[Elecraft] K3 Future Factory Hardware Updates; + New beta f/w release 3.27

[Don Wilhelm]

Joe,

Are you making an assumption that the P3 input impedance is 50 ohms?
That may or may not be true. I don't know the design parameters of the 
P3, but it certainly occurs to me that it is not necessary to use a 50 
ohm input impedance.

Yes, SDR-IQ and LP-PAN have the 50 ohm input, so connecting those 
devices to the K3 IF Out would cause loss.

73,
Don W3FPR

Joe Subich, W4TV wrote:
>   
>> A 50-ohm match is not required in any case.
>>     
>
> That’s not exactly true.  With devices like LP-Pan or 
> SDR-IQ that have 50 Ohm inputs connected to what is a 
> high impedance output, the transfer loss (antenna to 
> IF) was still in the range of -6dB even with the N8LP 
> modification.  The rest of the solution was to use a 
> Clifton Labs Z-10000 buffer amplifier (high impedance 
> input) in a unity gain configuration, install a 4:1 or 
> 9:1 (step down) transformer, or modify the SDR-IQ for 
> a 200 Ohm input.  
>
> 73, 
>
>    ... Joe, W4TV 
>   
>