OT1+, T2 & Yaesu FT-2800M
- Hey groups - When wiring up a recently purchased Yaesu FT-2800M for APRS use, I discovered that pin 3 of the 6 pin modular mic plug is what the radio uses to power the backlight on the handheld mic. Pin 4 is Ground, pin 5 is TX in (audio to the radio), pin 6 is PTT.
Pin 3 shows 7.95V on my multimeter. I've tested both the OT2m and OT1+, and they show 7.65 and 7.85 volts in the software config, respectively. I ran both for a few hours last night with no noticable degradation in performance (I know 7-8 volts is within the operating spec of the hardware, but it's on the lower end of things).
Of course, when powering via the radio, you'll loose the ability to report battery voltage via the comment field, but for my home setup, one less wire makes for an even cleaner install.
I don't know what the rated draw is for the mic backlight, but I don't see a max 30mA draw of the OT2m during transmit bursts causing any trouble. Of course, I would consult the FT-2800M service manual before trying to power a GPS off of it.
On a side note, I'm still surprised how much more happy the OT+ is when a lot of audio is thrown at it. I haven't figured out where the sweet spot is yet with the FT-2800, but at full volume, it's decoding pretty much anything I can hear.