+++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sun, 15 Apr 2001 18:13:01 -0500 From: "Dave & Judi Jaksa" Subject: RE: [Elecraft] K2 and KAT2 problem Bob, Here are a couple of ways to isolate the problem to either the K2 or KAT2. You can simply use the Menu to set CALP or CALS, both of which set L and C to 0 in the KAT2. This in effect bypasses the KAT2. You can also unplug both J7 and J8 and the K2 will revert to operation without the KAT2. Note that you must now use the K2 BNC jack, J4, for the antenna connection. There is no internal rewiring involved. I originally had a HI CUR problem on 80 and 160 with my K2. Traced it to a bad solder joint on C133, the bypass cap on the PA stage. Are you really drawing high current or is the K2 just telling you that you are? Check your current draw from your power supply with a VOM that will read at least 5 amps. Do you have the HI CUR problem into a dummy load too? If it works OK into a dummy load, you could be getting RF into the K2. Check your ground connections. If you still get HI CUR into a dummy load, look for RF on the 12 VDC bus. Hope this helps. 73, Dave, W0VX - -----Original Message----- From: owner-elecraft@qth.net [mailto:owner-elecraft@qth.net]On Behalf Of Bob Myers Sent: Sunday, April 15, 2001 4:18 PM To: elecraft@qth.net Subject: [Elecraft] K2 and KAT2 problem Folks, I have a problem with my K2 and/or KAT2. Up until now, for the past 8 months the K2 and KAT2 have worked perfectly. My symptoms are the inability to run more than about 1.6 watts without high current warnings (and very little output indicated on the output display on the K2 -- 2 LEDs) and then "Lo P" when activating the KAT2 tune function. I'm now testing with a dummy load. Otherwise the K2 seems to work okay. I'd like the best guesses please: K2 or KAT2 problem? If the problem is with the KAT2, is there any simple way to "uninstall" the KAT2 for testing only the K2 for power out? Or do I really need to remove the KAT2 and rewire the output as it originally was before the KAT2 was installed? Has anyone had this problem? Thanks Bob, W1XT Phoenix, AZ bmyers@superphoenix.com K2 s/n 1434 ++++++++++++++++++++++++++++++++++++ Date: Tue, 24 Jul 2001 17:28:06 -0700 From: Eric Swartz WA6HHQ - Elecraft Subject: Re: [Elecraft] K2 slightly high current on TX problem Hi Dave, What voltage is your power supply running (as read on the K2's display)? Voltages lower than 13.8v will cause more current draw for a specific power, which it normal. 73, Eric WA6HHQ Dave Kirkman wrote: > Just finishing up K2 #2060. Receiver works great > and transmitter is working but the current on all bands is > somewhat higher than specs call for. > Thanks in advance for any help. > > Dave Kirkman N8ATE in ++++++++++++++++++++++++++++ Date: Sat, 17 Nov 2001 09:32:16 -0500 From: "Tom" Subject: [Elecraft] Power measurements seem low Hi all, I checked my power outputs on the K2 at 10 watts and at maximum setting and came up with the following readings: 80 mtrs 9.9 at 10 watts and 11.2 max 40 mtrs 10.6 at 10 watts and 11.7 max 30 mtrs 10.6 at 10 watts and 11.5 max 20 mtrs 9.8 at 10 watts and 13.2 max 17 mtrs 10.2 at 10 watts and 10.4 max 15 mtrs 8.4 at 10 watts and 8.6 max 12 mtrs 7.9 at 10 watts and 7.7 max 10 mtrs 6.2 at 10 watts and 6.2 max I've been told I should be expecting close to 15 watts on the lower bands and I'm really not pleased with 15, 12 and 10 mtrs. Any ideas would be appreciated. Tom McCulloch, WB2QDG K2 s/n 1103 "Start by admitting from cradle to tomb isn't that long a stay" --- Fraulien Sally Bol - --- To subscribe or unsubscribe: http://www.elecraft.com/elist.html Post messages to: elecraft@qth.net (You must be subscribed.) Postings must be sent from the same addr. as subcribed. The qth.net list server rejects HTML encoded emails. Elecraft Web Page: http://www.elecraft.com ------------------------------ Date: Sat, 17 Nov 2001 19:27:44 -0700 From: "Len Koppl" Subject: Re: [Elecraft] Power Measurements Seem Low I had close to 15 W showing on 80 - 17, 14 W on 15, 13 W on 12, and less than 9 W on 10. I read the article by Gary Surrency on distributing the windings on T2, so I spread them out very evenly. No matter what I did, I could not get the power out that I had. For some unknown reason, I decided to check the calibration of the ATU (R1 and R2) and found it to be way off. Now I can get a full 15 W out on 80 - 30, 14.8 W on 20, 13.5 W on 17, 14.5 W on 15, 12.6 W on 12, and 