[Amps] L section of Pi-L filter

[Karl-Arne Markström]

1. Toroids have to be quite heavily dimensioned, as
they are storing a lot of magnetic energy in a small space.
At an L-network Q of 2 they have to store at least 2000 VAr in the toroid 
magnetic material, and the corresponding flux density is quite high.

Even the largest iron-power toroids available may be marginal in this 
application, as the core losses for i.a. #2 material are in the 10's of 
watts range.

2. Using "reasonable" network Q:s, the current in the L-network part is 
about 80 - 90% of the current flowing in the Pi-part, so the same wire 
gauges are required.

The "Pi-L Designer" utility by Jim Tonne is a very useful tool for output 
circuit design, together with the DL5SWB Mini Ring Core calculator.

73/

Karl-Arne
SM0AOM


----- Original Message ----- 
From: "Ulf Tjerneld" <star at frizon.org>
To: <Amps at contesting.com>
Sent: Wednesday, January 06, 2010 7:33 PM
Subject: [Amps] L section of Pi-L filter


> Hi,
>
> Question 1: I'm considering using toroids in the L-section of my RF tank. 
> Are there any guidelines regarding suitable cores, wires and turns?
>
> Question 2: If I stay with a traditional air wound coil for the L-section 
> what would be a suitable wire diameter for a 1 KW amp? I'm pretty sure it 
> does not have to be the same heavy gauge as in the Pi-section!
>
> Thanks for any answer!
>
> 73's  Ulf /SM0NOR
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.725 / Virus Database: 270.14.127/2603 - Release Date: 01/06/10 
08:35:00