[Elecraft] K2 crystal filter upgrade
I have an early K2 that has the original type crystals in both the CW and SSB IF filters (marked with ECS 4.91-20). If I am not going to increase the bandwidth of the SSB filter, is there any reason to replace the old crystals with the new units from Elecraft? Will the new crystals improve performance? Thanks for any feedback. Mike M. KU4QO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K2 keying mod
Don, As always, thank you for that detailed information. I do have a set of 2.04r firmware to install as I go through my A-to-B mod list. Best regards, Mike M. KU4QO On Fri, Nov 3, 2017 at 9:39 AM, Don Wilhelm wrote: > Mike, > > Order the SMT1B - PIN diode on carrier board p/n E120014 from Elecraft and > mount it as shown on page 60 of the latest K2 manual. > Note that you also will need to have MCU firmware at 2.04. If yours is > lower than that, also order FWK2MCIO. > The current firmware is 2.04r, and if you are dealing with a K2 below SN > 3000 and have not done the sidetone source change as indicated in the > KPA100 or KIO2 instructions, you must add it to use 2.04r because the > sidetone source is locked at U8-4. That is the only difference between > 2.04P and 2.04r. > > The rest of the components on the Control Board can be mounted as > indicated in the Keying Waveshape Mod documentation. If you do not have > that document, send me an off-list email and I can send it to you. > > I have been installing that mod on all the K2s that I upgrade. > > 73, > Don W3FPR > > > On 11/3/2017 8:56 AM, Mike Maiorana wrote: > >> I'd like to update my K2 (SN 336) with the keying mod to reduce CW >> bandwidth. The doc from Elecraft specifies a PIN diode that is obsolete >> and >> no longer available (5082-3081). >> >> __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] K2 keying mod
I'd like to update my K2 (SN 336) with the keying mod to reduce CW bandwidth. The doc from Elecraft specifies a PIN diode that is obsolete and no longer available (5082-3081). I'm not sure what specifications are important to spec a replacement part. Any suggestions for a suitable replacement, or maybe someone out there has the correct part that they could sell me? Thanks and regards, Mike M. KU4QO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K2 PLL range test fails
Thanks again Don. This was an interesting one. The DAC was constantly receiving data/clock signals from the CPU, even with all the controls at rest. You could see the DAC output voltage jump when the Band+ or Band- keys were pressed while in CAL FCTR, but then went immediately back to where it started. I was stumped. A little "googling" turned up an old post from 2004 by John G3NYX who had the same problem while building his K2. Someone suggested to him to move the RIT control and try again. Now, I confirmed that my RIT wasn't on so I figured that it would have nothing to do with this issue. I was wrong. I twisted the RIT knob a few times back and forth and then retested the PLL range. Now everything works! It seems that even with RIT off, the CPU still sends data to the DAC because of RIT. If the RIT control was a little noisy and was right in between two readings it would cause the CPU to constantly update the PLL reference oscillator DAC. CAL PLL worked great, the BFO adjustments are done and the radio is working great now. Thanks for your help Don! Mike M. KU4QO On Mon, Oct 16, 2017 at 8:11 AM, Don Wilhelm wrote: > Mike, > > Record your current filter settings and other menu settings, and then do > a Master Reset (hold the 4, 5 and 6 buttons in while powering on). > > There is a convenient form to record the menu settings in the K2 A to B > instructions which you can download from the Elecraft website. > > You may have to replace the firmware (to be determined later), but perhaps > RF board U7 is not receiving as it should. If you have a 'scope, you > should be able to see pulses on U7 pins 1, 2, and 3 as you rotate the VFO > knob. If all 3 pins show pulses, then most likely U7 is not working > properly. U7 pin 7 should move from 5 volts to zero volts in CAL FCTR when > you tap the BAND+ and BAND- buttons. If it does, then U7 is operating > correctly. > > Also make a quick check on the Thermistor board - a quick check is to > measure the voltage at U5 pin 5 - it should be 4 volts or 1/2 the 8 volt > supply. If not, check the Thermistor board for solder bridges. You can > see the back of the Thermistor board if you remove the Control