Posts Tagged ‘Baofeng UV-5R’
Review – BTech AMP-25 series for Analog & DMR
February 27th, 2018 | 
Author: The AMP-25 series VHF / UHF Amplifiers
The recently announced BTech Digital and Analog amplifier series puts a whole new spin on mobile operation. It performs more like a mobile than it does a power amp. The D series are true TDMA Tier2 DMR amplifiers.
Note: This review was done using an Anytone D868UV on both DMR and analog.
In the Box
Included with the 40W Mobile Amp are:
– Mounting Bracket
– 3′ Interface Control Cable (Kenwood K1 connectors)
– 3′ RF connect cable (SMA-M to SMA-F)
– Microphone and Hanger
– All necessary mounting hardware
– User Guide
General Description
– UHF or VHF Power Amplifier
– 2-6W > 20-40W Output
Modes of operation include:
| V25 U25 | V25D U25D |
| Analog (FM) C4FM (Fusion) P25 (Phase 1) NXDN IDAS dPMR MPT1327 | > DMR Tier II (TDMA) > P25 (Phase 2) Analog (FM) C4FM (Fusion) P25 (Phase 1) NXDN IDAS dPMR MPT1327 |
A Different type of Mobile Amplifier
I found these to be much more than a typical power amplifier. Although they can function as a simple ‘In and Out’ power amp, this is about as close to a full mobile as you can get. Although the driving 
force was my DMR handheld sitting in my cup holder, the transmit audio was that of the included hand microphone and the receiver audio out was coming through the built in speaker driven by a four watt audio amplifier.
Transmit Power
I tested the power on two different models. The VHF V25 (non TDMA) and the U25D for UHF DMR. The power was tested using the analog side of both into a calibrated Bird Termaline wattmeter. The maximum current drain from my 13.6V 30A power supply was just under 6A. This is low enough for the amp to be powered by the 10A accessory jack in your vehicle.
Enclosure
The basic frame measures 4.6″W x 1.3″H x 5.5″D (excluding the SO-239) and weighs in at 26oz. I was
curious to see the internal layout of the amp and to no surprise, there was a 5/8″ finned heat sink spanning the entire length and width of the case along with air vent along the back of the enclosure.
Operating Modes
These are single band amplifiers.
V25(D) = VHF 136-174MHz
U25(D) = UHF 400-480MHz.
Note: The V25D and U25D were designed to include DMR Tier II (TDMA) and P25 Phase 2 along with all other modes. Their operation varies slightly.
V25 / U25
To operate VHF through the UHF (U25) amplifier, or UHF through the VHF (V25) amplifier, simply power off the amplifier. This will allow you to run straight through directly to the antenna without power amplification on that band.
V25D / U25D
These amplifiers will only operate within their specified VHF or UHF range. This is due to the circuit switching design of DMR Tier II and P25 Phase 2.
Hook Up
The simplest configuration is using the included RF cable to attach the radio to the amp. You could add a Spkr/Micr to the handheld, but you would still be bypassing some of the best features.
I use the two included cables. The 3′ RF cable to attach the radio to the amp, and the control cable. This
allows me to use the full size hand microphone as well as connecting the four watt audio amp powering the speaker. The power included power cable is compatible with handhelds using the standard two pin Kenwood style connector, such as an MD380, D868, GD77, UV5R, F8HP, UV82, etc.
I use an Anytone D868 on DMR as well as analog with the hookup diagrammed below. Depending on your radios antenna jack, you may need to pickup an SMA-M to SMA-M adapter.
Convenience
All channel selection and volume adjustments are done using the handheld. No duplicate programming or code plugs are necessary. Whatever is in my handheld is what I operate in the mobile
Operating my handheld in the low power position, I still get 22W out on UHF and my handheld’s battery life remains excellent, but high power gives me a solid 39W.
Conclusion
I was glad to see someone finally develop what is a full featured mobile amplifier capable of DMR as well as all other modes including C4FM and D-Star that is small enough to mount in the car, boat, and on top of your computer. This amplifier is Part 90 certified and definitely worth considering.
