>Don't forget: in power amplifiers you use transmission line transformers,
not flux coupled transformers, so that >the core's main function is to
increase the inductance of the cores at low frequencies, not transfer
energy.
?? Do you mean "increase the inductance of the transmission line?"
-Rex-
K1HI
Rex Lint
Merrimack, NH
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of Alex Eban
Sent: Sunday, March 29, 2009 2:00 AM
To: dansawyer@earthlink.net
Cc: 'Amps'
Subject: Re: [Amps] 'red' cores versus 43 cores
What you need is a material with an initial permeability of about 125.
Forget about color codes, they pertain only to Micrometals cores!
You need a material similar to the 4C6 from Philips, now Epcos: it has a
lower tangent loss than most. Amidon has such cores. Try also Bytemark, I
think their material is #62.
Don't forget: in power amplifiers you use transmission line transformers,
not flux coupled transformers, so that the core's main function is to
increase the inductance of the cores at low frequencies, not transfer
energy.
Alex 4Z5KS.
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of Dan Sawyer
Sent: Sunday, March 29, 2009 5:27 AM
Cc: Amps
Subject: Re: [Amps] 'red' cores versus 43 cores
Thanks to all of you for the replies. The first interest is to build and
test a 300 watt input and output transformer pair.
The reason I chose #43 to discuss was it was mentioned in at least one
of the Motorola 2 to 30 MHz amplifier app notes. Should #61 be used for
this purpose? Should the input and output use the same material?
Dan kb0qil
Dan Sawyer wrote:
> Is there a straightforward practical or operational description of the
> difference between 'red' cores and 43 material. The magnetic differences
> are large. However, the 'red' cores are used in low power mixers and the
> 43 cores are used in rf power transformers for similar frequency ranges.
>
> What would happen if a mixer were made from a 43 core?
> What would happen is an output transformer were made from 'red' cores?
>
> Thanks Dan kb0qil
> _______________________________________________
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> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
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