Controlaire Mule transmitter output.
Posted: 29 Mar 2023, 04:30
I have been troubleshooting some Controlaire “Mule” single channel radio systems. During this exercise I decided to try and measure power output of the transmitters. I built a test rig with a load resistor (49.8 ohms) and measured the Vp-p and Vrms across this resistor with my oscilloscope.
I measured all 4 of the mule transmitters and using ohms law calculated the power output. Mule #1 was measured with the original output transistor and a 2n2222 (since after measuring Mule #1 the output seamed low in comparison). Mule 4 is a “extra power” version one and it does seem to have extra power.
I have a couple of questions:
1. Does this seem like a valid method of testing?
2. Has anyone replaced the output transistor (2n3643) with good results? I was thinking of trying an NTE123, but if someone has found a suitable replacement It would save me some time figuring it out and I would appreciate it!
Thanks for your time!
Test results:
I measured all 4 of the mule transmitters and using ohms law calculated the power output. Mule #1 was measured with the original output transistor and a 2n2222 (since after measuring Mule #1 the output seamed low in comparison). Mule 4 is a “extra power” version one and it does seem to have extra power.
I have a couple of questions:
1. Does this seem like a valid method of testing?
2. Has anyone replaced the output transistor (2n3643) with good results? I was thinking of trying an NTE123, but if someone has found a suitable replacement It would save me some time figuring it out and I would appreciate it!
Thanks for your time!
Test results: