J-Pole!

Most of the J-Pole

Antenna side of SO-239 soldered to the copper strapconnected to the long side of the J-Pole.

Note the screw connecting the body of the connector to the short side.

Socket side of SO-239 bolted to the short side of the J-Pole

With plans found here for a 2-meter j-pole my brother in law (the one with the skills) and I built this. We used the dimensions exactly as given except that the bottom extends about 5', rather then the 2' in the specs.

To test, we first took it outside, and supported it so it was vertical.  We connected a 9' length of RG58 coax to the SO-239 and to a meter, and the radio to the other coupling on the meter. On a simplex frequency on low power (1W), SWR was well under 1.2:1, so I tried a repeater about 12 miles away on high power (8W) . A member of my local club heard me and reported a good signal reception was strong but a little scratchy--I may need to fuss with that.

This was not at my house, so the next step is to find a place at my house where I can get a consistent signal and be heard consistently.

It's snowing now, so I'm on hold, but when it clears I will get to that.

Success! See this post  and this post for the process that go me here.

More on 2-meter antennae

mag antenna for top of car on the right, using baking sheet for ground plane, new ground plane antenna on the right, using just 12 gaugue wire and an SO-239 connector

Just for grins, I decided to go further with the attenna experiments.  I made another grond plane, using #12 AWG insulated wire, crimp-on ring connectors, and an SO-239 connector. Using the same dimensions as the one in this post but following +Martin Lorton more closely (e.g., no copper plate), I soldered the vertical and screwed the radials (via the ring connectors) to the SO-239.

I still get spotty reception, not much better (and sometimes worse) than the 15" antenna screwed on to the radio.  I borrowed an SWR/Power meter.  I need one more connector to test the mag, but I get  beter than 1:1.2 SWR on the groundplanes. The power meter shows I'm getting 1W and 5W on the low and medium settings, and 7+ on the high setting.

I also made contact yesterday using the mag antenna on the car through a repeater ~15 mi away from where I was.  That's the first time I had success with that antenna. I was getting what may have been reverse feed, so I'd like to check the SWR. I'll do that once I get the connector (need 2 days for Amazon Prime).

I may just have to live with the fact that my house is in a bad place, but I'd like to see if an alternate antenna will improve things. I may have to go to a J-Pole, mounted up high.

113th Anniversary of First Transatlantic Wireless Contact, 18 January 1903

Coast Guard Station, Eastham, MA--note the antennae set up for a variety of wavelengths. The actual first message was sent from Marconi Station, a few miles north.

113 years ago today, the first radio telegraph message from US President Theodore Roosevelt of English King Edward VII was sent from Marconi Station in South Wellfleet, Cape Cod, Massachusetts. Today, only some of the foundation remains of the original station. National Parks Service and local ham radio operators work the anniversary from the former Coast Guard Station in Eastham, a few miles to the south.

This area is part of the Cape Cod National Seashore. Cape Cod Marconi Radio Club (+Marconi Cape Cod) call sign is KM1CC. The event is also part of National Parks on the Air (NPOTA), celebrating the 100th anniversary of the National Parks Service (also a Teddy Roosevelt thing). The NPOTA id is SS03.

I observed some of the activity yesterday.  There were 2 voice stations and one CW (Morse Code) station working 10, 17, 30, and 40 meters.  The frequencies are posted on the KM1CC Facebook page and the @KM1CC Twitter Feed.    Volunteers were also setting up another CW rig.

2 meter antenna

To celebrate my new licensed amateur status, I decided to build an antenna for my new radio.

The radio is dual band (2 meter/70cm), but I decided to start slowly and make an antenna for just the 144MHz (2 meter) band, since that's the one I'll be using most.  I found the specs here (part of a compendium) I used the rest of the compendium as well as other reference material, particularly this video by +Martin Lorton,

I enlisted the help of my brother-in-law, who has skills (see the generator house).  In the interest of using what we (he) had, we used a copper plate instead of aluminum, and 10-gauge wire instead of welding rods for the radials. There may be a galvanic action problem, but we'll see.

Materials:

1.       SO-239 chassis connector https://www.radioshack.com/products/so-239-coaxial-socket?variant=5717635205

2.       6” SO-239 to SMA female jumper http://www.amazon.com/gp/product/B00COKNKS8?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s01

3.       18’ coax with PL-259 connectors http://www.amazon.com/gp/product/B001JT0CGI?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s01

4.       4-40 machine screws, washers, and lock nuts (4 ea)

5.       12 AWG wire (19 5/16” + loop,  4 x 20 3/16 +)

6.       Copper plate (~6” square)

7.       PVC pipe for stand

Process:

1. drilled a 5/8" hole and four small holes (for the 1/2" 4-40 machine screws) in the copper plate
2. attached the SO-239 to the plate with the machine screws
3. cut the wires to length (4x#10, 1x#12, 19")
4. bent the radials to 45 degrees, 4 inches from one end
5. soldered (instead of screwed) the radials to the copper plate
6. soldered the #12 wire to the center pin of the SO-239
7. connected the cables to the antenna, each other, and the radio
8. on the air (not yet...I need to hear activity in order to know what's up)

We found an old Archer 21-256 CB tuner (over 40 years old).  It claims to cover 2-175MHz. Just for drill, I cleaned it up and connected.  It showed my SWR was way off. I tried bending the radials up, and it got worse. I bent them down, not quite to vertical, and I got it to 1,2. I have no idea how accurate the device is or how effectively I used it, but I used it.

