The dimensions of both inductance and capacitance are Length.

Length is idependent of frequency.

On Sat, 13 Dec 2003 15:15:42 +0000 (UTC), "Reg Edwards"
wrote:

The dimensions of both inductance and capacitance are Length.

Length is idependent of frequency.

??? You feeling alright, Reg?
--

"I expect history will be kind to me, since I intend to write it."
- Winston Churchill

On Sat, 13 Dec 2003 15:15:42 +0000 (UTC), "Reg Edwards"
wrote:

The dimensions of both inductance and capacitance are Length.

Length is idependent of frequency.

??? You feeling alright, Reg?
--

"I expect history will be kind to me, since I intend to write it."
- Winston Churchill

A rule of thumb says that the screen around an oscillator coils could
be 3 times the coil diameter, and Radiotron Designer's handbook, 3rd
edition, 1941 says that the screen should go at least one coil radius
above the coil. But how far from the chassis should the coil winding
start?

73
Jan-Martin
LA8AK, http://home.online.no/~la8ak/c.htm

A rule of thumb says that the screen around an oscillator coils could
be 3 times the coil diameter, and Radiotron Designer's handbook, 3rd
edition, 1941 says that the screen should go at least one coil radius
above the coil. But how far from the chassis should the coil winding
start?

73
Jan-Martin
LA8AK, http://home.online.no/~la8ak/c.htm

On Wed, 11 Feb 2004 01:46:54 +0100, "Jan-Martin Noeding, LA8AK"
wrote:

A rule of thumb says that the screen around an oscillator coils could
be 3 times the coil diameter, and Radiotron Designer's handbook, 3rd
edition, 1941 says that the screen should go at least one coil radius
above the coil. But how far from the chassis should the coil winding
start?

73
Jan-Martin
LA8AK, http://home.online.no/~la8ak/c.htm

Wouldn't you presume one coil radius above the chassis?

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Wed, 11 Feb 2004 01:46:54 +0100, "Jan-Martin Noeding, LA8AK"
wrote:

A rule of thumb says that the screen around an oscillator coils could
be 3 times the coil diameter, and Radiotron Designer's handbook, 3rd
edition, 1941 says that the screen should go at least one coil radius
above the coil. But how far from the chassis should the coil winding
start?

73
Jan-Martin
LA8AK, http://home.online.no/~la8ak/c.htm

Wouldn't you presume one coil radius above the chassis?

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

I read in sci.electronics.design that Jan-Martin Noeding, LA8AK
wrote (in
) about 'Need more details for mounting high-Q oscillator coils?', on
Wed, 11 Feb 2004:

A rule of thumb says that the screen around an oscillator coils could be
3 times the coil diameter, and Radiotron Designer's handbook, 3rd
edition, 1941 says that the screen should go at least one coil radius
above the coil. But how far from the chassis should the coil winding
start?

The 'at least one radius' thing applies at both ends. The magnetic field
of a solenoid is axially symmetrical.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

I read in sci.electronics.design that Jan-Martin Noeding, LA8AK
wrote (in
) about 'Need more details for mounting high-Q oscillator coils?', on
Wed, 11 Feb 2004:

A rule of thumb says that the screen around an oscillator coils could be
3 times the coil diameter, and Radiotron Designer's handbook, 3rd
edition, 1941 says that the screen should go at least one coil radius
above the coil. But how far from the chassis should the coil winding
start?

The 'at least one radius' thing applies at both ends. The magnetic field
of a solenoid is axially symmetrical.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

On 11 Feb 2004 05:59:20 GMT, (Avery Fineman)
wrote:

A rule of thumb says that the screen around an oscillator coils could
be 3 times the coil diameter, and Radiotron Designer's handbook, 3rd
edition, 1941 says that the screen should go at least one coil radius
above the coil. But how far from the chassis should the coil winding
start?

About the same distance. :-) The old Radiotron book (I have a CD
for one of the editions as a keepsake) has charts showing the
inductance reduction and Q reduction for various relative diameters.
The closer the enclosure, the more reduction of both values. That
sould be accounted for in any resonant applications, especially those
for tracking as in superhet or TRF front-ends.

The conducting enclosure or shield contains the magnetic field on the
coil and, ideally, should have the same clearange from both top and
bottom of the winding. It will still work with an assymetric clearance
but L and Q are spoiled by the closer spacing.

Well, I forgot to say that I would leave the top side open, so it is
somewhat more distance from the hot side of coil to the metal surface
than in the bottom, but thanks to all for the reply

Toroidal cores are much less affected by conducting enclosures due to
the magnetic field contained largely IN the torus' core material.

Len Anderson
retired (from regular hours) electronic engineer person

on this side you you are put in an office landscape and all the tool
is a PC with Microsoft programs, soldering iron is not permitted any
more, you just have to be constructive, hi, so I now prefer thermionic
valves at home

73