Re: Grid Dip Oscillator
From: Alfred A. Skrocki[SMTP:alfred.skrocki-at-cybernetworking-dot-com]
Sent: Sunday, November 30, 1997 9:09 AM
Subject: Re: Grid Dip Oscillator
On Sunday, November 30, 1997 1:55 PM Malcolm Watts
> Perhaps I ought to clarify what I was trying to say as it appears
> to have been misconstrued in several quarters....
> > > Not really. You have to get too close to the secondary coil to
> > > use the thing and that seriously affects frequency.
> > Not so, Malcolm! The grid dip meter was a very effective
> > instrument to tune tank circuits with, the trick was learning how
> > not to over couple to the meter. When loosely coupled to a coil a
> > dip meter has no noticeable effect on the coils resonant
> > frequency.
> All the GDOs I've ever used are hand held beasts. The point I was
> attempting to make was that in using one, *you* have to get
> physically close to the coil and as we all know, that certainly
> *does* alter the coil's characteristics markedly. Having said that,
> perhaps there are GDOs one can operate remotely ???
In theory your correct but in practice a properly used Dip meter
won't interefere with tuning a coil or measuring it's resonant
frequence. There is a simple circuit I remember in a back issue of
Popular Electronics (in the 50's) that used a signal generator, an
inductor, a diode and microamp meter as a Dip meter and only the
coil needed to be in proximity to the tuned circuit to be measured,
but using even the hand held dip meters I've never experienced any
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Alfred A. Skrocki
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