Archive for the ‘dx’ Category
One person that always inspires me with his enthusiasm for Real HF Mobile radio, is Dave G4AKC.
Dave often takes off to the front of Blackpool promenade, on either his bike, or his recent electric trike towing a trailer load of equipment behind him, that puts most shack's to shame. His late night shift on the cold sea front, or early mornings well wrapped up, quite often produces some long path and rare DX surprises that you wouldn't get from the home QTH, due to a good signal bounce off the sea water and lower noise being out in the open making reception far easier.
The G4AKC website https://www.g4akc.co.uk/ where you can learn more about his exploits has now been added to my Blog right hand panel "Sites that do it for me links".
Another good Blog link EI7GL for Ireland has also been updated in "My Blog List" link again on the right hand panel.
|courtesy: KC8RP FT8 Info|
We are now half-way through this summer’s Sporadic-E season, normally the magic band’s best time of the year. The only exception to this being the winter months of those solar cycles that are robust enough to raise the F2 MUF up as far as 50MHz ... something that occurred for only two or three days during the peak of Solar Cycle 24.
Unfortunately, it really looks as if the old reliable bread and butter modes on 6m, CW and SSB, are fast going the way of the dodo bird, as very few signals on either of these modes have been heard here this summer. As speculated last year at this time, it seems as though the weak signal (WSJT) FT8 mode now reigns supreme on the band, which has come as a great disappointment to myself and many other diehard CW ops.
At the start of this year’s season I reluctantly decided to pay more attention to this mode and see if it could put any new DXCC entities into my 6m log ... if so, it would be time well-spent.
For the past several years, my main 6m interest has focused on European or South / Central American openings, which are usually unpredictable and short-lived. As usual, most of the season’s openings have been domestic, with signals from the central and south-eastern states being the ones most often heard. Usually, signals during these openings are strong and fairly reliable and lend themselves to easy two-way work on either CW or SSB. For the vast majority of summer time openings, FT8 is not needed, as signals are not weak.
For some reason, the popularity of this weak-signal mode on 6m continues to grow in popularity even though signals are so strong! Where this mode really shines is on the short-lived long haul openings to EU or on similar long paths from the PNW, of which there have been very few this season.
With everyone crowded into a narrow passband of ~ 2kHz, it doesn’t take much to mess things up for your neighbours if you don’t think carefully about how your operating can affect other users of that small sliver of space.
One of the most common examples of poor operating skills that I see is the seemingly endless CQ. This is much easier to do on FT8 than with conventional modes, as the software used can do this automatically for you, every 15 seconds ... while you fiddle with something else in the shack. I’ve seen some nearby stations call CQ continuously for over 60 minutes at a time, with no replies. What this does is make it difficult for other nearby users to actually hear / decode any weak signals on the band that are being covered by the loud CQing station(s) during this entire span of time. Strong local signals can wreak considerable havoc with weak-signal mode software as it's just not designed to happily handle strong signals and do a good job of decoding weak ones at the same time! Please think about this if you are one of those long CQers ... you are not the only one trying to use the band.
Another observation has to do with 'sequencing'. FT8 users must decide if they will transmit on the ‘even’ or on the ‘odd’ 15-second sequence. If you, and all of your neighbours are loud with each other, then it makes sense that everyone is better off operating on the same sequence. This way, all locals are transmitting at the same time which means they are all listening at the same time as well ... nobody causes QRM for one another if everyone uses the same sequence.
This comes off the rails very easily when just one or two strong neighbours choose to transmit during the receive sequence being used by everyone else.
There has been a long-standing precedent for sequencing, established and utilized by meteor-scatter operators for several decades. It calls for stations on the eastern-most end of a path (Europeans for example) to transmit on ‘evens’ ... the ‘0-15’ and ‘30-45’ second segment of each minute. Stations on the western-end of the path (NA) transmit on the ‘odds’ ... ‘15-30’ and ‘45-60’ second portion of each minute. When looking towards JA later in the day, everything reverses for NA stations, as they now become the eastern-end of the path.
Some operators seem to get totally confused by this or don’t check to see what sequence is being used locally before starting to operate ... while some don’t really seem to care.
