[Elecraft] KSYN3A tuning noise on 40m

[Arie Kleingeld PA3A]

Hey Guy,

thanks for your remark on the termination of the K3.

To give you a rough idea of the relative tuning noise, measured with the 
K3 dBV meter:
- 4 dB above noise floor (terminated 50 ohm)
- 5 dB above noise floor (open antenna input)
(values + or - 0.5 dB)

On 10m, the tuning noise adds about 2dB to the noise floor (terminated 
measurement)


About the conditions on 40m: well aware of that and the effect on 
hearing tuning noise, :-)   (...after nearly 40 years on HF. At least s7 
noise on 40m where I live now.)

The tuning noise on 40m just struck me. I did not expect to hear it that 
loud on the K3. I never noticed this with the old KSYN's so that is why 
I'm asking around in the reflector.
I would not have heard it if I did not have to do the calibrations after 
installing the KSYN3A's.

BTW: I never measured it on my K2 or FT1000MP (both are no longer in my 
possession so I cannot check that)

73
Arie PA3A




Guy Olinger K2AV schreef op 4-5-2015 om 16:59:
> As has been stated here before, operating a K3 rx with the input 
> unterminated is an invalid test. The rx will never be used this way to 
> routinely listen to "nothing connected".
>
> Terminate the antenna connector with 50 ohms to make any test of this 
> sort. Also remember that 40m band noise anywhere covers up a lot of rx 
> internal noise. Terminated noise readings as a possible impact on 
> received signals start to make sense on 10m and above.
>
> 73 Guy