LF: Iron dust toroids and heating

[Chris Wilson <dead.fets@GMAIL.com>]

Hello LF'ers,

24 May 2017


If I run the combiner on my 2 amps the LPF centre toroid heats up. I
made a silly mistake with setting my U3S driver the other night and
instead of TX'ing every 30 minutes it went on an every two minute
rampage before it soon self halted. The centre toroid winding has lost
most of its enamel coating and the Kaptan tape is crispy. It no longer
functions as an LPF, and I suspect the T225A-2 toroid is compromised
in its crystalline structure, through the very high temperatures, now.
115uH seems to be the calculated figure, if not actually measured (73
turns 14 AWG enamelled wire) of the centre inductor. An air core coil
of similar inductance isn't THAT big, (at least not the size of a
"small car" as someone on a US forum estimated :)) Is an air cored LPF
viable, or do i need to look at different core sizes or materials?
Thanks. LPF is at:


http://www.w1vd.com/LPF.html

Thanks.

  

-- 
Best regards,
 Chris                          mailto:dead_fets@gmail.com