I’m not complaining about what a given amateur chooses to do but simply describing some of the roadblocks to better use of FT8 and why it is not necessarily very well-suited for 90% of the typical propagation seen on 6m Es.
Many of the newer stations often seem to be using poor or makeshift antenna systems on 6m and are often not able to hear stations responding to their CQs, which may be strong enough locally to disrupt reception for those that are able to hear weaker signals.
I have deliberately made a point of never calling CQ on FT8. From decades of CW DXing I have come to understand that it’s much easier to work DX, on any band, by spending your time listening ... and then calling when the time is right. It’s no different with FT8, yet I see CQs that go on forever. Some will argue that if nobody called CQ, then there would be nobody to hear, which is of course valid ... the reality is, most amateurs cannot resist calling CQ, especially DX stations who enjoy working a pileup. There seems to be no shortage of CQers and those seeking DX should take advantage of that fact.
One loud station was seen yesterday calling another for over 90 minutes-straight. Perhaps he had wandered away from his shack and had forgotten to ‘Halt Tx’ before leaving! FT8 users need to understand how to use their software efficiently.
As for PNW to EU propagation this summer, it has been almost non-existent although I have worked CT1HZE in Portugal and JW7QIA in Svalbard ... by listening ... listening ... and calling briefly, both on FT8. In both cases, signals were brief but strong enough for CW! During the short-lived appearance of the JW7, two NA stations were noted calling ‘CQ JW’ the entire time. Perhaps if they had spent this wasted time more wisely by listening, they would have worked JW.
I’m happy to report that Svalbard was a new DXCC entity for me on 6m, #88, and the first 'new one' in a few years.
It seems that when used sensibly, FT8 is a useful application to have in your DX toolbox ... but for most daily summer Es operation, it’s just not needed. CW or SSB is well up to the task most of the time, even for small stations. Where FT8 shines is on the very brief, often unstable, long haul (EU-NA or JA-NA) paths and then, only if your neighbours don’t do things that will get them into the naughty-corner!
Now, let’s see what the second half of the season has in store for the magic band .... maybe the best is yet to come.
When it comes to crystal radios, there is nothing revolutionary regarding the CR-1’s basic circuitry but for some odd reason, it has achieved cult-like status as well as high dollar value.
|courtesy: Scotts Crystal Radios|
The article that piqued my interest appears on 'Scott's Crystal Radios' website and makes for an inspirational read, eventually revealing the inside core arrangement of the ferrite-loaded tuned circuits via an actual X-ray of the device! By the way, if you are looking for a nice set of older headphones, Scott's website is the place to visit!
|courtesy: Scott's Crystal Radios|
Scott was eventually able to achieve performance equal to that of his borrowed CR-1, with his own slightly modified versions, all in a similar-sized footprint. Perhaps this is one reason why the CR-1 is so much sought-after, as good performance in a very small package is not the norm when it comes to crystal radios. It's usually a case of ‘the bigger, the better’ when it comes to performance.
A recent search of my junque box revealed several NIB ferrite loopsticks that would allow a potntial reproduction of this interesting circuit.
Several years ago I spent an eye-opening winter learning about DX crystal radios as up to that time I had always believed it would be impossible to hear anything other than strong local signals on a crystal radio. I quickly discovered that there was a very large Crystal Radio Yahoo Group where menbers were working at the leading edge of crystal radio design. I also found that the group sponsored an annual Crystal Radio DX Contest which inspired me to dig deeper.
It wasn’t too long before I decided to join the fun and attempt to build a crystal radio DX-machine but I was in for a few surprises and a long learning curve ... it seemed that hearing broadcast band ‘DX’ on a crystal radio (anything other than loud locals) was not going to be an easy task!
Over the course of several months I tried many types of variable capacitors, tank coil configurations and antenna tuning circuits. I even erected a dedicated antenna system for the various experimental circuits I was putting together ... an 'Inverted-L', 50’ straight up and 70’ horizontal, along with a ground rod connected to several buried radials.
