Build an 8 Watt Dummy Load for the uBitx v5 v6
The assembly directions for the uBitx v5 warn the unit could go into transmit if powered up without the Key connector wired, so I needed to build an 8 Watt Dummy Load to handle this, just in case
I keep various resistors on hand suitable for making dummy loads, 2 watt, 3 watt, 51 ohms, 100 ohms, 200 ohms, 2K ohms
Resistors have a very useful property, when resistors of the same size and wattage are wired in parallel, the Watt rating the aggregate watt value of all the resistors, and the ohm rating is divided by the total number of resistors
Example: 2 100 ohm 2 watt resistors wired in parallel will create a dummy load rated at 50 ohms and 4 Watts 2 100 ohm 3 watt resistors wired in parallel will create a dummy load rated at 50 ohms and 6 Watts 4 200 ohm 2 watt resistors wired in parallel will create a dummy load rated at 50 ohms and 8 Watts
This one is good in theory, but not in practice, the heat generated at 80 Watt would destroy the resistors
40 2000 ohm 2 watt resistors wired in parallel will create a dummy load rated at 50 ohm and 80 watts
Endless combinations…….
1 BNC – right angle 4 200 ohm 2 Watt Resistors 1 Head Shrink Tubing
Not a lot of parts…..
To install the resistors, solder one end of each resistor to the center pin of the BNC and the other end of the resistor to the shield
While it is not required to cover the resistors with heat shrink tubing, it is a good idea, eventually someone will be an RF burn from the exposed wires
So I installed the heat shrink tubing and used my soldering iron to shrink the tubing to cover the resistors
Construction of the 8 Watt Dummy Load for the uBitx v5
Build an 8 Watt Dummy Load for the uBitx v5
