AmateurRadio.com

One of the things I’ve been up to the last few weeks is testing a new Bluetooth TNC made by Rob WX9O who is selling them as Mobilinkd. I had to put testing on hold while my Motorola smartphone went away to be repaired (by BuzzBox whom I can recommend highly.) In the meantime word got round and Rob sold out of these gadgets before I could write about it.

The price was around $49.95 which I thought at the time was amazingly cheap and probably explains why they are all sold out at the time of writing. The module is a small PCB slightly smaller than a Baofeng UV-3R and if you remove the belt clip it can easily be fixed to the back of it. My picture shows it strapped to the back of one of the Baofeng’s predecessors, where it makes a nice inexpensive and compact APRS tracker. The board and it’s battery (which can be charged using a USB cable as shown in the photo) are shrink-wrapped in a tough translucent plastic casing.

Ready-made cables are available. Rob sent me a Kenwood-format two-pin connector which fits the later model Baofengs and the two worked together perfectly. The audio levels were just right on both transmit and receive.

Yes, receive. This is no mere tracker. It’s a full KISS TNC and decoded all the packets received by the Baofeng. The software used was the latest APRSDroid running on my Motorola Milestone (a.k.a. Droid) smartphone.  Droid and TNC paired easily and made an effective APRS mobile station.

I did try to pair up the TNC with APRSISCE on an HTC Touch Pro running Windows Mobile 6.1. The two devices paired but could not connect as the Bluetooth software did not recognize the TNC as a valid device type. I think that is a limitation of the Windows Mobile Bluetooth software rather than the TNC module.

If you are interested in APRS and would prefer to do it over the radio rather than a cellular data connection (real hams use RF, right?) then this is a nice toy to play with.

I don’t know why it is, but whenever I buy some piece of gear I always seem to end up with duff stuff. My weather station that I received a few days ago will not register any rain. A little voice says “why do you need a gadget to tell you if it’s raining in Cumbria?” but that’s not the point. I would really like it to work. I have sent an email to Nevada (the dealer not the US state) but have yet to receive a reply. Watch this space.

My UV-3R+ has also developed a fault, or at least its battery has. It started having a flat battery when I didn’t expect it, but irregularly enough for me to think that perhaps I forgot to switch it off. But now the battery won’t charge up. The charger works and I can measure a charging voltage on the battery pins but when I remove the battery from the charger the voltage across the two internal contacts is about 1.3V. I’ve ordered a replacement from 409Shop.

Wu, BG6RRN

Today was cold and frosty. I was sitting downstairs in the warm browing through my newly-arrived January 2013 RadCom. In the shack my K3 was listening for beacons, my K2 was being a Robust Packet APRS gateway on 30m and my TM-D710 was being the local VHF APRS gateway whilst the other side of this dual band radio was running my Echolink node and logged in to the IRELAND conference (Echolink’s equivalent of D-Star’s reflectors.)

The Baofeng UV-3R+ on the table burst into life and I heard Wu, BG6RRN making a call. No-one replied to him so I called back. And so I found myself having a chat about Chinese radio equipment with a Chinese radio amateur using a Chinese handheld!

Wu spoke pretty good English – better than my Chinese anyway! He asked what I thought about Chinese radio equipment and I replied as diplomatically as possible that I liked it because it was cheap but the quality control could sometimes be better. Wu was familiar with the UV-3R+ I was using to link into my Echolink node and said that they were very popular in China as well.

Wu told me that he has had an Icom IC-7000 transceiver for a month but had so far not made any European contacts. He has never tried PSK31 so I encouraged him to try it. I hope I’ll hear him on the HF bands one day. Today’s chat may not have been a proper radio QSO but I do enjoy the opportunities Echolink provides to talk with hams with whom I would not otherwise make contact.

The $3.79 antenna

Among users of the Baofeng dual band UV-5R HT a popular topic of discussion is what antenna to buy for improved performance. The general consensus sees to be that the stock Baofeng antenna is not much good. But no-one wants to spend $30 on a $40 radio to buy an antenna made by Diamond or Comet. The trouble is that half the antennas sold on eBay seem to be fakes that are about as much use as a piece of wet string.

A popular choice recently is known as the “$3.79 antenna.” This antenna – which also goes by the name “$3.42 antenna” after a recent price cut by one eBay vendor, has an SMA-F connector and a very flexible 6.5″ whip. It’s very similar to the Nagoya NA-666 but with a different base. You can find sellers by searching eBay for “female universal antenna for Kenwood”.

Both the Baofeng stock antenna and the $3.79 jobbie appear to be made by the same manufacturer. Printed round the SMA connector of the Baofeng antenna is the words “FM/136-174/400-480MHz”. The $3.79 antenna has the wording “FM/136-174/400-470MHz” in identical print but on a red not a black background.

UV-5R stock antenna

Despite the aspersions cast on the effectiveness of the UV-5R stock antenna, I found that it isn’t half bad. In fact, it is one of the most accurately tuned rubber duck antennas I have come across and performs remarkably well for a 12cm (4.5in.) long antenna. As the SWR plot shows, the VHF resonant point is exactly at 145MHz. I am unable to plot SWR at UHF but I can measure it at a fixed frequency and it was 2:1 at both 145MHz and 433MHz.

$3.79 antenna

The $3.79 antenna appeared to be tuned to 154MHz. The tuning is not as sharp as the Baofeng antenna and the SWR at 145MHz was just over 3:1. I measured a similar SWR at 433MHz. The actual SWR of handheld antennas will vary depending on whether the radio is standing on a desk, being held in the hand or worn on your belt so an SWR of 3:1 is nothing to be alarmed about. Even the best HT antenna will exhibit a poor match in some situations.

