[Elecraft] Compare: K3 to Collins S-line receiver

[n7wy at rocketmail.com]

Rob Sherwood’s tables show that the 75S3B has about the lowest MDS of any receiver ever made.  

The dancing 75S3B analog signal strength meter needle is more appealing to me than a row of LCD indicator segments.

The 75S3B tuning rate is pretty high compared to the K3(s).

Tubes can be found, but it takes effort.

The 75S3B first IF is very wide so all the selectivity is imposed by the mechanical filters in the 455 KHz IF.   Thus, signals that can form IMD products are present at the 2nd mixer.   Probably one reason for the 75S3B’s lower IMD performance.


Rob Sherwood’s papers show that the 32S3B transmitter has very low 2-tone IMD compared with most of the recent TX that use solid state drivers and finals.


Yes, I did have an S-Line station for 15 years, but now it is K-Line.   


73,


Bob Rennard - N7WY