Wednesday, May 24, 2017

Working the impossible-to-work grids

By now everyone knows about the high-altitude circumnavigating balloons and the Ocean Floater. As I write , the Floater is still transmitting, as are 3 balloons, on JT65 and WSPR. Such feats were impossible for individual hams a few short years ago.

These long distance voyagers belong in the "Things We Thought Impossible a Few Years Ago" category. But what might be possible in the years ahead that don't seem feasible now?

U3S GPS module now externalized

I spent some quality time yesterday with a soldering iron, ohmmeter and electric drill and ended up (finally) with the GPS module of my Ultimate 3S now enclosed and remoted to the window sill of the shack.

Previously, the GPS was wired directly to the U3S and sat beside it on the shack desk. This necessitated leaving the U3S housing opened which in turn contributed to a bit of drift on received WSPR reports.

I tried to find an all-plastic housing (since metal would attenuate the GPS signals received) of the appropriate size - and then I remembered a small box I bought from the Four States QRP Club almost 10 years ago with the idea of doing something with it some day.

Tuesday, May 23, 2017

Wednesday, May 17, 2017

Ultimate 3S - success!

I've built two of the older Ultimate 3 beacon transmitters for other ops but never had one of my own until a few weeks ago. I finally found time to set up a proper build space here in the hamshack and broke it in by building an Ultimate 3S of my own.

Following the Ocean Floater and the many balloons that utilize this amazing and inexpensive device added further inspiration as did the news that Hans G0UPL is now developing an extremely lightweight transmitter designed for high altitude balloon flights.

At present my U3S is only in its larval stage. I will soon add additional bands (15m only for now) and the automatic band-switching board, a 5V internal converter and a detachable configuration for the GPS receiver that feeds time, grid and freq cal data to the U3S.

GPS receiver - U3S - wattmeter showing 100mW out

This is quite a lot of kit for the money - $33 if you don't need the aluminum/aluminium housing ($22) or GPS receiver ($23). For that, you get a transmitter that operates more modes than Kim Kardashian with a Kama Sutra.

Maximum output with only 1 (of three possible) transistor is 250 mW but I've turned mine down to 100 mW.

Initial reports on 15m at this late hour for that presently-handicapped band are proof positive that it works FB and I could almost say that this is a good kit even for a first-time builder. There are no SMD parts and the overall parts count is quite low.

Now to wind those toroids for the other band filters...

Tuesday, May 16, 2017


DX10 graph
Interesting product and idea.

The real benefit is from the website though and not the transmitter. I was hoping there was an option of using the comparative features of the website (even if for a fee) without having to buy their transmitter but that seems to not be the case.

Sunday, May 14, 2017

One year at sea and still going strong

I personally would have been seeking a liberty call long before now, preferably in Subic Bay or Pattaya Beach, but Bob ZL1RS's Ocean Floater is still plodding along and sending its telemetry on 30m JT9 and WSPR.

Based on Hans G0UPL's Ultimate 3, the Ocean Floater went to sea on 14 May 2016, powered by 18 D-cells in a series-parallel combination that was expected to last for 6 to 9 months. As of today it is about 1000 miles east of Cairns, Australia in the Coral Sea.

As I look at the map of the Ocean Floater's progress, I'm amazed at the technology that allows hobbyists to both launch and track such a device. But I also realize that a shipwreck victim on a raft could spend a year at sea (if they somehow survived that long) and not see so much as a glimpse of land.


Saturday, May 13, 2017

Initial thoughts on Elad's FDM-Duo

Some initial thoughts on the FDM-Duo compared to other stand-alone or SDR rigs (only the
FDM-Duo is both):

Flex 6xxx and Anan 10E - full SDR but no stand-alone operation
Flex 6xxx and Anan 10E - no callsign population of pan display
KX2 - portable but no pan display, digital audio connectivity for WSPR, JT65, etc
KX2 - CW, AM, SSB but no DRM, ESSB, WFM, and more
KX2 - 10 to 80m; DUO - 6 to 160m
KX2 - limited configuration for many parameters; DUO - perhaps overly configurable

For a QRPer who wants to operate casual CW and SSB, either portable or at home, the KX2 is the go-to rig, hands down. Advantages of the Duo over the KX2 come into play when the operator has other interests in mind and wants to use the Duo with a computer to unlock the many capabilities over what is possible with a stand-alone radio. In the short time I've had my Duo, I've operated it both stand-alone and via the SW-2 software.

Operating CW stand-alone, compared to the KX2, was an exercise in frustration. Setting the speed of the internal keyer requires a series of button presses to get to the proper menu. Or you can change it via the E1 knob provided you are willing to send a string of dits over the air as you make the adjustment. That's right - you have to be transmitting in CW in order to make the adjustment on the fly! At home I'll use an external keyer with a speed pot, but afield - there's no convenient way to change keying speed without subjecting your QSO partner to a string of dits as you tweak the setting.