DX-Operating on the Low Bands II
ON4UN, John Devoldere
4. THE FREQUENCIES
The frequencies used for DXing on the low bands are not the same in all countries. Therefore it is important that you know where to look for the DX. There are four levels we should look at:
1. What are the allocations in the three ITU regions?
2. What are the frequencies each individual country has allocated on the low bands, and are there mode-related subbands that are enforced?
3. Since subbands do not exist in a most countries, what is the (mode-related) band planning that radio amateurs have agreed upon in a worldwide contest? In others words, what does the IARU band plan say?
4. What is the common-sense band planning that low-band DXers apply, in case the IARU band planning does not meet our goals?
4.1. The ITU Allocations
The ITU has divided the world in three regions:
• Region 1: Africa, Europe, former USSR countries, Middle East (excluding Iran) and Mongolia
• Region 2: North and South America including Hawaii, Johnston and Midway Island
• Region 3: The rest of Asia and Oceania
The allocations are described in the Radio Regulations published by the ITU. Article S5 describes the allocations in detail. The RR publication can be bought from www.itu.int/ITU-R/publications/rr/index.asp. The following analysis is based on the 2001 publication of the RR.
4.1.1. 160 meters
1800 to 1810: No Amateur Radio allocation (used for Radioloca tion)
1810 to 1850: In principle, primary allocation for Amateur Radio, but… .
1810 to 1830: In more than 50 countries, primary allocation is for Fixed and Mobile services. Amateur radio is secondary.
1850 to 2000: Primary allocation to Fixed and Mobile services. In about 30 countries (eg, DL, OZ, OH, ON, HA, EI, 4X, OK, G, U, SM, etc) this section can be allocated to Amateur service but with a power limit of 10 W.
1800 to 1850: Allocated exclusively to Amateur Radio
1850 to 2000: Shared between Amateur, Fixed, Mobile, Radio location and Radionavigation. In most South American countries this section is allocated to Fixed and Mobile services on a primary basis (which means Amateur Radio is secondary).
1800 to 2000: Shared between Amateur, Fixed, Mobile, Radionavigation and Radiolocation. There are still spe cial previsions to protect the Loran frequencies, but as the system is no longer used, it is of no impact.
4.1.2. 80 meters
3500 to 3800: Shared between Amateur, Fixed and Mobile services
3500 to 3750: Exclusively Amateur Radio
3750 to 4000: Shared between Amateur Radio, Fixed and Mobile services. In LU, CP, CE, HC, ZP, OA and CX the Amateur Radio allocation is secondary. In VE and OX
3950-5400 can be used for Radiobroadcasting as a primary service.
3500 to 3900: Shared between Amateur Radio, Fixed andMobile services
3900 to 3950: Aeronautical Mobile and Broadcasting
3900 to 4000: Fixed services and Broadcasting
4.1.3. 40 meters
Before March 29, 2009:
7000 to 7100: Exclusive Radio Amateur (in some African countries, 7000-7050 is also allocated to Fixed service as primary service)
7100 to 7300: Broadcast (as if we didn’t know that…)
After March 29, 2009:
7000 to 7200: Exclusive Radio Amateur (in some countries Fixed service can be used as primary service)
7200 to 7400: Broadcast
7100 to 7300: Exclusive Amateur Radio
Before March 29, 2009:
7100 to 7300: Broadcast
After March 29, 2009:
7000 to 7200: Exclusive Amateur Radio (in some countriesFixed service can be used as primary service)
7200 to 7400: Broadcast
4.2. The IARU Bandplan
The IARU (International Amateur Radio Union) groups one National Radio society from each member country (the most representative one) and sets out as one of its goals to establish and maintain a band plan that has been approved by all of the IARU radio societies. The IARU is organized in the same 3 regions as the ITU (see section 4.1).
Table 2-1 (Source: IARU Web page) gives an overview of the band plan regarding 160, 80 and 40 meters in the three regions. This table does not mean that all countries in a given region are permitting operation in all of the segments men tioned in the table! It is obvious that the 7 MHz band plan will substantially change after March 29, 2009, when the new frequency allocations in the 40m band will come into effect.
4.3. Let’s be Practical
4.3.1. Let’s be practical on 160 meters
For successful DXing on 160 meters, knowing that most of the serious DXing on this band is done on CW, the band plan should reserve a window exclusively for CW. So far the IARU band plans have provisions for CW subbands and Phone + CW subbands. This probably stems from the historic days of Amateur Radio, but I cannot see any reason why the Phone bands should not be as exclusive as the CW subbands!
