User’s manual EXPERT 1K-FA
Pag. 16 of 76
5. EXTERNAL GROUND CONNECTION
WARNING! Before connecting an external ground as described below, check
with a qualified electrician that your national wiring codes permit such a
connection.
To reduce TVI, BCI and other RF problems it is sometimes helpful to connect the
amplifier to a good RF ground.
The inductance of such a connection has to be low, so the connection to ground should
be as short and direct as possible. Large-section copper conductors should be used for
this purpose. Terminating the earth connection with a small metal plate is suggested.
The best solution is to have a ground stake, driven into the ground, and used only for
the radio station.
Often good results can be acheived using correct earthing clamps, connected to the
mains water supply pipe (attention, most water pipes are now in plastic).
DO NOT use central heating pipework.
AVOID the electric circuit ground of the building (to be used for the 50/60 Hz safety
only).
WARNING! DO NOT
connect to gas pipes because there is danger of explosion !!
6. ANTENNA
Because this is a high-power amplifier, it is necessary to use correctly-rated antennas
and feedline cables.
Take special care with antennas with traps, because trap warming can occur during
periods of high-power transmission and a high SWR can result.
Always use antennas with SWR less than 1,6:1, even if the tuner is able to overcome
some mismatches greater than 3:1.
With the tuner the PA is matched, but with a high VSWR, the cable is mismatched and
there can be consequent loss of power, heating and high voltages present.
Always operate with the best possible matching because, despite the amplifier’s
protection against high SWR, continuous use into a mismatched load (a bit lower than
the protection threshold) may lead to damage.
It is suggested that suitable static protection be given to antenna feeder cables.
To Next Page
Loading...
