Posts Tagged ‘WSPR’
A VISUAL + AUDIO AIR CHECK OF DIGITAL MODE FT8 QSOs, ON THE 30-METER BAND
Here is a video capture of the reception and transmission of many digital FT8-mode amateur radio high-frequency (HF; Shortwave) communication signals. This video is a front-seat view of the software operation performed at the radio room of amateur radio operator, NW7US, Tomas Hood.
The software packages demonstrated are installed and operational on a modern personal computer. The computer is connected to an Icom IC-7610 radio transceiver, controlled by the software. While there is no narration in the video, the video provides an opportunity for you to see first-hand how typical FT8 operations are performed. The signals can be heard.
The frequency used for the FT8 communication in this video is on or about 10.136 MHz, in the 30-Meter shortwave amateur radio allocation (or, band). As can be seen, the 30-Meter band was active at this time of day (0720 UTC, onward–local nighttime).
In this video you see (and hear) NW7US make two-way contacts, or QSOs, with stations from around the country and the world.
There are amateur radio operators within the amateur radio community who regard the FT8 digital mode (FT8 stands for “Franke-Taylor design, 8-FSK modulation“, and refers to the mode created by Joe Taylor, K1JT and Steve Franke, K9AN) as robotic (automatic, automated, and unattended) computer-to-computer communications, and not ‘true’ human communications–thus negating the spirit of ham radio. In other words, FT8, in their opinion, is not real amateur radio. While they pontificate about supposed automated computer communications, many of those holding this position have not installed and configured the software, nor tried communicating with the FT8 digital mode. They have perhaps formed their anti-FT8 opinion in a vacuum of knowledge. (This writer has other issues with FT8, but not on this point–see below)
As you watch the video linked in this article, consider these concepts:
+ A QSO is defined (as per common knowledge–see below) as the exchange of at least the minimum information needed as set by the requirements of a particular award, or, as is defined by law–for instance, a QSO would have at least an exchange of the legal call sign assigned to the radio station and/or control operator, the location of the station making the transmission, and a signal report of some kind about the signal received from the other transmitter at the other end of the QSO.
+ Just how much human involvement is required to make a full FT8 QSO? Does WSJT-X software run all by itself, with no human control? Is WSJT-X a robot, in the sense that it picks a frequency, then initiates or answers a CQ call automatically, or is it just powerful digital-mode software that still requires human control?
The video was captured from the screen of the PC running the following software packages interacting together as a system:
+ WSJT-X: The primary software featuring the digital mode, FT8. (See below for some background on WSJT-X software.)
+ JTAlert: Provides several audio and visual alert types based on decoded Callsigns within WSJT-X.
+ Log4OM, Version 2: A full-featured logging program, which integrates well with WSJT-X and JTAlert.
+ Win4IcomSuite: A full-featured radio controlling program which can remote control rigs, and provide control through virtual communication port-sharing.
+ Com0Com: The Null-modem emulator allows you to create an unlimited number of virtual COM port pairs and use any pair to connect one COM port based application to another. Each COM port pair provides two COM ports. The output to one port is the input from other port and vice versa.
As mentioned, above, the radio used for the communication of FT8 at the station, NW7US, is an Icom IC-7610 transceiver. The antenna is an off-center fed dipole that is over 200 feet in total length (end-to-end measurement).
WSJT-X is a computer program used for weak-signal radio communication between amateur radio operators, or used by Shortwave Radio Listeners (SWLers; SWL) interested in monitoring the FT8 digital communications between amateur radio operators. The program was initially written by Joe Taylor, K1JT with Steve Franke, K9AN, but is now open source and is developed by a small team. The digital signal processing techniques in WSJT-X make it substantially easier for amateur radio operators to employ esoteric propagation modes, such as high-speed meteor scatter and moonbounce.