Board and > Front Panel. > > 73, > Don W3FPR > > > > > On 10/15/2017 10:02 PM, Mike Maiorana wrote: > >> Since fixing my BFO range issue I started going through a full alignment. >> I >> roughly set the BFO for all the filters. I noticed my frequency display >> was >> off about 1500 Hz, so I re-set the 4MHz oscillator, then tried to run CAL >> PLL. The CAL PLL started, but never finished. It just sat right around >> 12.1MHz. >> >> I went back and tried the "PLL Reference Oscillator Range Test", which had >> passed the first time I went through calibration. Now, it is "stuck" on >> 12.097MHz. What is strange is that it will jump briefly when I press Band+ >> and Band-, but it settles back to 12.097MHz. >> > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] K2 PLL range test fails
Since fixing my BFO range issue I started going through a full alignment. I roughly set the BFO for all the filters. I noticed my frequency display was off about 1500 Hz, so I re-set the 4MHz oscillator, then tried to run CAL PLL. The CAL PLL started, but never finished. It just sat right around 12.1MHz. I went back and tried the "PLL Reference Oscillator Range Test", which had passed the first time I went through calibration. Now, it is "stuck" on 12.097MHz. What is strange is that it will jump briefly when I press Band+ and Band-, but it settles back to 12.097MHz. I put a volt meter on pin 1 of U6 on the RF board to check the control voltage. When I press Band- I can see the voltage briefly drop to near zero. When I press Band+ it jumps to 7.5V or so, then goes back to the original value. If I rotate the VFO knob I can see the PLL frequency and the control voltage vary over a range of about 5kHz on the VFO. It seems that the PLL is moving with the control voltage, but the Band+ and Band- keys during Cal FCTR don't seem to be doing what they should. Is it possible that I fouled up another part of the calibration that is causing this weird behavior? It sure feels like I'm doing something wrong, but I can't figure it out. I did a factory reset (hold 4,5,6 and power on), but I'm still seeing the same issue with the PLL. Any help will be greatly appreciated. Thanks and 73 Mike M. KU4QO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K2 BFO test failed
Don, My replacement BFO crystals arrived today and I installed them. My BFO range is now 5.66 kHz. FIXED! Thank you! I have to add a note about what I call "Elecraft Mojo". The crystals were back ordered so there was a delay before they could be shipped. The package was sent Friday from California on its way to Florida. USPS web page said that the package would deliver on Monday. I checked the tracking info this morning (Sunday) and it said that the package was at the local sorting facility. So, on track for a Monday delivery. I went out to the mailbox to drop off an outgoing letter this afternoon and I was surprised to see a Priority Mail box inside. Sure enough, it was my Elecraft parts order, delivered by the USPS ON SUNDAY!!! To make sure I wasn't losing my mind I checked the tracking info again and sure enough, it was sorted and delivered today. I have NEVER received regular mail on a Sunday. Just more of that Elecraft Mojo. And, of course, my tiny little order was treated with the same urgency and respect as when I bought the radio new. What a great company. Now, off to finish the alignment! Thanks again and 73 Mike M. KU4QO On Sat, Sep 30, 2017 at 10:53 PM, Mike Maiorana wrote: > Don, > Thank you again for your very detailed response. I think I've found the > problem. > After doing the visual checks you suggested I wanted to try and isolate > the crystals to see if the problem was there. > I left L33 alone and carefully removed the BFO crystal that was accessible > without removing the inductor. Now CAL FCTR showed the BFO frequency as > 0. Interesting. > > I then removed L33 and the second BFO crystal. Using a simple crystal > tester/oscillator I have showed the second crystal (the one under L33) did > not oscillate. The other crystal seemed to oscillate fine. So, it looks > like an order for a pair of BFO crystals should get me back in business, or > at least let me continue the alignment. Hopefully this was the only problem. > > Thanks again Don for your expert advice. I'll follow up when I get the > replacement parts. > Best regards and 73 > Mike M. > KU4QO > >> >>> I'm having an issue at the BFO test. The BFO high frequency is >>> 4916.04 kHz >>> and the low frequency is 4913.82 kHz. That's a difference of >>> 2.19 kHz, well >>> below the 3.6 kHz stated minimum. >>> >>> >>> >> > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K2 BFO test failed
