Re: [Elecraft] Component ID
Scott, On the control board, U9 is the LM380 which you should have, and U7 is the 25LC320 serial EEPROM which you ALSO should have. So it sounds like you might be missing the LM380, eh? Well, based on my experience, you should go through everything again with a stronger source of illumination before calling Elecraft to ask to have a missing part replaced. :) Good luck! [EMAIL PROTECTED] wrote: HI I am inventorying my k2 kit and have a question. On the control board I should have a LM380N-8 audio amp. I don't have that, but do have a 25LC320/1fv0526. They are probably the same, but would rather be sure than sorry! Thanks Scott N5SM -- Marshall Jose, WA3VPZ ___ 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] Cutting component leads
The NASA wonks are correct in their citation of construction practices. However, as hams we like to know why as well as thou shalt not: In this case the bad thing being avoided is called cold-working. The solder used to solder parts is an alloy of two of more metals, which arrange themselves in a lattice of greatest strength immediately before solidification of the joint. Any deformation of that joint after solidification (including that caused by thermal expansion and contraction) is called cold-working, and embrittles the joint to some degree, setting it up for future failure in a way which is nearly undetectable by our feeble eyes. This is why you shouldn't use toenail clippers, etc. to get at the last nub of an exposed lead -- by doing so you are cold-working the joint. Clip it instead at the top of the meniscus formed by the solder on the lead. FWIW, SMD parts are designed to thermally expand at roughly the same rate as PCB material in order to minimize this phenomenon, or else they are constructed so as to relieve thermal stress. Darwin, Keith wrote: Above the board or above the top of the solder joint? Why leave wire protruding? - Keith KD1E - -- Marshall Jose, WA3VPZ ___ 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] New KPA100 Rev.
I'll come out of the closet and admit that I, too, used the expensive non-corrosive RTV to hold down the cores in my new K2. I did it because - I'm willing to accept the (warranty-breaking) consequences of doing so, - It's standard practice with spacecraft assemblies, which are held to a higher standard than ham radio kits, and - I had access to some :) PLEASE note that I have no intention of starting a religious war about construction practices. Elecraft's warranty policy is concrete and perfectly understandable, and I have no quarrel with it. My comment here is made only to reassure the nonconformists among us. :) Marshall, WA3VPZ Ron Willcocks wrote: Hi I have just finished making a K2/100 for a friend here I was a bit alarmed at having a choke this size dangling upside down on flimsy wires ( when in the K2) that I have broken the Elecraft Golden Rule and used a small amount of non-acidic RTV under each choke to hold it in place. ( I guess the Warranty just expired after admitting that!) I wonder if any other recent constructors have had the same concern for the mechanical stability of these components? Cheers.Ron ZL1TW ___ 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] BFO test failure (K2), Part 2 of RF board test
Chuck, - Perhaps the BFO is working but the signal isn't getting past the buffer Q24. When the K2 is in CAL FCTR mode, there should be something close to 8V at V ALC. If it's low or 0V, you won't see any frequency reading. - If D36 is backwards, that'll shut down Q24. Check D37 D38 too. - I like the K2 a lot, but I like L33 the least. Get out the magnifying glass and the strong lamp and scrutinize L33 for scuffs, dings, etc., i.e., anything which might cause a short or an open. Do you get a FCTR reading if the bottom cover is off? That's all I can think of off the top. Marshall Chuck wrote: My BFO does is not working. The freq. counter reads .0. I have tried following other posts on the subject and checked the voltages on U11 and verified that R98 and R99 are present, L33 is installed correctly. Are their any voltage checks I can run on Q24, or L33. Is there something else I can check? The troubleshooting guiding in the manual is based on info messages, which I am not getting any. I just completed the VCO voltage checks and that ran good. Everything was within range spec'd by the manual. Thanks, Chuck - K3TNT 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] No SSB Output