WSJT-X implements communication protocols or “modes” called FST4, FST4W, FT4, FT8, JT4, JT9, JT65, Q65, MSK144, and WSPR, as well as one called Echo for detecting and measuring your own radio signals reflected from the Moon. These modes were all designed for making reliable, confirmed QSOs under extreme weak-signal conditions. JT4, JT9, and JT65 use nearly identical message structure and source encoding (the efficient compression of standard messages used for minimal QSOs). They use timed 60-second Transmit/Rreceive (T/R) sequences synchronized with UTC (Universal Time, Coordinated). JT4 and JT65 were designed for Earth-Moon-Earth communications (EME, or, moonbounce) on the Very-High Frequency (VHF), Ultra-High Frequency (UHF) and microwave bands. JT9 is optimized for the Medium-Frequency (MF) and High-Frequency (HF) bands. It is about 2 dB more sensitive than JT65 while using less than 10% of the bandwidth. Q65 offers submodes with a wide range of T/R sequence lengths and tone spacings.FT4 and FT8 are operationally similar but use T/R cycles only 7.5 and 15 seconds long, respectively. MSK144 is designed for Meteor Scatter on the VHF bands. These modes offer enhanced message formats with support for nonstandard call signs and some popular contests. (The MSK in MSK144 stands for, Multiple Frequency Shift Keying.)
FST4 and FST4W are designed particularly for the Low-Frequency (LF) and MF bands. On these bands, their fundamental sensitivities are better than other WSJT-X modes with the same sequence lengths, approaching the theoretical limits for their rates of information throughput. FST4 is optimized for two-way QSOs, while FST4W is for quasi-beacon transmissions of WSPR-style messages. FST4 and FST4W do not require the strict, independent time synchronization and phase locking of modes like EbNaut.
As described more fully on its own page, WSPR mode implements a protocol designed for probing potential propagation paths with low-power transmissions. WSPR is fully implemented within WSJT-X, including programmable band-hopping.
What is a QSO?
Under the title, CONTACTS, at the Sierra Foothills Amateur Radio Club’s 2014 Technician Class webpage, https://www.hsdivers.com/Ham/Mod15.html, they teach,
An amateur radio contact (called a QSO), is an exchange of info between two amateur radio stations. The exchange usually consists of an initial call (CQ = call to all stations). Then, a response from another amateur radio operator, and usually at least a signal report.
Contacts can be limited to just a minimal exchange of call signs & signal reports generally between amateurs previously unknown to each other. Very short contacts are usually done only during contests while longer, extended ‘rag chews’ may be between newly met friends with some common interest or someone you have known for a long time.
Wikipedia has an entry for QSO, too.
My Issue With FT8 and WSJT-X
I have written in the past, on this website, about an issue that came about during the course of the development of the WSJT-X software package. The development team decided to widen the slice of ‘default’ (pre-programmed) frequencies on which to operate FT8. The issue was how the choice of new frequencies was made, and what choices were implemented in an upcoming software release. Read more about all of this, in these three articles:
Has this issue been resolved? For now, yes. There appears to be more coordination between interested groups, and the proposed new frequencies were removed from the software defaults in WSJT-X. At least, up to this point, at the time of publishing this article.
This article is part two of the series taking a look at band plans and gentlemen agreements.
See part one, here: Land (er, FREQUENCY) Grab. See part three, here: In Response — Can’t We All Just Get Along?
Displaced and Marginalized
There are some unhappy amateur radio operators in the world of shortwave operations. Users of Morse code, and digital modes other than the highly-popular modes engineered by Joe Taylor, K1JT, feel displaced on the many amateur radio bands where Joe’s wildly-popular mode FT8 has erupted.
Joe (born March 29, 1941), is a friend of hams everywhere, and is an American astrophysicist and Nobel Prize in Physics laureate (https://g.nw7us.us/2Ptquv1) for his discovery with Russell Alan Hulse of a “new type of pulsar, a discovery that has opened up new possibilities for the study of gravitation.”