New to the IARU 160 band plan is the inclusion of “digimode” windows. In creating these new windows, consideration should be given for everyone already on the band before a new exclusive area is created, and this should be done through planning with existing operators (CW and Phone)—rather than dictatorship—or the result will be a real mess and many hard feelings will be created. Before isolat ing several kHz from a prime area, the rule makers should make sure the operators already there (for many years) will have a suitable
place to move and will be found willing to do so. As Tom, W8JI wrote on the Topband Reflector: “We need a long-term plan that does not displace primary users. The IARU needs to seek input for 160 operators before they mess things up for everyone, and cause a lot of hard feelings that last for many years.”
Let’s look at the ARRL-published 160-meter band plan (Feb 2003). For some unknown reason, this is different from the IARU Region 2 band plan (same publication date). The ARRL band plan certainly makes more sense than the IARU-published one when it comes to digital modes on 160 meters.
ARRL Band Plan 160 Meters
1800 to 1810 Digital Modes
1810 CW QRP
1800 to 2000 CW
1843 to 2000 SSB, SSTV and other wideband modes
1910 SSB QRP
1995 to 2000 Experimental
1999 to 2000 Beacons
There is a major problem area in the choice of the frequencies for digital modes in the present (Feb 2003) IARU band plan. This band plan, where digital modes are squeezed in-between the CW and the Phone (+CW) section, is really unacceptable. Once 160 meters is hot again at the bottom of the solar cycle, this band plan is a guarantee for continuous conflicts and battles. The only reasonable solution is to use
1800 to 1810 kHz in Region 2 and 1810 to 1815 kHz in Region 1 (so long as Region 1 does receive 1800 to 1810) for digital modes. I suggest that all readers contact their national radio societies and ask them to submit a proposal along these lines to the IARU HF committee in your Region.
The clear distinction existing between the CW band and the Phone band is, in my view, not realistic during major contest weekends (CQ 160 contests, CQ WW, ARRL 160, etc). It does not make sense to have a rule that nobody follows. Take for example Europe, where today still many countries only have 1820 to 1850 kHz for both modes (CW and SSB). And if they have an spectrum above 1850, then the power there is (or should be) limited to 10 W (Remark S96 of the ITU frequency-allocation table). The IARU Region 1 band plan calls for no phone signals below 1840 kHz (thus, a carrier frequency of higher than 1843 kHz). This means that all these European stations have five “channels” to use for the entire phone contest. This obviously does not make any sense.
It is my opinion that during the major contest weekends the band plan should be set aside. Compare it to the following situation: In Europe most major roads have bike tracks along side major highways. A few weekends every year though, when major cycling events take place (Tour de France, for example), bikers can use the entire width of the road. Let it be like that during a few of the major contests. Why does the band plan allow CW fanatics (and I am one of these) to transmit all over the band, while the poor phone guys, who actually need much more room, can only occupy a small portion (in Europe)? Can’t CW fans relax during two or three contests every year and let the phone guys enjoy their contest?
And can’t the Phone operators relax a few weekends every year when the major CW contests are on? They could take the XYL out for a weekend. Why do some operators have to start QRMing QSOs under those circumstances? It saddens me to see that many people cannot appreciate that other people also want to enjoy
the hobby. Here too, we Top Banders should ask our IARU societies to come forward with more realistic band plans.
Let’s use the entire width of the road when the Tour de France is on! I love the way Mike, N2MG, put it on the Contest Reflector: “A band plan, to me, is a lot like handicapped parking. Nothing is more frustrating than driving around a small parking lot over and over trying to find a place because I don’t want to offend anyone by using one of several empty handicap spaces… When the lot is fairly empty, the dedicated spaces make sense—as do band plans. When at capacity, they do not. Blindly following band plans during a contest is like
telling someone (those supposedly protected by the plan) that their transmissions are more sacred than the contesters.”
It is amazing to see vastly different frequency allocations in an area like Europe, with its many relatively small countries. It looks like politicians and administrators love borders—But they should realize that radio waves ignore borders! If there is one area where legislation should be made at a European level, it is in the area of frequency allocations and power. Let’s all press our national radio societies to talk to the bodies governing frequency allocations to better align the alloca tions and to talk to the politicians to apply European-level rulemaking in this matter. Unless we push, little will happen.
