Wednesday, December 13, 2017

12V DC Power Strip

Assembled and tested, ready for use

I have been busy with some projects lately, and have not been active on the blog. This effort is a small part of my desk project that will be on the blog soon (give or take...).  The desk will accommodate (among other things) my amateur radio equipment.  Amateur radio stuff generally runs off ~12V DC (actually closer to 13.8). There are DC power strips available commercially, but because they handle 30 Amps or more and are intended to be fed by a power supply designed for a radio, they are expensive. I just want to power a fan that cools the radio and a station "on air" sign, so I don't need that.

So, I got a Harbor Freight givaway 110VAC power strip, and took it apart.

I cut off the power cord (it will make an extension cord someday), removed the safety ground copper strip, and drilled out the slots for the prongs of AC plugs to accommodate DC binding posts.
Strip with holes drilled, and some posts installed. Note the mod to the red post on the right.
I cut off the threaded bottom parts to leave just the post (see photo).  Then I soldered the bare binding posts to the copper strips on the positive and negative rails, and screwed bottom back on.
Next I needed a 12V supply. I bought an old wall wart for US$2 at a "Hamfest" (that's basically a flea market for amateur radio people, although there can be some high priced stuff there). Since the jack on the wall wart was not standard, I cut it off and just soldered the wires to the wires to the power strip. It will handle 1250mA, which should be sufficient. As shown in the first photo, it worked. Next step: plug the 200mm computer case fan into the power strip.

Fan plugged into power strip
I'll add the On Air sign after Santa Claus brings it.

Preview of the desk. The blue light to the right of the monitor and behind the radio is the fan--it has 4 blues LEDs, powered by the wall wart through the power strip. My old desk is on the left. It will be removed soon.
I've been using the desk, although we have a couple of additions to make.  We'll add a slide-out drawer for the keyboard and mouse, and a pull-out work surface on the right, over the computers. We also have some trim to add. When I say "we" I mean my brother-in-law--the one with the skills--under my "supervision."

Saturday, September 16, 2017

First 80M Contact--and I don't have an 80M antenna

My antenna is a G5RVjr--supposedly good on 10-40meters.  I use it on 20 and 40--I have had no success on other bands.

This week I'm chasing the Route 66 stations (see here), and I'm down to the last 3 out of 21.  Last night I was watching the spots for those 3.  One I couldn't hear, one couldn't hear me, and the other was on 80.  Just for grins, I went to see if I could hear it. I couldn't, but I did hear several other stations very clearly.  So, today I decided to see if I could transmit.  During the day I heard nothing.  Tonight there were no spots for Route 66 stations, but the New Jersey QSO Party was going on.  The first one I tried could not hear me, but another gave me a 59 signal report. First 80 meter QSO!

I have heard that it is possible to tune a 40m antenna for 80m but this is the first time I tried it.

Friday, September 8, 2017

Ambivalence re FT8



17:09 UTC today marked exactly one week of FT8 usage. For the 7 months preceding that, I had been focusing on JT9/JT65, and was amazed at how rapidly I was building up my list of contacts--640, at least 63 countries. FT8 puts that to shame: in ONE WEEK I had  312 QSOs with 29 countries. I worked 9 stations in my first 45 minutes using the mode.

FT8 is really addictive--it's hard to step away from--the instant response is great reinforcement.  I went back to JT65 the other day and found it WAY too slow. The difference is that you have to stay with FT8--on JT65 you can set it up and go do other work on the computer until you get an alert, then go back and jump in.

Right now, I love FT8.  It's a great way to build up contacts and fill in gaps for awards--as well as to communicate with the world (tiny messages notwithstanding). One negative I see now is that I expect to burn out on it--I can feel that starting to happen already. We'll see--the up side is that I've been motivated to go back to SSB at times--I've been in some contests, and I was able to work an Oklahoma station, which was the last state I needed for WAS Phone (now if I can just get 8 stations to return QSL cards...).

There is a philosophical discussion around whether FT8 is a real mode that should count for awards and such.   As a relatively new ham with no Morse Code nostalgia, I believe that there should be no distinction.  There are categories within the awards for various modes and bands, and those should satisfy the curmudgeons.  Amateur Radio has always been about  continuous improvement and use of new technology. To disparage people who do that is to disparage the service in an attempt to define a "real ham" in the image of one's own experience.

On the other hand, FT8 will take some getting used to.  It's different.  It's also fun and useful.


Wednesday, September 6, 2017

More on Worked All States Plus CQ WPX

In my last post on this subject, I mentioned that I just needed Maine for several endorsements. Well. I finally got Maine on FT8 on 40M, giving me WAS Digital.  I am still at 49, lacking Maine,  for WAS 20M and JT65.

Also, I made SSB contact with an Oklahoma station the other night, giving me WAS Phone, although I an awaiting 8 QSL cards for documentation. So, that's WAS Mixed, Digital, and Phone,

Meanwhile, I discovered the CQ WPX award, which counts prefixes. I qualify for WPX Mixed (400 contacts) ans WPX Digital (300) plus 20M and North America endorsements for both.  I was going to apply but LOTW wanted $56+ on top of the $12 CQ Magazine would charge for each.  I'll be happy with the accomplishment and forego the fancy certificates.