Many have asked questions like, “Did Joe Taylor K1JT Destroy Amateur Radio? Did Joe Taylor K1JT, Nobel Laureate and noted friend of hams everywhere, accidentally destroy amateur radio?” This question remains relevant, even as more and more FT8 operators take to the HF bands to chase wallpaper and awards.
FT8 Has Validity and Usefulness
Full disclosure: I administer a Facebook group for FT8 and FT8-related modes, because I believe that the mode has a valid place in our amateur radio technology portfolio. Here is the Facebook group URL, if you would like to join the fun: https://www.facebook.com/groups/FT8.FT4.HF.6m/. Understand, I have used and will continue to use FT8.
Because it has a place, it stands to reason that everyone should become more aware of the impact of using FT8 on the bands. It also stands to reason that it should be used ethically, and in the best spirit of amateur radio.
Many amateur operators use the FT8 digital mode as a novelty when there isn’t much else happening on amateur radio shortwave bands. One of the great things about it is that you can tell when a band is open–even though you don’t hear any other signals of other modes on the band in question, you very well may hear the roar of FT8 on the band where propagation actually exists to somewhere else than your QTH.
Others use it to finally get their DXCC, or WAS, or other award and wallpaper. This is especially popular during this season of the sunspot cycle where there are no sunspots–propagation is limited to lower-HF amateur bands because there’s just not enough solar activity to energize the ionosphere enough to open up the higher segment of shortwave.
FT8 Has Limitations
Can FT8 be used for two-way conversations? No. However, the JS8CALL digital mode is designed from the FT8 mode, by changing the protocol in a way that allows free text. It is designed for ragchewing and the new version 2.0 offers three modes of chat with 50 Hz and 16 wpm, 80 Hz and 24 wpm, and the turbo mode at 160hz and 40wpm with turbo only having a 6-second turn around time. The designated frequency is 7.078, which many find much nicer to use.
However, many find JS8CALL combersome, and non-intuitive. How fast and how reliably can it handle critical messages, say, during an emergency? I’m sure the software will improve, but how good is the protocol?
A mode such as Olivia has been field proven, and time tested. It can reliably handle traffic.
During the early days of widespread FT8 operation that came with the first public non-Beta release of FT8-equipped WSJT-X software, I tried to reason with the FT8 development leadership team. I made a polite attempt at explaining how incredibly rude they were in purposefully programming into the software the default operating frequencies such as 7.075, 14.075, and so on.
One of the main leaders of that team slammed me and stated that “we only suggested those frequencies; the operator is free to change them.” Additionally, he stated that the team used a common QSO/Mode spotting website to see what digital modes or other operations (like CW) were sparser. They perceived that the frequencies they proposed where no longer active because they saw few if any spots. They thought that no one would care.
I explained that a single website-spotting strategy was illogical and very lazy. This is true for several reasons, at least.
I guess you have to have a Ph.D. to know better than any average ham who went by gentleman’s agreements. I have an extremely dim view of JT and his disciples. CW is not the only operating group he’s engineered out of traditional slices of spectrum. Olivia, and other modes, now have been pushed down into PSK subbands, and everyone is feeling the crowding. As far as my thinking of FT8, well, it is radio, but it doesn’t foster goodwill and building serious communications skill. IMHO.
Play Nice, Be Positive and Polite. Smile.
I’ve received wise counsel from a number of fellow amateur radio operators. They implore us to not promote hostility between “us and them.” That even though the WSJT team is playing the playground bully, we should not be vengeful, but polite and willing to negotiate in good faith.
If we don’t play nice with the bully then the bully won’t play with us. And, the general public will side with the bully because the bully has the nice toys…
Good negotiations, though, take a willingness by both sides, so that conversation evolves, resulting in positive, cooperative actions embraced by both parties. There are other amateur radio operators who have made attempts to open up talks with Joe and crew. What are the results, so far?
