Elecraft › [K3]

K3 - ATU BYPASS relay/circuitry?

Classic

List

Threaded

3 messages Options

GW0ETF

K3 - ATU BYPASS relay/circuitry?

Maybe someone can answer this.....

Still trying to understand the K3 atu and why I still get random high swr readings on some bands into a dummy load; when I switch in BYPASS I hear a relay switching but I've never located this relay *or* the associated BYPASS circuitry on the schematics, ie. I can't work out what BYPASS is actually doing at the circuit level.

Anyone know??

Stewart Rolfe, GW0ETF

Bob Cunnings NW8L

Re: K3 - ATU BYPASS relay/circuitry?

There is no bypass relay as such:

http://www.mail-archive.com/elecraft@.../msg84916.html

Bob NW8L

On Thu, Jul 1, 2010 at 12:04 PM, GW0ETF <[hidden email]> wrote:

>
> Maybe someone can answer this.....
>
> Still trying to understand the K3 atu and why I still get random high swr
> readings on some bands into a dummy load; when I switch in BYPASS I hear a
> relay switching but I've never located this relay *or* the associated BYPASS
> circuitry on the schematics, ie. I can't work out what BYPASS is actually
> doing at the circuit level.
>
> Anyone know??
>
> Stewart Rolfe, GW0ETF
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/K3-ATU-BYPASS-relay-circuitry-tp5244635p5244635.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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

Don Wilhelm-4

Re: K3 - ATU BYPASS relay/circuitry?

In reply to this post by GW0ETF

Stewart,

If you are driving a dummy load and have the tuner in TUNE, you still
have do do a TUNE into the dummy so the ATU remembers the setting for
that band segment and into that dummy load. Remember that with the K3
ATU, the bands are segmented, so if you QSY beyond a band segment, you
will have to re-tune.

73,
Don W3FPR

GW0ETF wrote:

> Maybe someone can answer this.....
>
> Still trying to understand the K3 atu and why I still get random high swr
> readings on some bands into a dummy load; when I switch in BYPASS I hear a
> relay switching but I've never located this relay *or* the associated BYPASS
> circuitry on the schematics, ie. I can't work out what BYPASS is actually
> doing at the circuit level.
>
> Anyone know??
>
> Stewart Rolfe, GW0ETF
>