A Flag for North Dakota

Copyleft C008-2015 j5mc.org.  CC-BY-SANorth Dakota’s flag got some rather unsightly changes a few years back.  The long and short of it was the switch to unheraldric blue-on-red lettering and mandatory fringing.  To this day, you can’t find a correctly proportioned 33:26 copy of the flag on store shelves, but to be honest, North Dakota’s flag hardly stands out among the 56 territories and hardly says anything besides “Hey, we’re American too!”

In the 1950s, the North Dakota National Guard stated about as plainly as possible that the North Dakota flag was properly an army unit banner.  They made a Coat of Arms of North Dakota, which they hoped would form the basis for a new state flag, but that didn’t go according to plan right away.

That doesn’t mean that it was a bad idea, though.  My design inherits the core symbolism of the Coat of Arms, on a Canadian pale, adding a nod to North Dakota’s friends and neighbours.  It also looks like a Big N, which is sure to clear up any ambiguity.  The change to green or yellow alone will pop out from the bizarre uniformity of blue state flags.

Vert on a Canadian pale or a bend of the first charged with three mullets of the second

Flags for Minnesota

Minnesota’s flag is a bit of an eyesore, ranked at the bottom of subnational entities in North America.  We can fix that!

Quick, build on these SVG versions!  minnesota_flags.zip

My concept shares a similar central element to the current flag, while being simpler and more distinctive. The North Star is represented by a golden eight-point star, similar to a compass rose.  Here, I’ve included some titling to de-emphasize the South, West, and East points.  The white ring is an element of continuity from the present flag; at a glance, at a distance, they will appear quite similar.

The way the star’s rays pierce the white is technically a violation of heraldry rules about ‘tincture’, but I think it’s distinctive enough  Titling is also generally frowned upon in proper heraldry.  A more revolutionary redesign might also axe the titling and use a less commonly-seen star, say ten points of equal weight for the land of ten thousand lakes.

Of course, I’m not the first to think that the Minnesota flag is terrible.  There was a strong push in the late 1980s to change it, but it didn’t quite work out.  The one with the Green is called the “North Star Flag” and was designed by Rev. William Becker and Mr. Lee Herold.

The Minnesota Public Television Association, in map form

MPTA county map of MinnesotaI present you with this exhaustively researched map of Minnesota counties by public television affiliate.

This was partially based on channel listings from system operator websites and partially from channel listings reported to other sites for program guide purposes.

It is current and accurate to the best of my present ability as of late July 2013.

Networks are identified solely by the flagship station.  Counties where there is substantial overlap between two particular networks are indicated.

The map only accounts for MPTA members, and does not include adjacent public television networks TVO (north), TFO (north), SDPB (southwest), IPTV (south), or WPT (east).  It’s also debatable if CBC (north) counts as public television these days.

RTL-SDR, Round 1

sdrsharpAfter hearing from reddit all about a cool Software Defined Radio project, I obtained a BlazeVideo DVB-T dongle from eBay.  This spiffy device lets you scan almost anywhere in the RF band!  I’m still seeing what I can do with it, but it grabs local FM broadcasts without trouble.

The SDR# software recommended by one site seems to work fairly well under Windows XP.  I’ll also be making tests in Ubuntu and Windows 7 fairly soon.

Here’s some samples of what it sounds like, picking up broadcasts in my area:

Scanning for FM traffic should be easy with this thing. Programming it to decode digital ham radio modes — well, that’ll be a challenge!

What day is it on Mars?

There are many schemes to produce a viable calendar for Mars, perhaps the best known of which is the Darian calendar, which I’m working on my own alternative to.

The alternative starts with the biggest problem I have with the Darian calendar, its week cycle.  It assumes that people who live on Mars are going to want their own names for days of the week, and want every month to start with the same day.

I think that’s preposterous.

I believe most humans are comfortable with the names they already have for seven days in a week.  Since the abolishment of the French Republican calendar, the French have been keen to have a Vendredi following every Jeudi.  For us English speakers, there is a certain expectation we have going to bed on Saturday that tomorrow will be Sunday.


The key thing is… How do you decide which days on Mars are Monday or Tuesday?  I feel the best solution is to pick a particular date that the day of the week was the same on Earth and Mars … preferably a great moment in Martian exploration.

I can think of a few possible dates that might be suitable:

Tuesday, 1 Jan 1608, start of Year Zero for the  Darian calendar;
Thursday, 1 Jan 1609, start of Year One for the  Darian calendar;
Wednesday, 14 Jul 1965, the day Mariner 4, the first human space probe to Mars, flew by;
Saturday, 27 Nov 1971, the day that Mars 2 crashed onto the surface of Mars, its first direct interaction with humans;
Thursday, 02 Dec 1971, the day that Mars 3 successfully landed on Mars, the first successful probe landing.

