[Elecraft] K-1 4-band Availability/Status?

[Wayne Burdick]

The part we used was Sprague-Goodman GCL40000 (now obsolete). These are 1-40 pF with a very low temperature coefficient.

Trimmers still available have TCs that are 2 to 4 times worse, and have a higher minimum C. These are fine for applications where small drifts in C with temperature don't significantly alter the passband of the filter (e.g., in the KFL1-2, K2, and K3). But the KFL1-4 requires very high-Q filters in order to remove mixing products from both the pre-mixer and transmit mixer stages. The low minimum-C is needed for the higher-band filters.

We found that if we used trimmers with a worse TC on the KFL1-4, then power output would temporarily drop (in some cases by 50-70%) when the K1 was operated at an ambient temperature quite different from that at time of alignment. That would be unacceptable for a rig often used outdoors.

73,
Wayne
N6KR


On Mar 7, 2015, at 8:06 AM, "Wes (N7WS)" <wes at triconet.org> wrote:

> On 3/6/2015 9:33 PM, Don Wilhelm wrote:
>> The part number for the bare KFL1-4 board is E100129 as listed in the KFL1-4 manual.
> 
> Is there a commercial P/N specified for the capacitors?
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