Author Archive
K3 Weirdness in AFSK-A Mode (SOLVED!)
January 24th, 2010 | 
Author: During the BARTG test I had some weird moments after I QSY’d from 20m to 40m — DM780 would key the K3’s PTT (via HRD IP Server) but there would be no audio into the Line In port, and thus no RF output. Sometimes rebooting the K3 would work, other times quitting and re-launching DM780 did the trick. I’m not 100% certain of the cause but I’m leaning towards software rather than hardware.
Then I noticed low RF output at certain audio frequencies, and this only in AFSK-A reverse (USB) mode; no trouble in normal (LSB) AFSK-A mode, nor in DATA-A normal and reverse. The output power would be OK when the center frequency was set low on the waterfall (+/- 400 Hz, for example) but would drop off at higher Fc setings. And the cutoff point seemed to vary — sometimes I could get full 100W RF out at around 1500 Hz Fc (I typically use 1530 Hz as Fc for RTTY), other times the output would drop above 900 Hz and be effectively zero at 1300 Hz and above. After some messing around with soundcard and line input levels I seemed to have gotten it somewhat sorted out, but as I did all that in the middle of a contest while in semi-panic mode I didn’t take too many notes.
I did some basic tests today by transmitting RTTY diddles at 100W into the MFJ-267 dummy load/wattmeter while in AFSK-A REV mode; mic gain is adjusted for 3 flickering bars of ALC as per the advice of Elecraft. I got full 100W reading on the meter at 2200 Hz Fc, but it steadily decreased as I inched upwards — at 2300 Hz Fc the output was down around 60W, and by 2400 Hz the wattmeter needle barely moved. But when I switched from REV (USB) to NOR (LSB) I get full output right up to the top edge of the waterfall (2900 Hz Fc) — pretty much what I experienced yesterday during the RTTY test.
I then shut the whole system off for a while and repeated these tests an hour or so later to see if things changed from a “cold” state: starting out my output at 2200 Hz was down around 10 to 15W. The output then slowly rises as PA temperature (as measured by the K3’s built-in PA TEMP meter) reaching full 100W at 43 deg C. But after cooling off (PA: 35 deg C, front panel: 32 deg C) power output remains at full 100W! This is driving me absolutely bat-shit crazy.
I’m not really concerned that I won’t be able to transmit RTTY at high center frequencies as my operating style is to find and click on a signal in the waterfall, center it at 1530 Hz, then switch to a narrow filter setting; I’m more troubled by how the cutoff frequency changes, sometimes below 1530 Hz, and apparently is a function of temperature. It doesn’t appear to be a PA problem — the same power drops occur when bypassing the PA unit and running at 10W, and I’m getting full power in all other modes — so I’m going to guess it’s an issue with the DSP board and its handling of audio at the Line In port. More tests to follow, and when I have a better set of test results I’ll contact the boys in Aptos.
Update 26-Jan-2010: I believe it has been solved — the only things I didn’t check until today were the filter parameters in the CONFIG menu. Sure enough, I had FL3 set to 2.4 kHz even though the filter is actually a 2.1 kHz filter. Unsure how or why this caused the problem, but since setting it to the correct setting I am now able to get full output power at the mark frequencies indicated by the K3’s MARK-SH setting (2125, 1445, 1275 or 915 Hz). Not sure how the FL3 parameter got changed; perhaps inadvertently while running K3-EZ, or perhaps it was set improperly during my assembly and setup back in January ’08. In any case, all’s well that ends well. My apologies to Wayne, Eric, Lyle, Don, Greg, etc. for bothering them with what turned out to be user error. I will now sit in the corner wearing my “Dumb Ass” hat as penance.
BARTG Sprint 2010
Spent a few hours Saturday handing out QSO points on 20 and 40. No new ones for me, and I had a hard time working DX. Some weirdness with the K3 (see next post) has me scratching my increasingly balding head…
Summary:
- QSOs: 65
- US States: 35
- VE Provinces: 3
- Total Mults: 23
- Total Continents: 3
- Score: 4,485 pts.
Band-by Band Breakdown:
- 20m: 40 QSOs, 18 states, 4 provinces, 5 DX
- 40m: 25 QSOs, 15 states, 5 DX
HAM Radio?
A perennial annoyance of mine is the use of the phrase “HAM radio.” Not “ham radio,” mind you, but “HAM radio” with the word “ham” capitalized as though it’s an acronym like NOAA, IRS, MVP, UCLA or STFU. It usually occurs in news articles like this one which are obviously written by non-hams, but I also see it used in places like eHam product reviews by people who should know better. While no one can say with certainty how, when or where the term “ham” originated, it is beyond argument that it doesn’t stand for anything. It really isn’t a life-or-death problem, but every time I see “HAM radio” I have an overwhelming urge to slap someone. Is it just me?
Ooops… gotta run. My CELL phone is ringing.
NAQP SSB – Jan 2010
QRV 9.5 hours out of the 10 hours permitted for single-op class, all search & pounce. Started about 45 minutes late and took 3 breaks. By contest’s end at midnight I was pretty exhausted, not sure how people do single-op in the 48-hour tests.