We can hope that Joe Taylor and his group of developers and leadership take a proactive role and join a conversation that is with a wider group of amateurs than just the WSJT enthusiasts. We hope that they will play fairly, and cooperatively, with the rest of the amateur radio community.
Tomas Hood, NW7US, is a regular contributor to AmateurRadio.com and writes from Nebraska, USA. Tomas is the Space Weather and Radio Propagation Contributing Editor to ‘CQ Amateur Radio Magazine’, and ‘The Spectrum Monitor’ magazine.
This article is part one in a multi-part series. Part 2 is located here: One Aspect of Amateur Radio: Good Will Ambassadors to the World. Part 3 is located here: In Response — Can’t We All Just Get Along?
We’ve all heard it at least once: no one owns a frequency.
By law, amateurs must keep the transmissions from their station within the bounds of the allocations granted to license-holding operators–within these bands that are allocated for amateur radio use. Amateurs are expected to follow band-plans, which guide us to which mode can be used in a band.
Subbands — Band Plans
There are many decades of constant refining of the standard operating procedures–perhaps we can call them, traditions–that, for the most part, work out pretty well for most amateur radio operations on our precious allocations in the radio spectrum. Each band–a slice of radio spectrum between a lower frequency and a higher frequency–is made up of subbands. These subbands are slices within a specific band (allocation), in which amateurs participate in two-way communications by using a particular mode of transmission, like single side band or CW.
For instance, Morse code enthusiasts use CW (continuous-wave modulation, i.e., A1A) between 14.000 MHz and 14.150, which is the subband that exists in the larger allocations known as the 20-Meter Band. The 20-Meter Band is 14.000 MHz to 14.350 MHz, and the regulating bodies (such as the FCC in the USA) have directed through law that voice modes cannot be used between those subband frequencies from 14.00 MHz to 14.15 MHz. Voice modes can be used from 14.15 MHz up to 14.35 MHz, with certain license class variations. Read the PDF from the FCC: FCC ONLINE TABLE OF FREQUENCY ALLOCATIONS
CW is not the only mode allowed in the 14.00-MHz-to-14.15-MHz subband. The regulations stipulate that a number of data modes can be used in this subband. There are specific requirements that a mode must meet, in order to comply with regulations–these are known as the authorized emission types.
Amateur radio operators, decades ago, began discussing, then agreeing to, agreements between all operators as to where specific modes can be used, so those operating the different modes do not trample on each other’s transmissions. These agreements are known as our band-plan gentlemen’s agreements. They exist to help minimize interference–QRM–and to help foster good operating procedures between the different groups.
The band plans that have evolved through the decades are not regulations, and do not mean that any particular group of amateur radio operators own any frequency or subband. A mode does not own a particular subband. Amateur radio operators are not encouraged to start transmitting a mode that is typically found in that subband, if someone else is on that frequency using a mode not expected.
Just because some other operator is using the subband for a mode not in compliance with the gentlemen’s agreement, don’t purposefully try to eject that operator. At the same time, the gentlemen’s agreements exist to help amateurs avoid interference with others that are using different modes. Thus, the operator who has chosen to use a non-standard mode for a subband known to be used for some other mode should move that operation to the subband identified to be for that operator’s current mode of transmitter emissions. In other words, do not QRM another amateur radio operator, and do not cause confusion and frustration by barging into a subband for a mode that you are not intending to use. Use the mode expected in the subband of your current operations.
This concept is especially helpful when we consider weak-signal operations. If a very strong, loud teletype transmission begins in a subband that is set aside for weak-signal propagation modes like WSPR, then it defeats the efforts of the operators making the attempt to have successful weak-signal two-way communications. Thus, the teletype transmission should be made in a subband where teletype operation is expected and acceptable. And, WSPR should stay in the subband where people expect to find WSPR signals.
