K1 - problem with KAT1

[Raymund Band]

I have just installed a KAT1 in a K1 with 4-bands filter board. The KAT1
bridge adjustment and power calibration were performed without difficulty.

 

The K1 (serial number 25xx) has been used without any problems and the KAT1
has been used previously with a different 2-bands K1. Using Tune and testing
into a good 50 ohm load, everything worked OK on 7, 10 and 14 MHz but 21 MHz
showed a problem. After a long tune (about 1 sec), the display showed LO P
and the combined load/power-meter showed 0.5 watt. Another known good 50 ohm
load gave the same result.

 

Removing the KAT1 showed that the K1 could easily give 6 watts on all bands,
including 21 MHz.

 

With the KAT1 re-installed and looking at the results of the tune on all
four bands (7, 10, 14 & 21 MHz) on the ATU menu, the lowest 3 bands all
showed L = 0.0, C = 00, which seems reasonable with a 50 ohm load.

The highest band (21 MHz) showed L = 4.9 and C = 63. So something seems
wrong in the KAT1. Can it be power measurement (D1 & D2 etc)?

 

Ray / SM5XLP

 

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[Don Wilhelm]

Ray,

I would be highly suspicious of a relay that is not working properly.
Whether that is the result of a poorly or unsoldered connection or
because the relay is really bad is to be determined.  That relay just
was not operated on the other bands, but it happened to try to be
operated on 15 meters during the tuning process.

The relays on the KAT1 are latching types.  By using the L0-L4 menu
items and the C0-C5 as well as the N1 and N2 settings you can check the
relay operation.  First check to see if you hear a click when the relay
is operated - note that for the L0 and C0 settings there should be no
relay operated.

The schematic shows the relays in the reset position.

The capacitor relay checks are easy - when the relay is set, one lead of
the capacitor will show continuity to ground.  With C0, none of the
capacitors will have continuity to ground.

The check of the inductor relays is a little harder because the inductor
itself will show a DC path, so lift one lead of all the inductors and
then test across the inductor solder pads with your ohmmeter.  The L0
setting should show an zero resistance across each of the inductor
solder pads, as you select L1 thru L4, you should see the relay for that
inductor open.

If you don't want to lift a lead on the inductors,  you can test by
using the SWR indication as given in the KAT1 manual on page 14 near the
bottom of the page.

73,
Don W3FPR

On 5/11/2016 4:38 PM, Raymund Band wrote:

> I have just installed a KAT1 in a K1 with 4-bands filter board. The KAT1
> bridge adjustment and power calibration were performed without difficulty.
>
>  
>
> The K1 (serial number 25xx) has been used without any problems and the KAT1
> has been used previously with a different 2-bands K1. Using Tune and testing
> into a good 50 ohm load, everything worked OK on 7, 10 and 14 MHz but 21 MHz
> showed a problem. After a long tune (about 1 sec), the display showed LO P
> and the combined load/power-meter showed 0.5 watt. Another known good 50 ohm
> load gave the same result.
>
>  
>
> Removing the KAT1 showed that the K1 could easily give 6 watts on all bands,
> including 21 MHz.
>
>  
>
> With the KAT1 re-installed and looking at the results of the tune on all
> four bands (7, 10, 14 & 21 MHz) on the ATU menu, the lowest 3 bands all
> showed L = 0.0, C = 00, which seems reasonable with a 50 ohm load.
>
> The highest band (21 MHz) showed L = 4.9 and C = 63. So something seems
> wrong in the KAT1. Can it be power measurement (D1 & D2 etc)?
>
>  
>
> Ray / SM5XLP
>
>  
>
> ______________________________________________________________
> 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]
>

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