Transforming someone else’s junk
A rainy afternoon visit to the local flea market has allowed me to complete a project. One of the rules of amateur radio is that you can’t broadcast just anything at all. Hence, the need for something called a dummy load. Imagine a small collection of resistors, carefully matched to provide a measured resistance, with sufficient ability to dissipate a given amount of energy. Sounds simple. Except, as an amateur radio operator, there’s a rule that says you must limit your spending (and your transmitted power) to the amount required to get the job done.
I’d already fooled around with a calculator, and knew that four 100 ohm resistors and three 330 ohm resistors could be soldered together to be equal to 52 ohms (just what I needed). Since my resistors are good for 1 watt each, and I have seven, my QRP dummy load was within reach.
One small difficulty: I needed a “container”. This afternoon, in someone else’s junk pile, I found a small terminator unit, made with the over-engineering typical of military hardware. Originally designed as part of some Marconi test equipment, the metal box contained 2 female BNC connectors, 1 male BNC connector and three accurate resistors. Strip out the guts, add the 2 BNC connectors to my junkpile and think things through. How to employ the left overs…
Within the time needed to polish off a plate of gingerbread cookies (prepared in anticipation of my triumphant hunting trip to the flea market), I soldered up a suitable dummy load and tested it on my small transceiver.
Success! With that step out of the way, I can get back to learning about portable antenna setups. Summer is coming.
