prefix to many. He'd get on one evening and just work stations from, for example, Poland, ignoring all the others in the pileup for that evening. There's a post about Fred and his preference for low-frequency CW pitch here: http://www.mail-archive.com/elecraft@.../msg51753.html And my ex-roommate Ward Silver has a couple of paragraphs on the ARRL Contest Rate Sheet: http://www.arrl.org/contests/update/index.html?issue=2006-12-13 Again, this is a personal preference issue, there are no "right" or "wrong" answers. It takes a while to get used to listening at lower CW pitch. If you're trying to dig a single signal out of the noise you may have one preference. If you're being called by a dozen loud callers and want to be able to pull one complete call sign out of the pileup each time, you may have a different preference. 73 de Dick, K6KR -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of [hidden email] Sent: Monday, November 17, 2008 12:55 PM To: [hidden email] Subject: RE: [Elecraft] Filter questions >I prefer about 400 Hz, your preference may be different than this. Dick, What process did you go through to arrive at 400 cycles? I ask because I'm relatively new to CW and have experimented with the available frequencies in the K3, and find that if the signal is down in the noise, that higher frequencies seem to jump out of the noise better. However if the signal is strong, I prefer lower frequencies such as 400. OTOH, being relatively new to CW, I am open minded and defer to experience and would like to hear what you and others have to say on this subject. 73, Paul _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Dave-W5UN
Both issues sound like there could be an offset problem in the 250 Hz filters. I only have 5-pole CW filters here but I know Ed W0YK has reported offsets in his 8-pole 400/250s of up to 80 Hz. Given that the 250 Hz 8-pole is actually around 370 Hz wide according to Inrad plots, I don't see how even an 80 Hz offset could cause the problem you noted in #1 above. However I believe most of the 8-pole filters will have the problem in #2 above since they do not truly have zero offset. If I used 8-pole CW filters, I would measure the actual offset and enter it into the Filter Configuration menu. This would solve problem #2 above and it might also tell you whether you have a defective 250 Hz filter causing #1 above. |
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Elecraft believes the 250 hz filter problem is a defective filter,
and is sending a new replacement.. Bill, does your CW Skimmer signals stay right on frequency as you switch filters (as happens automatically with changing DSP width when filters are enabled)? Dave, W5UN At 23:03 11/17/2008, you wrote: >Dave Blaschke wrote: > > > > I will ask here before calling Elecraft. > > > > First, I have the following filters installed on the main rcvr, all 8 > > pole: 6 Khz, 2.8kHz, 1.8 kHz, 400 Hz, 250 Hz. > > > > There are two issues: > > > > 1. When I turn my 250 Hz filter on in config, and then select that > > filter (which is FL5 here)I can hear noise coming through but no cw > > signals come through. I can see the signals on my PowerSDR/LP-PAN > > setup and CW Skimmer. Signal comes through all the rest of the > > filters O.K. Yes, I opened the radio, and all the filters are installed. > > > > 2. I run CW Skimmer with my K3. When I change filters, the CW offset > > signal shown on CW Skimmer changes. I thought the 8 pole filters had > > no offset. Is anyone else experiencing this? Any comment appreciated. > > > > Dave, W5UN > > > >Both issues sound like there could be an offset problem in the 250 Hz >filters. I only have 5-pole CW filters here but I know Ed W0YK has reported >offsets in his 8-pole 400/250s of up to 80 Hz. Given that the 250 Hz 8-pole >is actually around 370 Hz wide according to Inrad plots, I don't see how >even an 80 Hz offset could cause the problem you noted in #1 above. However >I believe most of the 8-pole filters will have the problem in #2 above since >they do not truly have zero offset. > >If I used 8-pole CW filters, I would measure the actual offset and enter it >into the Filter Configuration menu. This would solve problem #2 above and >it might also tell you whether you have a defective 250 Hz filter causing #1 >above. > >-- >View this message in context: >http://n2.nabble.com/N6BV-report-on-K3-in-SS-tp1462519p1511809.html >Sent from the Elecraft mailing list archive at Nabble.com. > >_______________________________________________ >Elecraft mailing list >Post to: [hidden email] >You must be a subscriber to post to the list. >Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > >Help: http://mailman.qth.net/subscribers.htm >Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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> On Mon, Nov 17, 2008 at 6:45 PM, W5UN <[hidden email]> wrote:
> Elecraft believes the 250 hz filter problem is a defective filter, and is > sending a new replacement.. I thought so... > Bill, does your CW Skimmer signals stay right on frequency as you switch > filters (as happens automatically with changing DSP width when filters are > enabled)? No Skimmer does shift. PowerSDR does not shift because Larry N8LP and Scott WU2X read the filter offsets and adjust accordingly. 73, Bill W4ZV _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Dick Dievendorff
On Mon, 17 Nov 2008 14:42:22 -0800, Dick Dievendorff wrote:
>Eric Scace, K3NA, is usually worth listening to (or reading) on a lot of >topics; psychoacoustics seem to be of particular interest to Eric. He has an >interesting post on the TopBand Forum on this topic: >http://lists.contesting.com/_topband/2006-11/msg00205.html As a member of the Acoustical Society, Fellow of the Audio Engineering Society, and a student of psychoacoustics (the science of how we hear and interpret sound), I can vouch for the wisdom of Eric's advice. I've independently given the same advice. Someone else noted another good reason for listening to lower pitched CW -- hearing loss tends to be greatest at high frequencies! 73, Jim K9YC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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