Re: Grid dip meter

["Ray von Postel" <vonpostel-at-prodigy-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Colin:

>From the "Radio Amateurs Handbook"  1959 edition.  Catalog Section

James Millen,  Malden Mass.
Grid Dip Meter  No. 90651, 1.7 MHz to 300 MHz
 This unit came complete with coils to cover the above frequency range.

  Additional Inductors for Lower Frequencies
        No. 46702_ 925 to 2000 KC
        No. 46703_ 500 to 1050 KC
        No. 46704_ 325 to   600 KC
        No. 46705_ 220 to   350 KH


While not advertised in the catalog, Millen made a set consisting of the
grid dip
meter
and all of the coils from 300 MHz to 220 KHz all in a metal case.

The Millen line of products not only had the GDM, but oscilloscopes, antenna
bridges, r.f.
power amplifiers, variable frequency oscillators and other goodies and
components
for radio. Millen products enjoyed a reputation for quality.

Sorry I don't have any prices.

The Millen unit, with the power turned off, works well as a "wave meter"
with the
advantage that the meter on the instrument works as a resonance indicator.
"Radio Instruments and Measurements"  Bureau of Standards Circular C-74, shows
several uses of the wave meter that are applicable to Tesla coils.

Good luck.
Ray von Postel


Tesla List wrote:

> Original Poster: Parpp807-at-aol-dot-com
>
> Colin,
> You can find GDMs on e-bay but you will probably have to wind your own coil
> to get below 1.7 mHz. Also, check the ARRL and GBRH for construction
articles.
> A GDM is a handy gizmo. :-))
> A sig gen with a VTVM or oscilloscope also work.
>
> Cheers,
> Ralph Zekelman