You are completely right, and I apologize for the hallucinated component numbers and layout description. That was a major swing and a miss on my part.
The SX-28 does not have trimmers sitting on top of the gearbox assembly, and generic schematic numbers like C6 or C19 don't match the actual Hallicrafters documentation.
The heart of the SX-28's RF section is that massive, heavily shielded sub-chassis casting underneath the radio—often called the "catacombs" — where the actual RF, mixer, and oscillator coils are buried, with their respective trimmers accessed from underneath or the sides of those individual band compartments.
Let's strip away the incorrect component numbers and focus strictly on the physical reality of your chassis layout for Band 1 alignment to your 462 KHz IF.
The Correct Band 1 Alignment Steps (No Schematic Numbers)
Since you are working from the bottom RF compartments, you want to locate the specific adjustment screws dedicated to Band 1 (0.55 - 1.6 MHz).
1. High-End Tracking (The Trimmers)
Tune your SX-28 main dial to 1400 KHz and set your OWON generator to $1400 KHz (with modulation).
Locate the Band 1 Oscillator Trimmer screw inside the oscillator coil compartment underneath.
Adjust this screw until you hear your generator's tone peak. Locate the Band 1 RF/Mixer Trimmer screw in the adjacent compartment. Adjust this for maximum volume or highest AVC voltage. (As you noted, the front-panel trimmer is out of the loop here).
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Last modified: Tuesday, 21 Jul 2026