[Elecraft] KAT3 losses vs KAT3A

[GRANT YOUNGMAN]

> On May 19, 2015, at 8:30 AM, Bill McDowell <k4cia at earthlink.net> wrote:
> 
> The new KAT3A tuner has a relay bypass that results in lower losses.  What are the losses in the old KAT3 without a relay?  And do the losses occur when using a matched antenna with the old KAT3 NOT engaged.  The statement: "Lower loss on bands where matched antennas are used." is a little cryptic to me with respect to the KAT3A version.
> 
> Are the losses in the old version present irrespective of the tuner being inline or not?
> 
> Clarification would be appreciated.
> 

Eric (or maybe one of the other Elecraft team) addressed this a few days ago.

Apparently the KAT3 simply goes to a calculated “50 ohm match” position when you put it in bypass, e.g., it’s still in-line, it’s just set for a 50 ohm match.  Only there may be times when it does not get to the correct position, so if you’re not using an external tuner the KAT3’s position might not be optimum for a resonant antenna presenting a 50 ohm load.  The KAT3A uses a hard relay bypass to get around this.  I can’t say I’ve ever seen an issue related to this with my resonant antennas, but others may have.

I’d think the losses would be small (low tenths of dB) in any case, and most likely not worth replacing the KAT3 unless you’re buying a new radio.

YMMV

Grant NQ5T