Variable inductor,  .5 to 6 microhenries

These beautiful variable roller inductors were made for the US military for use in the 618-T transmitter. They are very compact, measuring 5 inches long (including mounts) and about 2 inches in diameter. The wire is of heavily silver plated copper, and is  .103 inch diameter. The coil itself consists of 19 turns of 1.65 inch diameter. Shaft is 1/4 inch diameter, and is supplied with an insulated shaft coupling (1/4 inch to 1/4 inch) which incorporates the "misalignment connector", a slotted arrangement which allows a small amount of "swivel" to the shaft, to accommodate slightly misaligned shafts. The coil is held with highest quality ceramic forms, and ends are G-10 (grade 10) glass-epoxy board.

Center shaft is G-10 as well. All springs, roller, etc. are also silver plated, and provide high tension of roller against the inside of the coil. Weight is 9.3 ounces, (265 grams). Provided with aluminum standoff mounts, exactly as shown.  Large quantities available, but when these are gone, there won't be any more! Get them while you can!

Our stock # VI-1    Price: $35 each (Order Now!)

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Reference: Step inductor type 1

Description: Photo shows 4 units in various positions. Unit on bottom left is new, in original Rockwell Collins sealed bag.

We have a large supply of these motor driven variable inductors for sale.

These inductors were a part of the Collins 490T-1 or 490T-1A antenna couplers. This coupler was rated 630 watts PEP. (Probably well under rated.) Made by Collins for the US military, they are of course mil-spec in construction. The nomenclature is: Coil: RF-Stepping P/N 777-3508-001. The drive motors are 28 VDC, but will operate (slower) on lower voltages. They are in an aluminum enclosure 5.75" D x 5.25" H x 5.75" W, not including drive assembly in back. The coil consists of approx. 26 turns, 3" diameter, approx. #14 wire. Measured inductance of the coil is 24 microhenries, end to end. When energized, the motor drives a sliding contact in steps, one turn at a time inside the enclosure. There are limit switches in the motor assembly, but We have not taken the time to diagram the wiring. These units should be great for remote antenna couplers for ham use. Some units have the original power plug attached, some do not, so state if this is important to you. Removed from equipment, and guaranteed.

Stock # VI-3 . Price: $25 each! ***We have a few brand new units, in original factory sealed bags with Rockwell Collins tags for $35 each. (Order Now!)

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Reference: Step inductor type 2

Description: Photo shows three units in various positions.

We have a small supply of these motor driven variable inductors for sale.

These inductors were part of a military antenna coupler, but the type of coupler is unknown. They are almost certainly Collins made. The nomenclature is: Coil, RF-Stepping P/N 528-0524-00. We counted 28 turns on the coil, approx. 2.75" diameter, inside and aluminum case. When energized, the 28 VDC motor drives a fiberglass insulated tube inside the coil, which selects each turn of the coil successively. When it gets to end of travel, it appears to start over again automatically, but We believe it has limit switches as well inside the small metal can (may be opened) in back. We measured inductance at 13 microhenries full length. Wire diameter appears to be about #14.Some units have original power plug, others do not, so state if this is important to you. The enclosure measures 5.75" D x 5.75" H x 5.25" W. Removed from equipment and guaranteed.

Stock # VI-4. Price: $25! (Order Now!)

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