Hobbico Frequency Checker

| Wondering if anyone has converted this item to run off an AC | adapter.

Dunno, but it would be trivial to do so.

| I would guess it would take an adapter that puts out about 4.5 | volts??

Sounds like a good guess. Note that not all wall-warts are equal, and if it says it puts out 4.5 volts at 100 mA, it might put put 6 volts at 20 mA or something similiar. You might want to put a 4.5 or 5 volt voltage regulator into the mix to make sure the voltage isn't too high.

Note that the frequency checker uses very little power. I accidently left mine on for 24 hours and it was still working -- obviously the 3 AAA batteries weren't dead yet. The only real reason to need an AC adapter would be for some sort of permanent installation. (And it must be nice -- none of the fields I fly at have AC power, though one does have solar provided 12 V power :)

I'd agree with making sure you get a good quality REGULATED and preferably one with a smoothed output as well (translation: at least a big capacitor across the output terminals), not just the cheapest one you can find. The last thing you want is mains hum or any other spurious signals flooding the circuitry!

Chris