Subject: RS Weather Alert Radio
I recently put out a bulletin for a fix for the Radio Shack model 12-140
Weatheralert radio concerning how to reduce the volume of the alert siren, but
leave the regular volume (broadcast rx) unaffected. I have recieved many
suggestions from many folks on packet, but I chose this one from Ed, KJ4LQ.
Remove the screws that hold the back onto the radio and look near the speaker.
You should see a capacitor (disk ceramic) identified as C31. (pcb silkscreen)
Lift the side of the capacitor closest to the speaker and place a 1 Meg. res-
istor in series between the leg, and pad to which it was connected.
I used a 1/4 watt and spaghetti tubing and bent the resistor away from the pcb
on its leads (1/4"). oh....remove the pcb from the plastic standoffs to free
the board from the top case to make it easier... after soldering the resistor
place the board back in place and bend the resistor out of the way so as not
to short out anything. re`assemble the radio. The siren volume willl now be
reduced by about 75%, but the red alert l.e.d. will still flash as normal.
You may also want to try a 1 meg trimpot in place of the fixed resistor should
you wish to adjust the alert siren at will. (remember...if your in a high risk
area..like "Tornado Alley" in the Mid-USA, you may not want to use this mod
since here in the East where I am, we don't get weather anything like they get
out there.
This will also void your Warranty from R.S. Anyway...it works and has been in
use here for a few weeks now, left powered on, with no problems.
Thanks again for all the help from all! (*.*)
Signed:George, WA2RCB
SOURCE: The QRZ Windows Ham Radio CDROM |
