You are completely right, and I apologize for completely mismapping your schematic. Thank you for the correction.
C40 is absolutely a fixed capacitor in the first audio stage (used for high-frequency roll-off/coupling near the 6SC7 audio pre-amp). The crystal filter network is indeed nestled downstream between **T2 (the 2nd IF transformer)** and the grid of **V6 (the 2nd IF amplifier tube, 6SK7)**.
With **C32 (5ΓÇô50 pF)** serving as the true front-panel Phasing Control, and **C29, C30, and C31** acting as the adjustable trimmers that balance the selectivity steps (Broad, Medium, and Sharp Crystal), the mechanism of your 9 kHz frequency shift makes perfect sense.
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Since your out-of-circuit jig proves both crystals are physically healthy $453 KHz slabs, the reason the original crystal registered at $462 KHz in-circuit is a **severe capacitive unbalance in that specific trimmer array.**
In a properly aligned Hallicrafters crystal gate, the crystal is driven by a balanced differential voltage from the secondary of T2.
* **C32 (the Phasing Control)** is adjusted by the user to introduce a precise amount of capacitance that exactly matches the static physical capacitance of the metal plates and holder encasing the quartz slab. This balances out the "blow-through" capacitance so that only the pure mechanical resonance of the crystal gets passed to the grid of V6. * **C29, C30, and C31** adjust the capacitive loading across the bridge to keep the circuit symmetrical as you switch through the varying degrees of crystal selectivity.
If **C29, C30, or C31** are severely misadjusted, heavily contaminated with decades of grime, or if the stray capacitance of the wiring surrounding the crystal socket is excessive, the bridge becomes completely lopsided.
When a crystal is forced to operate in a highly asymmetrical, heavily capacitive circuit, the circuit forces the crystal to look into a highly reactive load. This reactive loading pulls the series resonant path away from its physical $453.621 KHz center and slides it way up the slope toward the parallel anti-resonant peakΓÇöwhich happened to land right at $462 KHz on your bench.
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## Your Action Plan for the Alignment Guide
This is an invaluable finding for **sx28.info**. It means a reader whose radio is tracking at $462 KHz doesn't have a degraded crystal; they have an uncompensated crystal gate.
When you install the replacement terminal strip and select your baseline crystal, your path forward to fixing the pulling issue involves adjusting that specific cluster:
1. **Clean the Array:** Ensure the trimmer group (C29ΓÇôC31) and the rotor/stator of C32 are completely free of dust or oxide bridges. 2. **Inject the Baseline:** Inject your exact $453 KHz unmodulated CW signal into the mixer grid. 3. **Walk the Crystal Trimmers:** Follow the manual's specific sequence for adjusting C29, C30, and C31 in the Broad/Medium/Sharp positions.
By adjusting those trimmers, you are manually dialing out the stray capacitance that was warping the crystal's behavior. Once you restore balance to the bridge, the crystal will snap back down to its native $453 KHz home, and the 9 kHz phantom shift will disappear.
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Last modified: Monday, 10 Aug 2026