July 16, 2018

Recommended reading

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Just some interesting articles I've recently discovered and that I'd like to share. One about the mystery of Long Delayed Echoes that every now and then are observed on the MF and HF bands, and one about Portable Amateur Radio in the 1960s and up until now.

The Five Most Likely Explanations for Long Delayed Echoes by Sverre Holm, LA3ZA, University of Oslo

Portable Amateur Radio, W7ZOI/7 by Wes Hayward, W7ZOI

Enjoy!

Wes Hayward in 1967 operating W7ZOI/7 on the summit of Mt. Adams, Washington State (source)


Addendum:
Also make sure to check out Sverre Holm's excellent blog with lots of entries on QRP operation, Pixies, Altoid projects, Unusual HF propagation, and much more!

July 05, 2018

Magic Band Whispers - Morocco with 100 mW and an indoor dipole!

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Mission accomplished: my 100 mW WSPR signal was received via Sporadic E (Es) on 6m in Morocco! This was one of the goals I had set for this Es season for 6m WSPR (see also my blog entry of  May 17th). The transmitter and antenna used were a QRP Labs U3S and a simple homebrew indoor dipole in the attic for the 6m band!


CN8LI in Morocco hearing PA7MDJ

12 hours period of 6m WSPR reception at CN8LI


Morocco is my 70th DXCC reached with WSPR with 200 mW of power.

CN8LI keeps an interesting blog on cn8li73.blogspot.com.

May 18, 2018

Yaesu YF-122C CW filter / QRP CW contact with the Faroe Islands

Last edited: 20.05.2018

I'd been looking into buying a narrow CW filter for my Yaesu FT-817nd rig for some time, but the high price (about € 130) for both the YF-122C (500 Hz) and YF-122CN (300 Hz) had been holding me back. But this week I got the opportunity to buy a used YF-122C filter for less than half the price of a new one. I couldn't let this offer go.


My Yaesu FT-817nd last summer on the summit of Pilatus mountain in Switzerland

Today the filter was delivered by the mailman. I spent about half an hour on installing the filter, and after some initial tests I must say it's working great! Installation of one of the optional filters into the FT-817nd is easy; just take out some screws, remove the rig's top case, and push the filter board onto the designated pins on the main board of the transceiver!

The 500 Hz filter will definitely make CW QSOs with the FT-817 a lot easier, and I'm all ready to do some more SOTA activations with it coming summer.






Before installation. The filter goes onto the main board in the designated free space opposite of the tuning knob.

After installation

After installation of the filter I made a nice CW contact with the FT-817 with OY1CT on the Faroe Islands. The contact was made as PA7MDJ/QRP on 20m using just 5 Watts and my HyEndFed 10/20/30 wire antenna. You can listen to the contact below (sorry for the background noises, please don't pay attention to them, hi). This contact was made with the 500 Hz filter activated.




And while talking about the FT-817, one site I always like to return to for more information about this popular QRP and backpack rig is "The KA7OEI FT-817 pages". Another interesting site is "K6XX's FT-817 page". If you're a FT-817(nd) owner these sites might be of interest to you as well.

May 17, 2018

6m Sporadic E and the Maldives on 20m (WSPR chatter 5)

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It's May and that means that the Sporadic E (Es) season is upon us. I've always been fascinated by this unusual radio propagation phenomenon, and I have fond memories for instance of the 1990s when I did a lot of VHF band I TV DXing, with Es during spring and summer enabling me to catch TV stations from all over Europe and sometimes even beyond.

For this Es season I had planned to do some 6m WSPRing with my QRP Labs U3S. So recently I quickly built the U3S 6m LPF kit that had been lying around for some time, and I also made a simple 6m dipole. And with simple I mean really simple; just some wire cut to resonance, some pvc pipe insulators, and lots of hot glue. The antenna is placed indoors in the attic.


The centre insulator of the simple indoor dipole made for 6m WSPR

With my U3S on the HF bands frequency drift never had been a real issue (mostly 0 on the lower bands, and mostly 0 to 1 or an occasional 2 Hz on the 20m band), but now on 6m the drift was considerable, mostly 4 Hz, probably making decodes impossible or difficult. But setting the "park mode frequency" to mode 2 and 150 MHz (to keep the U3S' DDS warm in between transmissions) cured the problem and reduced the drift down to 0 to 1 Hz.