I have not raised anyone, with the antenna, but I had the same issue without it. This morning I heard 2 people on a local repeater and when they finished I asked if they could hear me. I had a nice conversation with one, so my radio transmits.  Now I just have to test the antenna.

I passed my Amateur Radio Operator test

Last night I qualified as a Technician Class amateur radio operator. I have to wait a few days before I can be on the air, while the FCC assigns a call sign to me.

I bought this inexpensive, handheld radio to get started. It will get me around the local area and I can participate in local activities including emergency management.

I expect to by an additional radio that will get me to other parts of the world, but I have to decide whether I will uprade my license first in order to be able to broadcast on more bands.  Meanwhile I am having fun!

Halloween Candy Cauldron V2.1 upGRADE

Forget all that stuff in my last post about what I cooked.  I went back to the Uno version, really at a loss about why everything stopped working.  I decided to check power, first on the 5V rails--no power!  Then, I check what was coming from the 5V pin on the Uno. Nothing.  The only answer (other than a cooked Uno, which I did not believe) was a bad jumper wire.  Sure enough, I did continuity tests on the wires and one was bad.  I replaced them and it worked. So, the sensor and amp are both fine.

I went back to the Trinket.  It's putting out static only.  Same sensor, same amp. So, maybe I cooked the Trinket.  I'll have to decide whether I want to solder up another Trinket and perhaps sacrifice it this year or wait until next. As for now, I've spent a WHOLE LOT OF TIME working on something that already worked,  I have the bigger cauldron, and I have a switch, and it works again.

My other upgrade for next year is to put the Trinket--or Uno if I can't get the Trinket to work--into low-power mode while it's dormant to save battery and avoid having to turn it on and off so much. I've just learned how to do that in concept and this appears to be a good application.

So. I can take it to work tomorrow to entertain my co-workers. Since Halloween is a Saturday, I'll decide then if I want to spend more time (and maybe money) getting the Trinket version to work again.

I feel much better! On to 3.0!

Halloween Candy Cauldron V2.1 (update,not upgrade--more of a downgrade)

I was having a problem with my candy cauldron: the Pro Trinket was resetting at random intervals, and the circuit would not resume unless I powered off and back on.

I surmised that the problem was power.  I was powering the 5V rails from the 5V pin on the Trinket. (This worked on the Uno, but maybe the Trinket doesn't put out as much current).  So, I took the 9V Vcc to the BAT and GND pins of the Trinket, then to the IN and GND pins of an LM7805 voltage regulator, and powered the 5V rails from the OUT pin on the LM7805.

All was good. No more reset.  I took the cauldron to a meeting in the morning and had fun.

Then I got greedy. The cauldron is very small, which limits the candy.  It's limited anyway, and in addition if candy is piled too high the sensor sees it and sets off sounds. Also, there was a sound problem: since the HC-SR04 sensor is ultrasonic, if the sound being played is long the sensor detects it and plays the next sound even if no one reaches in, and will continue until it gets to a shorter sound. For example: the howl is long but the cackle is short--if the randomizer selects the howl, it will play at least one additional sound until it gets one like the cackle; if it selects the cackle, it plays only that one sound. I had put in a 5 second delay to wait for the sounds dissipate, but that wasn't enough for all sounds and I didn't want to make it longer because that makes the candy grabbers wait too long.

So, I got a bigger cauldron and that worked fine--briefly. It played only one sound at a time since there is more room for the sound to dissipate. Then the problems: I do not know what happened, but it started producing static only and resetting--at first randomly and then continuously, then stopped producing sound altogether.  I thought I might have cooked the Trinket, but it doesn't work on the Uno either. The sensor is not registering, so I probably cooked my last one. According to my meter, there is a signal on the speaker pin when there is supposed to be, so I may have cooked the amp too. I swapped that out, with no success...but the amp I swapped to was the one I thought was cooked earlier but discovered I wired it wrong--maybe I really did cook it. I have more, but I need to solder on headers and a terminal block before testing.

So, I don't know if I'll be ready for Halloween.  If I get the amp to work I may invest in a retail HC-SR04 at Radio Shack while I wait for my $0.88 ones to arrive from China.

I'm not happy.