Measuring SWR can tell you whether an antenna is working as well as it should but it is no guide to on-air performance. After all, a dummy load will have a perfect 1:1 SWR and yet radiate nothing.

I measured the field strength of the signal radiated by the UV-5R at a distance of 1m using both antennas. I also tried a known genuine Nagoya NA-701 which is about the same length as the $3.79 antenna. There was nothing to choose between any of the three antennas at UHF. On 2m the $3.79 antenna was possibly marginally worse than the Baofeng UV-5R standard antenna. The Nagoya NA-701 was 3dB better, equivalent to doubling the transmitter power.

My conclusion after performing these tests is that buyers of the UV-5R (and the UV-3R which comes with an identical stock antenna) should save their money and use the antenna that came with the radio. To try to improve on this involves dabbling in the shark-infested waters of eBay and risking ending up with a worthless fake antenna that will need to be larger to give any improvement in performance. The $3.79 antenna is easily worth its price but it is 3 inches longer than the stock antenna and offers no significant improvement.

If you are a UK amateur and you like Chinese radios you’d probably never think of buying them from anywhere other than direct from China or Hong Kong, most likely using eBay. Ham radio dealers in Britain are widely regarded (rightly or wrongly) as rip-off merchants who work out the price by replacing the dollar with a pound sign and then adding on a bit more for good measure. Their pleas that the UK price includes VAT and the cost of providing a warranty usually fall on deaf ears.

In one of the discussion groups someone mentioned buying a radio from a British firm called Sinotel UK. I went to their web site and saw that they carried several models of hand-helds from China, including a new one I hadn’t seen before: a TYT UVF9 (pictured right.) But what particularly caught my attention was their prices, which were little more than what I have been paying buying on eBay. Their cheapest model, the Vero Telecom UV-X4 (similar to the Baofeng UV-3R) was just £29.99 (yes, a brand new dual band radio for 30 quid.) A UV-5R eas £34.99. The radio that had caught my eye, the TYT UVF9, was £47.99. It would cost me $68.50 from 409shop and I’d have to wait a couple of weeks for it.

I am not associated with Sinotel UK and have not even bought anything from them but if I want yet another Chinese handy to add to my collection I probably will.

I like my cute little Baofeng UV-3R+ though I find myself using its slightly bigger brother the UV-5R more often. Unfortunately the UV-3R+ has begun acting up with a fault that is difficult to fathom.

Quite often the UV-3R refuses to switch on. At first I thought that I had accidentally left the radio on and had depleted the battery, because I often do things like that. But the radio comes back to life if you remove and replace the battery or if you drop it into the charger for a few seconds. When I did this today the screen immediately showed a battery voltage of 4.0V which was expected given that it had been charged only a day earlier.

So the radio is failing to turn on even though there is plenty of juice in the battery. Like most HTs it has a “live” power switch and should turn on at the press of a button. The UV-5R on the other hand has a good old-fashioned rotary on/off volume control. Which, I now recall, was the thing that failed on my old Jingtong radio. Ho hum.

Back in February I bought a Baofeng UV-3R+. It came after an unusually long wait for products from China, in March. In that time, eBay vendors had begun advertising the new Baofeng UV-5R which had double the output power and a key-pad that could be used for DTMF. To add insult to injury the price of the 5R was less than I paid for the 3R+.

As the months passed the knowledge that the UV-5R could still be bought for an absurdly low price niggled away at me, until eventually I gave in and ordered one. Unlike its little brother the 5R got here in little more than a week. So now I have two Baofeng HTs. A ham can never have too many radios, especially at this price!

Baofeng UV-3R+ and UV-5R

After I sold my original UV-3R to make way for the Plus I had a few regrets. The original had the advantage of being lightweight and tiny. Although the Plus was only a few millimetres larger and a few grams heavier the difference felt more marked. It lacked the cuteness of the earlier model. But the drop-in desk charger was a nice standard accessory. The accessory port was the same as used by Kenwood and Wouxun, enabling some standardization. It is a nice little radio but functionally almost identical to the original 3R.

Baofeng UV-5R unboxed

The UV-5R is quite a big improvement over its little brother. It isn’t a lot bigger or heavier than the 3R+ but the extra size and weight gains you double the output power (4W compared with 2W) and a keypad which supports both frequency entry and DTMF. The latter makes the radio much more useful on Echolink.

The 5R feels solid and well built like the 3R+. In fact it feels like a radio that cost three times the price. I think Baofeng has hurt sales of the basic handhelds made by the Japanese “big 3.” Only rigs with ham radio specific extras like supporting D-Star or APRS will be able to justify a higher price. As neither of those things are useful for the typical Chinese business buyer of these radios I can’t see Baofeng starting to compete in that area. So Yaesu, Icom and Kenwood can breathe a sigh of relief.

Other things I like about the UV-5R are:

• 4W maximum power out
• Alphanumeric names for memory channels
• Backlit keypad – a classy touch
• DTMF – ideal for Echolink
• Analogue volume control with proper on-off switch .

I like the way the display (and keypad) lights up when a signal breaks the squelch and stays lit for a few seconds after the signal has finished. If you have more than one handie in use this feature lets you know which radio received the call. My Wouxun also does that.

There are a lot of other things to like, such as the voice announcement (my ham rigs don’t have that) and the fact that accessories and spare parts being really cheap. The same computer interface cable works with both Baofengs and the Wouxun. Headsets and speaker-mics work with two Kenwood radios as well.

Judging by the comments of some buyers in the user groups, “Baofeng quality” is still an oxymoron. You are taking a chance that the radio you receive will not have any faults. Sending the set back to Hong Kong But if you are prepared to take that risk (or pay a bit more and buy from a local dealer) then the Baofeng UV-5R is worth a lot more than you pay for it.