K5LAD's  4-1000A Amplifier


4-1000A.jpg (38279 bytes)

Click here for the documentation package on 4-1000A amplifier

circuit.gif (1497 bytes) 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.

4-1000A1.jpg (63995 bytes)

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.


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Here's a more recent picture of the front panel.


4-1000A2.jpg (51792 bytes)

Picture #2:  You're not going blind.  This picture is terribly out of focus.


P7180049.JPG (65334 bytes)

Another recent picture... looks like I need to get the Windex after that panel.


4-1000A3.jpg (67755 bytes)

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.

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Picture #4 is looking back toward the front where you can see the large black shield covering the front panel meters.

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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.

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Picture #6:  Another look at the innards.

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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.

4KPowrSupply.jpg (16541 bytes)  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.

To see thumbnails of these scanned pictures, click here.

Updated 01/18/09 01:43 AM

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