Available from Amazon: V25 V25D U25 U25D
and 
VHF /UHF
Digital / Analog
Mobile Power Amplifiers
Review – BTech APRS-K2 Cable (TRRS/APRS)
by John ‘Miklor’
APRS-K2
It’s long overdue, but there’s finally a TRRS/APRS cable available for radios using a standard Kenwood style K2 connector.
I’ve been wanting to get involved with APRS for a while now, and this made it extremely easy.
APRS-K2 interface cable
The APRS-K2 cable allows you to interface your handheld transceiver with your existing mobile device, including. iPhone, iPad, and Android.
One end of the cable uses the Kenwood style K2 connector, while the opposite end is 
terminated with a TRRS connector. Also included with the APRS-K2 is a Reverse Adapter to insure compatibility with all devices. This adapter allows cable to connect to earlier 3.5MM TRRS standards, such as Nokia.
App Driven
The APRS-K2 cable uses a virtual TNC found in several apps, such as APRSDroid, APRS.fi, and Pocket Packet. Plug in the cable, turn on the VOX, and you’re pretty much set to go.
Product Description
BTECH APRS-K2 TRRS / APRS Cable A simple way to start using APRS by using devices you already own. The BTECH APRS-K2 Cable will quickly connect your radio to APRS by using virtual TNC (app driven) on your tablet or device. The APRS-K2 cable is built with a custom circuit board that will automatically adjust the audio for clear packet transmissions with minimal adjustment; along with protecting your devices from strong over modulated signals.
Along with allowing APRS functionality the APRS-K2 cable can provide a simple interface gateway to allow several features to your radio!
Easily record radio conversations:
By connecting the APRS-K2 cable between your radio and any recording (line-in) device.
Use the APRS-K2 cable as a Mic In Connector:
Set up VOX on your radio to accept any form of incoming audio – such as a Push-to-talk application on a Phone – or a Line-out application from your computer.
Use the APRS-K2 cable to push transmissions over a speaker system:
Easily play audio over a intercom or speaker system from your handheld.
With a backup radio and your own ingenuity, the APRS-K2 cable can serve as an interface for a variety of applications for any amateur. Compatible with Kenwood K2 Accessory Slot Radios (such as BaoFeng, BTECH, Wouxun, TYT) Compatible with all phones, tablets, and computers with 3.5MM Audio In/Out Ports
Includes:
APRS-K2 Cable
Reverse Connector Adapter
Quick Start Guide
Conclusion:
The cable comes with a simple one page instruction sheet which should have you up and running in about 10 minutes after the appropriate app is loaded.
– Plug in the cable
– Set your handhelds volume control
– Turn on the VOX
– Set your handheld to 144.390 (US)
– Activate the app
That’s all it takes. If you’ve been considering building an APRS cable, you might find this an easy Plus and Play alternative.
The APRS-K2 can be ordered from Amazon, or if outside the US, you can go to their website and contact them directly. Baofeng Tech
Too many toys, too little time.
John ‘Miklor’ K3NXU
http://www.miklor.com
Review – BTech UV-5X3 TriBand Handheld
UV-5X3Although the case design is familiar, the radio inside is not. BTech has recently introduced the new UV-5X3 to the US Ham Radio market. This radio is a true triband transceiver with internal filters specifically configured for triband operation.The firmware in this radio has been reworked to include several new features not found in similar appearing radios.
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In the Box
Included with the radio are the:
– 1500mAh Li-Ion Battery **
– 85 page User Guide – English
– Charger base & AC adapter
– Hand strap
– Belt clip
– PTT Earpiece / Microphone
– Antenna (1) – VHF / UHF 6 3/4″ (17cm) A-V85
– Antenna (2) – 220 MHz 6 1/4″ (15.5cm)
.
** This is the identical battery that is commonly mislabeled as 1800mAh on some handhelds.
The UV-5X3 was specifically designed as a Tri-Band transceiver. The internal filtering allows not only the traditional VHF and UHF frequencies, but also includes the 222-225 MHz Ham band for the US.
