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MFJ-1623 Instruction Manual 

Window/Balcony  Mount Antenna 

 

6

someone may contact it, be sure to use well insulated wire and multiple counterpoise wires.  Insulate the 
far end of the counterpoise wire(s) with electrical tape to prevent accidental contact. 
 
When counterpoise wires are used outdoors, only place them high enough to walk under.  Use multiple 
wires spaced a few feet apart (at minimum). 
 

DANGER: 

Touching counterpoise and/or antenna wires while transmitting can cause an RF 
burn.  The wire must be well insulated and the end properly insulated.

 

 
There are cases very little deflection of the RF current meter can be seen.  However, even though the 
meter may not indicate much RF current change while adjusting the COUNTERPOISE control, even 
the slightest RF current peak indicates that the artificial ground is helping. 

Tuning Out Reactance of Long Ground Leads  

 
If the station ground has a long lead, you can connect it to the COUNTERPOISE binding post of the 
MFJ-1623.  Connect the station ground bus and accessories to the GROUND post.  

Do not reverse 

these wires.  

Follow the same procedure for maximizing RF Current described in the tuning procedure.   

 

WARNING: 

This unit does NOT provide a dc or ac safety ground through the 
COUNTERPOISE terminal.  A separate wire from the station ground bus to 
an electrical or earth ground must be used. 

 
TVI and RFI Hints

 

 
It 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 reference your problem or your problem is not solved by reading the manual, you may call 

MFJ Technical Service

 at 

662-323-0549

 or the 

MFJ Factory

 at 

662-323-5869

.  You will be best 

helped if you have your unit, manual and all information on your station handy so you can answer any 
questions the technicians may ask. 
 
You can also send questions by mail to MFJ Enterprises, Inc., 300 Industrial Park Road, Starkville, 
MS 39759; by Facsimile (FAX) to 662-323-6551; or by email to [email protected].  Send 
a complete description of your problem, an explanation of exactly how you are using your unit, and a 
complete description of your station. 

Содержание 1623

Страница 1: ...uning controls and only one tuning solution for given impedance match The MFJ 1623 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 An RF Current Meter indicates the summed antenna and counterpoise antenna currents making tuning p...

Страница 2: ...ch the mounting bracket in position by placing the bracket over or around the surface of the support NOTE THE ANTENNA SHOULD BE ORIENTED AWAY FROM WINDOWS AND OTHER OBJECTS THAT ARE WITHIN CLOSE RANGE IF POSSIBLE 4 Tighten the screws on the rear of the base plate against the surface of the support The screws should be tightened in equal increments to keep the force on the spacer plate proportioned...

Страница 3: ...he 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 receiver noise Note If...

Страница 4: ...imize RFI antennas should be kept away from other wiring as much as possible Also the antenna should be adequately insulated to prevent arcing or accidental contact if placed near other objects For safety it is always best to use both dc and RF grounds A DC ground may not be practical in some portable locations however It is always important to have a good RF ground provided by the counterpoise wh...

Страница 5: ...ch is properly set Installation of a Suitable Counterpoise Artificial Ground The MFJ 1623 includes a counterpoise set of wires that will work well from 80 10 meters It is important to keep the last few feet of the counterpoise wires as far as possible two feet minimum from each other and other near by conductors You can also build your own counterpoise system if you desire A RF counterpoise system...

Страница 6: ...mizing RF Current described in the tuning procedure WARNING This unit does NOT provide a dc or ac safety ground through the COUNTERPOISE terminal A separate wire from the station ground bus to an electrical or earth ground must be used TVI and RFI Hints It 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 ferrit...

Страница 7: ...MFJ 1623 Instruction Manual Window Balcony Mount Antenna 7 Schematic ...

Страница 8: ...ake 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 9: ...MFJ 1623 Instruction Manual Window Balcony Mount Antenna 9 ...

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