[Amps] 160M PI network Toroidal Coil

[Carl]

----- Original Message ----- 
From: "Jeff Blaine" <keepwalking188 at yahoo.com>
To: "Manfred Mornhinweg" <manfred at ludens.cl>; <amps at contesting.com>
Sent: Monday, October 07, 2013 3:07 PM
Subject: Re: [Amps] 160M PI network Toroidal Coil


> It probably does not matter in any event.
>
> Either the gentlemen is running CW/SSB - and in that case, whatever coil 
> he uses will work out FB as the duty cycle won't be much of an issue - a 
> few watts lost one way or the other won't be of significance.
>
> Or he will be running a data mode and without a lot of case, the 
> transformer be at the center of a self-correction event occurring long 
> before the coil (of whatever construction type) is a factor.
>
> 73/jeff/ac0c
> www.ac0c.com
> alpha-charlie-zero-charlie
>
> -----Original Message----- 
> From: Manfred Mornhinweg
> Sent: Monday, October 07, 2013 12:58 PM
> To: amps at contesting.com
> Subject: Re: [Amps] 160M PI network Toroidal Coil
>
> Carl,
>
>> The T-225/225B (there is no T225-2A) size buys you absolutely nothing
>> over the 200 size except a few more turns of wire of the same
>> diameter.
>
> Wrong. While the inductance per turns of the T-225 and the T-200 is the
> same, the larger core will run at lower flux density when used in the
> same amp, wound for the same inductance. So its volumetric loss will be
> much lower. It has more volume though, so that the total loss decreases
> only somewhat. But it has much more dissipation surface, so that it ends
> up being able to handle significantly more power, or run cooler at a
> given power level.

** Youre certainly wrong all right Manfred.

The slight size difference is not enough to make much difference especially 
when only about 1/2 the turns the core is capable of for a pratical SB-220 
conversion using stranded #14 are used and well spaced.  When using a pair 
of T200-2 or a single T200-2A the pair will run cooler.


>
> And the 225B size is of course much larger and very different from the
> non-B size.

** It is twice the height and the same diameter as the T-225. The T-200A has 
the same double height.


> And at least there _was_ a 225A. It shows up in older catalogs. The
> T-225A-2, as listed in an Amidon catalog from 1995, was very similar to
> the current B size, only that the inner diameter was a little bit smaller.
>
> Manfred

** I really dont care about ancient history but FYI I was selling the 225A 
back in 1985 and the B when it replaced it around 92-93.

Carl
KM1H


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