[Elecraft] [K2] Inductivity of Toroids

[Don Wilhelm]

Daniel,

The inductance of the RF Choke toroids measured at DC or low frequencies 
may not agree with the published inductane which is measured at a higher 
frequency.  Those RF Chokes are not critical, they just need to block 
the RF flow and the bypass capacitor takes care of the rest.

The inductors that are critical are those in the Low Pass Filter. In any 
case, wind them as instructed in the manual and spread the turns over 
85% of the core and they will work.  There are over 7000 K2s out there 
working fine with the toroids wound as instructed in the manual.

73,
Don W3FPR

On 1/1/2013 9:14 AM, Daniel Heise wrote:
> Dear K2-Experts,
>
> I´m just assembling my K2, and it´s true: It really is addictive :)
> After winding my first toroid inductors, I measured their inductivity 
> with an atlas LCR40 component analyser before I soldered them into the 
> RF board.
> Though I closely adhered to the manual, the measured inductivities are 
> almost twice as high than the values stated in the manual (on the 
> parts list in appendix A).
>
> It was good to read on the elecraft homepage, that the inductivities 
> are not too critical for the entire function of the transceiver. But 
> I´m still wondering if anyone else measured the inductivities of the 
> toroid inductors and made similar experiences...
>
> 73, Daniel
> DL6MCL
> Goettingen, Germany