Wind toroids or joust with lightning?

As has been the pattern this spring and now summer it’s an on and off rainy day. We’re 6″ ahead of our normal annual rainfall thus far and there isn’t any sign of slowing. That’s a lot of extra water. Today has also included mild thunderstorms periodically rolling through. With a four day weekend for Independence Day my plan for today was to work on getting my Cobra UltraLite Senior back in the air. About six weeks ago we had to take down a large tree that was arguably dead a couple of years ago but was serving the purpose of holding up one end of the antenna. However the rot had progressed to the point that one more storm was going to bring a stout limb down on the camper or a vehicle so the antenna came down along with the tree. The other trees that are close to it are tall and very full but they don’t have the substantial limbs up high enough for this antenna so I elected to move the end point to a new position and use a Channel Master 25ft antenna mast instead of a tree. This also has the advantage of moving the feedpoint a little closer so that it will fall away a bit more vertically from the antenna to the house as opposed to the more horizontal approach from the past installation.

Lightning Rod

Given the passing thunderstorms albeit mild ones, messing about with a 25 foot steel pole seemed like throwing your hat into the ring for a potential Darwin Award. So I elected to wind nine toroids instead of playing chicken with bolts of lightning. My guess is that the lightning always wins.

Out of the box, the WSPRlite transmitter supports the 20m and 30m bands. The low pass filter kit provides support for the 40m, 80m and 160m bands. As you can imagine the primary components of the low pass filter kit are a number of capacitors (14) and toroids (9).

Low pass filter kit components

So in between tending some chicken on the smoker I commenced to winding the toroids. The build instructions for the kit are very well done. One of the references for winding toroids is that of Genesis Radio which presents a very clear set of instructions for winding toroids if you are new to it. In addition, the build instructions include a simple continuity test sequence so that you can check to be sure that each toroid is soldered to the board correctly. This is a nice added touch as you can never be more than one toroid wrong as you progress.

One down, eight to go

I soldered each toroid to the board as I completed them in order to keep track as there are two different cores and six different turn counts for the nine toroids. It took about an hour to wind all nine and install them.

Toroids complete

Over the course of the evening I’ll complete the board and if the weather improves such that I can reconnect antennas I’ll do some WSPRing on 40m. Once I get my Cobra UltraLite Senior back up I’ll be able to WSPR on 80m and 160m. Stay tuned for more WSPRing, right now it’s time for dinner.


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