Richard Corfield (M0RJC)
Home made "FT-Meter" for Yaesu FT-897
The large 1mA meter is a bit sluggish to be really useful for modulation and power display. Maybe a peak hold circuit could help there as peak is the useful thing to know for those two parameters. I can always use the LCD display on the radio for the fast moving values.
I don't know if a 100uA would be less sluggish. Still, it's a nice big meter. It looks the part!
One idea I have is to build a driver circuit for it. It would be interesting to drive it from the low impedance output of an op-amp. I could also have a go at adding a differential signal in a feed-forward configuration.
The radio in this shot is running off battery power using an external battery pack which is also propping up the meter.
Home made "FT-Meter" for Yaesu FT-897
The large 1mA meter is a bit sluggish to be really useful for modulation and power display. Maybe a peak hold circuit could help there as peak is the useful thing to know for those two parameters. I can always use the LCD display on the radio for the fast moving values.
I don't know if a 100uA would be less sluggish. Still, it's a nice big meter. It looks the part!
One idea I have is to build a driver circuit for it. It would be interesting to drive it from the low impedance output of an op-amp. I could also have a go at adding a differential signal in a feed-forward configuration.
The radio in this shot is running off battery power using an external battery pack which is also propping up the meter.