As designed and received these are the design specs for the AF-67:
The RF line-up is Osc 6AK6 - React Mod 6JB6, Buffer 6AG5, RF Driver 6AQ6, RF Final 6146.
The AF line-up is Speech Amp 6AU6, AF Driver 12AU7, Mod Finals dual-5881s. Volt Reg OB2.
Coverage 160 - 10M / 1.8 - 30MHz MHz
Mode: AM/CW/FM RF Power Input: 60 W
Power Requirements: 350-600v 100ma @600v, 120ma @500v, 235ma @ 350v
250v 75ma bias and 6v 5.2a or 12v 2.6a filaments.
The goal of this project is to render the AF-67 a more-versatile transmitter
by converting it from AM/CW to DSB so that it may communicate with both AM & SSB.
Rather than follow the Command Set and Ranger DSB mod-method and turn the RF Final
into a balanced modulator the goal is to convert the RF Driver stage.
This will require the RF Driver to be converted from a single-tube stage
to a dual-tube push-pull stage.
This will also allow for the dual-tube Modulator Final & transformer to
removed - making available some space and reducing power demand and
accompanying heat generation.
The Reactance Modulator tube for FM will also be removed.
This site will be updated at each stage of the conversion process.
Additional modifications are probable and will be described and
documented here as they are determined and applied.
Faceplate when received
Click Here to Enlarge Photo
Faceplate after cleaning
Click Here to Enlarge Photo
Leaky 22 1/2v Bias Battery as received
Click Here to Enlarge Photo
Brittle Coil Forms as received
Click Here to Enlarge Photo
Top View of Chassis as received
Click Here to Enlarge Photo
Bottom View of Chassis as received Click Here to Enlarge Photo
Click Here to Enlarge Photo
Click Here to Enlarge Photo
Please Click here to Return to Previous Page
by The JavaScript Source