Don, Thank you again for your very detailed response. I think I've found the problem. After doing the visual checks you suggested I wanted to try and isolate the crystals to see if the problem was there. I left L33 alone and carefully removed the BFO crystal that was accessible without removing the inductor. Now CAL FCTR showed the BFO frequency as 0. Interesting. I then removed L33 and the second BFO crystal. Using a simple crystal tester/oscillator I have showed the second crystal (the one under L33) did not oscillate. The other crystal seemed to oscillate fine. So, it looks like an order for a pair of BFO crystals should get me back in business, or at least let me continue the alignment. Hopefully this was the only problem. Thanks again Don for your expert advice. I'll follow up when I get the replacement parts. Best regards and 73 Mike M. KU4QO On Sat, Sep 30, 2017 at 6:12 PM, Don Wilhelm wrote: > Mike, > > How did you check the value of the resistor. If you used your DMM while > it was in-circuit, then you have an open L33. The BFO would oscillate, but > the range would be restricted as yours is or more narrow. > > First thing, check capacitors C173 and C174 to be certain you have the > correct values installed. Those blue capacitors with the yellow printing > on them are difficult to read, so use a magnifier and lots of light. > > Then check D37 and D38 to be certain they are oriented correctly - the > slightly angled side is the "rounded" side. > > Make certain RP6 is well soldered - reflow with a hot iron (750 degF) and > apply a bit of extra solder - you really one need the flux. The iron dwell > time should be about 3 seconds, but watch for the solder to flow out onto > both the solder pad and the component lead to assure good soldering - up to > 5 seconds dwell will not hurt anything. > > Then when doing the BFO Hi and BFO LO frequency checks make sure RP6 pin 7 > goes to quite near 5 volts and also quite near zero volts. > > The above are the easiest items to check. > Keep in mind that the resistor which holds L33 is really an insulator, it > serves no electrical function. > > You are correct that a bad BFO crystal could cause the problem, but to > change them (change them as a matched pair), you have to lift L33. Not too > bad is you are careful, leave the leads connected to the resistor leads, > heat the solder pad and pull the resistor lead out - repeat for the other > side and lift L33 and the resistor off as an assembly. > > So try the easy stuff first, and if that does not cure it, contact > Elecraft Support and request a pair of BFO crystals and a new L33 and 5.1 > meg resistor to replace them. > > 73, > Don W3FPR > > On 9/30/2017 5:40 PM, Mike Maiorana wrote: > >> Thanks Don. >> I triple-checked the inductor wires and they are well soldered to the >> pads. I also verified the value of the resistor across it, 5.1 Mohms. I >> reflowed the solder anyway, but no change in the BFO frequency range. >> >> If L33 wasn't connected would the oscillator even run? >> >> If one of the two crystals was bad (or not soldered properly) would you >> also see a reduction in BFO range? >> What about if one of the varactors had failed? >> >> Any further advice will be greatly appreciated. >> Thanks and 73 >> Mike M. >> KU4QO >> >> On Sat, Sep 30, 2017 at 9:57 AM, Don Wilhelm > <mailto:donw...@embarqmail.com>> wrote: >> >> Mike, >> >> The inadequate BFO range is usually a result of the L33 toroid >> leads not being well soldered. The toroid wires are very fine and >> sometimes are not visible to the naked eye, so use magnification >> to examine them. When re-soldering, use a pointed tool to bring >> the fine toroid wires down onto the solder pad instead of further >> up on the securing resistor lead. >> >> For adjusting the 4 MHz Reference Oscillator (that has nothing to >> do with the BFO range), refer to the K2 Dial Calibration article >> on my website www.w3fpr.com <http://www.w3fpr.com> for the most >> >> accurate method of adjusting the Reference Oscillator. >> >> Be aware that the 4 MHz Reference oscillator can drift in normal >> operation, so soon after adjusting it, run CAL PLL and CAL FIL >> while it is still "on frequency". That oscillator is not used in >> operation for the K2 frequency display. In other words, simply >> adjusting the 4 MHz Reference does nothing for normal operation. >> >> 73, >> Don W3FPR >> >> >> On 9/30/2017 9:35 AM, Mike Maiorana wrote: >>
