[Elecraft] Source for Type 31 Toroids

[Ian White GM3SEK]

Fred Jensen wrote:
>On 2/10/2012 2:05 PM, Jim Brown wrote:
>> On 2/10/2012 1:39 PM, Ken Alexander wrote:
>
>> Amidon does not make this stuff. They are a distributor of Fair-Rite
>> and some other manufacturers, and NOT a good one. I'd bet there's no
>> one there who has a clue about anything technical. There USED to be a
>> ham there whose name was Amidon, but he's LONG LONG gone, and any
>> technical data there is a leftover from his days.
>
>Many years ago [as in maybe 54], I needed a ferrite core for a 4:1
>balun.  DX Engineering hadn't been invented then.  I drove over to
>Amidon [N. Hollywood/Burbank-ish] which turned out to be a suburban
>house.  A fellow, who's name was Amidon opened the door, installed me in
>a living room filled to the brim with all sorts of boxes and stuff,
>rummaged around in a bedroom and finally came up with the toroid core.
>He wanted a lot for the core, in fact more than the 16 year old had.  He
>finally asked me where I had come from, and when I told him S. Central
>LA, he gave me the core.
>
>The balun didn't work, probably because I wound it wrong.  I'm really
>surprised they are still in business.


Any company handling anonymous grey toroids needs to have perfect stock 
control... and Amidon still don't. I was sold a large number of #31 
toroids which turned out to be #43 material.

So if you do buy from Amidon, check the weight!

2631803802 = "FT240-31": 112-114g  [1]
2643803802 = "FT240-43": 120-122g  [1]
5961003801 = "FT240-61": 104-106g

Original data from G3TXQ, since verified from dependable suppliers.

[1] The Fair-Rite data sheet says "118.000g" for both of these cores, 
but in fact the weights of #31 and #43 are distinctly different.


-- 

73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek