[Elecraft] K3 6m pre-amp

[Jack Smith]

Yes, I have several ferrite core 2.5 mH chokes here, including the 
Hammond one you mention. There's a significant difference in high 
frequency performance of the pi wound on ceramic form versus the smaller 
pi-wound over ferrite and that's one of the things I'm hoping to 
illustrate in the article. Hence, I needed a genuine 2.5 mH "National 
Radio" style choke.

Jack


K7TV wrote:
> Try Antique Electronic Supply (www.tubesandmore.com).
> Their 2.5 mH is good for 160 mA, made by Hammond,
> core material is ferrite, 3 pi-windings, diameter 0.469", price 
> $3.95.
>
> Erik K7TV
>
>
>   
>> Another used-to-be-common part is a 2.5 mH RF choke, pi wound on a 
>> ceramic form. After a lengthy search, I found Hammond still makes these, 
>> only to learn that they were discontinued earlier this year. I managed 
>> to get one (at a price of $14) and it's good that I only needed one to 
>> use as a comparison reference for a QEX article I'm working on.
>>     
>
>
>