Date: Fri, 19 Jan 2001 14:21:54 -0500 From: "Johnson, Stephen" Subject: [Elecraft] Aligning the K1 the Easy Way ?! I have had a difficult time trying to align the K1 on 20m and 15m using the alignment instructions in the manual. Judging by other postings on the reflector, I am not the only one. The problem is that all four of the adjustable inductors on the filter board must be close to optimum to hear anything in receive or get a power indication in transmit. The four inductors are like a "4 digit combination lock" with lots of potential combinations. I never could guess the right one. The troubleshooting section of the manual talks about constructing an RF probe for the user's multimeter and then checking rectified RF voltages at various points in the circuit. I had an old RF probe already so I decided to give it a try. One of the test points is the premixer bandpass output (if I remember right, I think it's pin 6 on P1). With this approach, alignment is easy: 1) tune up the two pre-mix inductors using the RF probe for maximum output of the premix bandpass signal (it's present in receive and transmit). 2) Now tune the RF bandpass inductors for maximum reading on the multimeter. Since you have the combination for two of the "combination lock's digits" - - it's much easier to find the other two. 3) Go back and tune up the premix inductors for maximum signal heard. 4) If the transmitter is built, tweak all the inductor the settings for maximum signal output. This worked for me. Now all I have to do is find the problem in one of my RF bandpass filters on the other filter board! Steve Johnson, N2FT K1 SN 0368 ------------------------------ Date: Fri, 19 Jan 2001 14:51:28 -0500 From: "Johnson, Stephen" Subject: [Elecraft] Correction to K1 Alignment Posting When I did final editing on my prior message I inserted an error that I didn't catch. After tuning the pre-mix inductors with the RF probe and multimeter, tune the RF bandpass inductors in receive mode for maximum signal BY EAR. The rest of the instructions should work OK. Sorry for the confusion - - it really works! Steve Johnson, N2FT K1 #0368 ------------------------------ Date: Fri, 19 Jan 2001 12:40:57 -0800 From: Wayne Burdick Subject: Re: [Elecraft] Correction to K1 Alignment Posting Hi Steve, Thanks for posting your alignment method. Another method that works very well is to use an external general-coverage receiver. You can tune in on the appropriate signals generated by the K1, then peak the coils. For example, if you're on 15 meters and have the VFO set for 21000, the premixer should be generating a signal at 25915 kHz or so during receive or transmit (21000 + 4915). If you hang a 6" length of hookup wire at the output of the premix band-pass filter, your GC receiver can pick this up very easily, assuming it also has a wire antenna inside the shack. You can then either peak up the RF BPF by ear, or do it on transmit by setting your GC receiver to 21000. 73, Wayne N6KR ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Mon, 26 Feb 2001 08:52:51 -0700 From: Bruce Grubbs Subject: Re: [Elecraft] K1 alignment help needed Jim, I had the same problem. Here's a copy of an email from AB7MY detailing how to work around it. His method worked perfectly. 72 Bruce N7CEE Flagstaff, AZ DM45ef - ------ From: "Gary Surrency" To: "'Bruce Grubbs'" Cc: "Csinfo \(E-mail\)" Subject: N7CEE: RE: K1: No transmit monitor tone Date: Sun, 4 Feb 2001 10:19:24 -0700 X-Mailer: Microsoft Outlook CWS, Build 9.0.2416 (9.0.2910.0) Importance: Normal Bruce, Set the RX BFO properly first, using Spectrogram to peak the AF signal on noise, or use an AC voltmeter on the AF output and adjust C20 until maximum amplitude is found. Then turn off the sidetone completely (StL 0). Set the power level for 2-3 watts. Jumper OFS. Try adjusting TX BFO trimmer C13 to see if you can hear the beat note. If you still cannot hear the TX-generated tone, temporarily place a resistor of 47k-100k the Drain and Source leads of Q11 to allow more audio to leak into the AF amp at U4. Now you should be able to hear the TX tone well, and you can then increase StL to 1-5 or so to match the sidetone and TX signal. You may need to adjust the StL and Power level slightly so both are at about the same audio level for hearing the beat note. When OFS is complete, remove the jumper and 47k-100k resistor from Q11. The reason this is necessary on some rigs, is that we have two mute circuits that work almost too well. Q10 is a shunt mute FET, and Q11 is a series mute FET. Jumpering OFS prevents Q10 from muting, but it does not prevent Q11 from muting. Some J309s mute so well there is not enough AF signal leakage from U3 to U4 to be heard in the speaker. Wayne and I discussed this, and he has decided we will change the OFS method in a future K1 RF PCB revision. We'll enable the TX Mixer at U8 with a jumper while the rig is in RX, thus eliminating the need to prevent the two mute FETs from blocking the signal. This will require a change in the 6T supply trace routing to U8, so we'll need to revise the PCB layout slightly. I've asked for a 3-pin header and shunt block to be provided so the supply pin of U8 can be fed either 6R/AUX for the OFS adjustment, *or* 6T for normal operation. C13 must move the TX frequency, or you have something wrong with C13 or the TX Mixer/BFO circuit. - -- 73, Gary AB7MY ========= gary at elecraft.com Elecraft Technical Support ======================================== - -----Original Message----- From: Bruce Grubbs [mailto:n7ceeqrp at earthlink.net] Sent: Sunday, February 04, 2001 8:54 AM To: support at elecraft.com Subject: K1: No transmit monitor tone Got the missing parts... thanks, guys! I am unable to set the transmit offset using the method in the manual. When I jumper OFS I only hear the sidetone, not the transmit monitor tone. C13 does move the TX frequency, because I was able to set the offset using another receiver. Any suggestions? 