12.5 W on 10. So the three things to probably do are to 1) read Gary's article (I think it is titled 'Low Output on 10 Meters' or something close...), 2) get T2 to look like the picture in the article, and 3) run through the power calibration routine. My friend Dave, KGØEW just built an accurate QRP wattmeter, so I will re-do the procedure when I can get access to his new toy. 73, Len Koppl, KDØRC K2 #2239 ++++++++++++++++++++++ To: w0ifl@hotmail.com, elecraft@mailman.qth.net Date: Thu, 30 May 2002 13:37:44 -0700 Subject: Re: [Elecraft] Cal Cur From: k6se@juno.com Ron, W0IFL wrote: "On 80M, my current jumps up and down quite a bit" ========== This is a known issue, according to Gary Surrency in support. He says that some RF on 80m (and on 160m) is getting into the Current (& Voltage) Sensing circuit(s) on the K2 Control board. He suggests adding to the value of C42 on the Control board to increase it to at least 0.1 mFd. This will alleviate the problem. The best place for the new (or additional) bypass cap is directly between pins 4 & 8 of U3. Because these false current (and voltage) fluctuations occur, they they might exceed your CAL CUR setting on 80m and cause a HI CUR indication. 73, de Earl, K6SE +++++++++++++++++++++++ Reply-To: "Don Wilhelm" From: "Don Wilhelm" To: "=?Windows-1252?B?V9hJRkw=?=" , Subject: Re: [Elecraft] Cal Cur Date: Thu, 30 May 2002 17:59:13 -0400 Ron and all, The normal current for 10 watts is about 2.5 Amps -- BUT this is only for the base (bare-bones) K2. Each option adds a bit of current draw. My K2 with the 160 meter, SSB, NB and ATU options would draw about 2.8 Amps. The other thing that will cause higher current is to try to get as much power out as possible - the PA just tries to draw more current to satisfy the POWER requested setting. And be aware that the 'normal' current draw for the K2 is with a power supply delivering 13.8 volts (K2 will display about 13.2 volts due to the protective diode). If the power supply voltage drops, the K2 will draw more current - again to satisfy the power requested setting - the ALC circuit just works that way. Setting CAL CUR higher does no harm, you can set it to match your power supply rating if that is appropriate and you will get the warning message if it is exceeded. I have mine set to 3.5 AMPS - and I have determined that is a 'sensible' value for my situation. 73, Don Wilhelm - Wake Forest, NC W3FPR home page: http://www.qsl.net/w3fpr/ QRP-L # 485 K2 SN 0020 mailto: w3fpr@arrl.net *** Life is what happens when you're making other plans -- Mike Cross *** ++++++++++++++++++++ From: "Don Brown" To: "Gil Stacy" , Subject: Re: [Elecraft] 40M Tx Alignment Hi Current Concerns Date: Sun, 12 Jan 2003 14:23:48 -0600 Hi Sounds like your power supply is dropping out. With the supply voltage down to 10.8 volts the current will be high. The power supply should be steady at 13.8 to 14 volts. Some of the basic power supplies do not regulate very well. Another problem could be voltage drop in the power cable. Check the power supply with a voltmeter at the supply terminals and hit tune. The supply voltage should not change. The supply cable needs to be 18 or 20 gage wire to keep the drop down. Don Brown KD5NDB ----- Original Message ----- From: "Gil Stacy" To: Sent: Sunday, January 12, 2003 1:40 PM Subject: [Elecraft] 40M Tx Alignment Hi Current Concerns > > > > I am attempting the 40M Transmitter alignment in K2 #3104 and have high current concerns. With the power dial set at 2.0 watts, in TUNE mode, I peaked L1 and L2 to 3.6 a max of 3.6 watts. > I set the power dial to 5 watts, entered TUNE mode, and had a voltage drop from 11.7 V to 10.8 with a current drain increase from .22 to 2.14 amps. Recommended amps in TUNE mode are 1.3-1.6 amps. > At 10 watts in TUNE mode, the voltage drop is 1 volt with a current drain from .22 to 2.5 amps. Reommended amps in TUNE mode are 1.8-2.0 amps. > Voltage checks, recommended value in parenthesis where differs from actual reading. > Q6 B ok, C 10.8 (13.3), E .27 (.4) > Q7 B ok, C 11.16 (13.4), E ok > Q10 S 1.5 (1.6), G ok, D 1.5 (1.6) > Q11 all ok > > Q13 E ok, B ok, C 6.1 (7.5) > Q20 S ok, G ok, D 31mv (0.0) > Q24 G ok, S .81 (1.2), D .87 (1.3) > U9 1 ok, 2 4.8 (6.9), 3 5.02 (6.9), 4 31mv (0.0), 5 35mv (0.0) , 6 5.3 (6.9), 7 10.5 (13.8) > U10 ok > Q5 is untested as I have not pulled off the heat sink.Comments and suggestions would be appreciated. Thanks. > Gil KG4VCG +++++++++++++++++