Build your Own Programming Cable

by John ‘Miklor’ K3NXU

CP2102j[1] Frustrated with that generic programming cable?
This $2 solution might just be your ticket to sanity.

Let’s See…

You purchased a radio and programming cable, loaded the software, and that’s as far as you’ve gotten. You’re fighting with error messages:
– Radio did not respond
– Could not open COM port
– Run Time Error
and Windows (TM) 10 keeps changing your drivers.

Now you do what many owners do. Put the radio in the drawer to be worked on later. This is like buying a roll-away treadmill and putting it in the closet until the next time you want to exercise. (NOT going to happen)

But wait, yours has the company name and logo right on the cable.
– It doesn’t matter. Keep reading.

There are a few options available, such as an FTDI cable. It’s truly Plug ‘n Play, and costs about $20.

But here’s a project that just might solve the issue for around $2. All you need is a small flat blade screwdriver, a soldering pencil, and a CP2102 board.


The CP2102 is a USB to TTL UART chip. What?
Long story short… It’s the same thing that’s in your current cable now, except these work.

CP2102 boards can be found on eBay for around $2 and on Amazon.

Here’s How

Let’s start with that original cable.CP2102j[1]

Take a small screw driver and pry the open the case from the back where the cable enters.
It should only be snapped together.CP2102b
Unsolder the 3 wires connected to the board.  GND is Black, TX is Red, RX is White.CP2102c
Solder the 3 wires to the corresponding terminals on the new board.CP2102g

Note 1:
Some boards may have the TxD and RxD reversed. If it doesn’t work the first time, reverse the two wires. No damage has been done.

Note 2: Some boards have pins on the back requiring small connectors. You can either remove the pins, solder to them, or use the connectors. (Whatever floats your boat.)


When you insert the new board into the USB port, give Windows a chance to find and load the new driver. Should take about 30 seconds. When it says Driver Found, you’re done.

If the driver is labeled CH340 instead of CP210x in Device Manager, that’s not a problem. Both chips are designed to do the same thing.

But I don’t have a Cable

If you don’t have a generic cable, you can use 2.5 and 3.5mm stereo jacks. Here are the pin outs, and what Jim’s (KC9HI) cable looks like.
CP2102jim CP2102o



If you are adventurous, try retrofitting the new board inside the original plastic housing. This will require a Dremel tool, X-Acto knife, Glue, and some patience, but it can be done.

If the board only has 5 terminals instead of 6, it’s not an issue. You only need GND, TX and RX.

Some come protected with a piece of clear heat shrink over the board so you can see the cool blinking lights.

Note 3: If you are trying to retrofit the board inside an existing shell, the red board below is a bit shorter and easier to fit.          Amazon       eBay
For about a dollar or so more, you can find the same boards in a metal case.

What’s the Advantage

– First and Foremost, it works. Take the radio out of the drawer, program it and have some fun.

– Next, it only cost around $2 to save the generic cable from the trash.

– Very Important – Bragging Rights. Now, when you go to a club meeting and someone says they can’t get their cable to work, tell them they can build their own, just as you did.

I hope you had fun with this project. It’s super simple and very rewarding. I’ve made several and never had a failure. Say goodbye to driver issues.

My thanks to Jim KC9HI for his input on this project

More Information:

Sainsonic GT-3, GT-3 Mark II additional notes

Thanks to a reader in Denmark I ran into a new, undocumented feature present in modern UV-5R varieties which have both a Band and an A/B button. The feature has been confirmed in the GT-3, GT-3 Mark II and the to-be-reviewed GT-3TP, but might be true for recent UV-5Rs also.

1750 Hz and 2100 Hz burst tones
In most parts of the world burst tones were once used to open up repeaters but abandoned in favor of CTCSS.  It’s one of the reasons why I don’t look into that feature too closely anymore; it became sort of irrelevant. Some European repeaters will still open up when a 1750 Hz tone is transmitted in order to stay compatible with older ham equipment.

Without notifying anyone (what’s new) Baofeng added the 2100 Hz burst tone to its bag of tricks. The problem is that this tone is not documented anywhere in the manual, and that they use the Band key to generate 2100 Hz instead of 1750 Hz. So, if you follow the manual, you’ll send 2100 Hz instead of 1750 Hz.

This is what you should do:

  • Ignore the manual
  • press PTT + A/B to generate 1750 Hz
  • press PTT + Band to generate 2100 Hz.

I mailed this to John ( so it can be included in the documentation.

Burst Tones

GT-3 antennas
The SMA thread on GT-3 antennas isn’t very precisely made. You might feel some resistance once every 180 degrees when screwing it on. It’s no biggie an will resolve itself after some use, but worth knowing.

UV-5R ‘reverse’ function oddity
When you have a repeater programmed in one of the memories and assuming you only programmed a CTCSS tone for TX, not RX, you would expect CTCSS to be irrelevant when listening reverse. That’s not the case; your Baofeng will ‘invent’ R-CTCSS on the fly. According to some hams this behavior can also be found on certain Kenwood models.

UV-5R’s latest bug: listen to the beep

When it comes to keeping track of Baofeng / Pofung flaws, the Miklor page is way ahead of me. I only run into newer models by accident, but don’t order them anymore. It’s just too expensive.

The latest UV-5R bug pointed out by John K3NXU involves muted RX audio when the keyboard beep is switched off. Personally I find keyboard beeps very annoying, and always switch it off. No new model for me, that’s for sure…

It’s a bit of a silly bug, created by a sloppy programmer, and never caught by other Baofeng employees responsible for intercepting these things – if such employees actually exist. Let’s face it: the UV-5R is a dirt cheap product, having competent QA personnel on the payroll might not be feasible.

Not the first time
Since its inception the UV-5R had its fair share of bugs, from being off-frequency on receive to muffled TX audio to meaningless squelch levels. Under ideal circumstances bugs wouldn’t be a problem: just update the firmware and you’re fine. Unfortunately this can’t be done: UV-5R firmware can’t be updated afterwards.

If you can’t live with the bug, the only thing you can do is send it back or wait for a new version to come to market. If you bought directly from China, sending back the radio is often more expensive than buying a new one. Basically you’re screwed. Food for thought if you love conspiracy theories: Baofeng does it on purpose!


Which one? UV-5R vs UV-82 vs GT-3

There are now so many radios build around Baofeng UV-5R circuitry and software that potential buyers don’t know which one to pick. Most questions I get by e-mail are about choosing one of these three Baofeng radios: UV-5R (whatever variety), UV-82 and the new GT-3.


My personal opinion is: get the Baofeng UV-82.

  • Big, professional looking radio, dual PTT key is located where it should be,
  • Better overall performance thanks to more efficient stock antenna
  • One Watt of extra power output on both bands (5 Watts VHF, 4 Watts UHF),
  • Display located where it should be, doesn’t go dark after long transmissions,
  • Better designed keyboard with the 0 (zero) in the right place,
  • Better RX audio thanks to the bigger enclosure (improved acoustics),
  • No issues with muffled or low TX audio,
  • Battery life as good as the other two contenders.


  • Poorly designed charger. If you buy a UV-82, be prepared to fix it from the moment you pull it out of the box. It’s an easy job, click here to find out why and how.
  • Front-end just as poor as the other two, which means that the receiver overloads quickly. If you need a better receiver, buy a Baofeng UV-B5/B6.
  • New and/or after-market batteries are often labeled and advertised incorrectly. Whatever the label says or whatever the seller says, the battery is 1800mAh, not 2800mAh.