This is a QRP dummy load that I built at very little cost and it will
work well up into the VHF range. All parts were gotten from
Mouser, except the 1N34 germanium
diode. This was probably gotten from
Circuit Specialists. The load resistor is only one non-inductive
resistor of 50 ohms. This is different than most QRP dummy loads in
that the load is made of several carbon composition resistors. I
decided to splurge and just go for the 1 non-inductive load. This dummy
load isn't exactly QRP though. It will handle up to 15 watts of RF.
Also, it does incorporate a demodulator for DC output. For this you
must measure the voltage with a DVOM that has an impedance of 10Meg
Ohm's. Then voltage can be reduced to output power from;
P=V²×R
Here is a schematic and parts list along with some pictures in case
you would like to build one of these.
- 1 BNC Conn. - Mouser#523-31-221-RFX
- 1 Load 50ohm non-inductive - Mouser#684-MP915-50
- 1 Heatsink for Load - Mouser#532-577500B00
- 1 Metal Enclosure - Mouser#537-TF-770
- 1 Keystone terminals - Mouser#534-4189
- 1 1n34 Germanium Diode
- 1 4.7Meg ohm Resistor Carbon 1/4W
