Re: [Elecraft] K2 U10C Oscillating
Don, Thanks. The feedback capacitor solved the LMC660's instability problem. 73, David, NM5U - Original Message - From: Don Wilhelmmailto:w3...@embarqmail.com To: DAVID POWELLmailto:dwpowel...@msn.com Cc: elecraft@mailman.qth.netmailto:elecraft@mailman.qth.net Sent: Thursday, April 09, 2009 5:17 AM Subject: Re: [Elecraft] K2 U10C Oscillating David, The LMC660 op amp can have a tendency to oscillate when driving a capacitive load (see the LMC660 datasheet) although it is normally stable in the K2. Before replacing it, try the following steps - check after each one and stop if no oscillation. 1) Flush trim the leads of U10 and the nearby R-Paks. 2) Use a cotton swab and alcohol to clean any flux residue from the area of U10, RP2 and RP3. 3) Try adding a 10 pF capacitor between U10 pins 8 and 9 If the oscillation persists, replace U10. 73, Don W3FPR DAVID POWELL wrote: On my K2 (#3014) I hear signals and noises while tuning across 160m with the antenna disconnected. The worst is a strong but unstable signal that moves from about 1850 kHz to about 1910 kHz during about 15 minutes after I switch on the radio. I accidentally traced the signal to U10C on the control board: the signal jumped when my finger got near the left end of resistor pack RP2. (U10C appears to be a buffer for the V BIAS-XFIL line.) The signal is several kHz wide and resembles hash from a dimmer or switching power supply. I have verified the U10 circuit resistors and voltages as nominally correct. U10D, an identical circuit for the V BFO line has pretty clean dc at its output. Has anyone else seen this? Am I correct in concluding that I should replace U10? 73, David, NM5U __ 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
[Elecraft] K2 U10C Oscillating
On my K2 (#3014) I hear signals and noises while tuning across 160m with the antenna disconnected. The worst is a strong but unstable signal that moves from about 1850 kHz to about 1910 kHz during about 15 minutes after I switch on the radio. I accidentally traced the signal to U10C on the control board: the signal jumped when my finger got near the left end of resistor pack RP2. (U10C appears to be a buffer for the V BIAS-XFIL line.) The signal is several kHz wide and resembles hash from a dimmer or switching power supply. I have verified the U10 circuit resistors and voltages as nominally correct. U10D, an identical circuit for the V BFO line has pretty clean dc at its output. Has anyone else seen this? Am I correct in concluding that I should replace U10? 73, David, NM5U __ 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
Re: [Elecraft] Balance control
Ron Spencer wrote: Guys great addition, thank you. Anyone else notice a large increase in audio output with this latest version of firmware? I find it to be the case and welcome it. The heil headset I use takes more drive then the other headphones. Yes, I have noticed this too - but although my Heil headset is now usable on receive, it's still no use on 'monitor' where the audio is at a low level and is distorted - which was previously the case on 'receive' as well. 'Monitor' is fine on all other headsets I have tried with the K3, though. David G3XLW ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] [K2] Remote control programs
Julian G4ILO [EMAIL PROTECTED] wrote : I don't have any axe to grind for any of the programs mentioned, and in fact use none of them, but I have to take issue with the notion that HRD is great just because it's free. HRD is not great _because_ it's free, it's great _and_ it's free - although users that want to make a donation towards Simon's costs can do so (see his website). David G3XLW I love deadlines. I like the whooshing sound they make as they fly by. - Douglas Adams ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] K2/100 and ACOM-1000
Stefan I too have a K2 and Acom 1000 and have experienced the same problem. As I usually use the K2 for CW at just 100W I have done nothing to tackle the problem - I just use the Acom with my TS2000 on those rare occasions I want to run SSB. This is a known problem - take a look at this (and the subsequent messages in the thread): http://marc.info/?l=elecraftm=113376989224579 Hope that helps 73 David G3XLW ON4FG [EMAIL PROTECTED] wrote : Hi, I just got an ACOM-1000 that i am using with my K2. When I am drivng it with 13...14W for approximately 300W output, I noticed that I got a power output reading in excess of 1kW during the start of my SSB transmission, just for a second or less. CW seems to be ok. Does anyone else noticed this? What can be done about it? I heard that some FT1000 had a transient, putting 200W into the amplifier at the start of the transmission, and the PA did not survive this. I do not want this to happen with my PA. 73 Stefaan ON4FG / OP4T / TZ4T ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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: Elecraft@mailman.qth.net 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
Re: [Elecraft] 3B7 with K2/qrp
Okay...had to give it a try. Just worked him on 40m after about 3 minutes of calling. 2.5 minutes spent calling blind. Then I heard him call a G3, found the G3 on VFO B (no dual rx) and I was the next call. Doug has confirmed that his QSO followed mine. I was using my K2/100 at 100W. An Elecraft double! David G3XLW ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] STOP with the K3 posts already!!
Keith There's only one cure for these disturbing feelings. I think you know what it is. Just quietly submit your order, and you'll feel fine again. 73 David G3XLW Darwin, Keith [EMAIL PROTECTED] wrote : I don't need a K3 I don't need a K3 I don't need a K3 At first, resistance was easy. But then I'm seeing all the benefits and how cost-effective it is. And how it is so wonderfully designed And how flexible and robust the filtering scheme is And the sidetone is going to be pure (pure heaven) And support / repairs will be a breeze. And ... I'm getting weak and you guys are NOT helping! I need a K3 I need a K3 I need a K3 Someone please take my Visa card away before it's too late! LOL! - Keith N1AS - - K2 5411.ssb.100 - ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] Saving Energy and staying dry (WAS: FCC rules part 18[CF bulbs vs. LED])
Craig Rairdin wrote: I don't know. What has the planet done for me lately? Kept you alive? David - G3XLW ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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] KPA100 Completed
I ordered the KPA100 kit on Thursday March 8 and it arrived 2 days later on Saturday. I worked on it a couple of hours each night during last week, and put it in an EC2 enclosure this Sunday afternoon. The parts were all there (thanks Marina!), the assembly went very smoothly, and all tests were successful. I remain a most satisfied Elecraft customer! 73, David, NM5U (K2 SN 3014 with KAT2, KNB2, KBT2, KSB2, KDSP2, KIO2, K160RX, plus the K6XX CW tuning indicator and the EA3BLQ internal digital interface.) ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] Stripping enamel from toroid wires
Ron D'Eau Claire wrote: For example, in the KXB3080 installation, there's a small daughter board with two toroids on it and the solder pads are very close together. One wire runs very, very close to another wire's solder pad as it loops around the edge of the daughter board to its own solder pad behind it. We tell the builder to leave 1/8 of enamel on that wire just to avoid the possibility of a short circuit in case it gets pushed against the solder pad. There are been a number of builders who didn't read the procedure and tinned the wire all the way to the core. Then they had to troubleshoot the KXB3080 assembly to locate the short. It's an easy fix: just pull the wire away from the pad, but it underscores the importance of reading the procedures. Even highly-experienced builders need to read each step and note the critical information even if their method of doing the job is a little different from what is described. Thanks for a well timed comment, Ron. I was just putting my KXB3080 together - and things weren't working - when I read it. Over enthusiastic enamel stripping turned out to be the problem here; in my case I've solved it in a rather inelegant fashion by putting two (very) short lengths of insulation from some hook up wire onto the end of L2-1 and L1-1. It would have been much better to get it right first time, of course, but it all works now - I've just had my first 80m QSO on the KX1. So - thanks again. David - G3XLW ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
