Cecil Moore wrote:
Cecil Moore wrote:
I also have a GDO. If I get an open circuit dip, would
that be the parallel resonant frequency? If I get a
short circuit dip, would that be the series resonant
frequency?

I have a 20 turn choke wound on a 5.35" diameter
Quaker Oatmeal box at four turns per inch. I used
my Grid Dip Oscillator to determine the open-circuit
(parallel) self-resonance at 11 MHz. The short-circuit
(series) self-resonance is at 23 MHz.

This is a Knight Kit G-30 GDO with the original
6C4 still working. I built it from a kit in 1959.

What kind of wire, what kind of insulation, and how much gap between
turns? It affects the self-capacitance.

I'd like to try that on the VNA, but here in the homeland of porridge,
oatmeal boxes are rectangular! Also we'll soon have visitors arriving
for the rest of the weekend, so if anyone in the land of cylindrical
oatmeal boxes can get to it in the next couple of days, please go ahead.


--
73 from Ian GM3SEK