Table 2-2 shows the Top-Band European frequency/ power allocations as of February, 2003. Note that a number of countries have no allocation above 1850 KHz and that most of the countries that do have such an allocation impose lower power limits there. This makes it hard to consider this band section as a DX-hunting ground. Note that according to theITU rules (not merely recommendations) the power is sup posed to be limited to 10 W in those Region-1 countries that make frequencies above 1850 kHz available (Remark S5.96 of Article S5 of the RRS5 by the ITU).
In Europe, most countries today do have a high-power limit, at least at the bottom end of the band (1810 to 1850), where previously many were accustomed to only 10 W! So DX-Operating on the Low Bands 2-5
we should not forget that we have seen dramatic improve ments in the regulatory scene in the past 5 years. There is reason to hope that further improvements can be realized in the next few years.
In Europe 1840 kHz is the usual bottom end of the phone band. But it appears many operators are not aware that if they operate on a carrier frequency of 1840 kHz on LSB their sidebands spread 3.0 kHz down and that they are therefore taking out 40% of the primary DX CW window in Europe. Fortunately, the IARU band plan now clearly stipu lates that the 1840-kHz bottom-end means no one should transmit (on LSB) below a carrier frequency of 1843 kHz.
Note that contrary to what has been done on 80 meters, the IARU never created a DX portion on 160 meters, reserved only for intercontinental work. Common sense, however, has created de-facto DX segments on 160 meters. 1830 to 1840 kHz is generally considered the European CW-transmit segment, while the DX segment of 1820 to 1830 kHz is generally considered the DX window in Europe (that’s where the DX is, and where the Europeans—as well as US sta tions—should stay out of).
DXpeditions seem to use the 1823 to 1828-kHz window most of the time. More recently they have made the wise decision to work on the so-called half-frequencies (eg, 1823.5 kHz). This avoids the spurs and birdies often present in some receivers on even-kHz frequencies. In addition, always avoid 1818 kHz, the W1AW broadcast frequency used for code practice and bulletins. Other frequencies to avoid are exact multiples of 10 kHz (1810, 20, 30, etc) for North American stations and multiples of 9 kHz (1809, 18, 27, etc) for stations in IARU Regions 1 and 3. This is because of BCI images from broadcast stations in the MF band (10-kHz spacing in NA and 9 kHz elsewhere).
While it is true that frequency assignments are not the same in all places, it seems that the minor differences are not a huge problem. Over the years it seems that the different administrations are indeed trying to align themselves.
Band plan for Japan (recently changed):
• 1907.5 to 1912.5 kHz: CW only window (original allocation)
• 1810 to 1825 kHz: CW only (new allocation)hether or not this is an improvement is not clear. It is
obvious that this new window is now clear from low-power
Russian AM-stations, but since most QSOs in the 1810 to 1825-kHz window are no longer made in split-frequency mode, there are now other sources of QRM (the calling stations).
Band plan for Russia, as well as in the CIS (former USSR) countries:
• 1810 to 2000 kHz: CW
• 1840 to 2000 kHz: SSB and CW
Band plan for Australia:
• 1800 to 1810 kHz: Digital modes
• 1810 to 1835 kHz: CW
• 835 to 1870 kHz: SSB. In international contests SSB may be used down to 1830 kHz.
Dennis, KØCKD has compiled a list of the frequency allocations on 160 meters for all countries. See www. machlink.com/~k0ckdennis/index1.html.
4.3.2. Let’s be practical on 80 meters
220.127.116.11 The DX windows:
Although the 80-meter band is not allocated uni formly for all continents and countries, this does not really represent a problem for the DXer. On CW all countries have an allocation starting at 3500 kHz. The DX window for CW is the same all over the world: 3500 to 3510 kHz. A secondary de-facto window exists between 3525 and 3530 kHz, which is the lower limit for General and Advanced Class amateurs in the US.
The SSB 80-meter SSB DX window is 3775 to 3800 kHz. While the 3500 to 3510 CW DX window has been internationally recognized by the IARU in both Region 1 and 2 (see Section 4.1), this is not the case for the Phone DX window, which is only recognized by the IARU as a DX window in Region 1. This is not good, and some alignment in these matters in order.
