Sunday, March 08, 2020

FM deviator meter

Not much, here, found it interesting to have a deviation meter so on those rare occasions I'm working on FM will have something to base measures on.

This one does not comes with incorporated receiver as "traditional" ones do but relies on the discriminator out from a radio receiver or scanner. It will work in tandem with my scanner from previous post.

The circuit is based on the work by VK5DJ and VK5VI
Schematic is this one:

For 1mA panel meter I found 9K1 resistor in series from pin 7 (R15) on IC2 to be enough.

If you download the file from VK5DJ site there will be some mod's and better resolution diagrams, including "veroboard" design.

The end result, here on top of the COM205 scanner:



another view:



inside:



...still need to calibrate and "fill" the table on the front panel because It's easier and faster than making an overlay for the 1mA meter

Have a nice day!

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