LHS Episode #032: Screen-Doored Submarines

Well, January has pretty much come and gone. I sure hope the rest of the year sticks around a bit longer. Now that it's 2010, though, Linux in the HAM Shack has a lot of things planned for the future: contests, interviews with fascinating and influential people, trips to live events throughout the year and, as always, scintillating content about Linux and ham shacks.

As of Episode #029, we have achieved more than 50,000 downloads. Episode #029 also turned out to be one of our most popular. When Richard and I started this endeavor back in October 2008 we didn't really know what to expect out of the podcast, but I think it's safe to say that whatever expectations we may have had, we're certainly reaching or exceeding them. I only hope that we only have more room to go up from here. Thank you to everyone who listens to, participates in, or otherwise helps out with the podcast--especially Bill, KA9WKA, our beloved Show Notes compiler, and everyone who has made a donation to the program. We are only about $100 in donations away from our booth at the 2010 Dayton Hamvention and we hope that we'll be able to set up there and say hello to all of our fans, old, new and undiscovered, when it finally rolls around.

But for now, we wish you a speedy download and an enjoyable listen.

73 de Russ and Richard


Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].

Old Magazines

As part of a downsizing exercise I'm trying to clean out my shed of most of the QST magazines I have collected over the past 15 years. I was hoping to buy all the QSTs on CD from perhaps 1950 or 1960 to present to replace the paper copies and get several more decades to peruse when I'm an old codger vegetating in one of those assisted dying homes. I figured ARRL would offer the whole kit and kaboodle for perhaps $150 or $200. Going to the website I was dismayed to learn to get just 1995 to present would cost $310. OK, maybe I was a bit unrealistic, but how much does it cost to have an intern burn CDs from the already existing QST PDF database? Looks like I'll continue to have a couple hundred pounds of magazines in my shed for the foreseeable future. Oh well. If I ever lose my job I can use them to heat the house.

I also have a bunch of 73 magazines. No chance of ever getting them CD. NEVER SAY DIE! Not. What CQ magazines I had left I tossed out. I always thought it was a somewhat quirky publication, though I was a 73 fan at the time, so perhaps it was just me that was quirky.

I also found several years of Popular Communications from the 1980s. I loved this magazine when I was a teenager. I was a big pirate radio fan at the time and really enjoyed the spy stories. I almost threw the box out but decided to keep it. It's a window back into a time that we'll never see again when shortwave broadcasting was actually interesting.

Anthony Good, K3NG, is a regular contributor to AmateurRadio.com and writes from Pennsylvania, USA. Contact him at [email protected].

K3 Weirdness in AFSK-A Mode (SOLVED!)

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


SOS, XXX, and TTT

Last season while watching Deadliest Catch on Discover Channel, several times I heard the distress call "PON PON". Doing a little research (errr... a Google search) I learned that there are several distress signals beyond the venerable and familiar MAYDAY or SOS:

Distress signal: "MAYDAY" (CW: SOS)
Urgency signal: "PAN PAN" (CW: XXX)
Safety signal: "SECURITE" (CW: TTT)

I'm curious why we don't discuss or support the usage of PAN PAN (XXX) and SECURITE (TTT) in amateur radio?

Anthony Good, K3NG, is a regular contributor to AmateurRadio.com and writes from Pennsylvania, USA. Contact him at [email protected].

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.


Handiham World for 20 January 2010

Welcome to Handiham World!

Net or not?

TS-2000 HF station

We have been urging our readers and listeners to monitor 14.305 MHz for activity before we begin a new Handiham HF net on that frequency. I have heard some stations on 14.305 in the early afternoon Minnesota time. Lyle, K0LR, suggests that an afternoon time might find the band conditions being “short”, meaning that we could possibly get more stations checking in from the United States. If we were to look at evenings, I think the band has been dead as often as not, so we cannot wait until it is too late in the day. During the morning hours the band is open, but the skip is longer. As I write this at 09:30 local time, I hear a Spanish-speaking station on 14.305.