Fortunately, common sense sometimes achieves more than rules, and in Region 2 and 3 these same 25 kHz are also accepted as DX bands by most operators. Anyhow it’s common sense that reigns, since IARU band plans are not enforced by law in a great majority of countries. It really is a gentleman’s agreement that we should all follow, at least if it makes common sense! If not, we should ask our societies to change their band plans.
In the middle of the day, the DX segments can be used for local work, although you should be aware that local QSOs can cause great QRM to a DXer (at, say, 500 miles) who is already in the grayline zone, and who might just be enjoying peak propagation conditions at his QTH. In Europe situations like this occur almost daily in the winter, when northern Scandinavian stations can work the Pacific and the West Coast of the US at 1300 to 1400 UTC, while Western Europe is in bright daylight and does not hear the DX at all. Western Europeans can hear the Scandinavians quite well, and consequently the Scandinavians can also hear Western Europe well enough to be QRMed. The same is true for NA when Eastern NA local rag chews can interfere with DX for more westerly stations that still have darkness. Hams must be aware of these situations so they don’t inter fere with DXers in other adjacent areas.
Most countries in Western Europe can operate any where between 3.5 and 3.8 MHz, and in most countries there are no mode subbands imposed by the government. The band plan for Russia and CIS countries (former USSR) has changed and is now the same as in all Western European countries.
Band Plan for Western Europe and CIS Countries:
• 3500 to 3580 CW
• 3580 to 3600 RTTY, Packet, CW
• 3600 to 3800 SSB, CW
Band plan for Australia:
Australia has a somewhat peculiar band-plan. The most important change in recent years is the coming expan sion of the SSB DX section from 3775 to 3800 (starting in Jan004).
• 3500 to 3700 and 3795 to 3800 CW
• 3535 to 3620, 3640 to 3700, 3775 to 3800 SSB
• 3620 to 3640 Digital modes
Band plan for Japan:
• 3500 to 3520 CW only
• 3520 to 3525 Digital modes and CW
• 3525 to 3575 All modes
• 3747 to 3754 kHz All modes
• 3791 to 3805 kHz All modes
Band plan for the USA:
Since the FCC decided to expand SSB privileges in the US, first to 3775 and later to 3750 kHz for Extra-Class amateurs, the DX window has de facto expanded from below 3750 to 3800 kHz during openings to the US, although the top 25 kHz is the focal area.
18.104.22.168. Recommendations for 80 meters
Many amateurs are unaware that 80 meters is a shared band in many parts of the world. In the USA, 80 meters sounds like a quiet VHF band compared to what it sounds like in Europe. Because of the many commercial stations on the band in Europe, the 25-kHz DX window can often hold only five QSOs in-between the extremely strong commercial stations in the local evening hours. If you are fortunate enough to live in a region where 80 meters is either exclusive or not heavily used by commercial stations, please be aware of this and bear with those who must continuously fight the commercial QRM.
Fortunately there is a common (IARU) DX window in Regions 1 and 2, but this is not enforced and is not respected by all. US stations complain bitterly about poor cooperation from rag chewers (“pig farmers” as they’re sometimes called in the US), who have another 200 kHz that could be used for their local contacts.
The increased popularity of 80-meter DXing, together with the few DX channels available in the phone DX window, have created a problem where certain individuals would sit on a frequency in the DX window for hours (it seems like days) on end, without giving anyone else a chance. This problem is nonexistent on CW, where you have an abundance of DX channels in the DX window. This situation is also an excuse for creating DX nets, where ethics are not always the highest.
4.3.3. Let’s be practical on 40 meters
Forty meters is pretty straightforward. CW DX QSOs all happen between 7000 and 7010 kHz, with rare exceptions around 7025 kHz. Although no formal DX subband has been created by IARU, the 7000 to 7010-kHz window is the defacto DX subband on 40 meters.
In the European or non-US phone band, being as narrow as it is, you can find DX anywhere between 7040 and 7100 kHz, with 7045 to 7080 kHz as the prime focal area.
The big news for radio amateurs coming from the 2003 World Radiocommunication Conference is that there will be a dramatic improvement in the 40-meter band soon. The conference agreed to shift broadcasting stations in Regions 1 and 3 out of the 7100 to 7200-kHz band and to reallocate the band to the Amateur Radio service. The allocation in Region of 7000 to 7300 kHz remains exclusively Amateur. The broadcasting band in Regions 1 and 3 will become 7200 to 7450 kHz and in Region 2, 7300 to 7400 kHz. The changes will take effect on 29 March 2009. How the IARU societies will handle band planning is not certain at the time of writing.
