Converting the BTX-127 for AA Batteries


I wanted a MURS radio, so I called around looking for a BTX-127 at the local Radio Shacks. The only one I found was was a display model, and did not come with a battery or charger. I asked about buying a battery separately, and they said it was $38, and it would have to be ordered. $38 is more than the cost of the radio, so I decided not to order the battery. But, I decided to settle for the display model anyways, even without the battery and charger.

I came up with a scheme to allow the radio to run off 6 AA batteries, which fit into the battery compartment quite nicely by themselves.
I am a rechargable AA battery addict, almost everything I have takes AA's, and when I go to buy things, I look for stuff that takes AA's.

So, I decided to ignore the caution label in the battery compartment...

I know, the native battery is 7.2v, and regular AA's are 1.5v:
6 batteries x 1.5v = 9v

But, most rechargable NiMH/Ni-Cd AA's are 1.2v:
6 batteries x 1.2v = 7.2v! We have a winner.

Right now, I am using cheapo regular 1.5v non-rechargable AA's. I don't believe the extra 1.8v will harm the radio. It hasn't yet. Anyways, the voltage of regular AA's usually drops as they discharge. But, do this and the following AT YOUR OWN RISK.

You also should NOT use the BTX-127 charger with the AA batteries in the radio. Use a regular drop-in charger for your AA's.

This was not easy to do, and it is not recommended unless you are both technically inclined and determined to make it work. It could be time consuming, and it will likely take some playing around and experimenting, but people like me enjoy this kind of thing...

What I came up with is pretty crude, but it is both reliable and effective for me.
In retrospect, I should have done some things differently, like finding something plastic to tear up instead of using card stock and cardboard. There is a lot of room for improvement here. I plan to do something similar for my Uniden BC245XLT scanner in the near future.





Here's some things I destroyed to make this work. I cut up a mint tin, and took the springs out of some battery holders....
A pop can might work well too. The key is to have THIN metal.






Then, I cut some VERY THIN cardstock, so it fits like so:






I cut and folded some heavier cardboard, so it fit the gap shown.






So, I ended up with these parts. I had to sand the metal strips because they had a thin coating from the mint tin. This also allowed the metal to take solder better.
Then, I used a phillips screwdriver and hammer to put dimples in them.






I ended up having to cut some smaller pieces of metal too.
For this insert, I soldered the spring to the metal, and also soldered the metal pieces together as shown. I cut the srings a little to make them smaller. There is not a lot of space, so the key here is to use the THINNEST stuff you can find.
The metal is super-glued to the cardstock.
Be careful not to short anything out!






Same thing here, springs are soldered to metal. Metal is super-glued to the cardboard.






The other side...






Inserts in the radio...












Batteries in radio...
Pay VERY CLOSE attention to the battery polarity as you insert them! Don't put any in backwards! If you look hard, you will see a + and - in the battery compartment for you to follow. You should be sure to understand how the batteries are connected in this configuration, to be sure they are inserted correctly.






I found it easiest to insert the two bottom batteries on the end first, and then insert the middle battery along with the insert as shown.






Batteries in radio...






The end batteries on the top were the most difficult to make fit correctly, as there really was not enough space for springs. But, with the dimples in the metal, it made a tight enough fit for a reliable connection.

Again, pay VERY CLOSE attention to the battery polarity as you insert them! Don't put any in backwards!