Mode Zero

I recently got a Controlaire 10 transmitter and would like to change it to 2.4 using the innards from my Kraft 12 channel conversion. The meter from the Kraft is too small to fit the hole in the Controlaire. Does anyone out there know if I can used the Controlaire RF meter as a battery voltage check function using a momentary push button? . My Kraft has a RF strength / battery meter that had a factory installed battery test button with a 10K ohm resistor in series with the switched + battery lead to the + terminal on the meter and it worked.
I have a momentary push button which will fit in the old charge jack hole below the on/off switch.
I did not want to experiment with the Controlaire as you only get one chance before you let the smoke out so no guess work on this one.

Suggestions appreciated.

Thanks

Mike (MJF)

Yes, you can and it will work fine. Most of those meters were 100uA types, so you would nee quite a high value resistor.

If you are planning to use LiPo or LiFe cells to power it - or even if you are sticking with NiMhs, I would recommend sticking a suitable voltage zener diode in series, so that it becomes an expanded scale meter - ie: if you are using a 2-cell LiFe pack (6.6V nominal) use a 4.7 or 5.1 volt zener so that it will only show volts in excess of that value.

Modern packs drop off very sharply as they get near the end of their capacity, and an expanded scale meter gives you much better warning!

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Pete

Thanks for your quick response Mr Christy.

I will be using a typical 8 cell NiMh 9.6V nominal pack to power the transmitter.

Maybe I will start with a 47K resistor and see what readings I get from there.

Definitely do not want to damage the irreplaceable meter.

Thanks again


Mike