As important as band conditions is the question of when our members can get on board with the net! It does not matter if conditions are perfect if everyone is working at their jobs or otherwise busy and can’t get on the air. The original net schedule was set up for 9:30 in the morning Minnesota time, but most of us are busy at that hour. I’m not saying that we should keep the morning hour schedule, but nothing kills a net like bad timing! Before we decide to just keep the 9:30 morning hour but shift frequency from 14.265 to 14.305, let me know your thoughts. One successful Friday evening schedule we used to keep was on 17 meters, and I can’t call it a net, because the informal gathering started by Alan, K2WS, was a “non-net get together”, as Alan always reminded us. After all, the unofficial rule is that nets do not belong on 17 meters, at least not formal nets.

20 meters is different and nets are all right, even scheduled formal nets. Can we narrow it down to daytime or evening? And what day? Monday? Friday? Saturday or Sunday? Remember, we want to pull in working folks, so scheduling it in the middle of the work day may not be the best idea.

One of our repeater hosts, Chris, KG0BP, mused that we might not really need a daily Echolink net if net control stations are too hard to find. So what about that? Do we add a few HF nets and pare down the daily Echolink schedule?

Also at this time we are asking for HF net control volunteers. You will need at least a General Class license and an HF station with a 20 meter antenna.

George, N0SBU, has pointed out that once nets are suspended for the summer as many clubs do with their nets, it is usually pretty difficult to get those nets going again. The lesson to be learned from that is to keep your nets running! Taking time off or reducing your net schedule means that you may never get those times and frequencies back again. George would also like to see the Wednesday night Echolink net be used more often for training purposes, maybe every Wednesday night.

A couple of you thought that having the Echolink nets every other day, Monday, Wednesday, Friday, then on Saturday would be enough activity to keep things running.

Every net needs to have a critical mass of users. This is a basic truth: If you don’t have enough regular participants checking in, you will not keep your net running. That means paying attention to having the net on at a time when you can get people away from whatever they are doing and to the radio. Band conditions, in the case of HF at least, have to be suitable. If band conditions are not right, you may have few check-ins no matter how convenient you make the time and day.

Another concern is that we have competent net control stations. Every time a net is poorly run, we lose some stations who either give up while waiting to check in or simply get annoyed by the poor operating practices they encounter on the net. Every net has this challenge, too, not just ours. I have heard some terrible operating on HF nets whose participants were long-time license holders and whose net control station held a higher class of license.

As we continue with our planning for nets, keep these handy net control practices in mind:

  • Begin your net with a preamble explaining the purpose of the net, who may check in, and anything else about how the net will be conducted. This is the time to tell participants if the net is formal or informal and whether you need to be a net member to check in. The end of the preamble is the place to tell stations how to check in, namely, “Check in with your callsign only”, or other appropriate instructions.
  • Call for stations in this order:
    • Stations with emergency or priority traffic
    • Mobile stations
    • Portable stations
    • Stations on “short time”
    • Stations with announcements of interest to the net
    • General check-ins (and limit the crowd by geography, type of technology used to check in, callsign area, or whatever.) Example: “I will now take check-ins from stations outside North America.” or “I will now take check-ins from repeaters only.”
  • Be sure you have firm control of the net. Do not allow stations to simply give their callsigns and then start rambling on about the weather, their computer problems, and how their dog has fleas. Make it clear that stations checking in must give their callsigns and be recognized before the net control allows them to have their say! Do not let stations grab the air and take over. Net control stations should do the controlling.
  • You can make the net more interesting if you have a net topic. Sometimes the net will enjoy discussing a topic introduced by one of the stations checking in.
  • Don’t forget to call often for stations throughout the net time. Always allow enough time for emergency check ins to get your attention. You never know when the system may need to pass emergency traffic.
  • Be patient but firm, and always polite. Insist that everyone use their callsigns. This will help everyone keep track of who is on the air.
  • When the net winds down, thank the participants and the repeater and system owners, and mention when the net will be on again, then sign off.

For Handiham World, I’m…

Patrick Tice, [email protected]


Pat Tice, WA0TDA, is the manager of HANDI-HAM and a regular contributor to AmateurRadio.com. Contact him at [email protected].

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