Cheapest (~10-15USD/unit) Wireless Intercom or Simple USB Powered Walkie Talkie Hack

Introduction: Cheapest (~10-15USD/unit) Wireless Intercom or Simple USB Powered Walkie Talkie Hack

This is a simple hack (just connecting wires) to make a usb powered walkie talkie
i tried this when i was still in elementary school and forgotten about this for years, till recently when my brother ask me to recommend cheap wireless intercom that cost less than 20USD per unit, that can pass thru 3-5 concrete wall for his company.
so i did my researched, and found out it was impossible to get a commercial wireless intercom under 20USD per unit.
wired on was out of the question

my other solutions that fits within the budget was walkie talkie, but all walkie talkies, AFAIK are battery powered.
googled for a usb power ones and found a Motorola MR350R which cost about $30 per unit, $10over the budget

but luckily i remembered my elementary school days.

and tru a simple browsing, it cost:


i bought the walkie talkie from the, but the cable and charger use for this build was my old extra stuff.

I'll use the price from as a reference anyways

TOTAL: $34.38 for set of 2 (postage included) or ~$15 each set

half the price of a Motorola MR350R

price goes down if you buy in bulk.

also, other site(aliexpress) are cheaper. and if i all buy it from them, then the price goes down to ~$10 per set

soo, you can get 3 set per 1 MR350R bought

i just bought it @ dx for the convenience.

soo without further ado, here is a simple guide to hacking it

ATTENTION!!! you know the drill. i do not take any responsibilities and all resposibilities lies with you, the hacker, whatever it causes, including but not limited to, broken devices, electrical shock, fire, explosions, lighting strikes, volcano eruptions, etc..... you get my point.... : p

Step 1: What You Need

PER UNIT or node you'll need :
. walkie talkie power rated 0.5W-1W (3-4 AA / AAA baterry powered, im using 4*AAA powered ones )
- USB charger, ( i used 5v 500ma for this hack, you might need a higher current if you are using high power walkie talkie)
- usb cable data or powered
- scissors or wire stripper
- solder / tape / conductive glue / anything else to connect and hold wires to the walkie talkies (in mine, i soldered it)

3*AA powered walkie talkies are said to be safe here
i didn't try t for Lion, LiPO batt. powered ones, but you can use the same method, with a step down/up voltage regulator and higher current charger if the device is high powered.

Why do i use 4 AA/AAA powered ones? its operational voltage makes connecting to a usb charger simple. a fresh AA battery 1.5++V and goes down to 1V when it almost fully discharge or "emptied". so its operatinal voltage (since it ran in series config) is 1.5V*4 to 1V*4 which is 6V to 4V. power from usb is 5V and it is well within the range.

Step 2: Find the Polarity and Strip the Wire

find the polarity of the walkie talkie and where begin and end for a full connection

a simple way is just to look at the battery slot. just like the picture

then prep the wire. strip it to the small + and - wire. cut the other white and green

refference USB Pinouts

if yours is not a standard cable, find out its polarity.

Step 3: Connect the Wire to the Walkie Talkie the to the Usb

connect the wire like so.

then power on.

Voila! u have a wireless makeshift intercom / usb powered walkie talkie that u can use all day.

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    Pat Pending
    Pat Pending

    8 years ago

    Very nice instructable. What frequency do these WTs work on?


    Reply 8 years ago on Introduction

    FRS &G MRS band soo ~462mhz

    this instructable can be applied to other 3-4AA/AAA powered WTs of other frequencies. watch for the next one thou. i will it into a usb powered + battery UPS auto backup/detach mode. as soon i find the time. hahahahahaha....

    Pat Pending
    Pat Pending

    Reply 8 years ago on Introduction

    Very similar to 446 MHz PMR band WTs available in Europe.


    8 years ago

    I think the main reasons business class wireless intercoms are so expensive is because it operates in the gmrs band. bubblepack radios like this are in the FRS band, which was popular for little kids in the neighborhood to talk to their friends on till cellular phones and text messaging became popular. Now the FRS band is fairly silent these days.


    Reply 8 years ago on Introduction

    "business class wireless intercoms are so expensive is because it operates in the gmrs band"

    i dont think thats the reason. the walkie talkie i got operates at FRS &G MRS band.

    i think its a more about economics of it all.

    intercom has been largely replace by PBXs and VOIPs in the business world thus creating a small demand, lead lower supply and high manufacturing cost per unit.

    walkie talkie is still cheap because it is mass produce in a huge volume, since there is still a demand for it.

    Walkie talkie is still used in many Field operators like constructions, security, etc.... and even consumers still use them

    intercoms however, its used by corporations has diminished greatly replaced by many other things like PBX or similar devices. even in the consumer space its been replace by phones pc, etc....

    so, IMO, its economics......