I found info on building an electronic predator caller on line. Its based on a $10 10 watt megaphone from Harbor Freight. Not wanting to spend $100+ on one I decided to give it a try.
Here's what the megaphone looks like.
You need to remove the 2 screws to get into the guts.
You will need to get into the guts and remove the mike that comes with it and attach a cord that will plug into your mp3 player. I used an old cord I had but you could pick up one of the old style ear phone from radio shack cheap.
The megaphone uses 4 c batteries so if you want to add an external 6 volt lantern battery you can clip into the battery wires just be sure you match the polarity by marking the wire that attaches to the spring in the battery compartment and using it as your negative wire.
Carefully put it all back together then your ready to build a box to carry it in. You can use a plastic ammo box or if you're extra cheap like me you can get this box from wmart for $4. I cut the hole in the end and added a piece of scrap wood with a hole in it to support the megaphone on the inside.
I used silicone chalk to seal the megaphone in the box and added a screw to the the wood to lock it in place. Once the chalk is dry I'll mount the lantern battery inside and add bolts on the outside to wrap the wire around.
It works great and is loud enough to hear from over a 1/4 mile away in a 25-30 mph wind. I tried connecting it to my walkie-talkies to try to use it remotely but the walkie-talkies have too much hum to them. So I found about 20 yards of phone wire while dumpster diving at a construction site which lets me set up away from the megaphone.
You can get free mp3 predator calls at
Varmint Al\\'s web page
Topic: E Caller build along (Read 250 times)
