The MMMM Receiver

Prototype construction of the MMMM receiver. The, um, interesting position of the coils is explained below.

The 80m Madagascar Mighty Mite was suffering from “a tree falls in the forest but nobody hears it” syndrome. Eighty meters is a tall ask for Madagascar — there aren’t that many hams in the coverage area, and given local noise, I doubt any of them can hear well on 80m. It would be a long wait for a signal report about the on air performance of the MMM. Clearly, the thing to do was to create a mate for the MMM, the Madagascar Mighty Mite Mate (MMMM).

In keeping with the philosophy of back-to-basics rockbound simplicity, I decided to build an 80m version of the Sudden Receiver originally described by George Dobbs in SPRAT, and reprinted in 73 (October 1991, page 8, available online thanks to the Internet Archive).

Continue reading “The MMMM Receiver”

The Topper Amplifier Revisited

The amplifier built manhattan island style on a copper PCB I thought my 200mW Madagascar Mighty Mite (MMM) would benefit from some sort of afterburner, so I dusted off a project shelved in 2011: the Texas Topper amplifier. I had built based on a design by Chuck Carpenter and kitted by Rex Harper. I ran into a couple problems back then, including some difficulty getting the bias right on the mosfet at the heart of the amplifier. In another brilliant move, I managed to burn out said mosfet by grounding it while trying to get it and its heat sink to fit into a metal box.

Continue reading “The Topper Amplifier Revisited”

The Madagascar Mighty Mite

Finished mighty mite on copper board
The completed (yet unboxed) MMM.

Over the last few years, there have been a spate of postings from homebrewers taking inspiration from the Soldersmoke podcast to whip up various incarnations of the Michigan Mighty Mite, a very simple rock-bound QRPp transmitter. I’m a little late to the party, but here’s my story.

Continue reading “The Madagascar Mighty Mite”

SOTA: W3/CR-003

A boulder-strewn area surrounded by trees. In the distance, the western horizon
Operating position, with view to the west, towards the Potomac River and Virginia.

I was in the Washington, DC area for a day, and couldn’t resist activating Sugarloaf Mountain — it is just too convenient a SOTA peak to ignore. Everytime I’m in the area, I think about going up it, but often summer weather has foiled those plans. Not this time, though. It was a sunny day for my 45 minute drive out from Bethesda, MD to the trailhead.

Continue reading “SOTA: W3/CR-003”

Tropical Cyclone Enawo

This storm is already intense and predicted to hit the north-east side of the island tomorrow morning with hurricane force. For the last three years, we have been lucky with storms tracking to one side or the other of the QTH, but the track for this one cuts straight down the center of the island and should pass near the capital city, Antananarivo. The prediction has been consistent and is now close enough to be sure that we will experience some rough weather in the next few days.

To that end, for the first time, I have lowered the hex beam antenna. I collapsed down the telescoping sections of the heavy duty 10m spiderbeam mast and threw some additional guy lines over the central plate to which the arms attach. The wooden support beam goes two meters into the ground and is surrounded by buried concrete, so I am not worried about the base, but I do expect the fiberglass arms to be battered about. I considered dismounting the whole antenna, but that would have required more manpower than I have readily available, so it will have to ride out the storm.

Continue reading “Tropical Cyclone Enawo”

ARRL INT DX CW 2017

States and Provinces versus number of bands worked.

Conditions over the previous week have been good, so I decided to put in an effort on the ARRL INT DX CW contest this weekend. I knew from experience that I would not be able to work around the clock since the US and Canada are not typically in range in the morning, so I anticipated being able to get some sleep from about 4 am through early afternoon, which was fine with me. Reviewing recent logs and VOACAP predictions, I mapped out propagation paths and figured where I would point the hexbeam, and more or less stuck to that plan. Over the course of the contest, I put in about 23 hours in the chair.

I was effectively limited to three bands: 15m, 20m, and 40m. Ten was almost uniformly dead, and my 40m loop is very inefficient on 80m. Bands faded in and out more or less as predicted including some good spans of working the west coast on long path in the afternoons.

Continue reading “ARRL INT DX CW 2017”

Voice in CW band

Lately, I’ve been hearing a good deal of voice in the CW portion of 20m and 40m. I’ve already made some mental adjustment to being in Region 1, where the band plan allows for voice operation below 7.1Mhz on 40m, and even on the 30m band. However, what I’m talking about is very near the bottom edge of the bands…and sometimes slightly below. I have to assume the signal source is close, but I can’t spin my delta loop to get any hint of direction.

