18-01-2019, 05:01 AM
Hi Craig,
Your's is a 'front-end overload' problem caused by strong local signals and an extra long external antenna.
The recommended external antenna for Tecsun radios is only 10 m long with a 10:1 balun and around 7 m of coax feeder. You would do well to use the recommended length.
Were the problem to persist (due to proximity of the local stations) then Doug's notch filter suggestion should do the trick.
The problem could also be accentuated by the 1N4148 diodes D1 & D2 (connected back to back from the external antenna terminal to ground to prevent front end ESD damage) driven to conduction by the strong local signals and acting as multipliers.
Regards,
Nandu.
Your's is a 'front-end overload' problem caused by strong local signals and an extra long external antenna.
The recommended external antenna for Tecsun radios is only 10 m long with a 10:1 balun and around 7 m of coax feeder. You would do well to use the recommended length.
Were the problem to persist (due to proximity of the local stations) then Doug's notch filter suggestion should do the trick.
The problem could also be accentuated by the 1N4148 diodes D1 & D2 (connected back to back from the external antenna terminal to ground to prevent front end ESD damage) driven to conduction by the strong local signals and acting as multipliers.
Regards,
Nandu.