- 21 -
Transmitters having so-called broadband solid-state output circuits (no tuning or loading controls)
may be especially troublesome in this regard, whereas the older vacuum tube pi-network
transmitters can usually be adjusted for maximum output over a tuning range where the VSWR does
not exceed 2.5:l.
Lightning Protection
Modern solid state amateur equipment is particularly vulnerable to damage from lightning or
static induced transients that may appear on transmission lines. Lightning protection products
should be installed.
Troubleshooting
Check out your installation again, looking for loose connections and checking all dimensions.
Then refer to the list of possible symptoms below:
Symptom: Few or no signals heard: bands seem
dead
, SWR is very high.
Look for:
Open or shorted feedline, open or shorted matching line, broken connection at base of
antenna (feedpoint).
Symptom: High SWR on 20 meter; other bands OK.
Look for:
Missing matching line. Antenna not properly tuned. 20 meter radials not present or
wrong length. Consult instructions for tuning and radial information; install matching
line
RG-11 75 ohm coax, electrical length to be 1/4-wavelength.
Symptom: High SWR on some bands, but signals heard on all bands (conditions permitting).
Look for:
Missing or defective radial system. Install as per instructions and check connections to
radials and ground system. Keep this connection 6 inches or less.
Symptom: SWR on 15 meters seems to vary during a windy day.
Look for:
This is normal since the 15 meter wire is side mounted and when the antenna sways,
the distance between the 15 meter wire and main antenna will vary.
Symptom: SWR on 17 meters seems to be high compared to the other bands.
Look for:
This is normal. 17 meters has always been difficult to tune. A VSWR of 2.5:1 is
acceptable for 17 meters.
Symptom: Tuning is
sharp
with narrow bandwidth on 80 meters.
Look for:
Normal condition. The total length of the antenna represents such a small percent of a
wavelength on this band that sharp tuning is a normal condition.
Symptom: Antenna was installed on the ground and tuned OK, but tuning changed over a period
of weeks or months.
Look for:
Antenna installed over poor ground system. Ground conditions have changed, causing
shift in resonance. Install radial system as per instructions. Check connection to radial
