arnold chokes

Subj:	Arnold Toroid Choke Test
Date:	96-03-15 19:36:54 EST
Bob Shumann asked me for the following information, so I thought I would post
it for anyone new that might also find this info handy, also.

Kevin M. Conkey

Hello all,

I have put my chokes to the test.  For those of you that are unfamiliar
with the Arnold toroids, here are the specs from a previous post on both
the cores and the chokes I have made.

Cores were bought from Hosfelt Electronics.
Hosfelt stock number T-250-B
Mfg.# - FE-2500-1201
OD - 2.5", ID - 1.22", Width - 1"
Color - blue, 0.828 lb
Made from "Arnod HA" powdered iron
Initial Permeability: 60
Inductance per 100 turns: 2,032 uH
Mean path length: 14.96 cm
Cross section: 4.031 sq cm
Suitable for low freq choke or noise filter
PRICE:  $1.49 ea

I made 4 chokes with the Arnold ferrite toroids. They are wound with 24
gauge solid insulated hook-up wire.  There are 2 complete layers of
wire.  While I didn't count the turns exactly, I estimate that there
are between 110 and 120 total turns.  There should be about 65 on the
first layer and 50 on the second.  The measured inductance value for
each one is 2.81, 2.83, 2.94 and 3.10 mH.

I placed 2 in series per side of the 15 KV neon transformers.  I was
careful to use a lot of standard 7 mil. electrical tape between layers.
I was also very careful to keep the leads clear of all of the turns.
The voltage drop between the layers didn't cause a burn-out.  I made 2
consecutive runs of a full 5 minutes each with the coil belting out 5'
discharges.  The safety gap was firing every few seconds.  There appears
to be no problem with this design (so far).  I felt the chokes after
these runs and they felt only slightly warm.  It may have been just me.
I will have to make a few more longer runs before feeling these chokes
are going to be completely reliable.

So, there's the initial test of my chokes.

Scott Myers