The power of the U3S on 6m is less than on HF; on the "Magic band" I measured it puts out less than a 100 mW.

Es conditions so far haven't been great, and I've also noticed that there isn't really much of a "WSPR scene" on 6m  (which I find very strange, as 6m is really interesting to do WSPRing on to study the unusual and fascinating propagation phenomena of this band). Nevertheless, a couple of days ago my tiny 6m Es WSPR signals were spotted for the first time thanks to SV2HNH in Greece. On HF it wouldn't be that special, but now I was really excited about it.


SV2HNH hearing PA7MDJ on 6m




I will be WSPRing on 6m this Es season on and off. There's a very active monitoring station in Morocco (CN8LI), and for the remainder of the season I've set my goal to having my WSPR signals picked up by this station at least once.

Further exciting news is that my 200 mW WSPR signals were picked up on 20m by 8Q7HI on the Maldives, my 69th DXCC reached with 200 mW WSPR (see my WSPR DXCC list here). TX was my U3S, and the antenna used was a HyEndFed 10/20/40.


8Q7HI hearing PA7MDJ on 20m





See also:

https://en.wikipedia.org/wiki/Sporadic_E_propagation
https://en.wikipedia.org/wiki/Band_I

May 05, 2018

Life's too short for QRP! (WSPR chatter 4)

Last edited: 06.05.2018

Latest news 06.05.2018 - DJ0HO/MM has been confirmed as being located on the German icebreaker and research vessel RV Polarstern! See the addendum below!

I like the challenge of WSPRíng with 200 mW with my QRP Labs U3S. But sometimes you really want to be spotted by that special station, and after trying for a while you start to realize that 200 mW just ain't going to cut it, at least not without some extraordinary propagation conditions helping out.

Such was the case for me with DJ0HO/MM. This station the past two months or so had been making WSPR spots from the area around the Antarctic Peninsula and the South Shetland Islands (see also my blog entry of April 7). I really wanted to be spotted by this station, but my 200 mW WSPR sgnals just everytime failed to excite some electrons in the station's antenna.
So, giving the popular ham radio phrase "Life's too short for QRP" new meaning, I gave the U3S some rest and decided to do some WSPRing on the 20m band with my Yaesu FT991 instead, using no less than a massive 5 Watts of power, yes, 5000 mW! :-) In WSPR, and compared to the 200 mW I normally use, this was like going from QRP to high power QRO operations! :-) And it really showed; I got way more spots, much better SNR reports, and while I was at it I was spotted by stations in Japan, India and New Zealand to boot, countries I haven't been able to reach yet with my 200 mW signals (see also my WSPR DXCC list). But most importantly, I was finally also spotted by DJ0HO/MM!

The first spot for PA7MDJ from DJ0HO/MM appeared on April 29th from grid GC29ma, just north of the mysterious, remote, and desolate Elephant Island. Elephant Island is an ice-covered mountainous island, it's part of the South Shetland Islands, but lies in its extreme outer reaches. The island was named for the many elephant seals spotted on its shores by the early explorers. Elephant Island is most famous for having been the refuge of Sir Ernest Shackleton and his men marooned there after the loss of their ship in the Weddel Sea during the Endurance Expedition in 1915.
A second spot appeared two days later from grid GC39al. The antenna I used during both spots was a sloping dipole for the 20m band.


Elephant Island. Photo by Terry Allan (source).


DJ0HO/MM near Elephant Island hearing PA7MDJ on April 29th, 2018

Raising the power from 200 mW to 5 W is not automatically a guarantee that your signals will be picked up, and the fact that I was spotted by DJ0HO/MM only twice shows that it was still no easy feat.

DJ0HO does not have a qrz.com account, and it surprises me that almost no information can be found on either DJ0HO or the WSPR operations of DJ0HO/MM. The only thing I've been able to find is that the callsign belongs to a Dr. Walter Jörg Hofmann, the owner / skipper of a sailing yacht. I initially thought the WSPR monitoring was done from this sailing yacht. But the past few days on the map of wsprnet.org  I noticed that, after having spent many weeks in the Antarctic, DJ0HO/MM was moving up north, and at some point had reached the southern tip of South America and was sailing just east of Tierra del Fuego. I'm no expert at maritime navigation, but the speed at which DJ0HO/MM had managed to sail from Elephant Island to Tierra del Fuego made me suspect that this could not be a sailing yacht. At the time of writing the last spot in the wsprnet.org database from DJ0HO/MM was made on May 4th from grid FD66it.

