03-15-2014, 10:04 AM
Okay!
This morning, I opened the 4400 back up and removed the 10K shunt resistor in the LED Stereo Beacon circuit.
I tried a 2.2K resistor. It helped, but the Beacon was still fading slowly.
I then removed the 2.2K and tried a 1.5K. It made the Beacon respond better, but still faded somewhat slow.
Then, I paralleled that with another 1K (which equaled 600 ohms). More improvement.
Removed those two and installed a 470 ohm resistor. I think this is as good as it is going to get. It now fades away in just over a second when tuned off signal, much quicker than with a 10K, and better than with a higher value resistor. It does not fade as fast as it would with an incandescent bulb, but the fading action is good enough for me.
I think whoever had posted online about matching the current of the original bulb must have had a good point, as the LED works much better with a low value shunt.
Since I haven't soldered the 470 ohm resistor in yet, I might try a 390 ohm resistor (the next smallest size I have) before I button it up. But I don't think the 390 will make that much more of a difference.
This morning, I opened the 4400 back up and removed the 10K shunt resistor in the LED Stereo Beacon circuit.
I tried a 2.2K resistor. It helped, but the Beacon was still fading slowly.
I then removed the 2.2K and tried a 1.5K. It made the Beacon respond better, but still faded somewhat slow.
Then, I paralleled that with another 1K (which equaled 600 ohms). More improvement.
Removed those two and installed a 470 ohm resistor. I think this is as good as it is going to get. It now fades away in just over a second when tuned off signal, much quicker than with a 10K, and better than with a higher value resistor. It does not fade as fast as it would with an incandescent bulb, but the fading action is good enough for me.
I think whoever had posted online about matching the current of the original bulb must have had a good point, as the LED works much better with a low value shunt.
Since I haven't soldered the 470 ohm resistor in yet, I might try a 390 ohm resistor (the next smallest size I have) before I button it up. But I don't think the 390 will make that much more of a difference.
--
Ron Ramirez
Ferdinand IN