K1 Low Power on 20M band once ATU is installed...

[Elecraft mailing list]

Still have not figured out what's wrong with my newly built K1 w/  ATU.
 
For some reason everything is fine on the 40 M band but once I switch to 20
 M the power output
drops way down. On the low part of the band the power output is much higher
 but still too low.
 
I went thru all the C and L parameters in the ATU menu and checked the TX  
output power and SWR.
 
Here is what I found:
 
     http://n2zdb.com/K1problem20M.jpg
 
Since there are 4 inductors and 5 capacitors what does L0 and C0  represent?
 
Figuring there was a problem with an inductor - I added a short between all
 the inductors at the relays (pins 3 to 4). This did not make a difference.
  However when a wire was added to K1 pin 4 to k4 pin 3 the power did come
up  a couple of Watts.
 
I need an EXPERT to figure this out...does anyone have any ideas?
 
73's Michael
n2zdb
 
 
______________________________________________________________
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
Message delivered to [hidden email]

[Don Wilhelm-4]

Michael,

One possibility is a bad relay or a relay mounted backwards or a relay
with a poorly soldered connection.
You cannot reliably check the inductor relays without removing one lead
of the inductors.  Do that first.
Then in menu ATU CLP you should have continuity through all the inductor
relays.

L0 is the state where no inductors are selected, similarly, C0 is the
state where no capacitors are selected.

I can draw no conclusions from the relative power output between 40 and
20 meters.  You will have to lift one lead of all the inductors and see
if there is end to end (input to output) conductivity.  You should be
able to do that with a DC ohmmeter.  If you do not have end to end
continuity, you can check each of the relays that short out the
inductors to see which is the problematic one.

73,
Don W3FPR

On 2/27/2016 9:53 PM, Michael via Elecraft wrote:

> Still have not figured out what's wrong with my newly built K1 w/  ATU.
>  
> For some reason everything is fine on the 40 M band but once I switch to 20
>   M the power output
> drops way down. On the low part of the band the power output is much higher
>   but still too low.
>  
> I went thru all the C and L parameters in the ATU menu and checked the TX
> output power and SWR.
>  
> Here is what I found:
>  
>       http://n2zdb.com/K1problem20M.jpg
>  
> Since there are 4 inductors and 5 capacitors what does L0 and C0  represent?
>  
> Figuring there was a problem with an inductor - I added a short between all
>   the inductors at the relays (pins 3 to 4). This did not make a difference.
>    However when a wire was added to K1 pin 4 to k4 pin 3 the power did come
> up  a couple of Watts.
>  
> I need an EXPERT to figure this out...does anyone have any ideas?
>  
> 73's Michael
> n2zdb
>  
>  
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
>

______________________________________________________________
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
Message delivered to [hidden email]