This concept is also applied to VHF or higher bands. Why? If repeaters are parked on known repeater subbands, then weak-signal single-sideband communications can take place in a subband where repeaters are not allowed. By allowed, though, I mean, by agreement with gentlemen’s agreements. Regulators have stayed out of the amateur radio operations except by creating regulations at a high-level–for instance, the FCC stipulating that voice communications are not allowed between 14.000 MHz and 14.150 MHz, in the 20-Meter band.
The Frequency Grabs by the WSJT Developers, Planners, and Leadership
With several current release candidates of the WSJT-X software by Joe Taylor, the group of developers and leadership have programmed into the WSJT-X software a set of NEW default frequencies. These new frequencies are in addition to their current pre-programmed frequencies that the amateur community now identifies as, The FT8 Subbands.
The new proposed frequencies are right on top of other subbands where other modes have been operating for decades (such as PSK and Olivia, and many others). There was no community discussion, except within the WSJT community. And, when someone protested the take-over of other well-established subbands, those protests were shot down. The stated reasons included, “Well, those other modes are not very active or popular, because spots are not showing up on various spotting networks.” Such reasons break down on deeper consideration–for instance, most spotting networks are not programmed to automatically identify Olivia transmissions. CW, PSK, and FT8 are programmed into scanners, but other modes are ignored.
This behavior, considered rude, arrogant, presumptuous, and anti-gentlemanly (referring to well-established gentlemen’s agreements) has happened before, with the initial release of FT8. They (the WSJT-X developers and leadership) simply picked a frequency slice of each subband, without true collaboration with the wider amateur radio community.
When this columnist and fellow amateur radio community member, attempted a discussion, the retort from an official representative was an absolute dismissal of any protest against the choice and method of frequency options within the WSJT software. While the software marks these frequency as suggestions, only, these defaults are used without question by the operators of said software. And, the mode is so fast that there’s no human way of truly monitoring the frequency before use, to see if some other mode is in operation. Besides, weak-signals that are present but cannot be heard by one’s ear, might well be in operation. Subbands exist to keep QRM from covering up the weak signals of the mode expected at that frequency.
Enter the IARU…
The IARU has decided to step in and join the discussion. “The International Amateur Radio Union has been the worldwide voice of radio amateurs, securing and safeguarding the amateur radio spectrum since 1925.” The IARU guides regulating bodies like the FCC, regarding the administration and rule-making pertaining to amateur radio.
The IARU states, on their website,
The radio spectrum is a priceless natural resource. Because radio waves do not respect borders, the use of the spectrum must be regulated internationally. This is accomplished through the International Telecommunication Union (ITU), a specialized agency of the United Nations. Through World Radiocommunication Conferences (WRCs) held approximately every four years the ITU revises the international Radio Regulations which have the force and effect of a treaty. The Radio Regulations allocate the spectrum to different radiocommunication services such as broadcasting, mobile, radar, and radionavigation (GPS). The most recent WRC was held in October-November 2019. The next one is not yet scheduled but is expected to be held in 2023, so it is usually referred to as WRC-23.
New uses of the spectrum are being developed every day. This puts enormous pressure on incumbent users who are called upon to share their spectrum access with new arrivals. The allocation process is extremely complex, especially when satellite services are involved.
Reportedly, from first-hand communication from one IARU representative,
WSJT-X RC3 has 14074 kHz again for FT8. IARU is intervening. Stay tuned. I am asking for further suggestions.
73 Tom DF5JL
IARU R1 HF Manager
This is very welcomed news!
What ought to take place, as quickly as possible, is to rally the different interested parties, like the Olivia group, the PSK groups, the various CW groups like CWOps, FISTS, and the SKCC, and many others, for ideas and suggestions. A discussion must take place in the hope that new gentlemen’s agreements can be made, that include the FT8 and FT4 operations, without stepping on the subbands of other digital modes.
As Tom says, STAY TUNED.