I started to suspect that DJ0HO/MM was operated from a bigger ship, maybe a research vessel. In that case the most likely candidate would be the German research and supply vessel RV Polarstern. I checked the ship's 2018 schedule and learned that from March 17th to May 6th the ship was on a biological oceanographic research cruise (PS112) in the area "WESTERN ANTARCTIC PENINSULA SCOTIA SEA". The cruise would end on May 6th in Punta Arenas, Chile, which would have the ship sailing along the coast of Tierra del Fuego just prior to it! This schedule corresponds VERY closely to the movements I've seen for DJ0HO/MM!


The RV Polarstern (source)

The Polarstern 2018 schedule (source)

I thus can do none else than strongly suspect that DJ0HO/MM was located on board of the RV Polarstern! If somebody can confirm this, please contact me.

In other WSPR news; I've also been receiving some High Altitude Balloon WSPR flights including SA6BSS (BSS #?) over Greenland and VE3KCL (U3B-15) near Northern Africa. Also the hospital ship USNS Mercy (see also my blog entry of April 27)  is still active, and I've been receiving its WSPR signals again, this time from Sri Lanka.


WSPR balloon SA6BSS over Greenland heard by PA7MDJ


Addendum 06.05.2018
DJ0HO/MM indeed is the RV Polarstern! For some reason I'd missed it, but earlier Felix Riess DL5XL had already replied to my blog entry of April 7th with the following information:
---
Jörg, DJ0HO, is an electronics engineer on board the German icebreaker "Polarstern" (not exactly a "sailing yacht"). More information about the ship can be found here: https://www.awi.de/en/expedition/ships/polarstern.html - He uses a Red Pitaya STEMLab 125-14 with an active receiving antenna to monitor up to eight WSPR frequencies simultaneously and regularly uploads reception results to wsprnet.org through the vessel's satellite link. DJ0HO will be on board until the ship returns to its home port of Bremerhaven, Germany, in June 2018.
---
Thanks for the input, Felix! I appreciate it very much!



See also:

https://www.awi.de/en/expedition/ships/polarstern.html
https://en.wikipedia.org/wiki/Elephant_Island
https://en.wikipedia.org/wiki/Imperial_Trans-Antarctic_Expedition

April 29, 2018

North to Alaska! (WSPR chatter 3)

Last edited: 30.04.2018

What a pleasant surprise this morning to see that my 200 mW WSPR signals on 20m had been spotted by KL7L in Alaska!

I used my QRP Labs U3S transmitter and a sloping dipole cut for resonance on 20m.

This is WSPR DXCC entity 68 for me.


KL7L hearing PA7MDJ




KL7L is operated by Laurence Howell from his receive facility at Hart Lake Fishook (grid BP51ip) near Wasilla. about 50 miles north of Anchorage. Laurence seems to be very active with VLF, LF and MF receiving experiments, for which the Hart Lake QTH seems to be the ideal location.

In this article Laurence reports on his reception in Alaska of the VLF signals from the SAQ Grimeton transmitter in Sweden. You'll also find some photos there of the KL7L shack, the VLF antennas used, and the view from Hart Lake looking North over the Pole towards Europe (imagine, that's where my tiny WSPR signal came from!)


View from the KL7L Hart Lake receive facility looking North over the Pole towards Europe (imagine, that's where my tiny WSPR signal came from before being picked up by the antenna of KL7L!) (source)

Here you'll find a YouTube movie where Laurence shows a huge homebrew VLF receiving loop. More interesting YouTube videos from KL7L (user "hellozerohellozero") can be found here.

April 28, 2018

Homebrew SDR Tuning Knob Unit

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This is my latest little homebrew project; a tuning knob unit for my SDRPlay RSP1A software defined radio receiver. The project was inspired by the article "Wireless Tuning Knob" in the April 2018 issue of the excellent Practical Wireless magazine.

To make an easy to use tuning knob for your SDR receiver, the PW article suggests using the inners of a cheap wireless computer mouse, removing the mouse wheel, and connecting a rotary encoder instead. Then a tuning knob can be attached to the rotary encoder's shaft, and voila!

And that's exactly what I did, except I did use a wired USB mouse, not a wireless one, as I didn't want the hassle of having to change batteries all the time. The result is shown in the photos below. It works like a charm!