Baojie BJ-UV55 - new chinese mobile VHF/UHF radio

Baojie BJ-UV55 is the latest thing to come out of China in terms of amateur dualband (VHF + UHF) transceivers. As one being familiar with recent history should expect, it should be sporting a a very nice price, a nice package of features and a good build quality; and of course, some imperfections that an inexprienced company would make.

Yes, Baojie does sound like Baofeng, probably they're not related but the products seem to go by the same style; also, the BJ-UV55's menu apparently looks alot like (read that: almost identical to) the Baofeng UV-5R's.


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Codan Envoy - SDR-based HF transceiver

The marine radios manufacturer Codan has a new series of radios called Envoy, wich seems to be a very advanced HF transceiver. It is based on SDR technology and has 2 types of modern interfaces (one for use as a base station and a more compact one for use as mobile), it is IP capable and can be reprogrammed remotely via internet and has an internal software modem that supports high-speed data, chat and email.

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My first contest - CQ WPX SSB 2013

Last weekend I have participated for the first time in an amateur radio contest, just to get an idea about how it is: the CQ WPX SSB 2013 contest. I only had about 4 hours of continuous operation, and I just preferred to search and pounce as it seems the most effective way for a low power station. I entered the rookie / QRP / 20M category using the SDR transciever set at 5W output and the ground plane vertical, and had no problem working most of the stations I could hear; maybe just 3 or 4 did not reply at the first 2-3 calls so I decided not to waste time and move on.

I still managed to make 91 contacts that include a few new entities for me as well (hope they EQSL!), and the claimed score is 7371. It is way too low to think about any noticeable result, but I think with full 48h dedication it could have been rather competitive; I'm already making some plans for next year. Maybe a good sleep before the contest and a better antenna - wich might be useful in the second day, are all I need for now.

Developing a HF transceiver around an Arduino

As you probably know, the Arduino platform is a very useful toy for development of electronic gizmos, and after I saw the Myriad RF project I started thinking how a small portable HF transceiver could be developed around the versatility the Arduino provides. The idea is to keep in line with the Arduino philosophy and level of knowledge, so the end product should be fairly simple and affordable, but still offering alot of fun.

These are my targets:
- 8-band SSB transceiver (LSB: 80m/40m, USB: 20m/17m/15m/12m/11m/10m)
- weight: 500 grams
- output: 10W
- sensitivity: 0.5uV
- consumption: 400mA@13.8V standby / 2.5A@13.8V TX
- display: mode, frequency, step, supply voltage, S-meter, SWR
- encoder VFO with 2 selectable steps
- bandswitch button


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Raspberry Pi as a WSPR beacon

Probably alot of you know what the Raspberry Pi is - a US$35 micro computer the size of a credit card that can be used for alot of simple but cool projects. Well, some guys at the Imperial College Robotics Society in UK found out that you can actually output a modulated clock signal on one of the GPIO pins to act as a small RF transmitter, then Dan MD1CLV and Guido PE1NNZ took the idea further and implemented the necessary coding in order to make it a working WSPR beacon - project's name is WsprryPi .

Considering the limits for the GPIO output (TTL 3.3V @ max 50mA) we can't expect too much output power, 10mW (+10dBm) into 50ohm is a reasonable figure while about 20mW is the technical limit. One issue would be the fact that the output signal is a square waveform therefore rich in harmonics and a low-pass filter for each transmit frequency is mandatory (especially if you want to boost the power a bit); considering it covers from 0 to about 250Mhz, if you plan to make a multiband beacon out of it you will need alot of filters. At the moment it needs a permanent internet connection for time synchronisation, but i'm sure some handy fellow will implement a GPS time reference to make it completely standalone.

X1M - portable chinese HF transceiver

The Xiegu X1M is a recent attempt at HF portable QRP transceivers straight out of China, and it looks like they are on the right way: small and lightweight - check, simple and robust design - check, low power consumption - check, CW and SSB modulation - check, full HF coverage - check. Yes, it is not the prettiest girl in school ... but who cares when it is the cheapest ? No really, it costs about US$260 as a kit or US$300 assembled, half of what an Yaesu FT-817ND does.