I quickly learned about something I normally didn’t have to worry about when working with ‘active’ devices and that was overcoming system and component losses. In critical crystal radio design, it’s all about minimizing the losses in every stage and every component in the system since there are no amplifiers to help overcome these losses. Your system is only as good as the weakest link. In true crystal radio DXing, no active devices are permitted ... it’s just your crystal radio and the energy generated at some, hopefully far away, transmitter site!
After several months, I eventually ended up with a well-performing triple-tuned set that used lots of 'trapping' because of all of the very strong nearby signals here ... eight 50kW locals!
A description of the learning curve, with several do's and dont's to help new builders, can be found on my website here.
Back then, 80 stations were logged (from my location on Mayne Island in SW British Columbia) over the one-week Crystal Radio DX Contest.
SAN FRANCISCO, CA
100 MILE HOUSE, BC
MERCER ISLAND, WA
DAWSON CREEK, BC
NEW WESTMINSTER, BC
SALT LAKE CITY, UT
SAN ANTONIO, TX
ST. MARIES, ID
MEDICINE HAT, AB
TWIN FALLS, ID
LAKE OSWEGO, OR
ST. PAUL, AB
OREGON CITY, OR
SAN JOSE, CA
LAKE OSWEGO, OR
BRIGHAM CITY, UT
Old notes indicate that there were 14 stations at S9 or higher, requiring heavy trapping to hear anything close to their frequencies.
|My recent interest made me wonder what the situation is today when it comes to the number of strong local ‘blowtorch’ signals, surely the bane of all crystal radio DXers? Although there have been a few changes over the years, a quick scan of the band during the prime DX evening hours found that although one of the blowtorch signals (at 600kHz) was now gone, another had appeared at 1200kHz ... sadly no net difference.|
The top end of the band, always a prime area for good skywave DX, is unfortunately still dominated by a huge signal from KVRI just across the water near the Canadian / U.S. border. If KVRI were silent, the top end would be a wonderfully quiet hunting-ground for new catches. The new local blowtorch (CJRJ) on 1200 kHz will now cause problems for the middle of the band, which was always a good region for DX.
So it seems overall, there hasn’t been a huge change here other than in the middle of the band. It looks as though there are still some good watering-holes to be had but several traps will still be needed in any new system.
Once my present radio-bench project is finished (a '36 RK-39 crystal power oscillator) I’m looking forward to more research and design of a couple of new systems, starting with something similar to the CR-1 as well as some experimentation with toroidal coils. I always find the research and planning phase of any new project more interesting and fulfilling than the actual construction and implementation! Hopefully I’ll have something ready for the fall DX season!
Thanks to VA7MM, I will also have the loan of an original CR-1 next winter to make comparisons to any clone that I might build!
If building a DX-crystal radio is something that might interest you, there are several great websites offering inspiration and helpful info. The links for these may be found at the bottom of my own crystal radio page. As well, there are two active crystal radio groups on Facebook, where daily two-way discussion can be had.
Perhaps, with enough new interest, we can even revive the annual Crystal Radio DX Contest!
We just got back from a very enjoyable trip to Roatan Island that included 8 friends vacationing together. The snorkeling and beach time were lots of fun. We stayed at the Seaside Inn, highly recommended.
Of course, I took along some ham radio gear and made radio contacts from the island using the Slacker DXpedition method. The station was a Yaesu FT-991 driving an end-fed half wave wire antenna, cut for either 20m or 40m. I operating as K0NR/HR9 and my co-slacker Denny was on the air as KB9DPF/HR9. (Reciprocal licensing info is available from the Radio Club De Honduras.) We started out on SSB but that was tough going with poor propagation, so we soon found that FT8 was more effective.
We were pleasantly surprised with how well FT8 worked out for us as it was very compatible with the Slacker DXpedition philosophy. Here are the Top Ten Reasons to Use FT8 for Island Time DX:
- You can listen to your “island time” playlist while working DX.
- You don’t annoy your fellow vacationers by screaming into the microphone.
- You don’t have to worry about remembering proper phonetics.
- You can read the other station’s QRZ page while the computer completes the contact.
- You have time to visit the restroom without missing any contacts.
- You can upload your log to LoTW while operating.
- You have time to mix up a rum punch while making QSOs.
- It doesn’t matter if you slur your speech a bit due to that extra rum punch.
