Walkie-Talkie Maximum Volume Levels

Made a few simple maximum volume level measurements for the family’s HT collection to see which are loudest and in what configuration (radio alone or radio + speaker microphone). Now have a better understanding of what radios to use for different operating conditions after these tests.

Test Setup: FM Signal Generator was Pluto SDR with SATSAGEN control software. Signal generator was positioned nearby (upper right) sending a 1 KHz FM modulated at 2 KHz deviation test signal to the walkie talkie being tested.

Audio Path Measurement: Setup test on usual desktop workspace with Radio Shack 33-4050 Sound Level Meter up on a small tripod at right. Separation distance was about 12" with speaker output and sound meter microphone input roughly the same height above the table.

With hearing protection worn*, turned up the volume to maximum on the radio and recorded the Sound Pressure Level (SPL) with the meter set to Fast Response and Type C Weighting. The RS 33-4050 meter has manual range adjustment. Only the 100 and 90 ranges were used for these measurements.

* These tests were very loud, with my watch's Loud Environment warning going off multiple times. Hearing protection is needed for these types of tests.

Results: Measured all the HT's and confirmed that the Motorola's appear loudest, the Yeasu's appear quietest, and the others (AnyTone, Baofeng and Tytera) fall between. Speaker microphones make some difference, but not as much as I would have guessed prior to these tests. It's nice that the 12 Volt Power speaker microphone audio outputs are actually louder than the AT-D878 radios. Was surprised to learn that!

Future Thoughts: Would like to setup a test to measure the SPL output for a given / measured distortion level. Have the sub-system elements to conduct this test in the future, but need to write some SW to make it all work together nicely. Future fun!