[Lowfer] Ferrite Toroid vs. Binocular Ferrite

[Stan, W1LE]

Hello Jay,

Thanks for the details.
I noticed that you had migrated to the binocular cores, on your K9AY 
array for lower freqs.


Next question:
I see some bifilar windings are made from twisting a pair of wires 
together before winding onto the core.
Some bifilar windings are just parallel wires bonded together.
Are there any performance advantages or disadvantages ?


I hope every one on the Net is having the very best of this holiday season.

Stan, W1LE     Cape Cod    FN41sr



On 12/22/2010 6:17 AM, jrusgrove at comcast.net wrote:
> It's been my experience that binocular cores make better broadband transformers ... lower loss and
> wider bandwidth compared to toroidal cores. This is especially true when using conventional winding
> instead of bifilar on toroids. The binocular primary to secondary capacitance usually comes in
> around 10 pF ... which provides very good isolation at LF and VLF. If high primary to secondary
> isolation is important line the binocular tubes with some sort of tubing - I use 'unshrunk' heat
> shrink tubing. Some ferrite materials are rather conductive.
>
> Jay W1VD  WD2XNS  WE2XGR/2
>
> . ----- Original Message -----
> From: "Stan, W1LE"<stanw1le at verizon.net>
> To:<Lowfer at mailman.qth.net>
> Sent: Tuesday, December 21, 2010 9:31 PM
> Subject: [Lowfer] Ferrite Toroid vs. Binocular Ferrite
>
>
>> Hello The Net:
>>
>> For the same ferrite material, what is the difference in the performance
>> between
>> a binocular and a toroid form factor ?
>>
>> My preliminary thinking is that the same pri and sec turns will yield
>> the same bandwidth and performance  on either.
>>
>> What is the wisdom and experience ?
>>
>> Stan, W1LE      Cape Cod     FN41sr