Ross Phaser LFO....

[lightningfingers]

I've got to the LFO section of my ross phaser clone....i'm sure I put it together right, so how do I test it, what do I look for at the "output"??

Thanks :mrgreen:

[Mark Hammer]

Ideally, you have a scope.  But if you don't, the simplest thing is to set it for the slowest speed and use a DMM.

[gez]

In the days before I owned a scope I used to use an old log meter and stick a huge value cap in parallel with the cap which sets the rate.  This allows you to track the waveform smoothly by following the dial as the wave sweeps up and down.  I tuned a good many oscillators this way (and many were spot on when I finally got to check them with a scope)!

A DMM is the next best thing though (if you don't own a scope).

[StephenGiles]

I would have thought an analogue volt meter would be better because you can see the voltage rising and falling, all you see on a DMM are changing numbers.
Stephen

[puretube]

I second Stephen :wink:

[gez]

I meant that a DMM is the next best thing to an analogue meter (if you don't have one and assuming that you don't have a scope) - better than nothing (no you won't be able to track the waveform very well, but at least you know it's working)!

[puretube]

ooops: re-reading that post, I second GEZ & Stephen!  :!:

[lightningfingers]

Right, so at the slowest speed, I am looking for a changing voltage at the LFOs output?

[puretube]

yes.
I don`t have that schem exactly in my head (  :wink:  ), but if it`s the one similar to the SmallStone, you could try a 2k2 resistor in series with a low-current LED from output to ground: it should show short "flashes"
(short "on" - long "off").

On a scope, the trace should look like a couple of round-bellied,
hand-written "WWW"-s connected together.

[gez]

Or as 'Sexist Sid' might reply: "like a pair o' jugs wi'oot the nips shawin"

[lightningfingers]

:lol:  :lol:  :lol:

I will try using an LED, my meter seems to be telling me its working but I want to be sure...

Thanks a lot guys