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Ten-Tec 238C manual 
Part #74428  
First release, June 2009.  Printed in U.S.A. 

METER CALIBRATION 
 

A metal plate is installed on the front of the 
238C with 4 Philips screws.  This plate has 
the markings for the capacitor, inductor and 
center impedance switch.  It can be 
removed without taking off either of the two 
main knobs or the center switch knob.  
 
Disconnect the tuner from DC power 
connected to the rear panel 13.5 VDC jack.  
 
Remove the 4 screws that hold the metal 
plate in place and the metal plate itself.  
Behind the metal plate are two plastic 
screws for each meter movement.  Adjust 
each as needed to reset the indication to ‘0’.   
Re-install metal plate and reconnect DC 
power. 
 
 

 

 

 

 

Содержание 238c

Страница 1: ...tion ground system to the GND wing nut terminal on the rear panel of the tuner with heavy braid or wire The ground connection should go directly to the earth ground system using as short a lead as pos...

Страница 2: ...o power the peak reading power output circuitry Connect a cable from your 12 15 VDC power source to the rear panel 13 5 VDC jack Center tip is positive shell case is negative It is only necessary to c...

Страница 3: ...Ten Tec 238C manual Part 74428 First release June 2009 Printed in U S A Figure 1 1 238C Front and Rear Panel...

Страница 4: ...itional capacitors as needed for matching at lower frequencies When placed in the 12 o clock position the tuner is connected to the BYPASS configuration and the network has no effect on the transmissi...

Страница 5: ...m the output of your transceiver or linear amplifier to this jack 12 13 5 VDC The 238C dual cross needle wattmeter requires 12 15 VDC 13 5 VDC nominal for meter lamp illumination and to power the peak...

Страница 6: ...be sure that a dummy load or antenna is properly connected when power is applied Voltages in excess of ratings can occur if no load is connected BALANCED LINE OPERATION NOTE When using balanced line...

Страница 7: ...resistive impedance by means of a tuner will give identical performance To best understand the tuner adjustments required it is necessary to have a fundamental knowledge of how antenna systems functi...

Страница 8: ...tically provides the lowest network Q possible Low Q means low circulating currents hence low loss and it also provides the widest frequency bandwidth of operation before retuning is necessary Finally...

Страница 9: ...pedance switch It can be removed without taking off either of the two main knobs or the center switch knob Disconnect the tuner from DC power connected to the rear panel 13 5 VDC jack Remove the 4 scr...

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