Audio output meter.

[Kentode]

I'm about to start making Paul's Audio output meter and have just received the meter movement from China. They sent a 0-500 uA by mistake!

Here is the required r/c for R1 and C2.

0-100 uA 47K and 1uf.
0-250 uA 18K and 2uf. Based on these figures, how about
0-500 uA 9K and 5uf ?

I'd like to use as much of the scale as possible to make it easier to see small movements.

Any other thoughts?

[JonSnell]

R1 is 18k.
Replace it with an 8.2k and place a 10k preset in series with the meter movement. Adjust the preset to the desired level.
That will give you a decent scale to work with.
The voltage doubler won't be affected, I wouldn't think.

[Kentode]

Thanks Jon, that's an elegant solution!

I'm about to attempt my first alignment on one of a pair of Bush VTR 103's, starting with the tatty one which I'm using as a test bed before moving on to a very good condition (complete with red-topped aerial) example.

I'll post my results in the next few weeks...

A lot of overthinking going on, all you need is an indicator of a peak, the absolute range doesn't matter. If you can see the peak it is good enough.

[Kentode]

Me, overthinking? That's a first!

But yes, I agree.