eQSL From Lupo Radio

One of my best DX catches, a 25 watt AM pirate from Argentina, recently received.

Note from the station operator:

Sr. Chris Smolinski.

Le agradezco mucho su informe de recepción, RADIO LUPO transmite desde Buenos Aires Argentina, con un transmisor de 25 Watt de portadora, 2 válvulas 807 moduladas en G2.
Antena: dipolo horizontal a 12 metros de altura.
Le adjunto QSL

Gracias Chris Saludos LUPO.

Olvide mencionar que la emito todos los dias de 18:00 a 01:00 Hora UTC. + -.


Mr. Chris Smolinski.

Thank you very much for your reception report, RADIO LUPO transmits from Buenos Aires Argentina, with a transmitter of 25 Watt of carrier, 2 valves 807 modulated in G2.
Antenna: horizontal dipole at 12 meters high.
I am attaching QSL

Thank you Chris Greetings LUPO.

Forget to mention that I send it every day from 6:00 pm to 1:00 am UTC. + -.

Active Hula Hoop Loop Antenna

My primary HF antenna is a horizontal sky loop, with a perimeter of about 670 feet, I also have a 500 ft long beverage aimed toward Europe which is primarily used on the 48 meter band for Europirates. In addition I have a sloping folded dipole for the 43/48 meter band, although that antenna does not get a lot of use. These antenna work great on the lower end of the HF band, but as you might imagine are not ideal for the upper end, especially the 11 meter band which I like to listen to when there are openings to Europe.

I’ve been interested in building an active loop antenna for some time, and recently came across the Active Antenna Amplifier made by LZ1AQ. This amplifier has very good reviews, and LZ1AQ’s site has a wealth of technical information, including suggested designs. Originally I was planning on building a 2/4 crossed parallel loop (and still may one day), but as that is a major product (each of the four loops is 1 meter on a side), I decided to start with something easier to build, the two loops in orthogonal planes, which is described in section 3.4 of this document on his site.

Here is a photograph of my build of the antenna:

It was constructed with two old hula hoops. And yes, it’s not an optical illusion, one is slightly larger than the other. Each loop was wrapped with aluminum foil, to create a large diameter loop, with low inductance. The foil is not wrapped around the entire hoop, there is a small gap of about two inches.

As you can see hookup wire is wrapped around the aluminum foil, and twisted so it is tight and making good electrical contact. They are later covered with tape to be weatherproof. Wire ties are used to secure the loops to an 8 foot long piece of pressure treated 1″ by 2″ furring strip that I happened to have laying around. These wires then go to the amplifier board.

The loop amplifier uses shielded CAT-5e ethernet cable for the connection to the control board back in the shack. This cable carries the power for the board, control signals for switching the loop inputs, as well as the amplifier RF output which eventually goes to the radio. I used some more tape to seal the hole for the ethernet cable, to keep out moisture as well as insects. After the photo was taken, I added a small support arm, made of wood, and attached the ethernet cable to it with a tie wrap, to provide some mechanical support, and remove the strain from the ethernet jack on the amplifier PCB.

This is the rather crude enclosure I made for the control board, using an old plastic enclosure I had laying around.

The functionality of the control board is more completely explained on LZ1AQ’s site, but to summarize:

The first toggle switch selects either dipole or loop mode for the amplifier. I have mostly used loop more in my tests so far, but will experiment with dipole mode eventually. In dipole mode, each loop is used as one arm of an electrical dipole, rather than as a loop antenna.

The second switch selects either loop A or B, when only one loop is used.

The third switch enables crossed mode, when both loops are used at the same time. This can provide some relief from fading, as the two loops are orthogonal to each other. Otherwise, only one loop is used. On the LW and MW bands, this provides different directionality patterns, and works quite well. For example on 1490 AM I can completely switch between two different stations. Obviously this is dependent on the directions to the particular stations on a given frequency. If they are roughly 90 degrees apart and aligned with the loops, you get excellent directionality. If on the other hand they are at 45 degree angles with respect to the loops, you won’t get any.

The last switch is for power.

