Chitika: Dominican Republic

Showing posts with label Dominican Republic. Show all posts

Look at the drawing above. That is the banner logo of Rod Newkirk's column in QST magazine. For many years Rod regaled us with exciting reports on the activities of intrepid foreign radio amateurs, transmitting from exotic locations using ingeniously devised homebrew radio equipment. Look at the picture on the left side. See the palm trees? See the thatched roof shack with the dipole antenna? Well, that's pretty close to what it was like for me out on the Samana Peninsula in the Dominican Republic last month.

I set up the station under the thatched roof in this picture:

The red pins mark the spot:

Here I am, tuning the rig while looking across Bahia Rincon:

The rig was my Azores-built, oft-modified, NE602-based, ceramic resonator DSB transceiver with a recently added India-designed BITX IRF510 RF amplifier chain. A little article I wrote about the ceramic resonator VXO was featured in SPRAT 127. My antenna was a half wave dipole strung up in the thatched roof. Power came from 10 AA Batteries. So this was the Double A, Double Sideband, Dipole DX-pedition.

I had given some thought to building an SSB rig for this trip, but because of the efforts of Peter Parker, VK3YE, I felt compelled to take a DOUBLE Sideband rig with me to the beach.

Here is an old (2006) video on the rig. The power amplifier has been significantly modified:

Here is some more information on the rig, including a schematic for the receiver and the SPRAT article on the Variable Ceramic Oscillator:

http://www.gadgeteer.us/PORTABLE.html

Here is the log book for my contacts.

17 DECEMBER 2014

W1JPR PAUL MT. DESERT ISLAND MAINE

8P6AE (BARBADOS) COULD BARELY HEAR ME, BUT GOOD QSO

18 DECEMBER 2014

N4USA DAVE IN FLOYD, VA. FAIRS NET. (KK4WW.COM)

KE4UGF DON ALSO FAIRS, NICE GUYS. FUN CONTACTS!

KA4ROG ROGER NORTH OF ORLANDO

19 DECEMBER 2014

WB2HPV GUIDO TALKING TO ITALIANS EVERY MORNING FROM WAYNE NJ. HE HAD TROUBLE HEARING ME.

CONDITIONS SEEMED POOR, BUT I WAS HEARING AUSTRALIAN STATIONS

W8GEO GEORGE IN THE INTERCON NET. HEARD ME. ALSO ON INTERCON: KA4AOQ AND 6Y5MP (JAMAICA) ALSO HEARD ME.

N4PD PAUL

W3JXY/4 NAT IN KEY WEST

N1FM TOM, NORTH OF MIAMI SOLID QSO.

KM4MA PAUL IN ORLANDO WITH MARITIME MOBILE NET.

20 DECEMBER 2014

NA2LF LLOYD IN NY

WB8YWR JIM IN DALLAS

KM4MA.

W1AW/3 IN MARYLAND (TOOK ME A WHILE TO GET HIM)

21 DECEMBER 2014 NICE 4 WAY SPANISH LANGUAGE QSO:

KI4PZE MIGUEL

CO8OT JUAN IN SANTIAGO DE CUBA

WA4RME RAFA IN CHARLESTON S.C.

C08KB MARCO IN CUBA

Here is a short video showing the station and the location. Note the little birds (Golondrinas or Swallows) flying by. They nest in the thatched roof. They often got confused and flew inside the house. Billy and Maria rescued many of them. Whales breed in this bay in January and February. There are also manatees. It is really a beautiful place.

There were obviously other attractions (!) so I didn't spend a lot of time on the radio -- just a half hour or so every now and then. But it was really very satisfying to carry this little homebrew device with me, set it up in this amazing place, and use it to send my voice across mountains and hundreds of miles of ocean. I built this rig in the Azores and have used it in the UK, France, Italy and the Dominican Republic. It contains circuits devised by members of the British QRP club and by my friend Farhan in India. The ceramic resonator circuit is something I cooked up on my own. The microphone is from my old Sony Walkman and the pen that serves as its support is from that wonderful magazine "Electric Radio." In short, there is a lot of soul in this little machine. And it was a lot of fun to take it to the beach.

Thanks to Elisa for finding us this wonderful place. And to Rod Newkirk and QST for the DX inspiration.

