"Roger D. Johnson" wrote:
> I found a meter circuit on the below site that is almost
> identical to the Bird unit. It will be easier to describe
> the differences than to draw out the Bird circuit.
>
> http://members.dandy.net/~k0xp/Technical/PEPMeter/PEPMeter.htm
>
> In the Bird circuit:
>
> R1 and R2 are 1500 ohms
> R3 is 15k ohms
> The second stage is identical to the first
> R8 is 91k ohms
> V1 is in series with the meter (25k) not a voltage divider
> arrangement.
> The Bird has a small LED indicator when it's in PEP mode
> The Bird uses 9 volt batteries dropped to 6 volts by 6.2 volt
> Zeners through 150 ohm resistors. Very wasteful!
> I'm not sure of the value for the cap in the time constant
> circuit. The markings are not revealing and I have not
> unsoldered it to measure.
>
> 73, Roger
Hi Roger,
When you say "the second stage is identical to the first" do you mean
that the second amp has the same value resistors as the first amp (in
the bird) or that the bird second stage is the same as the schematic
that you refer to?
Thanks
Gary K4FMX
|