19 January 2016

World's smallest APRS transceiver

DB1NTO managed to create the smallest APRS transceiver in the world; it's so small that i'm sure it's hard to use with my big bear hands.



It is based off the very small and cheap Dorji DRA818V module I wrote about more than a year ago - a reader immediately saw the potential it had for APRS communications. The Dorji module is already a transceiver in itself (1W output RF amplifier included), it needed a GPS, a nice OLED display, a microcontroller, a Lithium battery and alot of code to make it work.



  Taner Schenker DB1NTO took on this challenge and after months of very hard work, redesigns and a few damaged parts he managed to create this little jewel. It's only 2x3x5.7 cm, weights a mind-boggling 38 grams and does almost everything you could hope an APRS transceiver would do.
For more information you should read this development forum topic, and this one as well. Big congratulations to Taner for this product, I hope it goes into production so we can all have one of these little toys.

20 December 2015

Yaesu FT-817, Elecraft KX-3 and other portable HF radios

I don't know about other people out there, but I use this blog as a personal journal, basically writing about stuff I like so I can remember later on. Hot new equipment that came out and I'd like to own at some point, ideas that cross my mind and I'd like to remember later or events that I want to capture before the moments fades. Same was with the Elecraft KX-3 vs Yaesu FT-817nd post almost 3 years ago, when I was deciding on what radio to get for portable operations and I wanted to put in writing my research.

Now, the conclusion back then was that the Yaesu FT-817nd was the better choice, not only having a more robust build but also covering more bands and being half the price of the Elecraft. Consequently, for the last 2 years the FT-817nd was my radio for most of the 75-80 portable activities I did - most of them being SOTA activations. Of course, during this time I had the chance not only to get to know it very well but also to compare it with alot of other radios popular among the portable radio crowd, so here's my input on the choices out there:



Yaesu FT-817/nd - Tough little swiss-army-knife of a radio, 1.2Kg, with 5 Watts and 160m to 70cm all-mode coverage it can basically do anything you want. It's probably the most used radio in SOTA - half of the activators I know use it and it's used at home for a variety of tasks too: it can be your satellite earth station, it can drive your microwave transverter, general coverage receiver in your travel bag, main HF station for QRP fans, use a cheap SDR dongle to add a panadapter for it or add Bluetooth CAT control and use your smartphone/tablet to control all it's features. Sure, alot of capabilities in a small package almost all the time means some things had to be traded, and this is pretty much true: the FT-817 is mediocre in receiver performance. But this isn't really important when portable - and you can always add an optional filter to improve things, general consensus being that the Inrad #720 filter is the best for SSB. The user interface can be improved too (screen too small, hard access to important buttons), although in SOTA activations you don't really need to play with the settings too much: just find a clear frequency, lock the front panel and start calling. The supplied rechargeable battery is almost useless (low capacity, low current capability, etc), but it can save you in a situation or two - I replaced it with the much better Sanyo Eneloop 2000mAh cells. Standby current could also be lower (~350mA on RX is too much for a portable radio) but overall it's the best compromise you can realistically get.

09 December 2015

SunSDR MB-1 listed and available in January

Ever since first news of it surfaced in June 2014, the SunSDR MB-1 made by Expert Electronics seemed to be exactly what the amateur radio market lacked: modern technology. At first it was expected by the end of 2014 at a price around US$ 4300 for the basic version and another US$ 200 for the optional internal tuner, then it got delayed for some unexplained reasons.



 At Friedrichshafen 2015 they had a fully working sample of the SunSDR MB-1 that I got to test a bit (most impressive thing on the show!) and I was told it was supposed to arrive by the end of 2015. Expected price around EUR 5000 for the basic version, with options for internal tuner and contest-class preselector.

Finally, today the SunSDR MB-1 was listed for the first time at WIMO, with availability expected in January 2016. Even though the price is EUR 6000 for the basic version, the extra internal tuner costs another EUR 500 and the microphone is optional at EUR 35, it still is a great deal as high-end amateur radio equipment goes.

 There are some differences from the original specs: it doesn't cover the 70MHz band anymore, output power is 100W/50W (HF/VHF) not 125W/60W, the CPU is not and Intel Core i7 but Core i5. They have changed the VHF connectors to N instead of SO-239, the OS is now Windows 10 instead of Windows 7 and they have improved the HF dynamic range from 120dB to 129dB. No words on the promised predistorsion yet.

07 December 2015

Icom IC-7300 available in January, official price announced

Icom's IC-7300 is probably the most expected transceiver of 2016, given the fact that it's the first direct-sampling SDR from one of the "big three" manufacturers, offers a working large-screen spectrum display and is expected to be quite affordable (more details in the original Icom IC-7300 article).



29 September 2015

YO SOTA Marathon 2015 - the story IV

This article is a sequel to YO SOTA Marathon 2015 - the story III.


 Day 5

 The night we spent at 2500m altitude was a true mountain experience - 11 people packed in one small room, and most of us didn't get enough sleep. At 06:00 we were already ready to go - mostly out of boredom since we couldn't sleep anymore anyway. Some of us (YO9IRF, YO6PSX, YO2BP, YO6PIB, HB9DST, YO9IPF) decided to go and activate YO/MC-008 Costila (10p) and the rest (YO2MSB, YO8SEP, PB2T, K2XYL) went ahead to Babele and took the cable car to Busteni, from where they drove to YO/EC-011 Postavaru (8p).

The path from YO/MC-006 to YO/MC-008, just follow the crest