# Re: [TCML] Admin: List status and help request

```Hi Steve,

```
Thanks for the reminder. I'll make sure that the postings are available and if there is a limit on the forum, then will figure out some crawling way of doing it.
```
Thanks for sticking around so long! :-)
Chip
On Wed, 10 Mar 2021, steve date wrote:

```
```Greetings Chip,

```
It's been a bit since I've "chipped" in with a response however my concern is that with the existing email system I have been able to save most emails to my hard drive via my client (Thunderbird).  I have thousands of past emails which I am able to search through off-line.
```Will a forum approach allow me to continue to collect my data base?
Just bringing this up for consideration.
steve-seattle

Here is my first saved email from when I joined the list in 1996:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subject: Frequency calculations

```
```>From gowin@xxxxxxxxxxxxxxxxxxxxxxxxxxx  Fri Dec 13 11:58:50 1996
```
```
Date: Fri, 13 Dec 1996 08:59:12 -0500
From: Dan Gowin<gowin@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
To:tesla@xxxxxxxxxx
Subject: Re: Frequency calculations

Tesla List wrote:

```
```>From Esondrmn@xxxxxxx  Thu Dec 12 14:39:51 1996
Date: Thu, 12 Dec 1996 12:51:00 -0500
From:Esondrmn@xxxxxxx
To:tesla@xxxxxxxxxx
Subject: Frequency calculations

All,

```
There was a Tesla Math Formulary published on this list on 8-10-95 - courtesy
```of Richard Quick I believe.  I was doing some calculations last night on my
```
new small coil and found a problem with equation # 6: Frequency of Coil. The
```formula given is: F=300,000 / T x W x pi x (.9144 / 36) x 4  where f =
frequency of the coil in khz, T = number of turns, W = width of the coil in
inches.

Using this formula, I get a number quite a bit lower (like 40 or 5% lower)
than I get using wheelers equation, caclulating the self capacitance then
calculating the resonate frequency .  I have measured the inductance of my
```
present coil and the self capacitance and the frequency and know these other
```methods work as they should.

Has anyone else tried using this formula?

Ed Sonderman
```
```
Ed,
In Foster's book on elctromagnetics I use the formulae
designed for circular pole antanae. And, Brent turner uses the
same formula in his book. But It's probably a good idea to calculate
your coils parameters ten ways from sunday. Sorry, I have not
used the "Richard Q." equation.

1.75(h/d)^0.2
----------------
(1*10^9)    (Fr*d)        = Nt

h = height of coil
d = diameter of coil
Fr = Frequency your shooting for
Nt = Number of turns

Hope this helps.
D. Gowin

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxxxxxx
https://www.pupman.com/mailman/listinfo/tesla

```
```_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxxxxxx
https://www.pupman.com/mailman/listinfo/tesla
```