UV-5R COR Signal

How to Get a UV-5R COR Signal

A while back, a discussion on a radio forum came about on how would someone get a COR signal out of a UV-5R for the possibility of using it as a portable repeater receiver. Now I will not debate that the UV-5R is not the best receiver to use for this as it has a wide open front end and subject to overload and desense. But ignoring that issue and trying to solve the answer to question lead me to split one open and look inside. With the help of a schematic and a DMM , an easy point to get COR can be achieved.

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.

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.




Here is the quick video on where you can get a COR signal if you really wanted to use a UV-5R for this purpose.

https://youtu.be/ejhxLleNXHw

Transmitter Spectral Purity - BTECH GMRS1

BTECH GMRS-V1 HT

In a follow-up to my previous post on the spectral purity of several transmitters, I decided to bench test the newer BTECH GMRS-V1.

The BTECH GMRS-V1 is basically a UV-82 rebranded and with software to lock down the HT so that its Part 95a compliant (such as you can not change the front control to VFO mode like on other Baofeng / BTECH radios).

It has an FCC ID of 2AGND-GMRS-V1. If you are interested in all the FCC details take a look here: https://fccid.io/2AGND-GMRS-V1

Overall, it looks to be a decent radio as I've used the UV-82's for sometime now and they are a better design than the older UV-5R.

Please note the SA output for this radio on one of the GMRS channels:

As you can see, this radio is much cleaner then the UV-5R and would be expected to be such for Part95 operation.

All the UV-82 accessories work on this radio too.

To date, the BTECH GMRS-V1 is probably the most cost effective GMRS repeater ready radio as it also provides VHF/UHF scanning/RX mode of the range of a typical UV-82. As I use this radio more, I'll post updates.