Posts Tagged ‘high frequencies’

Land (er, FREQUENCY) Grab (Part 1)

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.

Gentlemen’s Agreements

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.

On Facebook, you may also discuss your thoughts, in either the Olivia Digital Modes on HF group or in the Digital Modes on HF group.

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, NW7US

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.

What is the big deal with amateur radio? What is it that you hear? (Part 1)

Shortwave Radio - spy vs spy
Shortwave radio has been a source for great sci-fi plots, spy intrigue novels, movies, and so on, since radio first became a “thing.” But, what is the big deal, really? What is it that amateur radio operators listen to?

In this video, I share some of the types of signals one might hear on the high frequencies (also known as shortwave or HF bands). This is the first video in an on-going series introducing amateur radio to the interested hobbyist, prepper, and informed citizen.

I often am asked by preppers, makers, and other hobbyists, who’ve not yet been introduced to the world of amateur radio and shortwave radio: “Just what do you amateur radio operators hear, on the amateur radio shortwave bands?

To begin answering that question, I’ve taken a few moments on video, to share from my perspective, a bit about this shortwave radio thing:

Link to video: https://youtu.be/pIVesUzNP2U — please share with your non-ham friends.

From my shortwave website:

Shortwave Radio Listening — listen to the World on a radio, wherever you might be. Shortwave Radio is similar to the local AM Broadcast Band on Mediumwave (MW) that you can hear on a regular “AM Radio” receiver, except that shortwave signals travel globally, depending on the time of day, time of year, and space weather conditions.

The International Shortwave Broadcasters transmit their signals in various bands of shortwave radio spectrum, found in the 2.3 MHz to 30.0 MHz range. You might think that you need expensive equipment to receive these international broadcasts, but you don’t! Unlike new Satellite services, Shortwave Radio (which has been around since the beginning of the radio era) can work anywhere with very affordable radio equipment. All that you need to hear these signals from around the World is a radio which can receive frequencies in the shortwave bands. Such radios can be very affordable. Of course, you get what you pay for; if you find that this hobby sparks your interest, you might consider more advanced radio equipment. But you would be surprised by how much you can hear with entry-level shortwave receivers. (You’ll see some of these radios on this page).

You do not need a special antenna, though the better the antenna used, the better you can hear weaker stations. You can use the telescopic antenna found on many of the portable shortwave radios now available. However, for reception of more exotic international broadcasts, you should attach a length of wire to your radio’s antenna or antenna jack.

Check out books on radio…

I’m on Twitter, Facebook, and YouTube.


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