23-07-2020, 07:29 PM
Alignment of a sorts done. The highest band, OC1, is about 38m to 20m and is roughly correct now. Basically there is just the LO coil and the RF coil. 1st and last positions. The OC2 band depends on switching a fixed capacitor across those, hence the decision to solder low value ceramic disc capacitors across the backs of three and replace one entirely.
The only adjustments on MW & LW, apart from the two trimmers shared by all bands, is the ferrite rod coil positions and the LO coils for each.
I first rechecked the four IFT coils now that the "Full" RF out is working on the Advance signal generator. So the counter was connected. Either you short out AGC line or use the minimum signal possible. The rewound detector IF coil does clearly peak on a minimal signal. IF injected by 3 turns on ferrite and MW selected. In general the detector stage is normally less sharp due to the loading on it on any domestic set.
There are no individual LO and RF HF trimmer caps per band. So it's possible that the two trimmers on the tuner are just because it comes with them and that maybe they are supposed to be fully tight?
Next just the replacement whip and possibly polish out the abraded areas on the surface of the scale.
The only adjustments on MW & LW, apart from the two trimmers shared by all bands, is the ferrite rod coil positions and the LO coils for each.
I first rechecked the four IFT coils now that the "Full" RF out is working on the Advance signal generator. So the counter was connected. Either you short out AGC line or use the minimum signal possible. The rewound detector IF coil does clearly peak on a minimal signal. IF injected by 3 turns on ferrite and MW selected. In general the detector stage is normally less sharp due to the loading on it on any domestic set.
There are no individual LO and RF HF trimmer caps per band. So it's possible that the two trimmers on the tuner are just because it comes with them and that maybe they are supposed to be fully tight?
Next just the replacement whip and possibly polish out the abraded areas on the surface of the scale.
