Operating instructions

MFJ-933 Loop Tuner
TM
Instruction & Technical Manual
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LOOP CONSTRUCTION
LOOP CONSTRUCTION
Loop construction for the MFJ – 933 Loop Tuner is reasonably simple, and Table
3 lists the maximum tunable length for the most efficient operation for the upper
frequency limit of each band. Each length can be tuned lower in frequency.
Exact frequency coverage depends on each individual installation configuration
involving choice of wire length and diameter, shape of loop, Loop Tuner
TM
height
above ground level, and operating environment.
Table 3: MFJ – 933 Most Efficient Single-Band Loop Lengths
Band (meters) Most Efficient Single-Band
Loop Lengths (feet)
80 63.0
40 28.0
30 20.0
20 13.0
17 9.0
15 7.0
12 5.5
10 4.0
Table 4 lists the loop lengths for the most convenient band coverage. These
lengths will allow the most frequency coverage for each loop.
Table 4: MFJ – 933 Convenient Multi-Band Loop Lengths
Band (meters) Convenient Multi-Band Loop
Lengths (feet)
40, 30 20.0
30, 20 13.0
30, 20, 17 9.0
20,15 7.0
17,15,10 4.0
The loop can be constructed from wire, tubing, sheet, and an especially good
material is 1” wide PC board. However, finding a piece of PC board long enough
to form into a circular loop for 7.175 MHz may prove to be difficult! This leads us
to the unique opportunity to EXPERIMENT while using the MFJ-933 Loop
Tuner
TM
to resonate the loop antenna you design.