For me, I think that the Mars 2 crash is the best day.  It’s the first time that anything manmade interacted with Mars.

There is a concept similar to Julian Date used by the Mars24 software from GISS  (whose site is unfortunately down at the moment):  The Mars Solar Date.  With some calculation [MSD = (seconds since January 6, 2000 00:00:00 UTC)/88775.244 + 44795.9998] it can be found that Sat 27 Nov 1971 1200 GMT is equivalent to MSD 34804.187.

The Martian day at the Mars 2 site was roughly 1000 GMT to 2300 GMT on 27 Nov 1971.   With MSD 34804 defined as a Saturday, other days may be determined with modulo 7.

34804 % 7 = 0 , indicating Saturday.  So, accepting my premise that the Mars 2 crash should be the day-of-week epoch, then MSDs with modulo 0 are Saturday, 1 indicates Sunday, 2 is Monday, and so on.

So Today? If my numbers are right and the MSD at 2200Z 14 Jan 2013 is 49426, then it’s Friday on Mars!

Update: GISS is back up!  You can download Mars24 here.  You’ll need Java 1.6+ to run it.

Qualitative analysis of Amateur TV Transmission range

with some quantitative simulation data from the 4nec2 antenna modeller

Using the the Raspberry Pi as a media center

So my ham station is running pretty well…  at least in the “it basically works” sense.  I set the crontab on my Raspberry Pi to automatically do an audio station ID every 10 minutes.  I used fldigi and Audacity to mess with the sound files.

Overall, the sound quality is passable, but it has some severe popping issues at the start and end of playback that haven’t been resolved yet.  Video quality on the composite out is good, but fiddling with the overscan values gives results that really do vary by TV.  Also, while a 16:9 picture format is an option in config.txt,  as it stands today omxplayer plays anything on composite out as if it’s in a 4:3 environment.  A bit frustrating.

I’m also having trouble with an ancient VCR in my media stack…  Well, I could go on, but what I really wanted to post about today was my antenna modelling and range tests for the station.  It has about 13 mW of transmitter power, so the signal is not going to get too far for the moment.

The antenna I’m using, a monopole antenna that’s 2 wavelengths long, has a reasonable efficiency, but a radiation pattern that throws a lot of power in the wrong direction.   I also haven’t done any impedance matching, so the VSWR is about 2.4, not the worst for such a simply made thing, but not ideal.

Qualitative results from a walkabout

My rubric

good – good picture, little fiddling with receive antenna
fair– good picture, more fiddling with receive antenna
marginal – acceptable picture after fiddling
poor – major fiddling to get anything recognizable

Open-space paths
30 m – good
55 m – marginal

Less obstructed indoor paths
30 m – good
40 m – fair

Fairly obstructed indoor paths
53 m – marginal
53 m, down one floor – poor
53 m, down two floors – negligible

Some notes on 4nec2

4nec2 is really sweet package, more intuitive and less computer intensive than HFSS, a  commonly used antenna modeler.  And unlike HFSS, 4nec2 is free! However, 4nec2 isn’t very cooperative with Windows Vista/7 if you install it under Program Files.  Instead of reinstalling in a random directory, I fixed this by editing the shortcut properties to always run as administrator.

pix, plox

Video Sources: Software Vision Mixing

As part of my goals for the Amateur TV project, getting video from a computer into the station video input.  One of the first steps is getting usable software capable of, at minimum, Station ID overlay.

I was introduced to the concept of the “Software Vision Mixer” today, a handy thing for grabbing screen areas and, ideally, dumping them to a network stream for distribution.

The free versions of ManyCam and XSplit work fairly well, but leave unsightly watermarks in their output.  On the Linux side, I’ve poked at dvswitch and not gotten much out, same with FreeJ  and WebcamStudiorecordMyDesktop works rather well, but it’s built as a simple, direct pipeline to an encoded file, rather than something useful for a live stream.

Backhaul is also another main concern.  I can generate a stream and send it up to a livefeed site and play it back on the output computer, but then I’m stuck if the Internet goes out.  If I produce everything on my local network, I have to set up a streaming media server (not a short order for some of the common protocols out there — I’m looking at you, RTMP!), or kludge together a point-to-point data stream to carry the video.  It’s a whole new project in itself!

Amateur TV cable frenzy

Recently, I ordered a high-quality RF video modulator, and have been putting it through its paces in the lab!  I’ll have more to say about RF performance, but right now I have a connection problem…

I have a serious a lack of cables on-hand!   So far, the video equipment uses a haphazard mix of BNC, RCA, and F connectors, and there’s very few RCA and F connectors on hand around here.  Plus, the processing loop of the modulator took up my last good short RG-6 cable.  Darn!

