LNR W4OP Owner's Manual

A WORD ABOUT TUNING NARROW BAND ANTENNAS WITH
GRAPHING ANTENNA ANALYZERS.
Analyzers like the Rig Expert series sample only so many points when constructing
a graph. 80 points in the case of the RigExpert series, when not being controlled by
a PC. If you are sweeping say +/- 4MHz,a sample is taken every 100KHz. On an
antenna with a 2.62:1 SWR bandwidth (-3dB points) of 16KHz, the dip may not be
seen or will be quite shallow. Once you find the dip, center it, narrow the Range
and resweep.
Typically, on 40M as an example. I do the final tuning with a sweep range of 40KHz.
This will give a true indication of SWR.
TUNING SMALL LOOPS IN GENERAL
Once you have the SWR centered on your operating frequency, you may wish to
make small adjustments in the coupling loop height to achieve even lower SWR.
Use the same procedure as above– step away from the loop while making your
adjustment.
The unique hybrid matching network makes height adjustments of the coupling
loop less necessary than would be the case with a classic coupling loop.
One might ask why an azimuth motor control was not included. For almost all practi-
cal propagation elevation angles, a small transmitting loop is virtually omnidirection-
al. For close in man made noise sources, you may find that you can rotate the loop
to minimize that noise source. Noise sources above or below the height of the loop
will likely not be diminished much if at all.
SPECIFICATIONS
Coverage
Polarity Low Angle:
Polarity High Angle:
Loop Diameter
Design Z:
Power Handling:
Weight:
Shipping Size
Materials:
Hardware:
Connector:
LNR Precision
Asheboro, NC
www.LNRprecision.com
E-Mail: support@lnrprecision.com
6.9MHz– 29.4MHz
Vertical
Horizontal
45"
50 Ohms
15W SSB/CW 10W DIGITAL
3 lb
16 X 16 X 3"
6061-T6 Aluminum, CPVC,
Stainless Steel
Female gold/teflon BNC
SMALL RX/TX HF LOOP
MODEL REMOTE W4OP
40-10M STL
PARTS LIST
PART NO. QTY DESCRIPTION
SUBL1001 1 MAIN RADIATOR ASSEMBLY
SUBL1002 1 COUPLING LOOP ASSEMBLY
L1003 1 COUPLING LOOP THUMB SCREW
SUBL1004 1 3 PIECE SUPPORT MAST
L1005 1 TABLE/RAIL CLAMP
L1006 4 STABILIZER FOOT 1" x 8"
L1007 4 RED STABILIZER FOOT THUMB SCREW
L1008 1 HOOK&LOOP TIE WRAP 6"
SUBL1010 1 REMOTE MAIN TUNING UNIT
L1012 1 SMA CONTROL CABLE
SUBL1013 1 HANDHELD REMOTE
L1014 1 OWNER'S MANUAL
FIG. 1