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4-250 final with a pair of 100TH modulators

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6 Ft tall commercially built, ham modified driven by 6L6's. Beautiful piece of gear, nice metering with a 10W crystal controlled exciter built in. Uses a 2E26 to drive the final, 10-12 watts out. the 4-250 Final runs nice at 250W out tuned into a dummy load. I have tuned the transmitter on 80 and 40 M only but it has 5 different band switch positions. Previous owner (SK) used it on RTTY. Other modes probably SSb but i never had any info about it. Needs a speech amp like the one on page 271 of the 1957 and earlier ARRL handbooks. All you need it what is to the left of transformer T1. I have not actually measured the plate voltage but at 170 ma Ip it puts out the 250W so the Ep must be about 2500V. The top of the rack (closed) is a panel that was used for switching from open wire, dummy load (Internal) or coax. I am to old to play with this transmitter any longer. It's sitting on a furniture mover. It will take several of you to remove the HV Xfr and load the transmitter into your truck or trailor. I would suggest you bring an old or new, whichever mattress to lay it down on after removing the HV transformer and tubes. There was no paper work the came with the transmitter so what i have is my locally generated stuff. Any questions pse call Larry W0OGH @ 520-335-4817. $500 with a new final.

John McGrath N9AMI
AMI# 1488
Executive Director

Posted : 08/05/2023 3:07 am