[Elecraft] re: K3 BCB reception weak

[wayne burdick]

N4LQ wrote:

> Is sensitivity very low below about 1000khz in the BC band or is it 
> just me?
> It really drops off there and I can only pick up a couple of really 
> strong
> stations below that. I did install the KBF3. Does that attenuate the BC
> band?
> I did make sure the ATU was in bypass.
> Steve Ellington
> N4LQ at insightbb.com

Hi Steve,

All PIN diodes, including those used in the K3's T-R switch, are 
susceptible to increasing intermodulation as the applied signal 
frequency decreases. We selected diodes that perform very well at low 
frequencies, but as a precaution, we designed the T-R switch to have a 
high-pass response below 1 MHz. At 500 kHz, the roll-off is around 15 
to 20 dB. At 1.5 MHz, the roll-off is only a dB or so. We feel that 
this is a good tradeoff.

There's a note about this in the Owner's Manual (in Rev. C, it's on the 
right side of page 36). But I'll also add this to the Specifications 
page.

73,
Wayne
N6KR

---

http://www.elecraft.com