CHAPTER 4
Adjustment for Operation
Between 7.3 and 10.5 MHz
The Discoverer 7-1 can be adjusted to cover any
frequency between 7.3 and 10.5 MHz instead of
the normal 40-meter band. The VSWR at
resonance will be less than 1.5:1 and 2:1 VSWR
bandwidth will vary from 200 kHz at 7.3 MHz up
to 750 kHz at 10.5 MHz.
On the 30 meter Amateur band at 10.1 MHz,
typical 2:1 VSWR band width is 650 kHz.
To adjust the Discoverer 7-1 to a setting above
7.3 MHz, the linear-loading wires should be
shorted out at the appropriate locations. The
top and bottom linear-loading wires should
both be shorted out at the same distance from
the 40 meter insulator. See Figure 9. The
"short" can be fabricated from a piece of short
hook up wire twisted around the linear-loading
wires at the specific location, and clamped in
place using small guy wire clamps (not
supplied). The DE5 section should be set at 40
inches for all frequencies within this range.
Figure 9 Adjustment of LLW
Shorting Wire
