[Collins] KWM-380 low pass filter help

[Dr. Gerald N. Johnson]

On Wed, 2008-12-10 at 19:10 +1030, Lee wrote:
> Hello All
>  
> Does anyone know where I can get the toroids used in the A2A1 low pass
> filter board?
> I had a look using google and couldn't anything that looks like them I
> have measured aprox
> 12mm o/d 12mm height and 5 mm i/d as you know 12mm is 1/2" aprox. 
>  
>  
> Thank you.
>  
> 73 Lee

Fitting toroids takes a lot more than just the physical dimensions.
There are many possibilities in core permeability and windings to make
each one unique.

What are the ratings needed for the inductances? Is this the RF low pass
filter or an audio low pass filter?

While often not reasonably priced, Surplus Sales of Nebraska, has many
Collins parts including for the KWM-380. I don't have any documents on
that radio so I can't dig for those details.

-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer