Uploaded September 2022 | Updated September 2026, 5 hours ago
This is a fairly easy repair for Midland WR-100 weather radios that exhibit a silent, weak, or squealing tuner. While it is possible your issue may be different, I have found the ceramic IF filter (black rectangular box labeled CQ 33-450E on the circuit board) has a tendency to leak (electrically), creating a low resistance path between the ground and IF input of the tuner chip. To test if this is the issue with your radio, carefully desolder and remove the original filter, and power up the radio. If your radio was dead silent before, you should hear louder hiss and static with the filter removed. If you have a small (~68pf or greater) ceramic capacitor at hand, you can place it across the input and output pads (the off-center hole and end hole closest to the display), and you should hear your local weather radio station. If the radio works well and you live close enough the transmitter, with very weak or no adjacent signals, you may choose to leave the capacitor in place of the filter. For best performance, it is suggested you replace the filter with another filter. The original filter has a center frequency of 450kHz and a 6dB bandwidth of ±7.5kHz. A commonly found online (as of posting this) exact drop-in replacement is the LT450EW. The lower profile LTS450 series filter has the same pin spacing and will work as well. Wider filters with D suffix (±10kHz BW) and C suffix (±12.5kHz BW) will also work.
I’ve had three of these Midland weather radios working around the house and garage for 15+ years, and so far all three have been working without issue. I’ve only been introduced to the problems with these radios when I started to pick them up from thrift stores with the intention to give them to family members.
I happened to have been repairing this radio just while the weekly test was sent, didn't even get a chance to finish soldering it before the test.
This is a fairly easy repair for Midland WR-100 weather radios that exhibit a silent, weak, or squealing tuner. While it is possible your issue may be different, I have found the ceramic IF filter (black rectangular box labeled CQ 33-450E on the circuit board) has a tendency to leak (electrically), creating a low resistance path between the ground and IF input of the tuner chip. To test if this is the issue with your radio, carefully desolder and remove the original filter, and power up the radio. If your radio was dead silent before, you should hear louder hiss and static with the filter removed. If you have a small (~68pf or greater) ceramic capacitor at hand, you can place it across the input and output pads (the off-center hole and end hole closest to the display), and you should hear your local weather radio station. If the radio works well and you live close enough the transmitter, with very weak or no adjacent signals, you may choose to leave the capacitor in place of the filter. For best performance, it is suggested you replace the filter with another filter. The original filter has a center frequency of 450kHz and a 6dB bandwidth of ±7.5kHz. A commonly found online (as of posting this) exact drop-in replacement is the LT450EW. The lower profile LTS450 series filter has the same pin spacing and will work as well. Wider filters with D suffix (±10kHz BW) and C suffix (±12.5kHz BW) will also work.
I’ve had three of these Midland weather radios working around the house and garage for 15+ years, and so far all three have been working without issue. I’ve only been introduced to the problems with these radios when I started to pick them up from thrift stores with the intention to give them to family members.
I happened to have been repairing this radio just while the weekly test was sent, didn't even get a chance to finish soldering it before the test.
