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MFJ-1642 Portable  Whip Tuner 

Instruction Manual

 

Tuning Chart 

 
You may wish to remove or make a copy of this page and place it near the tuner.  Insert your own 
values for each frequency according to your station. 
 

Freq MHz 

Counterpoise 

Matching 

Antenna 

Hi/Lo Z switch 

Extra cap switch 

1.8 

 

 

 

 

 

1.8 

 

 

 

 

 

2.0 

 

 

 

 

 

2.0 

 

 

 

 

 

3.5 

 

 

 

 

 

3.5 

 

 

 

 

 

3.5 

 

 

 

 

 

3.75 

 

 

 

 

 

3.75 

 

 

 

 

 

3.75 

 

 

 

 

 

4.0 

 

 

 

 

 

4.0 

 

 

 

 

 

4.0 

 

 

 

 

 

7.15 

 

 

 

 

 

7.15 

 

 

 

 

 

10.1 

 

 

 

 

 

10.1 

 

 

 

 

 

14.2 

 

 

 

 

 

18.1 

 

 

 

 

 

18.1 

 

 

 

 

 

21.2 

 

 

 

 

 

21.2 

 

 

 

 

 

24.9 

 

 

 

 

 

28.5 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
 
 
 

Содержание MFJ-1642

Страница 1: ...s and only one tuning solution for given impedance match The MFJ 1642 has rear panel connectors for coaxial input and a Hi Z Lo Z switch for reversing the L network An internal input isolating current balun provides isolation of DC and RF grounds for optimum tuning of the RF counterpoise MFJ 1642 Supplied Components 30 10 meter operation MFJ 1956 12 ft telescopic whip antenna Counterpoise assembly...

Страница 2: ...ore adjusting the tuner This should be done with a dummy load Tuning Procedure WARNING Never transmit while changing the INDUCTOR SELECTOR 1 First tune for maximum receiver noise as follows While listening to your desired receive frequency adjust the ANTENNA control for maximum receiver noise Adjust the MATCHING control for maximum receiver noise Adjust the COUNTERPOISE control for maximum receive...

Страница 3: ...nd provided by the counterpoise when using any whip or long wire antenna This is because the MFJ 1642 tuner needs something to push against in order to force current into the antenna If a good RF ground is not available RF will usually find its way back into the power line RFI transmitter audio circuits RF feedback or the operator RF burns Water pipes provide good dc and ac safety grounds but they...

Страница 4: ...or less or as complicated as several wires cut for different bands Always insulate counterpoise wires and keep them from accidentally contacting animals people RF sensitive devices and wiring For best performance try to position the counterpoise wires in a straight line if possible A counterpoise wire must be well insulated For best performance several wires a quarter wavelength long on different ...

Страница 5: ...is possible for RF to flow down power cables into the house wiring This may cause TVI Stereo VCR or other RFI problems As a precaution a ferrite core can be clamped around power leads The MFJ 701 RFI FREE CHOKE KIT makes it easy to eliminate common RFI problems Technical Assistance If you have any problem with this unit first check the appropriate section of this manual If the manual does not refe...

Страница 6: ...a copy of this page and place it near the tuner Insert your own values for each frequency according to your station Freq MHz Counterpoise Matching Antenna Hi Lo Z switch Extra cap switch 1 8 1 8 2 0 2 0 3 5 3 5 3 5 3 75 3 75 3 75 4 0 4 0 4 0 7 15 7 15 10 1 10 1 14 2 18 1 18 1 21 2 21 2 24 9 28 5 ...

Страница 7: ...MFJ 1642 Portable Whip Tuner Instruction Manual 7 Schematic ...

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