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

If you look closely, just in front of my keyboard you can see the Michigan Mighty Mite that I rebuilt this morning (scroll down to see the previous post). Looks like I was using a polivaricon as the capacitor. Other than the cap, all the parts used in this 2014 version were from the 1993 effort. Here is how it is described in "SolderSmoke -- Global Adventures in Wirless Electronics":

I decided to start off slow, with small projects that seemed likely to succeed. The secretary in our office in the Embassy, Mady Bullen, had an interest in ham radio that had been sparked by service in far-off places where short-wave was the only way to talk to home. She would pass me old issues of CQ magazine. It was in the March 1992 issue that I found the Michigan Mighty Mite.

It was originated by Ed Knoll, W3FQJ and developed by Tom Jurgens, KY8I. It is about as simple as you can get in a radio transmitter: just one stage, a crystal controlled oscillator.

An oscillator is basically an amplifier in which some of the output signal is fed back into the input. If you provide enough feedback in the right way, the amplifier will “take off” and begin generating a signal. The howl you hear when the microphone of public address system gets too close to the speaker is this kind of signal. The speaker (the output) is sending energy back to the input (the microphone) and what was an amplifier turns (annoyingly) into an oscillator. In this case it is an audio frequency oscillator because all the filters and tuned circuits in the PA system are built for the audible frequencies. But the same thing will happen at radio frequencies. That’s what the Michigan Mighty Mite is all about.

I put the thing together using parts obtained from the Santo Domingo Radio Shack store. The resonant circuit used a coil that was just some wire wound around a discarded plastic 35mm film container. Homebrew radio projects rarely work the first time you power them up. I had to fidget with this thing quite a bit—obviously there wasn’t enough feedback. I had my Drake 2-B on and tuned to the crystal’s frequency. As I poked around on the little circuit board, I suddenly heard a little chirp from the 2-B. There it was! The little device that I had put together was producing radio frequency energy on the 40 meter band. Hooray! The joy of oscillation! Now I felt like I was truly in league with Faraday and Marconi, with Shep, Stan and Bollis, and with Serge! Hilmar would have been proud of me (but he still would have been horrified by my sloppy wiring).

I never was able to talk to anyone with that little device—the power output was very low, and my antenna for the 40 meter band was very poor. But it didn’t really matter. I had had my first real success at homebrewing a piece of ham radio gear.

Our book: "SolderSmoke -- Global Adventures in Wireless Electronics" http://soldersmoke.com/book.htmOur coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmokeOur Book Store: http://astore.amazon.com/contracross-20

For the first time in years I got on the air on New Year's eve. I fired up the HT-37 and Drake 2-B on 20 meters last night right at 0001 UTC (well, with these rigs I should say GMT!). There was a moment of stress when, as I was trying to adjust the key, the whole thing fell apart and the little ball bearings spilled out. Yikes! It was as if the radio gods were trying to tell me something. It took me a few minutes to re-assemble my straight key, then I called CQ. The HT-37 puts out a lot more power than I normally emit, and it caused the Carbon Monoxide detector to go off, sparking a minor panic among family members. (See, this never happens with QRP!) With that resolved I had nice QSOs with K5KFK in Texas, W6VNR in California, and N1WPU in Maine. This morning I worked WA0ZDE in Missouri. The old HT-37 was drifting a bit, but Rick said he kind of liked that. (I put a muffin fan on top of the transmitter -- that should settle it down a bit). By the way, my key is a bit unusual: it is just a cheapo key, but I have it mounted on the base from a Vibroplex bug. I never mastered the Vibroplex, and ended up giving the bug parts to HI8G in Santo Domingo -- Gustavo planned on using them to fix another bug that had been given to him years before by Fred Laun (K3ZO).

Rick, WA0ZDE ( who I talked to on 20 this morning) sent me a VERY SKN photo collage (see below). I see that Rick also tends to hold onto his gear for a long time.

HNY to all! GL in 14. 73!

Chitika

A Thatched Roof, Some Palm Trees, A Dipole, and a Homebrew Rig

Bill's Dominican Mighty Mite (1993)

Happy New Year! Straight Key Night

AHMED HASSAN MOHAMMED

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