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Myriad RF - an Arduino transciever shield

Lime Microsystems is a rather new and fabless company specialised in multi-band multi-standard transciever IC's; their only creation so far seems to be the LMS6002D, wich is a chip no bigger than the nail on your index finger but includes all the logic necessary for a configurable broadband transciever IC supporting all the modern 2G, 3G, 4G, CDMA, HSPA, WiMax or LTE standards: two ADC's, two DAC's, three low noise amplifiers, filters, mixers, gain control, the lot.

Unless you are a seriously antisocial tech-freak that won't sound extremely fascinating, luckily the best part is still to come: they have worked together with their distributor Azio and have implemented the tiny creation in a board called the Myriad RF, wich is basically an Arduino shield that houses an equally versatile transciever, allowing a ... myriad of RF-based projects to be prototyped around these two tiny boards; the Myriad RF does everything radio-related and the Arduino controls it and interfaces with the user and other pheripherals. Everything (software, PCB design etc) is open-source and it becomes a great learning tool, plus it brings advanced radio technology closer to hobbyists.

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The 630m band is official

The European Communications Comitee (ECC) of the European Conference of Postal and Telecommunications Administrations (CEPT) have recently approved the new European Table of Frequency Allocations and Applications in the frequency range of 8.3KHz to 3000GHz. It is basically the mother of all frequency table allocations, but it is only a recommandation and each country has a specific law that dictates exactly how the radiowave bands are to be used.

For example, the new ETFAA still doesn't mention the 60 meter or 4 meter band even though these bands are legal in some of the European countries, but it introduces the new 630m band wich is expected to be adopted by the state laws of each European country in the next period. The 630m band lies from 472 to 479 KHz and the official transmit power limit is 1W EIRP, with the possiblity to increase this limit to 5W EIRP if you are at least 800Km away from the borders of any of these countries : Algeria, Saudi Arabia, Azerbaijan, Bahrain, Belarus, China, Comoros, Djibouti, Egypt, United Arab Emirates, Russian Federation, Iran, Iraq, Jordan, Kazakhstan, Kuwait, Lebanon, Libya, Morocco, Mauritania, Oman, Uzbekistan, Qatar, Syrian Arab Republic, Kyrgyzstan, Somalia, Sudan, Tunisia, Ukraine or Yemen. Adding this to the fact that the band is only 7KHz wide, it would seem the appropriate use for it is weak-signal narrowband modes, such as JT65 or the specially crafted JT9.

You can view or download the full table here:

European Table of Frequency Allocations and Applications

DXpedition videos - T33R, T88CJ, VP88SSI, 7J1RL

After the previos post about DXpedition videos, I decided to add some more. Here they are:

T33R T33T Banaba Island (1990)

T88CJ Palau (2008)

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Kenwood TS-990s - inside pictures

Some pictures of the Kenwood TS-990s popped up recently, it's a real beauty.

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A bit of solar activity

Hopefully these days we will finally get a bit of solar activity and of course, a bit of 10m openings. The number of sunspots continuously grew in the last five days (60 > 63 > 88 > 90 to 115 today), the SFI is a mediocre 115 and in the next few days quiet to unsettled  geomegnetic levels are expected.

I had the chance to work a bit in 10m SSB and I got 2 new entities (GU3UOQ - Guernsey and XT2TT - Burkina Faso), it still appears to be open right now (about 19:00) as I am recieveing strong stations from South America on JT65-HF (LU5FD, PY2VM etc), as well as ZS1AW from South Africa. Unfortunately 10W doesn't really cut it for me, I guess JT65 is indeed a low signal mode and not a low power mode.

Kenwood TS-990S instruction manual is public

Kenwood has released the TS-990S instruction manual today, so it brings much more info about the contest-class long awaited chunk of iron. I didn't get the chance to read it yet but I will come back with some comments shortly, in the meantime you can download it here:

Kenwood TS-990S instruction manual

V53ARC - multiband WSPR beacon in Namibia

In the last few days my station has been running continuously on WSPR frequency hopping between the 80m, 40m, 20m and 10m bands, and I got the chance to spot on 10 meters the V53ARC WSPR beacon in Namibia.

