++++++++++++++++++++++++++++++++++++++++++ Date: Tue, 24 Apr 2001 06:19:40 -0500 From: Mike Subject: Re: [Elecraft] K1 NB makes SiG go away? Andy Anderson wrote: > However, I noticed that now when I select SIG to show signal strength > in the display, I get an inital display of bars (all the way across), > then they go away and are now replaced with _ _ _ (three underscores). This is what you'll see when you select the signal meter, if your AGC menu selection is OFF. Find AGC on the menu and turn it back ON. Also, the SIG menu item is used for S-meter *calibration* and *not* to make the display show the signal strength. That is done by holding the BAND pushbutton a second until the desired display shows up. I think that's what you meant, though. 73, Mike / KK5F ++++++++++++++++++++++++++++++++++++++++++ Date: Wed, 25 Apr 2001 21:26:59 +1200 From: "Ron Willcocks" Subject: [Elecraft] KNB1 test. Am very pleased to report the K1 with KNB1 installed passed the "electric fence" test at our Club rooms tonight. Very impressive even on the HI setting. It makes the noise blanker on one of the Club sets look a bit pathetic. Another Elecraft success story. Cheers......Ron ZL1AJP ++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sun, 10 Jun 2001 13:21:04 -0500 From: Mike Subject: Re: [Elecraft] Ground Loop in KNB1? Scott Prather wrote: > My K1 with the KNB1 and KAT1 is producing a thump on key-up ... The > thump is present with the radio operating into an antenna or a dummy > load, and as you tune from 14.1 down towards 14.0, the thump gets > progressively worse until it's really severe just a few kHz above > the band edge. Turning on the KNB1 considerably reduces the severity > of the thump, but it's still present. > > Has anyone else seen this problem? Scott, This is a fairly well-known problem with the KNB1 that is easily fixed by a solution that Wayne has provided to those who have reported the problem: Add a capacitor (about 0.01 uF) from U1 pin 1 to pin 8 on the KNB1. I could hardly use the K1 around 14.015 kHz due to this noise. Turning the KNB1 ON would eliminate it, using another frequency would eliminate it, and finally the adding the capacitor eliminated it completely under all conditions. The problem was so severe, with so simple a solution, that I've wondered why this hasn't been made a "Builder's Alert." I expended several hours of fruitless troubleshooting on it a couple of months ago until John/K7FD emailed me with this info. 73, Mike / KK5F +++++++++++++++++++++++++++++++++++++++++ Date: Sun, 10 Jun 2001 16:23:56 -0700 From: Wayne Burdick Subject: Re: [Elecraft] Ground Loop in KNB1? Mike wrote: > > Scott Prather wrote: > > > My K1 with the KNB1 and KAT1 is producing a thump on key-up ... This is indeed supposed to be corrected in the KNB1 kit, and will be the subject of a builder alert. It's on my to-do list! tnx Wayne N6KR ++++++++++++++++++++++++++++++++++++++++++ Date: Wed, 13 Jun 2001 17:01:11 -0700 From: Gary L Surrency Subject: [Elecraft] K1 Builder Alert #4 Background The KNB1 noise blanker can be a source of audio noise during keying under certain conditions. This is most often noticed on the 20m or 17m bands, around 30 to 50 kHz up from the lower edge of the bands. This document describes a simple modification to insure this does not occur. Changes Needed Remove the KNB1 from the K1. On the bottom side of the KNB1 PCB, install a small .01uF disk or monolithic cap across pins 1 & 8 of the 12C509 NB PIC, U1. Use as short of leads as possible, and press the capacitor flush against the bottom of the PCB with the cap centered between the two rows of pins for U1. Reinstall the KNB1. No further changes are necessary. Test the KNB1 to be sure it works as before, and check to see if any noise is now heard across the tuning