Slightly misaligned tuning handle and how to extend AM band reception?
Hi there,
About the Panasonic RC-7469 I have, the radio tuning handle appears be misaligned by a tiny bit. Not a major issue, rather a minor detail.
The picture says it all: the handle is always "above" the tuned station. Pictured is where I get clear sound for 600KHz AM, but it is misaligned on the FM band as well. Having dismantled a few, mechanically tuned radios very long ago, I vaguely remember there is a shaft on the tuner knob on which a cotton cord is tightly wound, winding again on the tuner dial (if round), or just moving the handle directly (sliding-type).
Since both FM and AM dials are misaligned by the same angle and that the tuner knob is has no built-in maximum and minimum (free-turning), then the cord linking everything together bust have slipped around the shaft of the tuning variable capacitor.
Given how tight everything must be for proper tuning, I wouldn't trust myself to re-wind the tuning cord from scratch, especially not on a 50 year old device.
What is the right way to correct the misalignment? Off the top of my head, I was thinking maybe there's a way to hold the variable capacitor shaft in place while letting the tuning cord "slide" around it? I didn't find detailed pictures of the inner parts of the clock, let alone a service manual.
As a related question while fumbling around the tuning circuits: how would it be possible for this radio to pick up AM stations in the 1600 to 1710KHz range? Adding a switch to toggle between "normal" and "extended band"?
About the Panasonic RC-7469 I have, the radio tuning handle appears be misaligned by a tiny bit. Not a major issue, rather a minor detail.
The picture says it all: the handle is always "above" the tuned station. Pictured is where I get clear sound for 600KHz AM, but it is misaligned on the FM band as well. Having dismantled a few, mechanically tuned radios very long ago, I vaguely remember there is a shaft on the tuner knob on which a cotton cord is tightly wound, winding again on the tuner dial (if round), or just moving the handle directly (sliding-type).
Since both FM and AM dials are misaligned by the same angle and that the tuner knob is has no built-in maximum and minimum (free-turning), then the cord linking everything together bust have slipped around the shaft of the tuning variable capacitor.
Given how tight everything must be for proper tuning, I wouldn't trust myself to re-wind the tuning cord from scratch, especially not on a 50 year old device.
What is the right way to correct the misalignment? Off the top of my head, I was thinking maybe there's a way to hold the variable capacitor shaft in place while letting the tuning cord "slide" around it? I didn't find detailed pictures of the inner parts of the clock, let alone a service manual.
As a related question while fumbling around the tuning circuits: how would it be possible for this radio to pick up AM stations in the 1600 to 1710KHz range? Adding a switch to toggle between "normal" and "extended band"?