K5LAD's 4-1000A Amplifier
NOTE: Some of the following pictures are old scanned photographs taken quite a few years ago and they are not too sharp. There are several newer pictures taken with a digital camera, which are mixed in with the older pictures. It will be obvious which ones are the older scanned shots and which are the newer digital shots.
Picture #1: A poor picture but it shows the nice front panel. I had the aluminum panel brushed, clear anodized and then
had the lettering engraved into it. The engraved letters were filled with black paint to make them more readable.
Here's a more recent picture of the front panel.
Picture #2: You're not going blind. This picture is terribly out of focus.
Another recent picture... looks like I need to get the Windex after that panel.
Picture #3: An overhead look down inside where you can see the B&W 850A tank coil and bandswitch. Behind
it, and tied to the bandswitch is the box containing the tuned input circuitry. The smaller aluminum box in the
upper left had the circuits for the ALC output and the RF output metering.
Picture #4 is looking back toward the front where you can see the large black shield covering the front panel meters.
Picture #5: Another look at the back side of the front panel showing the meter shield a bit better. The large white
thing in front of the 4-1000A is the filament transformer. That bottle takes a lot of current to light it up. The reason it
is white was to try to reflect a little of the heat from the side of the tube chimney.
Picture #6: Another look at the innards.
Picture #7: I did not even attempt to build the high voltage power supply inside the amplifier case. The power
supply, shown here, is in a wooden box with wheels. It just rolls around to whatever spare space it can find. The
transformer, at the bottom left, is the potted version from the BC-375. It is mighty heavy but sure is nice. Relays
and controls are in the bottom and the filter capacitors and bleeders are in the top. There is also a muffin fan to
keep things coolish inside.
Picture #7b: This is the same picture as the one above, it just doesn't
show quite as much of the clutter in the shack. That is kinda like, outta sight -- outta mind.
Updated 01/18/09 01:43 AM
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