- If the run rate is really slow, the pc screensaver will kick in to entertain you.
- You can actually make contacts when propagation sucks.
Over the past few months I’ve spent some time tuning around the international shortwave bands.
I vividly recall how jam-packed these bands were when I first discovered the magic of radio, back in the peak years of Solar Cycle 19. Much has changed in this part of the radio spectrum since then, but after having read so many dire comments describing the demise of international SW broadcasting, I was pleasantly surprised at what I discovered.
Although there are certainly not the large numbers of stations there once were, there is still a large amount of activity to be found throughout the various bands allocated to international SW broadcasting.
Trying to keep track of station schedules and frequencies is a hobby unto itself but now made easier with the availability of so many online information sources. As when younger, I found the best way to stay organized was to keep a SW logbook, eventually settling on a simple ‘diary’ format which is still evolving.
Its next refinement will be an additional notebook having separate pages devoted to each individual frequency within a given SW band. This will allow for updating frequency information from various postings of the daily online ‘heard’ reports.
I’ve always had a great interest in QSLs and collecting cards was one of the things that initially attracted me to SW radio back as a pre-teenaged DXer. For me, not much has changed in the last several decades and I still enjoy QSLs ... the real, traditional cards, as opposed to the now popular e-card. For me, an e-card just doesn’t have much appeal for some reason but for many others, they work just fine.
As I slowly re-learn much of what I had forgotten about SWL’ing, I discovered that there are still many SW broadcasters that will acknowledge a reception report with a real paper card ... just like the good old days!
If you are keen on doing some serious listening, I cannot recommend the WRTH highly enough.
Studying the latest WRTH revealed the QSL policies of most international as well as domestic SW broadcasters as well as contact information. It is a superb annual reference and well worth the investment! With this information in hand, my listening has become more focused on recording and submitting reception reports to those stations still practicing the courtesy of acknowledging reports with a traditional QSL. Many stations also issue an e-card, but these are of little interest to me at present.
With a small amount of spring-summer time devoted to SW listening, I generated and submitted a few reception reports along with linked audio files on my website ... so far, the following QSLs have arrived:
|Radio Exterior de Espana|
|15520 kHz - Noblejas, Spain|
|Radio Free Asia|
|9950 kHz - via IBB on Tinian Island, S. Pacific|
|All India Radio (AIR)|
|9865 kHz - Bengaluru, India|
|DX Clube Sem Fronteiras Broadcast via WRMI 7730 kHz, Miami|
|T8WH - 9965 kHz Palau, South Pacific|
|HSK9 - 5875 kHz Udon Thani, Thailand|
|Radio Liangyou - Hong Kong|
|9275 kHz via Bocaue, Philippines site|
|Radio Romania - 9730 kHz - Bucharest, Romania|
|Radio Nikkei 2|
|3935 kHz - Chiba, Japan|
I’ll do an upcoming blog on some of the great information and online sites to support international SW listening activities.
This summer's 6m sporadic-E (Es) DX season is now well past the half-way mark and things have been different ... a lot different. For me, the past 40 plus summers of activity on the magic band have always been interesting, if not down right exciting ... particularly when the band opens to Europe from the west coast.
These usually very short-lived paths have been my main interest for the past several years and the bread and butter mode is normally a fast CW exchange, usually taking less than 20 seconds before signals would vanish, as the always quirky west coast path to Europe would jump to another region. But this has all changed dramatically.
I have seen many strong openings involving loud FT8 signals from various parts of North America but when tuning down to the CW/SSB section of the band, found nothing but ghostly silence! Gone are the familiar voices of friends met every summer for decades or the recognition of an old friend's fist on CW ... for me personally, most of the magic was missing this summer. I wonder if this is all part of the natural evolution of amateur radio or does the FT8 revolution signal the long term fate for many of the older conventional modes?
|Track the pole's movement here.|
|July 18th courtesy: http://www.on4kst.org/chat/index.php|
|July 20th courtesy: http://www.on4kst.org/chat/index.php|
|Overnight decodes July 8-9|
Thanks to Paul, K7CW, for doggedly sorting through my all-night decode file which may be viewed in full here.