Re: [Elecraft] K2 BFO test failed
Thanks Don. I triple-checked the inductor wires and they are well soldered to the pads. I also verified the value of the resistor across it, 5.1 Mohms. I reflowed the solder anyway, but no change in the BFO frequency range. If L33 wasn't connected would the oscillator even run? If one of the two crystals was bad (or not soldered properly) would you also see a reduction in BFO range? What about if one of the varactors had failed? Any further advice will be greatly appreciated. Thanks and 73 Mike M. KU4QO On Sat, Sep 30, 2017 at 9:57 AM, Don Wilhelm wrote: > Mike, > > The inadequate BFO range is usually a result of the L33 toroid leads not > being well soldered. The toroid wires are very fine and sometimes are not > visible to the naked eye, so use magnification to examine them. When > re-soldering, use a pointed tool to bring the fine toroid wires down onto > the solder pad instead of further up on the securing resistor lead. > > For adjusting the 4 MHz Reference Oscillator (that has nothing to do with > the BFO range), refer to the K2 Dial Calibration article on my website > www.w3fpr.com for the most accurate method of adjusting the Reference > Oscillator. > > Be aware that the 4 MHz Reference oscillator can drift in normal > operation, so soon after adjusting it, run CAL PLL and CAL FIL while it is > still "on frequency". That oscillator is not used in operation for the K2 > frequency display. In other words, simply adjusting the 4 MHz Reference > does nothing for normal operation. > > 73, > Don W3FPR > > > On 9/30/2017 9:35 AM, Mike Maiorana wrote: > >> Hello all. I have a K2, 6000+ serial number, that I'm trying to get >> working >> correctly. Unknown history. A quick test showed the filters were not >> properly adjusted (could hear both sidebands of carrier on some bands). I >> thought it would be best to do a top-down alignment. >> >> I adjusted the 4 MHz oscillator, verified the PLL reference oscillator >> range (12.43 kHz), VCO test and VCO alignment. No problems up to that >> point. >> >> I'm having an issue at the BFO test. The BFO high frequency is 4916.04 kHz >> and the low frequency is 4913.82 kHz. That's a difference of 2.19 kHz, >> well >> below the 3.6 kHz stated minimum. >> >> __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] K2 BFO test failed
Hello all. I have a K2, 6000+ serial number, that I'm trying to get working correctly. Unknown history. A quick test showed the filters were not properly adjusted (could hear both sidebands of carrier on some bands). I thought it would be best to do a top-down alignment. I adjusted the 4 MHz oscillator, verified the PLL reference oscillator range (12.43 kHz), VCO test and VCO alignment. No problems up to that point. I'm having an issue at the BFO test. The BFO high frequency is 4916.04 kHz and the low frequency is 4913.82 kHz. That's a difference of 2.19 kHz, well below the 3.6 kHz stated minimum. I verified the crystals at X3 and X4 were the correct type, along with the values of D37, D38, C173 and C174. I didn't see any PCB trace damage in the area. I reflowed the solder on those pins but didn't see a significant change in the BFO frequency range. I checked the VBFO control voltage and had 7.81 V at the high BFO frequency down to 0.00 V at the low BFO frequency. Any advice on how to move forward? Thanks and 73, Mike M. KU4QO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] options and firmware level
Hello everyone. I have an older K2, SN 336, and am considering purchasing a KAF2. My K2 has firmware 1.04C and I/O 1.02. The manual for the KAF2 says that it requires firmware version 2.01 or later, and that "if you have an earlier version 1.xx you should have received an upgrade". Does that mean that I should have received an update from Elecraft automatically, or does it mean that I should have purchased a firmware upgrade before buying the KAF2, or? I started looking at what it would take to update my K2 to the latest revision... Wow, lots of work and a bunch of money. But it is nice that I CAN upgrade it ;-) Thanks for the help! 72 Mike M. KU4QO ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net http://mailman.qth.net/mailman/listinfo/elecraft You must subscribe to post. Subscriber Info (Addr. Change, Unsub etc): http://mailman.qth.net/subscribers.htm Elecraft page: http://www.elecraft.com
