[Elecraft] KSYN3A Synthesizer problem?

[Wayne Burdick]

Roger,

More on this...

Since KSYN3A buyers may not always see the FAQ, we'll be adding something like this to page 1 of the KSYN3A installation manual:

* * *

Note on K3 low-frequency (100-400 kHz) receive coverage with the KSYN3A installed:

With a KSYN3A installed, the K3 VFO can be tuned as low as 100 kHz. Sensitivity will be very good in the 600-meter band (470 kHz) if a KBPF3 filter module is installed, and the antenna is connected to either the RX ANT IN or XVTR IN jack on the KXV3 module. However, below 300 kHz, sensitivity starts to decrease quickly, because the K3's receiver was optimized for use on higher bands. Typical sensitivity at 300 kHz will be about -100 dBm. The preamp should be turned off at very low frequencies because it is not useful here; it will only increase noise level.

* * *

Let me know if you think further clarification would also be helpful.

Thanks,

Wayne
N6KR


On Apr 6, 2015, at 4:01 PM, Roger D Johnson <n1rj at roadrunner.com> wrote:

> My new boards arrived today. I popped one into the K3 for some testing. I was especially interested
> in the low frequency performance as I like to DX the LF broadcasts from 153 to 279 kHz. What I found
> was that below 400 kHz, the noise level rises and at 100 kHz it's almost 20 over 9 on the S meter!
> I calibrated my NaP3 spectrum analyzer program and took some measurements of the noise level.
> 
> 500 kHz  -127 dbm
> 400         -127
> 300         -124
> 200         -113
> 100         -93
> 
> That's a 34 db increase in noise level!! Is this the way the new boards are supposed to work?
> I expected a decrease in sensitivity below 500 kHz but not this. Any ideas?
> 
> 73, Roger
> 
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