[Today’s run: 3 miles ]
Topic today is an old Heathkit Cantenna 50 ohm RF dummy load.
A dummy load is useful for two reasons. It lets you do antenna-type things without actually sending out a signal (or much of one anyway). And, it acts as a standard output load that you can use to tune your equipment before actually putting it on the air. This one is supposed to be good for frequency up to 300 Mhz and for about 1 kilowatt of output power, for short periods.
The thing is basically a large 50 ohm non-inductive resistor that hangs off of the lid, down into a bath of mineral oil. The oil allows the resistor to dissipate heat more efficiently, therefore making the load useful with higher transmitter power than the resistor alone.
I have had this one for awhile and have kept it in a plastic pan like you might use to wash your feet, about that size. The problem was that the can leaked mineral oil and generally made a mess.
This week I finally got a clue and decided to buy a new can! Sure enough, they had brand new, empty 1 gallon paint cans at Lowes home improvement store, so I bought one. I filtered the old oil (about half of it was in the basin and half still in the can) and put it all in the new can. So far it has stayed in there.
Success! I think I will keep it in the basin for awhile yet.
Here is the picture: it is sitting on the hood of my old truck. Shiny new paint can, same old lid and fixtures. The original can was painted black, so the lid still has some black on it. Maybe I will repaint it.
