Guys,

Was trying to figure out whether this is necessary. (not a big deal but extracting the K3 from the bunch of connection is a pain)

It appears to me that this mod may be needed if one has two radios and an A/B switch which has insufficient port to port isolation.

Some hand calcs (assuming an A/B switch with 40db isolation)
A radio running 100 w
B radio attached to the other port

Hand calcs indicate 780 mv possible at the input terminals of B.
S9+60db is 50 mv. It seems like 780mv is high enough to require this protection mod. (when the K3 is transmitting the B radio would also need protection.....)

It is not clear at all how the A/B switch isolation is measured and whether it is db power or db voltage. Yes, some A/B switches ground the unused ports. Is that included in the isolation figure quoted?

Does anybody have some quantitative data?

73 de Brian/K3KO
No virus found in this outgoing message.
Checked by AVG - www.avg.com
Version: 8.5.409 / Virus Database: 270.13.62/2315 - Release Date: 08/20/09 
06:05:00
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Reply via email to