Treat, I assume your scope was AC-coupled when you measured U3-4; some scopes misbehave when DC-coupled. I looked at the PC layout and wondered if a solder bridge to a nearby pad might cause the symptoms, but it doesn't look like it. The trace running from U3-4 goes around a bit, but it doesn't pass by any node whose impedance drops when the circuit is energized. You would do well to verify the DC voltages on U3 given in the DC voltage chart. Perhaps that will help you determine if U3 is defective. That's all I can think of. Marshall Jose, WA3VPZ Treat Hull wrote: First, I used my scope and verified that I had a good BFO signal to U5 pin 6. Then I set up my audio signal generator for about 50 mV peak-to-peak at about 1,000 Hz and fed it into the mike connector pins 1 and 7 (which I had wired for a Radio Shack mike with AF to Pin 1, PTT to Pin 2, and 7 and 8 to ground). When I used my scope to trace the AF signal, I started with the K2 powered down. I found that I had a strong AF signal all the way to Pin 4 of U3. However, when I powered up the K2, I lost all AF at Pin 4 of U3. Working backwards, I found that I had AF as far as the junction of C32 and C33, but no further. It's as though Pin 4 of U3 is going to ground when the unit powers up. It behaves the same way with PTT open or closed. ___ 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] WA3WSJ: Bead-Wire Antenna
Since the wire is quite thin, the resonant element which results will have a rather high-Q and therefore best used for a narrow range (such as the CW sub-band). My wife does beading and uses the stuff; it looks to me like stranded stainless wire with a nylon jacket. My guess is that the high Q will win out over the skin effect of the SS. Furthermore, although nylon is lossy at RF, that usually applies where the tangential electric field is relatively intense, such as when the nylon serves as an insulator or a capacitor dielectric, rather than merely as a jacket. I also think Ed will have loads of fun in spite of the losses. :) Stay dry, man! Marshall, WA3VPZ Steve wrote: Ed, Some of this stuff is plastic coated steel or stainless steel, similar to a fishing leader. This could explain the difficulty in soldering to it. If it's truly not copper based, I would be concerned about potential resistive losses for long antenna runs. Is there a way to determine what material this wire is made from? Steve aa8af -Original Message- I received lots of emails concerning my Bead-Wire Antenna. I've decided to post on the reflectors rather than send out to each Individual op. Here's what I did to make my antenna. I went out to my local craft store called The Rag Shop and bought a 40' spool of flexible bead wire. ___ 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 U10a on control board oscillates on receive
Followup: After receiving a wonderful and long list of suggestions from Gary, I understood that the U10a oscillation on receive is not a pathological matter and that I shouldn't worry about it. And, embarrassingly, in pursuit of the low-TX-power problem I discovered an unsoldered joint on a relay coil pin, which made contact long enough for the initial alignment to fool me well, but then opened up later and caused detuning of the preselector/driver filters. Mea culpa. K2 #5715 now lives, and in perfect operating condition. Cheers! Marshall, WA3VPZ Marshall Jose wrote: My K2's ALC circuit on the control board oscillates at around 50 Hz during receive. During receive, the V PWR voltage is set to zero, so maybe there's some instability associated with driving U10a into its non-linear region. At any rate, it has no effect on receive operation since the BFO buffer the V ALC signal controls is effectively blocked further down the xmit signal path. But I've noticed that it can cause trouble because when it's in that state it won't re-enter a linear mode until the power control is increased during xmit above a certain level. And I've noticed some rather severe limitations on the power I can transmit in the higher bands, and have wondered about the words in the troubleshooting section: If you have seen a slow (10-20Hz) oscillation superimposed on the transmitter's output signal, it could be due to ALC modulation. Increase the value of R98 (RF board) to the largest size that permits full output on 10 m. http://www.elecraft.com -- Marshall Jose, WA3VPZ ___ 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] K2 U10a on control board oscillates on receive
My K2's ALC circuit on the control board oscillates at around 50 Hz during receive. During receive, the V PWR voltage is set to zero, so maybe there's some instability associated with driving U10a into its non-linear region. At any rate, it has no effect on receive operation since the BFO buffer the V ALC signal controls is effectively blocked further down the xmit signal path. But I've noticed that it can cause trouble because when it's in that state it won't re-enter a linear mode until the power control is increased during xmit above a certain level. And I've noticed some rather severe limitations on the power I can transmit in the higher bands, and have wondered about the words in the troubleshooting section: If you have seen a slow (10-20Hz) oscillation superimposed on the transmitter's output signal, it could be due to ALC modulation. Increase the value of R98 (RF board) to the largest size that permits full output on 10 m. Has anyone seen this behavior? Can anyone suggest a course of action? I have a full suite of RF test equipment, so I can chase a signal through the whole unit if necessary. Thanks, -- Marshall Jose, WA3VPZ ___ 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
