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In the years before amateurs in the UK had access to the 630m band as we know it today (472-479kHz), hams there could apply for a 'special research permit' allowing them to operate between 501 and 504kHz.


One of the first and most active stations was operated by Finbar O'Connor, EIØCF, located in the most northern part of Ireland, near Malin Head. In the early days, Finbar might as well have been AC4YN in Lhasa, Tibet, as a 630m or a 2200m QSO with EIØCF was a much prized DX trophy and a genuine 'right of passage' for many little backyard LF and MF stations throughout Europe.

Nowadays, 630m activity in Europe is not as robust as it once was but Finbar is still active on MF from his modest station. He reports being copied in North America on several occasions. Although mainly active in the WSPR mode, Finbar is now considering the two-way JT9 weak signal QSO mode and may hopefully once again, tease east coast North American MF operators with a new rare entity from his seaside location.

Finbar's WSPRlite setup for 630m

Over the years, EIØCF has gone portable as well as marine mobile to demonstrate the viability of this part of the spectrum for very reliable groundwave comms using equipment that is both simple and quick to deploy. Although he used a CW-based system, his conclusions could just as easily apply to SSB or digital modes.

EI0CF/marine on 630m!

What follows is a delightful adventure, in Finbar's own words, describing some of his field trips back in the 500kHz experimental days ... perhaps it will inspire some North American portable work or provide ideas for an emergency prep 630m grab-and-go kit, or just get you excited about our newest amateur allocation.


                                    ******************
              Operating Portable on 501 - 504 khz Medium Wave



Operations on the north flank of Slieve Snacht Inishowen Peninsula.

In June 2009 Ireland joined a growing number of countries permitted to operate on a small portion of the medium wave band, just below the commercial broadcast segment, in the range 501 - 504 khz. Several stations were granted permission and operations commenced. As has been documented elsewhere many stations have been worked, both in band and cross band, at home and abroad, ranging from Continental Europe, across the Atlantic to the USA and Canada, down to the southern end of Ukraine and finally up to Iceland, Norway, Sweden, Finland and also being heard in Moscow.

A notable feature of this band is the steady reliable nature of groundwave coverage and with this in mind I recently availed of the facility whereby portable operations can take place. Comreg, together with the IRTS and the individual involved, require that each event is applied for, giving relevant dates, location, contact details, hours of operation and the power of the transmitter being used.

In the period leading up to all this it was necessary to build and test a viable portable station based on the use of my Berlingo van. A 30' part of a 40' Spiderbeam fibreglass  pole was used with a simple round wooden peg to secure the 'Tee' wire antenna, which was fabricated from twin twisted multistrand speaker wire. The vertical used both, while the rest was pulled apart to form the two horizontal legs.

A 100 metre roll of 1.5 mm insulated earthing wire was cut into 16 lengths to provide radial wires, with lugs soldered to one end and a bonding bolt used to secure a single point for the radial kit. The far ends formed a small loop which was sealed and secured with insulating tape. The loop provided an eye for a small L shaped stiff wire, fashioned from discarded coat hangers, an ideal and cheap way to hold the ends of the radial wires in place in the ground.

To secure the antenna support to the van, I refer you to the excellent idea described by John EI7BA, on his web page, for a ball hitch connection:

http://www.qsl.net/ei7ba/a_ball_hitch_mobile_mount.htm

Using this superb idea, I got the welder out and made one for myself. It worked perfectly.

I now had the support and wire antenna, with a ballpark figure for what might resonate, along with the radial kit. I next needed a dedicated antenna tuning unit. An old variometer and two extra fixed multitap coils were selected. A home made 1 amp ammeter and SWR twin meter unit completed the fit-out. These were all assembled on a base with a handle on the top, making it easy to move around whilst out and about.

The main antenna for 500kHz was disconnected and left floating and the van set up with all this gear, but no transmitter. Instead, my little antenna bridge running off a 9-volt battery provided the necessary signal to start testing for basic resonance.

Whether from sheer good luck or some sub-conscious input, resonance fell within the range of the variometer with only one of the two extra coils in circuit. The relative height and length also play a part in the range of resonance secured. Matching to 50 ohms was then optimized by selecting 4700 pf Mica capacitors using Croc Clip links. The available value ranged from 1 nF to 14 nF.

I have a selection of 500khz transmitters, two of which are to the design of Roger, GW3UEP, who lives 10 miles inland from the coast, in south Wales. His 500khz web site is well worth checking out, containing plans for versions of his 500khz transmitters, test equipment pictures and recordings of 500khz activities.

http://www.gw3uep.ukfsn.org/

One of these was used to put some RF into this first portable style installation, and by arrangement, Roger listened and heard my signal. We delightedly completed a short contact, with my transmitter running just 10 watts.Things were looking good.

One of the very valuable things about portable operations stems from the need to bring together several elements to secure a working radio station, without the usual backup we enjoy from home. Planning is essential. Doing a dry run, i.e. actually physically building the intended station then notating all the gear required and making a list as well as providing backup items, particularly those that which if broken or lost, would render the whole radio station non-viable. This also extends to the operator of the equipment. Will they be warm or cool enough, have shade, food, water and enough needed rest? Always be prepared to abandon the project if safety is compromised, for whatever reason.



Now that I had a viable portable station for 500kHz working, it was time to head off and test both the equipment and myself in the real world, but without any live transmissions taking place.