Below is a waterfall of part of the MW band. Half way through, I switched from loop B to loop A. On many of the channels you can see a significant change in the signal strength, sometimes stronger, sometimes weaker. You can click on the image to view it full size.

It even does a good job on the lower end of the LW band, here is WWVB:

I’m quite pleased with the performance of this antenna, especially on the 11 meter band. And the directionality on the MW band is a bonus. On the lower HF frequencies, the full sized sky loop and beverage antennas perform much better, as you would expect. Still, this is a respectable antenna for the size, and would be very useful for someone with limited space that precludes the use of large antennas.

If you like my loop antenna, you might enjoy some of my radio related Apps

Project: Exterminate Yellow Jackets

For several years, yellow jackets made it extremely unpleasant, and often downright impossible, to enjoy sitting outside during the summer on the deck. As everyone who has experienced yellow jackets knows, these are extremely aggressive and downright hostile insects. While bees are generally peaceful and useful creatures, helping to pollinate, yellow jackets don’t pollinate, and are generally pure evil. My goal now every spring is to do my best to completely eradicate them from the area. Many of the yellow jackets found in the United States are not even native, but invasive species from Europe, if you need additional incentive to obliterate them. Again, to repeat. Yellow jackets are mean and nasty wasps. They do not pollinate flowers and help fruit grow. They are not critical to the ecosystem of your back yard. You can do your best to completely eradicate them from your yard, and feel no guilt doing so.

Most people wait until they are being bother by yellow jackets to put up a trap or two in the summer. By then, it is far too late. Yellow jacket nests can have several thousand wasps by mid summer, and you may well have multiple nests in or near your yard. It is simply impossible to trap them all by this time, in fact their nests will probably increase in population faster than you can trap and kill them. You’ll find it impossible to sit outside and enjoy summer, being forced to hide inside and watch reruns of old TV shows.

But it turns out, there is a solution. You need to act now. Yellow jacket nests are annual, only the queen survives winter. Once the weather warms up (as in right now) the queens emerge, to establish the new nests for this summer. While later in the season they have their evil minions to do their bidding, gathering food and generally making your life miserable, right now they have to do the dirty work. Which means this is your opportunity to trap and kill every single queen you possibly can. And it’s not that difficult to do.

After experimenting with various commercial yellow jacket traps, most of which used expensive pheromone based lures that had to be replaced often, and often did not even work very well, I stumbled on this style trap made by Victor:

The trap is a plastic bottle with a top that screws on. The top has small holes in it, under the yellow top (which keeps out the rain), which the wasps can fly into. But due to their erratic flying pattern, they have a difficult time escaping from the trap. So they are stuck inside, and finally die.

I bait the traps with a grape juice / cranberry juice mix, I find this works best, although you can try plain grape juice or other juices, and see what works best for you:

I pour a small amount of juice into each trap, this lures the yellow jackets into the trap, where their meet their demise:

I purchased a dozen traps several years ago, and place them in various locations around the perimeter of my yard. You can probably get by with just a few, if you have a small yard. You do want to find the ideal locations to place them, which depends on where the likely yellow jacket nests are located. I find that placing them on the sides of my yard near the woods captures the most wasps, which makes sense. After a few years of using them, I now know where they should be located, but to get started you can experiment by spacing the traps near the most likely areas, and then seeing which traps capture the most wasps, and which capture few, or even none. Move the traps away from areas that are not productive to those that are, of course it may take a season to completely figure it out, but even with non optimal locations, you will likely capture and kill many queens.

You need to periodically examine the traps to check for dead wasps, as well as refill with more juice as needed. Obviously you want to carefully examine the trap before opening it, to make sure all the wasps are dead, or in poor enough shape that you can kill them after dumping out the contents. Queens are fairly easy to identify, they are much larger than the usual yellow jackets you see.

There are plans online for building your own trap from a 2 liter soda bottle. I’ve tried this, and have not had much success, but you might want to give it a try and see how it works for you.

Again, it is imperative to get your traps out now, so you can capture and kill every queen yellow jacket possible. Each queen you kill means one fewer nest, which means thousands fewer yellow jackets invading your barbecues this summer.