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Hardware / Technical

                  Speaker Microphone Pin Out
                  Dual PTT Switching
                  Programming Cable
                  SMA Antenna Connection
                  Extended Antenna Threads
                  Erratic Charger Behavior



Speaker Microphone Pin Out
3.5mm Plug     
Sleeve Mic –      PTT     Rx Data     (to the radio)
Ring Mic +
Tip +V                (from the radio) 

2.5mm Plug
Sleeve Speaker –    PTT     Data GND
Ring TX Data      (from the radio)
Tip Speaker +
Connect Sleeve to Sleeve for PTT

Note: This plug is Anytone, Baofeng, Kenwood and Wouxun compatible.

Graphic by electronicholas
 Walt, N3PLA, took the diagram to the next level
and added the Dual PTT and a TRRS jack.
Great job, Walt.


Dual PTT Switch
Baofeng UV-82 series

A standard single button remote spkr/micr will select Display B (the bottom display) when keyed.

There are earpiece/microphones available that incorporate two PTT buttons. The wiring configuration for these is shown below.

Connecting contacts X to A will key the transmit channel in the upper display.  Connecting X to B will key the lower channel.


Recently, a Dual PTT Spkr/Micr was put on the market for the UV82 series. The top button selects display A, the side button selects display B.   Info_here
Keep in mind, this microphone was designed for radios having the Dual PTT option as part of the radio.  Adding the extra switch to the microphone will Not add the function to your radio.

for Anytone, Kenwood, Wouxun, Baofeng

Provided by Jim KC9HI, Paul AE5JU
The RXD line from the module goes to the sleeve of the 3.5MM plug.
The TXD  line from the module goes to the   ring   of the 2.5MM plug.
GND line from the module goes to the sleeve of the 2.5MM plug.

There are several variations of CP2102 boards available.
The pin location and labels may vary.
Below are two examples.
Builders Note: Some boards have the TXD and RXD pin labels reversed.  If your cable does not work, switch the TXD and RXD wires.

Below is a sample cable constructed by Jim, KC9HI
An excellent project for a new ham.

  A Project describing how to build a programming cable can be found HERE


Radios requiring a 3 pin 3.5mm plug,
BTech UV-2501/5001, 25X2/X4, 50X2
QYT KT8900 / KT-UV980, Juentai JT6188, etc

use the following configuration.

 A Project describing how to build a programming cable can be found HERE

The Leixen series (VV808 / 898)
requires an 8 contact RJ45 connector
A Project describing how to build a cable using an RJ-45 be found HERE
Yaesu  FT-7800, 7900, 8100, 8800, 8900
Link to Cable Diagram

(My thanks to Ettore IZ3ZVO)
 The CP2102 USB-UART is by Silicon Labs and can be found on eBay ($2).
Windows, MAC and Linux drivers can be downloaded at: 
Builders Note: Using an old Cloning or Programming Cable/Plug may not work.  The wires in some are hair thin and many can't be soldered.
for Baofeng UV-3R
Most  Anytone & Baofeng radios
require an
antenna with an SMA Female fitting.
Most Wouxun KG-UVxx models require an SMA Male fitting.
Baofeng UV-3R requires
SMA-Male, UV-3R+ requires SMA-Female

Unlike horseshoes, close doesn't count.
Always confirm the connector type before ordering.

SMA FemaleSMA Female
example of SMA Female

SMA RP (Reverse Polarity) and
SMA Male are NOT compatible.
  Note: SMA-RP connectors are found on most Wi-Fi Routers.
Examples of Various SMA Formats
SMA FemaleSMA Female
SMA FemaleSMA Female

SMA Female

Reversed SMA-Male Connectors are
commonly found on Wi-Fi Routers

RF Connector Identification Chart

To use an antenna with a BNC Male requires the following adapter:

     SMA Female (above) to mate with the radio
     BNC Female to mate with the BNC Male antenna.

Another option is a jumper (pigtail). This relieves the stress of a heavier cable when using an external mobile or fixed antenna. 

SMA-F Antenna Extended Threads
Some antennas with SMA-F connectors have an extended thread.  Most radios such as the UV-5R and UV-3R+ require a standard SMA-F.
The illustration shows two different Nagoya NA-771 antennas.
Some antennas with extended threads ship with a spacer to fill the gap. 

Note: If the radio requires extended threads, such as a BF-888S, an antenna with standard threads will not make connection unless you trim the outer shell or lip of the antenna so it is flush with the base.

If the antenna has extended threads and there is a gap or airspace, a #8 O-Ring can be used to fill the gap. Some antennas include this in the package.

If there is no gap or airspace, do Not add the O-Ring. This may actually prevent your antenna from making a good contact and cause damage your radio.

The wrong threads (if too short) will result in poor reception and over heating of the transmitter as there is no solid antenna connection.


Erratic Charger Behavior
This includes: Battery not charging, Light staying Red and Erratic Light behavior.
On many chargers, internal contact to the circuit board is made via tension clips. If there clips do not have the proper tension or the copper pad is not clean or is oxidized, a good contact will not be made. This is normally an easy fix.
This brief video will show you the inside of the charger base and a simple fix.
by John Reinhart

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