Tuesday, 28 January 2014

LNA4HF Review

Affordable, portable and works, this is a must-have for upconverter owners and shortwave listeners.

What is it? 

The LNA4HF is a low-noise amplifier (also called signal booster) for long -, medium -, and shortwave reception, amplifies signals 80 - 100 times between 0.15 MHz and 30 MHz. 
It will let you hear more signals with your RTL-SDR plus Ham-It-Up setup, and can be also used for standalone receivers.

How much?

Costs 27 USD / 20 EUR / 16 GBP including shipping, available from Adam, the manufacturer via his webpage. You pay for the item when it arrives, no shipping worries.
Contact the seller, Adam directly via email for orders: adam9a4qvwashington@yahoo.com. Remove the capital of the USA to get his real email: name (4letters) and callsign (5 characters).
Disclosure: I received my sample for free for testing. Thanks. This is the second product I receive from the manufacturer for testing, and like before, no instructions nor "please write this". Adam simply answered my emails and updated his product blog with answers to my questions. 

Size and power

Measures 25x25 mm, or one square inch. Small enough to be placed in an electrical box. 
Signal connectors are SMA female. 
Wide range of power options:
1) 6-12 V via supplied red and black cable. 
2) 5V supply by soldering a piece of wire onto the board, so power from the the Ham-It-Up can be used. This is great for those who wish to install the LNA in an enclosure, close to the upconverter.
3) 13.8 V (car battery), place a 470 Ohm resistor in line on the red (positive) cable. 

Fine tip solder and advanced soldering skills needed for 5V modification (components are the size of an ant's head), 470 Ohm resistor costs around a dollar.
I simply used six AA batteries in a cardboard tube, taped wires to batteries, and ran them to the board power supply.
After providing power to its brother, the LNA4ALL with screws, seeing chunky red and black wires
in the bubble wrap envelope was a relief.

Low-pass filter

Interference from signals above 30 MHz (Broadcast radio etc) are reduced due to a low-pass filter at the antenna input. The bypass switch will be rendered useless on the Ham It Up - no signals above 30 MHz, shortwave only.
Tested efficiency by tuning to strongest boadcast station, gain up to 42.1 dB, LNA4HF made an audible and visible difference when inserted into the signal chain.
Disable the low pass filter and get a preamp covering 0.15 Mhz - 2000 MHz by cutting the electrical connection as per Adam's instructions, as I already bought a preamp for VHF (and hate to solder) it's not tested.
"Simple modification" is not the first expression I'd use for any modification involving soldering on this board, the 2-euro coin in the image above is slightly larger than a quarter dollar coin - SMA connectors look huge in comparison. The option is provided, which is great, but if you want a preamp for 30 plus MHz buy an LNA4ALL, that works with car batteries out of the box.


Preamps should be placed right after the antenna for optimum performance, so electrical noise picked up by antenna cable will not be amplified any further. In theory. Daily practice is to place any preamp indoors, where I can easily provide power and won't have to worry about waterproofing. 
A cheap and cheerful solution is to place the preamp and power supply in an electrical junction box, add a switch for On/Off, place the preamp right at the antenna, and turn on power when you need it. This is a tried and tested solution with a 9V battery for field trips and / or maximum performance.


Works as advertised, signal height is 20 dB higher in SDRSharp. Audible difference.
Tested on four shortwave frequencies with an outdoor discone, same settings in SDRSharp, only removing the LNA4HF for comparison.
Beginner setup, no elaborate noise reduction measures, only a modded USB cable connecting a R820T stick, pigtails between Ham-It-Up and LNA4HF, 10 foot coax to discone. Urban location with significant FM, pager and UHF interference.

Utilizing the performance potential can be only achieved with an optimized antenna system - a proper shortwave antenna and noise reduction measures will make a huge difference.
Still, even with this VERY basic setup the improvement is clearly there.

Using with standalone receivers

Shortwave aficionados will love this preamp - the low pass filter reduces local interference whilst simultaneously amplifies signals.
An Icom IC-R5 (handheld wideband receiver, about 70-80 USD on eBay used) easily received the same stations used for testing the LNA with an upconvrter - why not connect the preamp to the Icom?
Connecting the preamp between the antenna and the receiver resulted in better signal quality - see video below. Same antenna and same volume settings, Band Scan.

Note 1: the shortwave receiver and antenna above is a far cry from a dedicated shortwave receiver and proper antenna, included here for comparison purposes only.
Note 2: video above with a discone, a longwire plus preamp will possibly overload and damage an Icom IC-R5, this hasn't been tested.