If you have suggestions, please comment. This columnist will summarize the main ideas of the comments and forward them to Tom. You may also contact the IARU managers and let them know your suggestions.
Discussions in the Olivia community are ongoing, too. Join in at OliviaDigitalMode.net even if you are not yet an Olivia operator.
If you use FT8 and FT4, voice your concerns and ideas, too. Open dialog, without declaring war, is welcomed and hopefully will prove productive.
This article is the first in a series focusing on band plans, and gentlemen’s agreements. Please stay tuned for more installments.
Tomas Hood, NW7US, is a regular contributor to AmateurRadio.com and writes from Nebraska, USA. Tomas is the Space Weather and Radio Propagation Contributing Editor to ‘CQ Amateur Radio Magazine’, and ‘The Spectrum Monitor’ magazine.
|Step-down converter based on LM2596. Note the damaged chip|
Ok, now I’ve done the test. My QRPLabs U3S runs off a 12 Volt power supply. There are two step-down converters, one for 5 Volts for the processor and another adjustable one for the power amplifier, if one can call 0.2-0.5 Watts a power amplifier. See picture of these voltage converters in this post.
I happened to make a new cable for 12 Volts which had the polarities inverted – and puff – there was a noise and absolutely no response from the U3S. I feared that I had blown the entire circuit. As my power amplifier was turned off, only the 5 Volts supply was affected and upon inspection I found that the voltage converter had a destroyed chip.
Since since they are so cheap, I had a spare. Luckily for me, the U3S worked as it should after replacement. So the LM2596 can take a reversed polarity and sacrifices itself in order to protect the rest of the electronics. Nice!
This post first appeared on the LA3ZA Radio & Electronics blog.
These last few days I’ve been experimenting with my QRPLabs Ultimate 2 and Ultimate 3s transmitting on 7 MHz. In addition to WSPR, the modes transmitted have been FSKCW with 6 second long dots, and Slow Hell with 17 second long characters. The result as received this morning can be seen on the display from the grabber of Les, G3VYZ in Northumberland, UK. This is a stack of 6 consecutive 10 second frames as can be found on the QRSS grabber site of AJ4VD.
|FSKCW and Slow Hell reception of LA3ZA at G3VYZ|
My signal is on 7,039.870 kHz and has been set up with a FSK shift of 6 Hz. Power output was 0.2 W and the distance is about 890 km.
It works but the reception is much less reliable than for WSPR, which is not so unexpected. At the same time the WSPR signal was received all around Northern Europe (G, GM, DL, OON, OE, LX, LA, OY, OH, PA, SM) as well as on the Canary Islands, 3930 km away.
For those of you with an interest in amateur LF work, you may be interested in the upcoming WSPR test transmissions from Ron, WH2XND / NI7J, located in Phoenix, Arizona.
One of Ron's several experimental licences allows him to run as much as 10W ERP from 68-76 KHz. To generate this amount of ERP at 75 KHz requires a lot of power and I suspect that he will still be well under his licence limitations ... amateur-sized antennas are just not very efficient on these low fequencies.
Previous experiments a few years ago, at lower ERP, produced impressive results, as shown by one of the WSPRnet maps for an overnight session on 75.075 KHz.
Ron used one of the Hans Summers U3S transmitters to generate his LF WSPR signal, amplifying it with a 400W Hafler audio amplifier. This winter's tests will be at 800W, with a W1VD FET amplifier designed for VLF.
Ron's experimental licence also covers 470 - 495 KHz at a whopping 100W ERP and 130 - 140 KHz at 50W ERP ... some serious power.
You may also find Ron's interesting and well-illustrated website description of some experimental antenna work that he has been doing on MF, LF and what it takes to resonate a typical Marconi 'T' on these bands.
|MF- LF 'T' Antenna At WH2XND|
|75 KHz Loading Coils!|
Ron has tentatively chosen late November or early December for his 'almost' VLF tests and when the date and frequency are finalized, I will post the information here on the blog.