5. SPLIT-FREQUENCY OPERATION
The split-frequency technique is highly recommended for a rare DX station or DXpedition working the low bands. It should logically also be the way we work DX on 160 meters. Signals on Top Band are often so weak that working split should really be the rule rather than the exception!
It is the most effective way of making as many QSOs as possible during the short low-band openings, because the marginal conditions often encountered are conducive to chaos if stations are calling the DX on his frequency. It also gives a fair chance to the stations that have the best propagation to the DX station. With list operations this is not necessarily so, and stations having peak propagation can bite their fingernails off while the MC is passing along stations who barely make contact and have to fight to get a 33 report. With split
opera tion the DXer with a good antenna and with good operating practice is bound to have a lead over the modest station. This is only fair. Why else would we build a station that performs better than the average?
There are two good reasons for the DX station to work split frequency:
1. First he must realize that when he stops his CQ, there are likely to be many stations calling him. Though he might pick out a good strong signal, others may still call him, and his reply to a particular station may be lost in the QRM. This will result in a slow QSO rate, even though the DX station hears the callers well. If he works split, the callers will have more chance to get the DX’s reply right the first time. The reason here is obviously that callers cannot cope with the QRM they are creating themselves on the DX’s frequency. In this case the DX station should simply specify a single frequency (eg, up 5) where he will be listening.
2. Another reason is that there are such large numbers of stations calling the DX station that the DX cannot dis criminate the callers. In this case it is the DX station that will not be able to handle the situation without going split. In this case he will specify a frequency range where he will be listening, in order to spread out the callers, and make the layer less thick.
A few general rules apply for split-frequency operation:
1 . If possible, the DX station should operate in a part of the band where the stations from the area he is working cannot operate, or in a section of the band that is generally considered the DX section.
2. The DX station should indicate his listening frequency at least every minute. It only takes a second to do so, and it goes a long way toward keeping order.
3. The listening frequency should be well outside the DX window. Too often I hear a DX station on 3503 listening 5 up, ruining a major part of the DX window. There is no reason why he should not listen 10 or 20 up. The same applies to phone operation, where the DX station trans mitting in the window should listen outside the DX window for replies.
4. If the DX station is working by call areas, he should exercise authority to reject those calling from areas other than those he specifies. He should not stay with a particular call area too long. At five stations from each area, at a rate of three QSOs a minute (that’s fast!), it takes almost 20 minutes to get through the 10 US call areas!
5. The DX station should check his own part of the world to make sure the frequency is clear. This can be done periodically, especially if there is a sudden drop in QSO rate. Changing the transmit frequency a few kHz may bring relief.
6. If the DX station’s listening frequency is being jammed, he should specify a frequency range instead of a single listening frequency.
7. On CW the split should be at least 5 kHz. For splits less than 5kHz the pileup’s key clicks are likely to spread onto the DX-station’s frequency.
8. Depending on the band plan in the country of the DX station, split-frequency operation may be unavoidable. This is the case when working the US from Europe on 40-meter phone. Under such circumstances, always make it a point to indicate your receiving frequency accurately, and make it a single frequency. If the pileup is too big, make it a reasonable range—10 kHz is usually sufficient. There is really no need to take more of the frequency spectrum than is absolutely necessary. (However, one valid reason to use a wider range than normally necessary is to elude deliberate jammers.)
9. Don’t forget that the quality of the operator at the DX end (or DXpedition) is often judged by how wide a listening range he needs to handle the pile-up!
Some time ago I read on the Topband Reflector: “I’ve never seen the reason to operate “split frequency” unless the country’s band plan does not allow a station to operate on a desired frequency used by another country. I see no reason for a DX station to transmit on one frequency, listen on another and have a bunch of folks that didn’t hear the frequency change transmission clutter up the band calling blindly on 2 or 3 different frequencies.” W4ZV refutes this statement as follows: “The DXer realizes that his signal is weak compared to the hordes calling. In light of the increased numbers of callers brought by packet spots, this is even more understand able. He understands that HIS signal is apt to be covered up by those stations. Since many callers have adopted the ‘call until doomsday’ technique, the DX is much less likely to complete a QSO within a reasonable period of time.
