From: "Barton B. Anderson"
Date: Sat, 23 Feb 2002 16:23:51 +0000
Subject: Re: [TSSP] Marc's flat coil
--Boundary_(ID_FPY6f9zJfQYI/9zV1a1BvQ) Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT Hi Marc - Neet! Glad to see another flat coil being measured. Can you do me a favor and check the outer diameter around the coil to ensure it's 20" consistently around the coil? Also, have you measured the bare and insulated wire diameter with a dial caliper? I'm finding it difficult to figure out how to get 756 turns with heavy build (the total insulated wire diameter should be somewhere around 0.0146". If it's nearer to 0.0136", then it's single build). With this single build value, the outer diameter calc's to 20.005" which matches your measurement. Take care, Bart Metlicka Marc wrote: > All, > Flat coil update from Marc M.: > > I finished unwinding and rewinding the 20" OD coil, It is flat and has > very little "lifted turns". > I have so far (last night) checked some parameters and have gotten: > > 20" coil wound with 28g heavy build mag wire, all windings are tight, > But in using duct tape as a holding surface, the coil looks kinda like a > "brick wall" due to the tape overlaps. I don't think it will effect > operation, But it may be note worthy? > I have counted 756 turns from a 38" ID around a brass bolt, outward. > Sooo: > 756 turns > 10" radius > dc resistance checks at 125.46 ohms > Inductance measures at 93.06mh @ 1khz > series Q = 4.3 > A quick check of selfC measures at 40pf from inside wire outward and > 38pf from outside end inward (measured just for giggles) > > All measurements were made with an esi model 250 DE universal impedance > bridge. > All measurements were made with the coil 38" from the floor, positioned > on an all wood bar stool, 5' clear space on all sides and a ceiling > height of 7' 8". There are some heavy metal items against the wall and > around the coil starting at 5' away (drill press, hobby lathe, "HUGE" > heat sink on an ac drive leaning against wall) so if needed i will clear > further. > > Tonight i will sweep for fo, double check selfC with my general radio > capacitance bridge and do some playing around, also try to get Paula to > count turns for accuracy (after counting the 3k coils turns twice for > me, this may be difficult?), I will post results. > > Any further suggestions for testing will be greatly appreciated and I > will promise to give 110% to get accurate results. > > Take care, > Marc M. --Boundary_(ID_FPY6f9zJfQYI/9zV1a1BvQ) Content-type: text/html; charset=us-ascii Content-transfer-encoding: 7BIT Hi Marc -Neet! Glad to see another flat coil being measured. Can you do me a favor and check the outer diameter around the coil to ensure it's 20" consistently around the coil? Also, have you measured the bare and insulated wire diameter with a dial caliper? I'm finding it difficult to figure out how to get 756 turns with heavy build (the total insulated wire diameter should be somewhere around 0.0146". If it's nearer to 0.0136", then it's single build). With this single build value, the outer diameter calc's to 20.005" which matches your measurement.
Take care,
BartMetlicka Marc wrote:
All,--Boundary_(ID_FPY6f9zJfQYI/9zV1a1BvQ)--
Flat coil update from Marc M.:I finished unwinding and rewinding the 20" OD coil, It is flat and has
very little "lifted turns".
I have so far (last night) checked some parameters and have gotten:20" coil wound with 28g heavy build mag wire, all windings are tight,
But in using duct tape as a holding surface, the coil looks kinda like a
"brick wall" due to the tape overlaps. I don't think it will effect
operation, But it may be note worthy?
I have counted 756 turns from a 38" ID around a brass bolt, outward.
Sooo:
756 turns
10" radius
dc resistance checks at 125.46 ohms
Inductance measures at 93.06mh @ 1khz
series Q = 4.3
A quick check of selfC measures at 40pf from inside wire outward and
38pf from outside end inward (measured just for giggles)All measurements were made with an esi model 250 DE universal impedance
bridge.
All measurements were made with the coil 38" from the floor, positioned
on an all wood bar stool, 5' clear space on all sides and a ceiling
height of 7' 8". There are some heavy metal items against the wall and
around the coil starting at 5' away (drill press, hobby lathe, "HUGE"
heat sink on an ac drive leaning against wall) so if needed i will clear
further.Tonight i will sweep for fo, double check selfC with my general radio
capacitance bridge and do some playing around, also try to get Paula to
count turns for accuracy (after counting the 3k coils turns twice for
me, this may be difficult?), I will post results.Any further suggestions for testing will be greatly appreciated and I
will promise to give 110% to get accurate results.Take care,
Marc M.
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.