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 7 

Alignment and Test 

 Connect a power supply or battery to the KX1 and turn on power. 

 Tap 

M E N U

 and scroll through the entries until you find 

A T U

. To select the mode for the ATU, hold 

E D I T

. If you see three dashes (

- - -

) instead of the 

A T U

 parameter, refer to Troubleshooting.  

 Using the VFO knob, set the 

A T U

 parameter to the first relay test setting, 

L 0

. You should hear a 

relay switch when you move to 

L 1

, then to  

L 2

, and finally to 

L 3

. The same should be true for 

C 0

 

through 

C 3

, as well as 

N 1

 and 

N 2

. (If you don't hear any relays switching, see Troubleshooting.) Exit the 

menu. 

 Select 40 meters using the KX1's 

B AN D

 switch. 

 Connect a 50-ohm dummy load to the KX1’s antenna jack (5W or higher rating).   

 Set the 

A T U

 parameter to 

C A L

 using the menu. Tap

 MENU 

twice to exit the menu.

  

 Pre-set potentiometers R1 and R2 on the bottom of the ATU board to exactly their mid-points.  

 Touch the (+) lead of a digital multimeter (DMM) or analog voltmeter to the small hole near the 

"

REFL

" label on the bottom of the KXAT1 board. Connect the (-) lead to one of the KX1's long standoffs.  

 Set the voltmeter for 2 or 3 DC volts full scale. 

 Locate a non-metallic tuning tool for adjusting ceramic trimmer C9. You can use a small flat-blade 

screwdriver or jeweler’s driver with tape wrapped around the metal shaft to prevent you from contacting it. 

 Enter TUNE mode by holding 

M E N U

 and 

B AN D

 together (the KX1 will display forward power, 

e.g. 

P 4 . 0

). Adjust C9 for the lowest possible voltmeter reading—the null may be sharp. Cancel TUNE 

mode by tapping any switch (the KX1 will display SWR, e.g. 

r 1 . 0

). 

 If your voltmeter has a lower scale than 2 or 3 V, set it for this scale, and repeat the previous step. 

 

Optional Power Calibration: 

The KXAT1 will provide acceptable power-reading accuracy with R1 and 

R2 set to exactly their mid-points. More accurate adjustment requires a calibrated wattmeter: 

 Connect a known-accurate wattmeter between the KX1 and a 50-ohm dummy load. 

 Enter TUNE mode. Adjust R1 

(FWD)

 on the KXAT1 so that the KX1’s power display agrees with the 

wattmeter. Tap any switch to exit TUNE. The SWR display should show 

r 1 . 0

. If it doesn't, chances are 

your dummy load is not 50 ohms, or the null adjustment (C9) was not done correctly.

 

 Adjust R2’s rotation to match that of R1 (visually). 

Installing the Bottom Cover 

 Turn off the KX1 and re-install the bottom cover. 

Be very careful not to pinch the battery wires 

between the bottom cover and the ATU module or the nearby long standoff.

 

 

Summary of Contents for KXAT1

Page 1: ...hing parameters are saved so that the settings can be recalled immediately on any band change ATU parameters L C SWR etc can be viewed using the KX1 s ATU menu entry Additional settings are provided t...

Page 2: ...620072 P3 Connector 5 pin male 0 1 spcg 1 E620073 R1 R2 Potentiometer 100 k trimmer low profile 2 E520012 R3 Resistor 200 ohms 1 4 W 5 red black brown 1 E500020 R4 Resistor 3 3 k 1 4 W 5 orange orange...

Page 3: ...Install the IC socket at U1 Align the socket s notched end with the notch in the component outline On the bottom side install R3 200 ohms red black brown and R4 3 3 k orange orange red Install D1 and...

Page 4: ...the board as possible see above i In the following steps inductors L1 through L3 will be wound and installed There is no need to adjust the windings to precisely match the inductances shown on the sc...

Page 5: ...0 25 cm lengths of 26 enamel wire one red and one green Inspect the wires closely to make sure the enamel coating is not chipped or broken Twist the two wires together crossing over each other about 3...

Page 6: ...rom the KX1 transceiver 2 thumbscrews and turn it upside down with the BNC connector on the left On the KX1 PC board locate J8 2 pins J7 3 pins and J6 5 pins Remove the jumper installed between pins 1...

Page 7: ...ning tool for adjusting ceramic trimmer C9 You can use a small flat blade screwdriver or jeweler s driver with tape wrapped around the metal shaft to prevent you from contacting it Enter TUNE mode by...

Page 8: ...will still be displayed in TUNE mode Note The KXAT1 cannot display SWR continuously during TUNE so an external tuner with built in SWR bridge is recommended Most stand alone tuners include a bridge Im...

Page 9: ...toss the wire into a tree try to keep all but about one foot of wire exposed A wire that is mostly in a tree will still radiate but not as well Wire antenna length Since the KX1 can only match a mode...

Page 10: ...is strong lightweight and easy to keep straight A 25 ft length weighs less than half an ounce Adapters To go from BNC directly to wires you ll need an adapter The smallest suitable adapter is the Pomo...

Page 11: ...e antenna farther away or use a balun If the tuner is unable to achieve a low SWR on some bands even with several different antennas you could have a single defective relay or component on the L C boa...

Page 12: ...chniques to improve accuracy During transmit the VFWD line provides an analog power indication to the KX1 s main microcontroller At other times this line used to transmit digital data between the ATU...

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