range. Technical Details The 6R/AUX line goes low and high when the K1 is keyed. The 12C509 KNB1 PIC normally sleeps except when it is sent an auxbus command. It interprets the keying transitions on the 6R/AUX line as a possible command. In doing so, the microcontroller exits sleep mode and briefly turns ON its on-chip RC oscillator. The added .01uF capacitor suppresses oscillator harmonics on U1's Vdd pin that can enter the RX signal path. - -- 73, Gary AB7MY ========= gary at elecraft.com Elecraft Technical Support ++++++++++++++++++++++++++++++++++++++++++++ Date: Wed, 27 Mar 2002 21:39:37 -0500 From: "Charles L. Gardner, Jr." To: elecraft at mailman.qth.net, res05gc2 at verizon.net Subject: [Elecraft] Problem with KNB1 Noise Blanker Page 4 of KNB1 Noise Blanker "Assembly and Operating Instructions": "the toroid core for inducton L2 is marked with an orange dot to differentiate it from L1. Be sure to use the correct cores in the following steps. Problem: both cores are the same with neither having an orange dot. Advise please. Many thanks. 73 Charlie WA4HKN K1-4 #1074 +++++++++++++ From: BobDobson at aol.com Date: Wed, 27 Mar 2002 22:06:09 EST Subject: Re: [Elecraft] Problem with KNB1 Noise Blanker To: res05gc2 at verizon.net, elecraft at mailman.qth.net On mine, the "dot" was rather a dark orange-brown smear on the edge of the toroid core. This differentiated it from the unpainted black core. Try giving the core a close look under a strong light. Hope this helps. 73, Bob WA4FOM +++++++++++++++++++ To: elecraft at mailman.qth.net Date: Wed, 27 Mar 2002 23:53:28 -0600 From: n4so at juno.com Subject: [Elecraft] Miniature 10uH RF chokes Attenuator on/off audio pop elimination page 349 of Mouser catalog 434-21-100 for 10uH Epoxy Conformal Coated page 350 Miniature Epoxy Coated Chokes 43LS105 for 10uH. About 40 cents each. Ref: Appendix B, top left corner of Attenuator and K1 pins 3 and 8 Ken Brown-N4SO Mobile, AL EM50tk Elecraft K-1 4 ele. monoband yagi N4SO at juno.com ++++++++++++++++++ From: "Morrow, Michael A." To: "'Trevor Jacobs'" , elecraft at mailman.qth.net Subject: RE: [Elecraft] K1 Noise Blanker Date: Sat, 8 Feb 2003 15:23:43 -0500 From: Trevor Jacobs > Now upon building the NB I installed the LED rather than the second > diode to give it a higher level of noise attenuation. The LO setting > works great, but the HI setting doesn't do anything. The LED is > installed as it should be (that was my first thought). > > The way I am reading things, I should see more noise attenuation > in the HI mode, OR, does it mean a HIgher threshold? The HI setting sets the **threshold** higher. A higher noise pulse amplitude will be required to activate the NB, compared to the LO (low threshold) setting. Further, by installing the green LED option at D2, you have moved the HI threshold even **higher** than what it would have been had you installed the normal 1N4148 at D2. You may want to go back and install the 1N4148 instead. Thus, it is no surprise that you now hear very little effect when you are in the HI setting. It now takes a very large noise pulse to activate the blanker. As page seven of the KNB1 manual states, the LED should be used only if you are in a high noise environment (i.e., the noise pulse amplitudes are high). 73, Mike / KK5F ++++++++++++++++++ From: Kevin Rock To: elecraft at mailman.qth.net, ARDUJENSKI at aol.com Date: Mon, 05 May 2003 10:15:41 -0700 Reply-To: kevinrock at earthlink.net Subject: Re: [Elecraft] KNB1/B2?? I find the noise blanker helpful when an electric fence fires up in the area. I have also used it to lessen the noise of mixers when my YL starts making something in the kitchen while I'm trying to copy CW. I haven't been able to defeat the blender with it though :) Kevin. KD5ONS +++++++++++++++++++