It has been a very long wait for the FCC to implement these bands after they were approved for amateur use in 2007 and 2012 at the World Radiocommunication Conferences in Geneva. Canadian amateurs have had 630m since 2014 and 2200m since 2009 ... in the meantime, we have been anxiously awaiting the arrival of American amateurs to liven things up and to garner new interest in these bands.
Before operating on these bands, amateurs in the USA are required to register their intent via a simple web form found here on the Utilities Technology Council's website. Then follows a 30 day waiting period during which the UTC will check out your location to be sure that you are not located within 1km of any power lines that might be carrying LF or MF PLC (Power Line Carrier) control signals. If you hear nothing back from UTC within 30 days, you are good to go.
A positive outcome of registering via the UTC form is that there can be no PLC signals implemented on the lines near you at a later date! By registering your intended operating location(s), you are locking-in these spots for no further PLC development. If you have an EOC or Field Day site that you think you may want to operate from at some point, register these as well.
I think it is important that even if you do not intend to operate on either of these bands or perhaps a few years down the road, that you register as soon as possible ... the fewer PLC signals operating close to or within the amateur radio spectrum, the better, and this is one way of furthering that goal.
There has already been a vast amount of published information on both of these bands, describing transmitters, receiving systems and transmitting antennas so I won't go into much detail here regarding these topics ... and besides, it's always very interesting to search these things out yourself, learning as you go. Be assured that either of these bands will present interesting new challenges not encountered in typical HF operation, but all of the basic principles you are used to still apply ... it's just that things are much bigger down below the broadcast band!
Far and away, the best source of information for US amateurs can be found on John Langridge's (KB5NJD) NJDTechnolgies website. John has been operating on MF for several years already with an experimental licence (WG2XIQ) and is more than an expert on this topic.
His daily blog includes a detailed account of worldwide activity on 630m and makes for fascinating reading. His website provides all of the information and valuable links that you might need to plan your own LF or MF station. The information on his site, if printed out, would make a wonderful LF / MF Handbook!
My own blog and website also contain much helpful material, with a particular emphasis on Canadian activity on these bands. All of my blogspots dealing with 630m can be found here and contain enough bedtime reading to keep you busy for many nights.
If you are thinking of getting on either of these new bands, particularly 630m, here is a short Q & A that may help you through the initial planning stage of how to get started.
What modes are commonly used on these bands?
At present, due to the low level of two-way amateur radio activity, the WSPR mode has been dominant. This is a weak-signal 'beacon-only' mode so most two-way contacts take place either on CW or on the weak signal JT-9 mode. JT-9 has been specifically designed for HF and LF / MF weak signal two-way work and can dig as deep as -27db into the noise to provide a contact that could never be completed on other conventional modes such as CW.
With the influx of new activity on these bands, particularly on 630m, I expect that most two-way work will equal or surpass the amount of WSPR activity and that JT-9 and CW will do most of the heavy-lifting.
How far can I work on these bands?
Although the erp limits appear to be QRP-sized, this is somewhat misleading ... it is astonishing what can be done. Don't think that '5W eirp' means that you can only run a transmitter capable of generating 5W. Because antennas are so inefficient on these bands, it is often necessary to run several hundreds of watts in order to achieve the legal eirp limits. The bigger and more efficient your antenna, the lower the power needed becomes. On many nights, 5W eirp will get you clear across the country on MF.
However, if you build something for 630m that only produces 25W of power, you will still have the capability of working many stations in other states on most winter evenings or mornings, as propagation, the 'great equalizer', can be amazing at times.
Presently, most stations operating on WSPR will often be detected from one coast to the other and those with excellent locations near the coast will soon be working stations down under or in Europe, either on CW or on JT-9. If you can, design and build for the maximum eirp, 1W on 2200m and 5W on 630m.
What type of transmitter do I need?
