14-04-2017, 03:57 PM
(This post was last modified: 14-04-2017, 04:03 PM by Geordie McBoyne.)
"Long wave coverage is way out, signals are coming in between 300 to 400Khz, faulty oscillator padding capacitor perhaps?"
In fact the long wave padding capacitor is missing. Connecting a 200pF capacitor across the LW padding trimmer restores long waveband coverage. The precise value will be determined by trial and error, it is likely to be between 120 to 150pF.
The first attachment shows the position of the trimmers. The second picture shows the position of the tuning coils. Bottom left the medium wave bandpass coilset, to the right the long wave bandpass coilset. The local oscillator coils are at the top of the picture, MW on the left side of the coil former.
Geordie McBoyne.
In fact the long wave padding capacitor is missing. Connecting a 200pF capacitor across the LW padding trimmer restores long waveband coverage. The precise value will be determined by trial and error, it is likely to be between 120 to 150pF.
The first attachment shows the position of the trimmers. The second picture shows the position of the tuning coils. Bottom left the medium wave bandpass coilset, to the right the long wave bandpass coilset. The local oscillator coils are at the top of the picture, MW on the left side of the coil former.
Geordie McBoyne.