Case DesignThe UV-5X3 has the traditional case design, which allows me to use my high capacity BL-5L 3800mAh battery with no alteration to the base. Accessories such as my mobile battery eliminator, Spkr/Micr, etc. are fully compatible.
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Transmitter
The frequency range is VHF 130-176 / 222-225 / UHF 400-480 MHz, supporting both Wide and Narrowband with 2.5kHz steps.The radio’s filtering scheme allows for full power on all bands. My OTA audio reports have been clean with clear with mellow audio. Power levels are respectable using a Bird VHF/UHF Termaline.
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DTMF / IRLP Access
Something new also appearing on this model is a DTMF gain adjustment, allowing me to adjust the DTMF audio to the transmitter to a comfortable level for both repeater control and IRLP access.
If you are in a area that requires tone burst for repeater or network access, the 1000Hz, 1450Hz, 1750Hz, and 2000Hz burst are accessible by pressing the PTT along with one of the four pre-assigned keypad keys.
The receiver sensitivity is excellent, and the audio quality is clear, loud, and undistorted. Along with the 3 TX/RX bands, the receiver also includes the traditional commercial FM radio band. (65MHz-108MHz)
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Tone Scanning – The receiver also has the ability to identify the tone of a repeater being transmitted by a received signal.
This feature gives me the ability to add / delete channels from the scanning list using the keypad. No longer a software only function. The more I can do from the keypad, the better I like it.
A Long Press of the [*SCN] button will start the scanning process.Channel Mode – When scanning with the Display Sync set to ON, the upper and lower display will scan together. This is explained below under Display Synchronization.Frequency Mode – When entering Scan, the image below will appear on the screen. Enter the first 3 digits set the range start, the second 3 digits sets the stop.
Example: Entering 146 : 146
Start the scan range at 146.000
Ends the scan range at 146.999
AntennaI found two antennas included with the radio. One was the standard upgraded A-V85 antenna, and a slightly shorter one for the 220MHz band.
Antenna (1) – VHF / UHF 6 3/4″ (17cm) A-V85
Antenna (2) – 220 MHz 6 1/4″ (15.5cm)
The separate antenna specifically tuned for 220 MHz is a great addition. The SWR shows 1.3 which is excellent. No compromise. I labeled my 220 antenna, as they are very close in appearance.
.Display
The radio has a tri-color display, allowing the color options of the blue, orange and purple. The LCD can be formatted in either of three formats. Choices are Frequency, Channel number, or up to 6 Alpha Characters.Display Synchronization
The UV-5X3 supports display syncing, which gives ability to track both the upper and lower LCD. I keep mine set to display the channel name in display A, and the frequency in display B. When you change the channel, both the upper and lower displays move together.
.Programming
Manual programming is pretty straight forward once you enter a few channels. A programming guide can be found at Manual Programming with a Menu Definition summary available at Menu Definitions.
The software support for the UV-5X3 can be found in the Latest Daily Build of CHIRP. There are a few new options that will be added to the 5X3 in the near future. One is the ability to Stun, Kill, Revive. This gives you the ability to disable your radio remotely.
The new chipset (RDA1846S and RDA5802N) provides reduced AGC switching noise and a low-IF digital audio processor for improved sound quality.
The programming cable requires a traditional two pin Baofeng / Kenwood style. There are several cable available. The generic cables may require special drivers, due to the use of cloned chips. For Plug and Play, a cable using an FTDI chip is recommended.
ConclusionThe UV-5X3 firmware has obviously been reworked to include:
– Tri-Band Support: VHF/1.25M/UHF
– D-ANI (Display incoming DTMF Tones)
– Synchronized Displays
– DTMF audio gain level adjustment
– Add / Remove Channels from Scanning list via keypad (LCD Dot Indication)
– On the Fly scanning by Frequency Range
– 4 Tone Burst options
– Remote Stun, Kill, Revive