If you enjoyed this article, or wish to support this blog, 

... go to Amazon and buy my book Tips and tricks in the book will save time and money, reduce frustration with computer settings and help you build the best antenna system from shortwave to microwave. Detailed and illustrated step-by-step descriptions on easy-to-do antennas, from shortwave to microwave.
Basically all you need to know to enjoy radio.

Monday, 13 January 2014

Review: Baofeng UV-5R

... also known as Baofeng UV-5R Plus Qualette.

Review primarily for mariners, secondarily for all interested in a cheap, portable and altogether excellent walkie-talkie.

What is it? 

Handheld radio covering 137-174 MHz and 400-520 MHz, costs 55 USD / 40 EUR / 34 GBP including  external speaker microphone, USB cable and protective cover, free shipping from Hong Kong took 2 weeks to Ireland.
Transmits and receives on Marine Channels, Personal Mobile Radio, Amateur bands, Family Radio Service, GMRS, practically any analog frequency used by ordinary folks.

Useful features

Weight 244 g / 8.62 oz with battery and protective cover, fits in your palm, size equivalent to a digital camera. Icom lists the M87E as "compact and lightweight", this is 36g lighter and about the same size.
Quality feel, first impression is "heavy, well built". Fit and finish is good, pushing buttons and rotating knob feels positive and reassuring.
Flashlight: LED on top, dedicated button for continuous light or strobe. Surprisingly strong light and usable torch, one less item to carry on duty.
FM radio: Listen to Broadcast Radio from 65 to 108 MHz. Automatically muted if incoming transmission detected.
Loud: 1000 mW audio output power. Fills a room easily.
Alarm: flashing white light, siren and automatically transmits on last selected frequency.
Display: standby / receive / transmit glows in different colours, user selectable. Alphanumeric display, so instead of 156.800 you can enter CH 16.
Dual watch, monitor two frequencies at the same time.
External speaker microphone: keep the radio in your pocket, speaker mic on shoulder. No armpit rope, no fumbling on your belt.
Power: selectable Low 1W and High 5W, independent reviews confirmed 10% less in real life, still on par with radios costing minimum 2-3 times more.
Computer programmable: via free software.
Long battery life: standby over 2 days, full charge in 4 hours. Half charge in 2 hours.
Cost: radio only 30 dollars. Dropped, overboard, destroyed - 30 dollars gone. You can even buy the old UV-5R for 20 dollars (shipped) which will be 80% identical cosmetically and offers exactly the same performance.

Yachting use

Any scenario when you need communication with crew members, or as an emergency radio.
Man overboard: Lone helmsman in the drink has at least a chance to call for help and / or direct rescue operations. GPS capable, buoyant Marine VHF e.g. Icom M91D is over 400 dollars.
Crew ashore: lounge on the beach and listen to local tunes, monitor two frequencies at the same time, port captain calls with clearance, crew member surfaces from nightclub, crew finished provisioning in supermarket 2 miles away - you will know that you're ready to go, no need to carry expensive (or yacht property) Marine VHF or second walkie talkie.
Party time: audio ear-shatteringly loud at 1000 mW output power, previously mentioned Icom only offers 700mW. In comparison: your laptop's built-in speakers maxxed out is probably quieter than this radio.
And a lot more, small size, high power output and low cost makes for a versatile radio.

Different versions - which one to buy

Recommended: UV-5R Plus Qualette Yellow. Easier to find in the dark and deep cupboards.
The original UV-5R, introduced few years ago revolutionized the handheld ham radio transceiver market due to low cost and usefulness; update added more interior metal, better antenna and firmware updates, most recent incarnation called the UV-5R Plus, subject of this review.
Latest models can be spotted from the antenna: taller with square top, no grooves on the bottom, superior to the original (first version) antenna.
BEWARE: Ebay sellers feature the old antenna, often showing images with the new and old antenna side by side. Confirm antenna type before ordering.
Same brain, different body: UV-5R2 loses Band button, UV-B5 has rotary channel selector instead of flashlight, larger body and worse display. "Qualette" designation means radio comes in yellow, blue, camo and
red colours. UV-5RA looks better, rounded curves, less compatible accessories.
As long as the radio features the new, improved antenna and comes with firmware 297 it is the latest version.
Whilst you're on Ebay order SMA female - SMA female barrel connectors for 1 dollar each, enables industry standard antennas and adapters to be used.