And then tonight, I had an odd one — in the SSB portion of 20m, but on lower side band (not a matter of DSB, I checked). Here’s a bit of captured audio from 14236.5khz at 15:38z 19DEC (quality’s not great because I just recorded off my headphones with my cell phone…)

In all cases, these signals sound like a bunch of buddies talking informally, without callsigns or any formal procedure. I have to assume it is unlicensed operation, most likely in an area where there isn’t really much provision for enforcement.

Anybody recognize the language in the audio clip? I’d love to know what their chatting about.

CQ WW SSB 2016

zonesConditions were up and down over the weekend, but not so bad as I had expected. At times, I could hear, but not be heard with 100W, so again a bit more power would have been helpful. I was probably on the air for about 24 hours out of the contest period, but did use some spotting assistance, so I won’t enter in the classic category this year. Tactically, that puts me at a disadvantage, but since this was a casual operation, I’m not too concerned about score.

I am aware of one other station from Zone 39 operating in the context, FR4NT. If cluster spots are any indication, he did a great job, with long runs particularly into Europe.

I ended up working 94 DXCC entities, some of them new to me. Through the magic of an excel spreadsheet, here they are: Aland Islands, Antigua & Barbuda, Argentina, Aruba, Asiatic Russia, Australia, Austria, Bahrain, Belarus, Belgium, Bonaire, Bosnia-Herzegovina, Brazil, Bulgaria, Canada, Canary Is., Cape Verde, China, Corsica, Crete, Croatia, Cyprus, Czech Republic, Denmark, East Malaysia, England, Estonia, Ethiopia, European Russia, Federal Republic of Germany, Finland, France, Greece, Guam, Hungary, India, Indonesia, Ireland, Isle of Man, Israel, Italy, Japan, Kaliningrad, Kazakhstan, Kenya, Kuwait, Latvia, Lebanon, Lesotho, Lithuania, Luxembourg, Macedonia, Madeira Is., Malta, Martinique, Mexico, Micronesia, Montenegro, Morocco, Namibia, Netherlands, Norway, Oman, Panama, Poland, Portugal, Puerto Rico, Qatar, Reunion Island, Romania, Sardinia, Saudi Arabia, Scotland, Senegal, Serbia, Slovak Republic, Slovenia, South Africa, Spain, Sweden, Switzerland, Tanzania, Thailand, Tunisia, Turkey, Ukraine, United Arab Emirates, Uruguay, US Virgin Islands, USA, Wales, West Malaysia, and Zimbabwe.

Prep for CQ WW SSB

zone39I should be able to put CQ zone 39 back on the air this weekend, at least for part of the CQ WW SSB contest. I’ve had a ton of travel and a few other projects over the last few months, and have been off the air except for portable operations outside Madagascar. Timing is good this weekend, though, for me to get on the air as 5R8SV from the house in Antananarivo.

I think the ionosphere may have taken my inactivity as a personal affront, because it seems to have tanked. Not having really paid much attention to propagation conditions for a couple months, I am stunned by how far the averaged sunspot number has plummeted (to 12!).

I just ran some simulations for the upcoming weekend, and 100W with a hexbeam may be marginal for Europe, much less the US. I hope some of the higher bands will pop open here and there, but I am not expecting much.

I just looked at conditions over on solarham and hope that the choppiness of the last few days will settle down for the weekend. We’ll see!

storms-hoI should be in Madagascar in a few weeks, but I’m not sure whether I’ll be at home in Antananarivo or in the northern part of the country. There’s a chance I’ll be in Nosy Be, if so, I might be operating that contest QRP portable. While lower power might be a challenge under these conditions, Nosy Be is on NW corner of the island, and surrounded by salt water, so maybe worth a shot.

The last year of QRZ updates

jacklemurI make small status updates every month on the 5R8SV page on QRZ.com, but after a while, the page becomes too long and the info grows stale. I would hate to lose this record, though, because it’s a nice account of what I’ve been up to, so I am pasting the last year’s worth of comments below and cleaning up the QRZ page. Continue reading “The last year of QRZ updates”