If your interests are only in CW, then the sky is the limit when it comes to design. There are numerous simple solid state transmitter designs out there, using inexpensive FETs to generate power. I'm hoping, along with many others, that there will be a considerable amount of CW activity on 630m and even a simple 25-watter should provide you with lots of fun. There may also be some appetite for QRSS CW which can give the weak-signal digital modes a run for their money while still using a simple transmitter.
If you are interested in digital modes, such as WSPR or JT-9, the easiest way is through the use of a transverter to take care of converting your HF transceiver's capabilities to LF or HF. There are presently a few commercial transverter options available and can be found on the NJDTechnologies links page.
A good choice is the inexpensive 630m transverter produced by John Molnar, shown below and available both as a kit or prebuilt. It works well and is very popular.
|630m Transverter - John Molnar WA3ETD / WG2XKA|
|G3XBM -630m Transverter|
If you want something in the 'Collins category', the tranverters (both 2200m and 630m models) produced by VK4YB's Monitor Sensors provide around 70W output and are incredibly well designed and built. I have been very happily employing a 630m model for well over a year now ... my review of the transverter can be found here.
|VK4YB - 630m Transverter|
I would like to put on a beacon. What do you suggest?
The best and most informational type of beacon is a WSPR mode beacon. A WSPR beacon operator can always determine where his beacon is being heard, in real time, along with how well it is being heard, by watching the uploaded 'spots' of his beacon on the WSPRnet. You will have much better coverage with this weak-signal mode beacon compared to one on CW ... for every CW report received, you would likely get ten times or more that number on WSPR.
Although WSPR is a great mode for checking out propagation, it's very easy to get into the habit of nightly beaconing and not developing your station any further. If you do run a WSPR beacon, be sure to try some of the other two-way modes such as CW or JT9 and call CQ regularly ... ham radio is all about making two-way contacts!
I don't have enough property for the large antennas required, so I won't be able to use these bands.
Even if you are limited in space, you can still enjoy these bands. There are many examples of stations on small city or suburban-size lots that are consistently heard across North America on 630m. If you have the room for an 80m or 40m dipole or inverted-L, that will be enough space to work these bands. An inverted-L for example, can be base-loaded and tuned to resonance. Along with several ground radials, even a small antenna system like this will allow you to work skywave DX or be heard across the country when propagation is good. I'm constantly amazed at how well these bands propagate with very low amounts of erp. Don't let living on a small lot stop you from exploring these bands!
All I hear is noise on these bands ... how can I use them if I can't hear anything?
Growing noise floors are common to everyone and this is often the biggest challenge for LF and MF operators, especially those in densely populated regions. Armed with a little knowledge and investigation, oftentimes seemingly impossible QRN can be substantially reduced if not eliminated entirely ... even easier when the noise source is found to be in your own home! While some amateurs just give up at this stage, most will see it as an interesting challenge to be overcome and part of the many learning experiences offered by these new bands.
In addition to the informational links provided above, I have just added a new 'Getting Started On 630m' page to my website. This page has a two-part article that I recently wrote for The Canadian Amateur, our national amateur radio journal. The articles describe a simple way of getting on 630m CW as well as providing some basic antenna information and ideas.
This blog also has extensive writings involving 630m over the past few years, describing equipment used and suggestions for new operators, much of it involving homebrewing. There are several links on the right that will take you to specific blogs dealing with 630m.
For present LF and MF operators here in Canada, the arrival of our American friends to these bands is generating much excitement and anticipation. The opening of these bands in the USA will pump new life into this part of the spectrum for all North American participants and the opportunities for homebrewing and experimenting are boundless. It should be a very exciting winter!
If you have not taken the 60 seconds required to register your station on the UTC webpage, please don't neglect to do this via the link provided above. There have, reportedly, been thousands of amateurs doing this already, as it effectively locks-out their locations for any future PLC deployment that might keep them off these bands at a later date.
See you in mid-October on 630!