72, Bruce N7CEE Flagstaff, Arizona +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Mon, 26 Feb 2001 11:03:02 -0800 From: Eric Swartz WA6HHQ - Elecraft Subject: [Elecraft] K1 Builder Alert #3: Inability to hear TX signal when making TX Offset Adjustment K1 Builder Alert #3: Inability to hear transmit signal when making the TX Offset Adjustment 26 Feb. 2001 Impact: All K1's Background: When making the 'Transmit Offset Adjustment' (K1 Rev D manual, page 47) on some K1s no TX signal tone is heard. (This adjustment has you match the K1 sidetone frequency with the TX offset.) The reason this happens is because on some rigs we have two mute circuits that work almost too well. Q10 is a shunt mute FET, and Q11 is a series mute FET. Jumpering OFS (as noted on page 47) prevents Q10 from muting, but it does not prevent Q11 from muting. Some J309s mute so well there is not enough AF signal leakage from U3 to U4 to be heard in the speaker. TX offset can still be set using an external receiver as a reference, but the following procedure is suggested if you want to use just the K1. Modification to TX Offset Adjustment instructions. (Please read the TX Offset instructions on page 47 first.): 1. Set the RX BFO properly first (K1 Rev. D manual page 40), by adjusting C20 until maximum amplitude is found using an AC voltmeter on the AF output, or using Spectrogram to peak the AF signal on noise. 2. Then turn off the sidetone completely (StL 0). 3. Set the power level for 2-3 watts. 4. Jumper OFS. 5. Try adjusting TX BFO trimmer C13 to see if you can hear the beat note. If you still cannot hear the TX-generated tone, temporarily place a resistor of 47k to 100k across the Drain and Source leads of Q11 to allow more audio to leak into the AF amp at U4. Now you should be able to hear the TX tone well. 6. You can then increase StL to 1-5 or so to match the sidetone and TX signal levels. You may need to adjust the StL and Power level slightly so both are at about the same audio level for hearing the beat note. 7. When the TX offset adjustment is complete, remove the OFS jumper and the 47k to 100k resistor from Q11. +++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sun, 01 Jul 2001 09:19:08 -0500 From: Mike Subject: Re: [Elecraft] K1 rookie-builder needs help! Steve, It's very likely that your filter board coils are still just too far out of alignment. The tuning of the four slug coils on each band on the filter board is fairly critical. You won't hear anything except contant level noise until you get ALL FOUR slugs close to the proper position. A good way to do that is: (1) Use an external signal source (such as another NEARBY transceiver into a dummy load, and the K1 antenna jack connected to wire run near the signal source) that puts out enough signal that the K1 will hear it even while still un-aligned. Once you can find the signal, you can SLOWLY peak the coils. Make SURE you reduce the signal source strength as the receiver sensitivity increases as you peak the coils. Eventually you'll want to use a very weak signal for alignment purposes. (2) Tune the coils VERY slowly. Most mis-alignments occur when the coils are tuned too fast to pick up the barely perceptible increased noise or signal that occurs as the peak is approached. The peak on these coils is fairly sharp. GO SLOW! If you don't have (1) above, then you'll have to make due with (2) only. Attach a good length of wire or external antenna and TUNE SLOW. Also, I found the 20m coils to be the easiest to peak, so you might begin the alignment on 20m rather than on 40m. And did I mention that you need to tune the slugs very SLOWLY? 73, Mike / KK5F roysteve wrote: > > K1 question! > Brand new ham and kit-builder here. I'm on page 40, Band-Pass Filter > Alignment. Antenna jack appears to be "dead." I've tried attaching > everything from a plain 20 foot wire to my dad's (WB5VNZ) antennas... > nothing. Everything has gone very smoothly so far and my K1 #410 > (ok, I was a little slow to get started!) has passed all the checkpoints > > up to this page. I do get constant "atmosphere" noise and a constant > tone of some > sort on both 15 and 40 meters at a specific frequency but the BNC jack > gives me zero response. I've tried tweaking the inductors but this does > not help. > I've not slept, eaten or bathed for 37 hours trying to get over this > bump in > the road; wife and cats are starting to get worried. Any suggestions, > offers of > help and/or even sarcastic comments would be appreciated. > > Thx! > Steve Collazo > KD5NSD > Beaumont, Texas +++++++++++++++++++++++++++++++++