Don, OK, I got the KXAT1 working! Turns out the documentation was right -- the wires *are* numbered correctly. My bad. (Shame on me -- no more late night soldering for Scott...) I got a rock solid 0.000V calibration null and the power readings are within 0.1 watt of what I'm getting from the DL1. Now it looks like all I need to do is build an antenna and wire the stereo plug to my J-38 key. Then it's play time!
So, thanx again, Don! Scott AC0FQ Scott Wright wrote: > Don, > > Thanx for your reply! > > "When viewed as in the diagram, the leads coming off the core closest to > you are numbered 2 and 4..." > > That's gotta' be the problem then. In my documentation, those two wires > are labeled as 1&3. Had they been labeled as 2&4, I would have had the > "clean, drop-in install" I referred to in my original e-mail. Couple > that with the informational statement, "...the wires labeled (1) and (3) > should originate from below the core...", it was easy to convince myself > that such a bizarre lead routing alignment was necessary. > > Oof dah... > > OK, I'm off to unsolder T1 and try to get it installed correctly. I'll > let you know what results. > > Again, thanx for the pointers! > > Scott > AC0FQ > > > Don Wilhelm wrote: > >> Scott, >> >> The problem lies with #4 and #7 below. >> Look carefully at the diagram of T1 on page 5 of the KXAT1 >> instructions. If yours looks 'backwards', then it may be wound in the >> wrong sense. When viewed as in the diagram, the leads coming off the >> core closest to you are numbered 2 and 4, and the turns from that end >> progress clockwise around the core. >> If you have the sense 'backwards', the leads will cross over under the >> core when it is mounted - that is not what should happen. If you have >> it right, the leads will drop straight down from the core onto the >> board when it is mounted. >> >> Yes, all the T1 leads will appear to be shorted together after T1 is >> installed - that is not a valid check. >> >> If everything is correct, you will find a deep null when adjusting the >> capacitor. The voltage at the null point should be in the tens of >> millivolt range. If you do not find the null, then look for something >> wrong with T1, C9, C10, R4 or R5. Also check the orientation of D1 >> and D2. >> >> Do not attempt power or SWR calibration until after you can achieve a >> good null - all attempts to do so will lead to frustration and >> incorrect results. >> >> 73, >> Don W3FPR >> >> >> Scott Wright wrote: >> >>> I'm having trouble with my KXAT1. More specifically, (1) I can't get >>> the power reading to adjust up to anywhere near the actual TX power and >>> (2) the SWR reading with the DL1 dummy load attached is 9.9, which I >>> assume is not a good thing. >>> >>> Here are the data bits: >>> >>> 1) There's no 30/80m module. >>> >>> 2) I ohm'ed out the DL1 and it reads 50.1 ohms. Close enough. >>> >>> 3) With the R1 pot set at ~50%, the KX1's power display is 0.7 watts in >>> 'tun' mode. The power reading at the DL1 is 3.6 watts, which is pretty >>> much the same reading I got after I finished the KX1's transmit section >>> (before adding the AT). Cranked fully CW (?), the maximum displayed >>> power reading is 2.1 watts on the KX1. >>> >>> 4) During calibration, nulling the voltage on the REFL test point >>> results in a voltage of approx 1.75 volts. I've seen posts on the >>> reflector where folks are getting nulls well below 1V. I suppose this >>> isn't a good thing, either... >>> >>> 5) I ohm'ed inductors L1, L2, and L3 after installation and all three >>> read <0.3 ohms. I'll assume that means good >>> stripping/tinning/soldering. >>> >>> 6) I tried ohm'ing transformer T1 after it was installed to see if I >>> had any shorts but I'm reading <0.3 ohms across any combination of >>> leads. This (sorta') makes sense -- given how it's gonna' react to DC >>> -- but doesn't tell me anything. >>> >>> 7) I quadruple checked my installation of T1. The picture and notes in >>> the assembly manual are a bit confusing and unlike all other Ls and Ts >>> I've installed so far, the footprint/silkscreen for T1 doesn't line up >>> with how the winding is described. What looks like a clean, drop-in >>> install results in -- as I read it -- incorrect phasing. Matching T1's >>> wiring diagram / picture to its silkscreen forces the leads to run under >>> the toroid in a "contorted" fashion. As ugly as it was going in, that's >>> how I have it soldered in place. >>> >>> 8) When instructed to tune, the resultant SWR is always displayed as >>> 9.9. (I can hear the relays clicking on-and-off in rapid succession >>> during the tune...) I tried the inductor/capacitor test outlined in the >>> KXAT1's troubleshooting guide, but regardless of the L0/1/2/3 or >>> C0/1/2/3 setting, the SWR always displays as 9.9 >>> >>> So, I'm at an impasse. I don't wanna' start randomly removing >>> components -- I haven't yet had to remove a single component from the >>> KX1 or the AT -- but I'm at a loss as to what to do next. >>> >>> Are there any other troubleshooting steps?? I'll never claim to be a >>> guru on this stuff -- in fact, I'm not 100% certain how an AT even works >>> -- so any additional guidance would be greatly appreciated. >>> >>> Thanx!! >>> >>> Scott >>> AC0FQ >>> KX1 s/n 2177 >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[email protected] >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> ------------------------------------------------------------------------ >>> >>> >>> No virus found in this incoming message. >>> Checked by AVG - www.avg.com Version: 8.0.237 / Virus Database: >>> 270.11.13/2001 - Release Date: 03/14/09 06:54:00 >>> >>> >>> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