Spreading the pile has only one goal: to make it more likely for the DX-station to pull a call out of that mass of noise… The split frequency method attempts to make the pileup more efficient and to work the maximum number of stations in a given period of time. In some latitudes, that window of opportunity can slam shut very quickly. The DX op may grow weary of getting up well before dawn for mornings on end in order to be able to log just a few QSOs even though he hears a swarm of callers…What we need to do
is listen to what the DX op wants. If it appears at odds with your personal operating ethics, don’t call him. If you’d like to be in his logs, follow his instructions and observe what he is doing. What we really need is some restraint on the part of callers when the DX station comes back to someone rather than a continuation of this mindless calling, calling and calling.”
Tom, W8JI’s comments on this same subject are: “The real problem is many people who rarely work 160, or who are parked on a coastline with all the US behind them, think 160 is like 80 or 40. Factually if you are inland, DX signals are not that strong and local signals are devastating. 160 is a band where DX should always be split, unless it is a ragchew among friends. This is especially true in contests. Simplex DX opera tion in a 160 contest is just plain silly, unless we want only the big stations to work DX.”
Who am I to argue with such arguments? The question is to which extent this can really be realized (see also Section 20).
5.1. 160 Meters
Rare DX stations should as a rule operate split fre quency. The generally accepted transmit window for the DX stations is 1820 to 1830 kHz, with 1822 to 1828 kHz as the most popular range. It is good practice to use half frequencies; eg 1823.5, 1824.5 kHz. (See also Section 4.1.)
JA stations now can use 1810 to 1825 kHz, in addition to the old 1907.5 to 1912.5-kHz window (both CW only). You should stay out of the 1810 to 1825-kHz window for every thing except for JA stations during the opening hours between Japan and the USA or Europe. JA stations should always work split frequency to keep the EU or USA stations out of their window so that their strong local signals don’t cause havoc.
JAs should listen above 1830 kHz. For European and US stations: Never call JA stations on their frequency. Force them to go split frequency. They will be happy to listen above 1830 and this will greatly improve the QSO rate.
If you want to call CQ JAPAN, do it above 1830 and indicate your listening frequency either as “QSX 15” or simply as “DWN 15.”
I’ve seen some advocating the use of split frequency during contests. Nowadays our narrow 160-meter band is already fully congested during these contest periods. If we all take two channels for a QSO it will become much worse. Split frequency during contests is not realistic to me, despite what the ARRL band plan advocates.
5.2. 80 Meters
On CW the main reason for the DX station to go split is when the pileup gets too big. Another nice reason for the DX station to listen “up 25” to cover General-class stations in the US.
On SSB I can think of many good reasons to go split: in the first place, not to occupy the DX window more than necessary. Therefore the DX station should always indicate a listening frequency outside the DX window (below 3750 kHz). US stations wanting to work Europe should transmit above 3800 and listen below 3750 to keep the DX window as uncongested as possible.
Middle-East stations should transmit on a frequency below 3750 kHz when working North America to avoid QRMing European stations. Stations in the Pacific working Europe should transmit above 3800 kHz and listen below 3800 kHz to avoid US QRM.
It is not reasonable for a European to transmit inside the US phone band (3780 kHz, for example) and listen on 3805 kHz. If this is done, two windows inside the US subband are occupied for one QSO, and the potential for QRM and confusion is increased. The inverse situation is equally undesirable.
Every year I hear hordes of European stations trying to work USA stations in the ARRL DX phone contest in the shared band 3750 to 3800 kHz, where they must overcome local US and Caribbean-made QRM. I always enjoy doing the contest just below 3750, listening above 3800 kHz, and never have any such problem.
5.3. 40 Meters
The nature of the pre-WRC2003 frequency allocations in different regions made split-frequency operation a very common practice on 40-meter phone. After March 29, 2009, a new nternationally agreed band plan will come into effect. It seems that finally Europe and the USA will be able to work each other on SSB without having to go split.
Until March 2009, however, US stations in the 7150 to 7300-kHz window should be aware that they operate in the midst of very strong broadcast stations in Europe. These broad cast stations are not on the same frequency 24 hours a day, and what may be a clear frequency one minute can be totally covered by a 60-over-S9 BC station the next minute. These BC stations usually appear on the hour or on the half-hour. Especially in contests, make sure your supposedly “clear” transmit frequency remains clear! During contests various DX stations may be using the same listening frequency when working split. Therefore it is essential that the caller not only gives his own call, but also the call of the station being called. Going just by timing does not always guarantee a real QSO.