Plus… I honestly don’t know where the test monitor I’m using came from, it’s an ancient JVC monstrosity with two video inputs.  It has the air of an old transmitter monitor from the gigantic  connectors poking out of the back!

At first I thought they were N connectors, but they didn’t look quite right, and of course didn’t hook up to the handful of N connector things I dug out.   My next guess was 75Ω TNC, not that I had any such thing on hand, but a check of the plug diameter threw that out too.

In the end, I found out that it’s actually old-style Amphenol UHF connector.  It’s still in the Wikipedia infoboxes, but I doubt too many folks still use it.  It’s a big, unwieldy, and expensive alternative to connectors that were designed after 1950.

Apparently the advantage to folks living in 1972 is  you can just solder the thing to the end of your cable and never have to go out and buy a crimper.  Unfortunately, I have to live in 2012, and I’ll be needing a spool of RG-6, ends,  and a crimper for a host of pesky RF cable runs sure to come in the development of this and other projects.

What I need to hook up together (diagram to follow):

Video Sources

Potential sources: VGA, DVI, Composite, S-Video.  Component, HDMI

Composite can go straight in;  S-Video and Component possibly, with cheap combiners, VGA/DVI/HDMI with expensive converter boxes.

Video Modulator

Video In: F connector

Audio In: RCA cable

Video/Audio Out:  F connector


Video In: 2x RCA connector, F connector

Video Out:  RCA connector, F connector

Audio In: 2x L+R RCA connectors

Audio Out:  L+R RCA connectors, F connector

Test Monitor

Video In: N connector

Video Out: N connector

Audio In: Mono RCA connector

Audio Out: Mono RCA connector

Stereo Encoder


Other video sources



To do

Turn up computer video generator

Add stereo encoder to the mix

Test Passthrough Mode on Test Monitor (need connector)

Get a power amplifier for the signal (very expensive! </Mr Dink>)

Ham Radio Fun

Qtel running on Ubuntu 11.10

With some help from these guys, I’ve gotten Qtel running off an Ubuntu 11.04 64bit boot disc.

Qtel seems to be about as well-maintained as the original EchoLink program, so no real problems, aside from glaring issues like:  Your microphone has to be connected to the same device as your soundcard (bad news for me, trying to use a USB mic)

Though with an open-source program, ostensibly I could eventually fix this myself.

I used online instructions from these blogs, the comments on the latter one were especially helpful.




Also helpful was installing the stock Skype package beforehand (found hereish),  mainly because it had already got me over the hurdle of installing ia-32-libs

One extra thing I had to to, aside from the instructions, was

sudo apt-get install libqt3-mt


pdasp qtel

from the terminal launched the program.  It didn’t show up in Unity at all, though beforehand I’m told it would end up in the older ubuntu program menus.

As an aside, the Unity interface in 11.10 and 12.04 are very unkind to third-party programs, but it’s probably not going to be enough to put me off of updating to the new LTS.

So now the only problem is remembering what random string I used for my login, and I’ll be hamming it up on Linux in no time.  73s from KD0GWG!

AM radio fun!

A quick day project in the lab:  AM radio!

  • 2x 741 op-amps
  • 3.5mm stereo patch cable (from computer sound card output)
  • ~1MHz sine wave from Function Generator

I wired the audio input into a unity-gain inverting op amp.  This was the inverting input for the next stage, an op-amp wired in differential amplifier mode.  (The non-inverting input accepted the carrier wave.)  I used 620 k resistors, because nobody else uses them.

The result?  Muddy, and especially muddy when I cranked up the voltage on the carrier wave.

Ways to improve:

I could have wired the sound straight in to the op-amp, but I had originally tried to boost the audio signal to equal the carrier wave… this washed out the signal in practice, so I switched to unity gain.  Next time skipping this first stage could cut down on distortion.

I had tried to use a giant transformer loop as an antenna line, but after messing around I quickly figured out it was irrelevant, and all my emissions were coming from the line between the second stage output and the ground.  The only really straight part of this line was the resistor, which made a rather poor antenna.

The sound was a lot better when I cut the peak voltage on the carrier wave, and a little better when I lowered the frequency.  Since the audio signal stayed at about the same strength, I believe the first effect is due to the nature of amplitude modulation (closer peak voltage implies deeper modulation, which means stronger signal)  The frequency effect probably has everything to do with the fact that a 741 amplifier is rather taxed beyond 400 kHz.

So I bet there’s a better amp for this, too.  I’ll try an instrumentation amplifier next time… or maybe something FET-based.