Example of a 4-1000 amplifier
This amplifier was built by Terje, LA2GH
The fan is below the socket of the valve. Behind on the right is the DC supply
inductor vertically aligned. This prevents the HF from reaching the DC supply.
Great care must be taken to avoid harmonics at this coil as it could explode
if oscillating within the 1 - 30 MHz region. Some bypass capasitors are also
visible in the same region. Top right corner shows just the signal entry to
the output pi-filter.
High voltage is applied to the anode at the top of the valve. The connector
to the anode is home made. The signal passes two parallel high voltage capasitors.
To the lower left, a closer look at the supply system of DC to the anode with the
DC supply inductor. HF is lead out through the two capasitors.
The output pi-filter. Top, the plate variable capacitor. Below a roller inductor.
At the very bottom you see the variable tune capacitor. Plate capacitor must be able
to handle voltages in the kV range and more.
One of the two TX/RX relays. Situated behind the pi-filter.
Front view of the amp. Top cover removed. Pi-filter tune to the right. Lower
centre, input tune. A variable capacitor for the input pi-filter. Toroidal inductors
are switched by relays.
Back view. High voltage connector is froim a car trailer connector. A low-power
PSU is included in the amp for control logic. RF in and RF out has different connectors.
The constructor LA2GH with his amp and Z-match. His boxes are home made as well as
the interior.
Comments, ideas or some wisdom? please mail me at
clank@c2i.net.
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This page has been created in a text editor by a real programmer.