Not only the BC stations cause problems, but also non-Amateur-Radio phone traffic between 7000 and 7100, much of which comes from Mexico and South America. Many pirate stations transmit on channels that are organized in 5-kHz steps. Therefore it is a good idea for the DX station working the USA to try multiples of 2.5 kHz to avoid this kind of QRM.
5.4. DX Subbands in 160-Meter Contests?
Over the past years we’ve seen rules for DX subbands on 160 meters come and go. This is especially a critical issue on Top Band, since local stations are extremely strong and DX stations are usually very weak, much more than on 80 and 40 meters.
The classic scenario we had on 160 meters was to reserve 1820 to 1830 kHz only for a DX station to call CQ Contest, after which others could reply to his CQ. The problem is “What is DX?” Usually DX means a station outside your continent. This means a P4Ø or a PJ2 in South America could sit in the DX window and works hordes of US stations in North America, while a KP2, FM or FG cannot because they are also in North America.
And when the band is open between US and Europe who’s DX? The Ws are DX to me and I am DX to the Ws, so who should be in the DX window? What should I do if I’m in the window and a
European comes back to me—He may even be a new multiplier for me. Typically he is just a nice guy, who wants to give me some points. I could ignore him but he will probably keep on calling. So do I have to chase him off with a curt “QSY—I can’t talk to you.”? That’s not a very nice thing to say to someone who’s new to the game or who just is trying to do me a favor.
Well, how about considering two windows—one where the USA can call CQ, and one for Europe. But where should the Africans and others go in this scenario? Well, then I guess we need four DX windows, one each for the USA, Europe, Africa, and Asia (the Pacific can use the European window since opening times do not really overlap). But the 160-meter CW band is only 30-kHz wide. Let’s see; we can reserve 10 kHz for Europe, another 10 kHz for the USA, and 5 kHz each for Asia and Africa. But that does not solve the prob lem—Where do the European stations go that want to work Europe? And how about the US stations that want to work US stations? They can do it in the US window, which means they will have 10 kHz, and they will all be sitting one on top of another in this crowded space. Impossible! All of that chaos, while the African and the Asiatic windows will be half empty with the small amount of activity from there.
Well, maybe, we could give zero points for working your own continent. That would be the end of my contesting on Top Band. I don’t want to spend 30 hours working only 150 DX stations outside of Europe. That would be really boring. Today we have a vibrant and exciting worldwide contest for everyone to participate in. If we make it a pure DX-to-DX contest it would be a dull, boring and insignificant contest.
So, let’s forget about these DX windows and find technical solutions to the problems we face on Top Band. Let’s clean up our transmitted signals and use better, more directive and more selective receiving antennas. Let’s concentrate our energy on creating solutions rather than workarounds. more I think about it, the less sense these DX Windows make to me. Considering all of the above it looks like it was a wise decision for CQ 160 to abandon the DX Window.
6. RIT (THE CLARIFIER)
Zero beat is a term indicating that the two stations in contact are transmitting on exactly the same fre quency. Unless working split frequency, it is common practice to zero beat on phone. The RIT (Receiver Incremental Tuning, also called the receiver Clarifier) on some older transceivers created problems where stations in QSO drifted apart, after which the operator used RIT to compensate. They would be better off making sure that they stayed on the same frequency.
Fortunately, modern equipment is practically immune to frequency drift, so this is not as much of a problem as it used to be, especially with some of the home-built equipment of old. Bill, W4ZV, recommends checking your actual transmit frequency with a separate receiver, especially when you get a new transceiver, to make sure you are placing your TX signal where you think you are! He added “My 1000MP has some quirk I have never figured out which makes me need to add70 Hz to the TX frequency to be zero beat.”
As an example of where this is a problem, let us assume station A does not have a stable VFO. If station A and station B start a QSO at zero beat (both on exactly the same frequency), there are three sequences of events that a monitoring station might observe:
1. Neither station uses RIT: One station always follows the other. The QSO may wander all over, but at least there will be no sudden frequency jumps when passing the microphone, and the QSO will be on one drifting fre quency.
2. One station uses RIT, the other does not: If we are still listening on the same frequency that the QSO began on, there will be a frequency jump at the start of transmission of one of the stations, but not for the other station. The QSO will still drift.
3. Both stations use RIT: Again, if we are listening on the original frequency, there will be a frequency jump at the start of transmission for both stations, and the two stations may drift away from one another. The QSO will take up more space on the band, and it will be very annoying to listen to. Should RIT be used in such a case? Decide for yourself.
