KAT100 Power Calibration at R4-help!

[Gil Stacy]

No joy during power calibration.  On my KAT100, I’ve completed the initial
tests involving the LED sequences, the Menu and Relay tests and all appears
fine.  However, after completing the SWR Bridge Null Adjustment at 10mV and
then moving to the Power calibration of R4, at pin 5 of U5, with 20 watts
out of my K2/100, I only detect a range of mV (app. 100-20) on my DVM—no
where near target of 2.7 V.  My set up is dummy load (15w) on RF In and coax
from K2 to ANT1 on KAT100 with the control cable (K2 and KAT100) and power
cable to the KAT100 removed.  In accord with manual, before power was turned
off at K2 and KAT100, , K2/100 was set to CAL mode and Menu exited prior to
shutdown. The power level of the K2/100 is set at 20 watts.  In “TUNE”, the
K2’s LCD registers HiCurr and then 9.9-1.  With the K2/100 set at 20 watts,
at the KAT100’s  Ant. 1 jack, I detect 20 mV and with an RF probe, 2.7 Vrms.
  Solder joints look good and parts placement seems to be correct. All
diodes properly oriented.  T1’s leads show correct placement with clean
solder on the wire above the board. With all power off, K17 shows 0 ohms
from pins 1-3 and 1-4.  K2 in Tune mode at 20 watts on LCD was less than 30
seconds and the dummy load showed no signs of noticeable warming.  Help with
troubleshooting would be appreciated.

Tnx es 73.

Gil NN4CW


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[Don Wilhelm-3]

Gil,

Check your cables carefully - often a bad coax cable sneaks in and causes
funny results.
You did remember to disconnect the control cable to the KAT100 and
disconnect its power did you not?

Other than that, it sounds like your setup is correct.  If you continue to
have trouble, check the SWR Bridge/Wattmeter section carefully.  The most
likely things that could be wrong are T1 (rewinding it is the easiest way to
check it for shorts between the windings), and diodes D1 and D2 (check for
proper orientation - the banded end should point to the right side).

73,
Don W3FPR

> -----Original Message-----
>
> No joy during power calibration.  On my KAT100, I’ve completed
> the initial
> tests involving the LED sequences, the Menu and Relay tests and
> all appears
> fine.  However, after completing the SWR Bridge Null Adjustment
> at 10mV and
> then moving to the Power calibration of R4, at pin 5 of U5, with 20 watts
> out of my K2/100, I only detect a range of mV (app. 100-20) on my DVM—no
> where near target of 2.7 V.  My set up is dummy load (15w) on RF
> In and coax
> from K2 to ANT1 on KAT100 with the control cable (K2 and KAT100)
> and power
> cable to the KAT100 removed.  In accord with manual, before power
> was turned
> off at K2 and KAT100, , K2/100 was set to CAL mode and Menu
> exited prior to
> shutdown. The power level of the K2/100 is set at 20 watts.  In
> “TUNE”, the
> K2’s LCD registers HiCurr and then 9.9-1.  With the K2/100 set at
> 20 watts,
> at the KAT100’s  Ant. 1 jack, I detect 20 mV and with an RF
> probe, 2.7 Vrms.
>   Solder joints look good and parts placement seems to be correct. All
> diodes properly oriented.  T1’s leads show correct placement with clean
> solder on the wire above the board. With all power off, K17 shows 0 ohms
> from pins 1-3 and 1-4.  K2 in Tune mode at 20 watts on LCD was
> less than 30
> seconds and the dummy load showed no signs of noticeable warming.
>  Help with
> troubleshooting would be appreciated.
>
> Tnx es 73.
>
> Gil NN4CW
>
>
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