Friday, August 11, 2017

Worked All States, but need Maine for 5 more awards/endorsements

Here's my current Logbook of the World (LOTW) status.

WAS Award                  States
Mixed 50
40M 26
20M 49
Phone 37
Digital 49
JT65 49
JT9 15
PSK31 11
40M Phone 12
40M Digital 21
40M JT65 19
40M JT9 3
40M PSK31 1
20M Phone 28
20M Digital 49
20M JT65 49
20M JT9 13
20M PSK31 10
Triple Play 86
5-Band 75

The only state I am missing for 20M, Digital, JT65, 20M Dgital, and 20M JT65 is Maine!

So, any Maine Hams out there: look for W1LEM on 20M and on JT65 (please).

Monday, June 26, 2017

Fourth of July Lights


With my grandchildren coming for the Fourth of July, I went looking for projects to do. This is one, thanks to John Wargo--original and Fourth of July Version.

I made slight modifications to the Fourth of July version, using a Trinket instead of the Pro Trinket, because I had some of the smaller ones inventory. I also decided to leave off the LiPo charging backpack,  used a pushbutton switch, and used perf board for tidiness.

I used John Wargo's code almost exactly. The only difference is that he used pins 9, 10, and 11 but the Trinket does not have those pins.  Only pins 0, 1, and 4 on the Trinket handle PWM, so I replaced the array provided in the code "int ledPins[] = { 9, 10, 11 };" with "int ledPins[] = { 0, 1, 4 };".

Fritzing Diagram of Circuit

Construction

Parts (references to Radio Shack are good as of writing--no guarantee how long they will last)
  • Adafruit Trinket 3V
  • pushbutton switch (example--any SPST switch will do)
  • Radio Shack Dual Proto Board (or any perf board)
  • Wire Light LED Strands (1 each red, white, and blue)
  • 47 Ohm Resistors (3)
  • JST-PH Breakout Board
  • 1 Quart Ball Mason Jar (any jar with a lid will do--this size works well)
  • Wire Light LED Strands: Red, White, and Blue (note that these are NOT what's shown in the Fritzing diagram--I used the closest image they had in the parts bin).
  • 47 Ohm Resistors (3, one for each LED strand): see Adafruit descriptions of the lights, above--no resistor is needed with coin cells, but " If you want to use a 4.5V power supply, use 20-220 ohms (or larger)"--so I chose 47 for the 3,3V Trinket (having noticed how much brighter the LEDs were off the Trinket vs. off the CR2032s with no current-limiting resistor).
  • Tinned copper bus wire  and hookup wire-- like this, for example--depending on distances and how much insulation you need
  • Gaffer Tape
  • 500 mAh LiPo battery
  • JST-RCY cable Note:  the battery I used (see link above) has a JST-RCY connector and the JST breakout board has a JST-PH connector, I needed this cable and the next to use it. If yours has a different connector, you may not need these at all,  or you may need something instead of the -RCY cable. The 100mAh version shown in the Fritzing diagram, and most (or all) of Adafruit's LiPos, have JST-PH connectors, making all this unnecessary. I could have just cut the -RCY connector off and spliced on the -PH cable, but that was too permanent for me...and now I have a useful -RCY to -PH adapter.
  • JST-PH 2-pin Cable
Tools
  • Drill (I used my drill press--you just need a way to drill holes)
  • Step Bit (I needed ~16mm for my switch--different switches will have different requirements)
  • Wire tools: strippers, flush cutters, etc.
  • Normal soldering equipment: iron, sucker, helping hands, etc.
Process

The bulk of the time was spent in design--mostly how to fit everything where I wanted.  The mason jar lid cramped my style. Even thought the Trinket is small, it took some maneuvering to get the perf board, theTrinket, and the JST breakout next to the whole I drilled.
  1. I laid out the space requirements on the inside of the lid, then cut the perf board to size and experimented with positioning until I was no unhappy
  2. I drilled the hole in the lid for the switch
  3. I made the RCY to PH JST cable to connect the battery: I just soldered the 2 together and heat shrinked
  4. The LED strands referenced above come with coin cell battery holders. I needed to cut the leads from the battery holders to use them, taking care to note which lead is positive (mine had white markings on the + lead, but I tested it to be sure and marked each with red and black Sharpies).
  5. Wire it up
  6. Test and correct as necessary.
  7. Solder.
    I used tinned copper bus wire to make a ground bus down one side of the perf board, fed by the negative pin on the JST-PH breakout.
    To that, I soldered the GND pin on the Trinket and the negative leads of all 3 LED strands.
    I soldered one resistor to each positive LED lead and heat shrinked it for insulation, then soldered the other leads of the resistors to the proper Trinket pins. 
  8. I used gaffer tape to secure the circuit to the lid and the battery to the jar

Video






Saturday, June 10, 2017

Worked All States!!

I did it! Yesterday afternoon I had a JT65 QSO with a station in Hawaii. When I checked my Logbook of the World account this morning, it was confirmed.  That completes my 50 states (mixed). I have other Worked All States (WAS) awards to pursue, but I'm really happy to have this completed.

Twenty Meters was great yesterday--I made this contact with Hawaii before I repaired my antenna (one of my side of my G5RV Jr. had broken loose from the cord that ran from the dogbone to a tree...later yesterday with help from another ham I inserted a bungee cord, re-tied the cord, and raised and tightened the antenna).