With just a couple of weeks left in the normal Es season, it will be interesting to see if FT8's extra few db will extend it longer than usual!
John, VE7AOV, has been operating from his apartment, in the heart of the very large and noisy greater Vancouver, for several years now ... not simply 'operating', but thriving, from his cozy fourth-floor apartment radio station. The wallpaper shown below would not usually be expected to grace the shack walls where antennas are not permitted!
It's soon apparent that John has also overcome the usual problem of noise ingression, from every appliance and random RFI generator in the complex. This is no lucky fluke but all by design, and delivered via an all but invisible classic antenna system made of #26 wire and a few Starbuck's stir-sticks!
|600 ohm #26 balanced line|
I'll let John tell you a bit more before sending you to his fascinating website, Intuitive Electronics, where you can learn more about his system and the engineering behind his successful, low-noise installation.
When it comes to a high frequency ham station, the antenna alternative chosen by most apartment dwellers is no antenna at all. The design here is a wisp of an antenna that bothers no one and which can work Japan, Australia, France, European and Asian Russia, the Caribbean, Central America, Polynesia and South America from the Pacific coast of Canada. It is a simple solution for apartment dwellers, it is a cheap solution and it causes no t.v.i. or other r.f. problems. It is far preferable to the alternative selected by so many fellow apartment dwellers: no antenna at all.
An implication that it seems to be impossible to rid from the minds of fellows using a Marconi antenna is that they are not just pumping 100 watts of r.f. into their antenna but that they are also pumping that same 100 watts of r.f. into their ground, that is to say the building’s wiring, the safety ground wiring. R.f. in the safety ground is well coupled into the power and neutral conductors of a residence and, in North American code, is even hard connected to the neutral line at the service entrance. The house wiring becomes part of the antenna system.
The ground wiring and everything connected to it is every bit as much a part of the antenna as is the live element. Both radiate just the same amount of r.f. power, fellows. The ground wiring along with every electrical power consumer in the building is worked against the live element. Thinking of what is connected to ground in your house is thinking about one side of your antenna. It’s not just appliances that get the “benefit” of r.f. The land line telephone system, the cable television system, the garage door opener, the security lights and…you name it. They are all “feeling” that 100W of r.f. With regard to r.f., there is no distinction whatsoever to be made between “hot” and “ground”.
You know the reason why vertical antennas have gained a reputation for being noisy on receive now, too. Most verticals are Marconi antennas. Both the safety ground and the neutral serve all the houses in the neighbourhood. The receiver is wired into the electrical appliances of the entire neighbourhood.
This radio station, located four stories above grade and in a wooden building full of apartments would be a worst case for r.f. in “ground”. This station has no r.f. in the station. It has no r.f. in “ground”.
The station has no interference issues. The Building Manager, the Building Superintendent and the administrator for this building’s cablevision have been aware of the station from the beginning. There has not been a single complaint of t.v.i. or any other complaint about the station. That’s a clean record extending back to 2006. There are no red faced, spluttering tenants hammering on the door of this station! At this station, all the r.f. produced by the transmitter makes its appearance out on the antenna. The radio station’s r.f. is not referenced to station ground. Station ground “knows nothing” about the r.f. being generated.
In the present case, that is to say a station to be operated in an apartment building, it is required to have an antenna that is “invisible”. Now it’s not possible to achieve that literally but at least the antenna should be so inconsiderable that there will be no complaints from neighbours about having to look at it. The antenna here is made of #26 A.W.G. wire. That’s wire that is 0.40mm, 0.016 of an inch, in diameter. Four stories up, it’s difficult to see the antenna and that’s even when knowing where to look for it. Part of the antenna’s run is through trees and in among the tree branches it pretty much is invisible. It does not annoy neighbours by casting a shadow; there is no shadow.
In spite if the naysayers, John's small gauge antenna has survived years of winter storms, regular occurrences here on Canada's western edge ... simply because it presents such a low cross-section compared to most conventional antenna wires.
To read more about enjoying your hobby again from your new 'restricted' location and more than likely, learn something new about old fundamentals, give John's website a very close inspection ... there is much wisdom and many gems to be found, even if you don't live in an apartment!