Apparently it is on the air since 2009 and this is the first time I spot it, and by looking the callsign up over the internet I found it's story.

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DXpedition videos - VP6T, 3D2C, BS7H, 5A7A, AH1A

 Ever since the beginnings of my ham radio adventures i've been curious about operating from parts of the world the civilisation hasn't reached yet; I guess it's one of the few ways you can still be a hands-on pioneer these days. Dxpeditions, SOTA, IOTA, you name it, I want to see how it has been done and how was the feeling to do such a thing, what equipment did they use and what challenges they had to overcome, how they laid out their antennas or how much planning was put into.

Recently have been published two videos of DXpeditions that took place last year. The first one is 3D2C in Conway Reef, wich doesn't have an embed option so you need to check this link out in order to view it:

3D2C Conway Reef 2012

 The second one is VP6T Pitcairn Island, you can check it out below:

There are also older DXpedition videos that I really enjoyed, made just like a documentary with plenty of info:


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Over the Horizon radars and ham radio interference

Since the early days of the cold war and culminating with the Russian Woodpecker, ham radio operators have reported powerful jamming-like wideband signals creating disturbance in the amateur short wave (HF) bands. These are created by powerful over-the-horizon (OTH) radars that use the HF spectrum to "visualize" significant portions of the entire planet in just one sweep by using the all-so-loved (by us amateurs) phenomenon of ionospheric reflexion.

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WSPR and antenna radiation pattern

WSPR seems to be not just a tool for actively monitoring the propagation status, but it can also help you trace the radiation pattern of your antenna. Of course, for a reasonable trace we would need WSPR stations all over the world using all types of antennas, but I guess we will have to make do with what we have for now.

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SDR Basics explained

I just found a great video that explains exactly how Software Defined Radio (SDR) works, directly from the guys at FlexRadio. If you're interested in SDR, in ham radio or radio communications in general, this is one educative piece of material you can't miss. It's about 1 hour long though, so you might want to bookmark it for the weekend.





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Kenwood TS-990S revealed

The long awaited contest-class rig from Kenwood, the TS-990S, is bound to make the grand debut probably this month, after a series of teasers have stirred up the spirits and imagination of amateur operators all over the world. Kenwood openly states they tried to put their best into the TS-990S, trying to achieve the ultimate contest and DX legend transciever status, and this reflects just by having a quick look at the black button-fest beast.

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Flex SmartSDR revealed

SDR technology is probably the biggest thing in ham radio in the years to come, and the direct digital sampling based transcievers can offer a whole new range of posibilities to the avid amateur operators. The Flex-6000 series looks to be a great exponent of this technology and probably a key turning point in amateur radio equipment history - for us folks that follow such a thing of course, and recently FlexRadio has released more details about how the new concept will work and how the software needed to operate the new transcievers looks and feels.

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Tmate2 - external CAT console

SDR recievers and transcievers often suffer from the lack of a proper interface with the user;  the computer's mouse and keyboard do not offer the same warm feeling of direct control as a proper knob and a nice set of firm buttons for some users, therefore external consoles have found their way to the market.


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Elecraft KX3 vs Yaesu FT-817ND

I am looking lately at a transciever for portable operations this summer, and after some reading and thinking I also found a discussion on one of the blogs I follow, where Roger G3XBM posted about the FT817 vs KX3. 

This is an interesting issue as the Yaesu FT-817 is basically the definition of portable QRP transcievers, and the Elecraft KX3 is one of the hottest ones out there at the moment, offering a very high-performance reciever in a small and medium-priced package due to SDR-based technology, wich is one of my main interests in ham radio.

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Lightweight beam antennas: Moxon vs Spiderbeam

The 2013 solar maximum is almost here, the 10 meter band will be booming soon and you cannot let it go by without using a decent antenna; it would be a shame, considering how cheap it is to build yourself a decent performing beam in this band.
Today I am looking at two of the most efficient designs that a homebrewer can use for such an antenna: the 3 element Moxon and the Spiderbeam; both are variations of the 3 element Yagi and require just a mast, 4 fiberglass fishing rods and some wires to get going.

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