Radio comes with battery, battery charger, wrist strap, FBI style earpiece, and belt clip. Belt clip screws on, strong enough for all-day use. Charger and adapter takes up little luggage space, important for international travel.
Package prices will be cheaper than purchasing accessories separately, do yourself a favour and buy a USB cable for PC programming.
Digital camera cases or a phone pouch can be used as radio is tiny.
Since the radio is around for a while, large range of accessories available. None of the newer models offer this diversity of accessories.
Speaker Mic: around 10 dollars, comes with clip, functions as a speaker (listen to received audio) and as a microphone (press the button and talk into it). Standard Kenwood-style two pin connector.
USB cable: 6-10 dollars, enables programming with computer, free software available.
Rubber sleeve: 6-8 dollars, protects from scratches and bumps.
Cloning cable: Copy frequencies and settings for 5 dollars in a few seconds between two radios.
High-capacity-battery: standard is 1800 mAh, 3600 mAh for 20 dollars.
Battery case: operate with six AA batteries, 9 dollars for the privilege. As standard battery is 7.4V presumably radio works with rechargeables, I haven't tested this.
Battery eliminator: 12 V (read: standard boat or car) supply, replaces battery pack, 9 dollars. Note that the charger adapter outputs 10V DC, I cut the adapter cord and hooked up to a 13.4V battery - charged the radio fine. If you need tethered operation stay safe and spend 9 bucks, charger might overheat from extra voltage.


Radio comes with detachable antenna, SMA - Female
connector, looks like regular SMA connector turned inside out, signal pin inside,  rest of metal visible = ground.
SMA female barrel adapter required for regular SMA antenna connection, SMA male - BNC female for antennas featuring BNC connection.
Other adaptors (N-type shown) can be used to connect to mast-mounted antennas, as N-type connector is most often used in professional radio applications.
All antenna cables shall be 50 Ohm aka "radio coax". Ask for RG 58 cable, or LMR 240, LMR 400 for less cable loss or for long cable runs.

Antennas and performance improvements

For normal operation stock antenna is perfectly fine.

For maximum range or better performance on VHF (Marine Channels) you must buy a longer antenna. Nagoya 771 or 773 around 10 dollars, Diamond handheld antennas 20-30 dollars. Looks like a horsewhip, 15-20" / 30-50 cm lengths. I have a Nagoya 773 on order as it's collapsible, will report back on performance.
To improve performance of any handheld antenna use the following:
Tiger tail, rat tail, counterpoise, same stuff, piece of wire connected to antenna ground: metal surrounding the center pin around the antenna socket.
Length should be 75 divided by MHz of interest, for maximum efficiency on marine channels use 20" / 50 cm length wire - if no measure available roughly three palm's length, wrist to elbow distance or shorter and longer side of regular A4 paper together.
Above 400 MHz use 7" / 17.5 cm length of wire, palm's length, safe bet.
Connect the wire to metal base, round wire connectors shown are a perfect fit. Plastic surrounding the socket needs to be cut, screw the antenna on and mark at the back of the radio first.
If using non-standard antennas, due to gap tiger tail is not flush and moves around, washers needed for a tight fit.
Tiger tail effectiveness: 50 % to 100 % improvement on both transmit and receive.

Computer programming

Definitely order a USB cable to use free software called CHIRP, setting up the radio with Marine and PMR channels takes 10 minutes.
You will need to download USB cable driver, CHIRP, then follow the detailed guide available on the miklor site.

IMPORTANT: Fully plug in the USB connection cable, small plug to small socket and larger plug to larger socket, last few mm makes a difference, repeat: fully plug in connection cable.
With Chirp Installed, Radio connected and turned on, Go to Radio, then Download from Radio (or press ALT+D). Software downloads channel settings from radio.
You may delete or edit channel settings individually, explore Radio - Import From Stock Config options.

Online support and resources

Sort of cult following for the UV-5R, lots of info on the web.
User guides on the Miklor website, please read them first.
Then play with radio and CHIRP, maybe google upcoming questions: probably it has been asked before.
Factory helpline, chat and support does not exist, but any and all of your questions will be answered by subscribing to the UV-5R Yahoo Group mailing list.
Miklor.com: all your need to know about this and other models, FAQ and user guides are excellent.

Legal Issues

Radio might not be legal TO TRANSMIT in certain countries, states, jurisdictions, or on specific frequencies. Using the radio as a radio scanner e.g. listening should be ok.
Please check local laws and regulations before transmitting with this radio.

If you enjoyed this article, or wish to support this blog, 

... go to Amazon and buy my book Tips and tricks in the book will save time and money, reduce frustration with computer settings and help you build the best antenna system from shortwave to microwave. Detailed and illustrated step-by-step descriptions on easy-to-do antennas, from shortwave to microwave.
Basically all you need to know to enjoy radio.