Some recent transceivers not only have an RIT control but also an XIT control (TX clarifier). This one makes things even more complicated. Be careful when using XIT. There are some instances, however, where RIT can be a welcome feature:
1. Some operators like to listen to SSB signals that sound very high-pitched, like Donald Duck. That means that they tune in too high on LSB. To the other operator, their transmission will sound too low-pitched, because they are no longer zero beat. Tuning in a station using RIT will allow one to listen to the voice pitch he prefers, while staying zero beat with the other station(s) on frequency.
2. When trying to get through a pileup, it can be advanta geous to sound a little high in frequency. Adjusting the RIT slightly in such a case will yield that result.
3. Let us assume our transceiver is designed for working CW at an 800-Hz beat note, and it is only when listening at this note that the transmit frequency will be exactly the same as the receiving frequency. You can use RIT to offset the transmit frequency (by, say, 300 Hz) to bring the note down to 500 Hz, and still transmit on the receiv ing frequency. So you can see that RIT can be a useful feature without creating unnecessary QRM at the same time.
As previously stated, except for intentional split frequency operation, most DX QSOs on 80 meters are on one frequency. There is no need to waste space on the band by working a station slightly off your frequency.
By the way, I never use the RIT on my transceiver. So far as I am concerned, the modern transceiver with dual VFOs simply has no need for RIT or XIT. My FT1000 second VFO is, under normal circumstances, my TX VFO, and I can do all the tuning around I want with the first VFO without changing my transmit frequency. Why would I want to use that tiny RIT knob when I can use the big main knob?
7. ZERO BEAT
The terminology zero beating stems from AM days. On AM one used to really zero-beat. When the transmitter VFO is tuned to the receiving frequency, a beat note is produced. This audio note is the mixing product of the two signals. When the beat tone becomes 0 Hz, the transmitter and receiver are on the same frequency.
On CW, most transceivers are designed so you are transmitting on the same frequency as the station you are working only if the beat note is some specific frequency. With older varieties of transceivers this was a fixed beat note, usually 800 Hz. This beat-note frequency is usually specified in the operating manual. Because many hams do not care for the specified 800-Hz beat note, they just listen to what pleases them (450 Hz is my preference). As a result of this, those operators are always off frequency by 350 Hz or so on CW. This is not a problem if the receiving station uses a 2-kHz filter, but it could be a real problem if he uses a 250 or 500-Hz filter. Also, think of all the wasted space on the band. This is the reason that in the past I advocated the use of a separate receiver and transmitter on CW. Then, at least you could really listen to your own frequency!
More modern transceivers on CW provide for operating right on frequency. A good transceiver should at least have an adjustable pitch control. The CW monitor note should also shift accordingly—continuously adjustable down to 200 Hz is the best. Some people like to listen at very low pitches. (W4ZV likes 250 Hz.) The only precaution here is to tune in the station you want to work at exactly the same beat note as your CW monitor note. That’s all there is to it. This way, you can get easily within 50 Hz of the other station and still listen to your preferred beat note.
There is a lot of personal preference involved in choosing the beat note itself. It is very tiring to listen to a
beat note higher than 700 Hz for extended periods of time. The ability of the ear to discriminate signals very close in frequency is best at lower frequencies. For example, listen to a signal with a beat note of 1000 Hz. Assume a second signal of very similar signal strength and keying characteristics starts transmitting
50-Hz off frequency (at a 950-Hz or 1050-Hz beat note).
Separating these two signals with IF or audio filters would be very difficult. Let us assume we have to rely on the “filters” in our ears to do the discrimination. The relative frequency difference is:
⎛ 1050 −1000 ⎞
⎜ ⎟ ×100 = 5%
⎝ 1000 ⎠
If you were using a 400-Hz beat note, the offender would have been at 450 Hz (or 350 Hz), which is a 13% relative frequency difference. This is much more easily discernible to the ear.
It’s a good idea to do some checks with a local station (or with a second receiver) to make sure you are truly “zero beat” on CW. This will save you lots of frustration. In contests I have often cleaned up my QRG and worked even the very weak signals, only to find out that there was a guy with an S9 signal calling me 400 Hz up. He was strong but I never heard him, while I easily worked stations that were 40 or 50 dB weaker than he was…
ON4UN, John Devoldere