Hello All,
Just thought I'd post this since I've seen many posts in the past, sometimes with incorrect information.
Generally for light duty repeaters, I use some Motorola mobiles that have been modified for better cooling. But for the link radio (linking to a hub repeater), the LPI Motorola's are getting harder to come by.
That being said, the uv-5r's in low power setting are an interesting experiment that I'll be using for a new site. But much of the stuff on the internet to get a COR signal off the UV-5r is just plan wrong.
Looking at the schematic diagram, the TDA2822 opamp that is used for the speaker, only gets power when the PL/DCS is unlocked. Otherwise, the TDA has NO power. Therefore, its a great place to use to get a COR signal. I've tested this and I'm using this currently attached to a high impedance input on an Arduino I'm using as a controller.
You can see the NPN transistor (Q19) that is providing the power to the op amp. This only comes on when the PL/DCS code opens.
At any rate, just thought I'd share. Oh, on one other note, the surface mount op amp is very,very sensitive to heat. So if you do solder on that pin 2, be very careful you don't overheat it otherwise you'll destroy that chip.
-J
Just thought I'd post this since I've seen many posts in the past, sometimes with incorrect information.
Generally for light duty repeaters, I use some Motorola mobiles that have been modified for better cooling. But for the link radio (linking to a hub repeater), the LPI Motorola's are getting harder to come by.
That being said, the uv-5r's in low power setting are an interesting experiment that I'll be using for a new site. But much of the stuff on the internet to get a COR signal off the UV-5r is just plan wrong.
Looking at the schematic diagram, the TDA2822 opamp that is used for the speaker, only gets power when the PL/DCS is unlocked. Otherwise, the TDA has NO power. Therefore, its a great place to use to get a COR signal. I've tested this and I'm using this currently attached to a high impedance input on an Arduino I'm using as a controller.
You can see the NPN transistor (Q19) that is providing the power to the op amp. This only comes on when the PL/DCS code opens.
At any rate, just thought I'd share. Oh, on one other note, the surface mount op amp is very,very sensitive to heat. So if you do solder on that pin 2, be very careful you don't overheat it otherwise you'll destroy that chip.
-J