Worked 20m for about 40 min, then switched to 15m for about 30 min to see if the band was open (not so much, only 4 Qs). Spent the next 3h 45m bouncing between 20m and 40m, then took a 30 min break. Came back on 40 for an hour, took another 45 min break, worked 40m for another 15 min. Took a final 30 min break to run to the QuikiMart for contest supplies (cigarettes, donuts, bottled water for coffee, important stuff like that…), then spent the remaining 3h 15m of the test on 80m.
That last stint on 80 was the most enjoyable contest experience I’ve had since… well, since the last time I worked 80m with a sense of purpose. That would have been back in New Jersey in the late 90’s when I had a dipole and 600 watts; now I run 100 watts to an 12′ mobile screwdriver antenna that doesn’t tune better than 3.0:1. Little pistol station? Hell, it isn’t even a .22 target gun! Yet I had a blast. The guys I worked were great and very patient as I repeated my call and exchange countless times. And some QSOs were so easy I almost forgot I was on 80m.
I hit the triple crown five times, working K7RL (WA), N6ML (CA), NC4KW (NC) and NK7U (OR) on 20/40/80, and K4SSU (GA) on 15/20/40.
I’m still not ready to make the big leap to flat-out contesting (trying to work every station I can hear, rack up as many points as I can, sit at the mic/key/computer for the duration, etc.). I’m still in it mostly for the QSLs and ulterior award-chasing motives so I still skip a lot of possible QSOs if the station is in a state already confirmed. But I gotta tell you, each time I play in one of these tests I get sucked in a little… bit…. more…
The numbers in the “worked” column for WAS-Phone went from 19 to 43 in a hurry, and just 12 hours after the contest LOTW has more than doubled the Phone confirmed column (currently at 34 and counting). Doing the search/pounce thing limited me to working only those stations who were running so I missed many needed states that I heard who were strong but also in S&P mode. On 80m, my WAS-Phone count went from 0 to 25 in less than 4 hours.
Summary:
- QSOs: 154
- US States: 37
- VE Provinces: 3
- Total Mults: 84
- Score: 12,936 pts.
Band-by Band Breakdown:
- 15m: 4 QSOs, 3 states
- 20m: 46 QSOs, 23 states, 3 provinces
- 40m: 64 QSOs, 30 states
- 80m: 40 QSOs, 25 states
CQ 17m…
Having grown tired of 20m, I’ve been monitoring 17m during the daylight hours over the past week or so. I’ve largely ignored 17m, even back in the old days — there are only 6 DX countries in the log from New Jersey, and no US or Canadian QSOs. This must change!
The band is mostly quiet but with spurts of activity when the waterfall will light up for a minute or two before resuming room temperature. Since November I’ve logged digital QSOs with 8 DX countries and 16 states. So far all the DX has been from the south and east — EA8, F, KP4, OM, ON, PJ2, PZ, TI.
One day last week I left SuperBrowser running on 17m while I was out of the shack. When I later checked the history I saw that there were a few JAs on the list just before sunset. I filed this away for future reference. Yesterday I sat down at the rig at around 2330 UTC to do some CW listening on 40m, when I noticed it was getting dark outside. I tuned the Tarheel up to 18100 and found the band dead quiet. What the hell, I thought, might as well fire off a quick CQ before QSYing down to 40. My first call was returned by JA8GLZ on Hokkaido — my first Asian DX on 17m. With a big signal, too! (One look at his QRZ page will explain the big signal.)
After that QSO… nothing. Not a whisper of activity. QSY to 40m…
My big issue with 17m is hearing the DX. I hear other statesiders working into EU but cannot hear the DX side, not even a trace on the waterfall. I’ve received broken responses to several CQs but have been unable to pull a callsign out of the garbled text, a sign that my Tarheel is getting a signal out but just not receiving quite as well. What to do? Perhaps a dipole in the attic? Might be a little quieter than the vertical. On the bright side, this is not exactly an ideal time to be QRV on 17, so I can anticipate better results as the days get longer and the sunspots multiply.
PSKFest 2010
A half-hearted effort, 7 hours in two shifts (1000-1500 & 2200-2400). Made 82 QSOs, (51 on 40m, 30 on 20m, and 1 on 80m). I just wasn’t as focused as I could have been this time, was doing some work on the Mac while calling CQ on the Dell, doing my best Rick Wakeman impersonation…
Still, I was able to check off a few needed squares on my 40m WAS grid (IA, MA and MI). Also worked TF (Iceland) for a new one from Texas.
This was the second PSK contest I’ve worked (the PSK Deathmatch in December being the other) and have to say I really like PSK as a contest mode, even more so than RTTY. The bandwidth savings are obvious — a whole lot more PSK signals can fit into a 100 kHz swath of spectrum, but also the copy on weak signals is vastly superior to RTTY, and the 100w maximum output levels the playing field to allow anyone with a modest antenna to be competitive.
PSKFest 2010 Results
- QSOs: 82
- US States: 32
- Can. Prov.: 2
- DXCC: 9
- Score: 3526
RTTY Roundup 2010
First contest of the year for me but was only able to put in 7 about hours on 40m (0244-0952 UTC) and logged 103 QSOs.
Not much luck with DX but nabbed LA (Norway, a new one from Texas) and a few other Europeans (G, I, OK, PA, SP), plus EA8, FM, HI, JA, KH6, KP4, P4, VE and XE. Stateside, I managed three new states on 40m (HI, RI and WY).
I wasn’t able to do anything on Sunday, just exhausted. Final score: 4,532