Several sites were chosen and tested, with particular emphasis placed on remoteness, i.e. high up on mountains or near the sea. All sites worked very well, but those by the sea proved really excellent. Reception of NDB’s (Non Directional Beacons) provided a ready supply of medium to low frequency signals for range testing. I was now itching to “ have a go “ out in the wilds, on 500kHz! Using the method required by Comreg, an application was made for several sites, on specific days.




In early June I loaded up the van with all the gear and headed off for the mountain above Redcastle, County Donegal. Using a narrow track and climbing higher, to about 270 meters, a place was found leading to an old quarry. Typically, it had started to rain. By the time I had erected the support pole, pulled out and secured the top hat wires using light nylon line and deployed the radial wires around and below the vertical drop wire, my trouser ends were very wet!

Plugging in the 12-volt supply, the receiver was very quickly perked up, using the variometer. The Morse key connected to the QTX transmitter and the transmit / receiver switch flicked over. Time to get some RF flowing in the antenna. Sure enough, on key down, the antenna current meter shot right up to 400 mA, but the SWR match was not exactly perfect. Time to work those Croc Clips and start selecting shunt capacitors to find the perfect match. Soon I had that sorted to my satisfaction, with antenna current now up to 550 mA. A quick return to receive showed that Roger, GW3UEP was already tuned up on frequency.




"..... GW3UEP DE EIØCF/P HW K"

He came back straight away! Oh joy, we were on the air on 500, in a remote mountain area, the top of my antenna almost tipping the clouds as they swept past. I was open to the elements, standing at the back door of the van with the tips of my fingers reaching for the knob of my very favourite old Amplidan morse key, snug beside the other bits and pieces of equipment on the van floor!

My logbook, with its pages flapping back and forward in the wind, soon had the first 500kHz portable contact documented. A full hour later, solid steady signals continued at a distance of 250 miles. Proving just how good groundwave signals can be, I terminated communications from the remote portable location, happy with the results. Within 12 minutes I had dismantled the station and was on my way to Moville, along with a strong cup of coffee at the café on the town's main street.

Several other portable operations have since taken place. A number have also occurred at my home location. We live right beside the sea; high tides lap up on to the salt marsh, which is part of the property.




Driving a single earth rod into the sea shore to a depth of 1 metre, with no radials and just a single wire between the rod and the ATU earth, the 1 amp RF meter had its meter needle slamming against the end stop. Lots of antenna current for 15 watts transmitter output power. Those same 15 watts only providing, at best, 550 mA, whilst up on the mountain sites.

Finally, it was thought productive to try a kite-supported antenna from the seashore portable set up. Winds on the day selected seemed strong enough to enable my Delta shape kite to head aloft with a flying line and antenna wire attached. The Berlingo van was driven down on shore, everything connected and tuned up. All was well, or was it?

The receiver now seemed quite dead with no band noise and no antenna current on transmit. Looking skywards I could see nothing. My eye followed the antenna wire heading for deeper water. Then I saw it. The kite had plunged into the sea! The following 30 minutes entailed untangling loads of seaweed with the line wrapped around rocks, barnacles and everything imaginable. What a mess! I almost gave up, but knew that Roger would be coming up on frequency, on sked, in about 15 minutes.

Eventually I managed to get the kite skywards again but by now the wind was acting more unpredictably. I established contact with Roger and he immediately gave me an S 7 report for my 15 watts. This equated to the report I would get from my main station antenna running 100 watts. My single ground rod and 150 feet of wire were doing the business.

We carried on our contact, but what remained became a battle of wits, with a kite constantly diving down and soaring up again. Several times the antenna wire was in part lying on the sea shore and antenna current way down to 200 mA or lower. My left hand was on the variometer tuning knob, tweaking the setting as best as possible, while pulling in the slack to keep the antenna wire off the ground. Feeding the wire out again to a misbehaving kite, I kept keying away with my right hand, keeping Roger updated so he could understand why my signal was changing both in pitch (sudden antenna mis-match conditions) and signal strength.

Luckily he was also making a recording, which proved later to be a fascinating record of a difficult portable antenna and station operation. It’s remarkable how tolerant, despite the wildly changing antenna conditions, the system actually was in practice. Communications were maintained despite all these negative factors and severely decreased radiated power at times.


Several other tests were conducted within these experiments which would have been almost impossible to conduct without the challenges thrown up by my portable operations. To my mind the 501 – 504khz band exhibits a distinct advantage for enhanced groundwave coverage over that available to higher frequencies.

Relatively simple equipment deployed in remote locations, with or without the availability of the power grid, would provide a solid backbone link or network in times of emergency. Transmitter power output was kept deliberately low to ensure that a higher ERP would not mask any possible weakness in the system. I am happy to conclude that Medium Frequency CW proved it’s worth once again.

Already I have further plans to test smaller, more compact portable antenna and earthing systems in more remote locations.

Finbar O’Connor EIØCF Malin, County Donegal.

YLD - 335kHz courtesy: http://www.ve3gop.com/

This coming weekend will see another monthly CLE challenge. This time the hunting grounds will be 335.0 - 349.9 kHz.

 





For those unfamiliar with this monthly activity, a 'CLE' is a 'Co-ordinated Listening Event', as NDB DXers around the world focus their listening time on one small slice of the NDB spectrum.

A nice challenge in this one is to hear YLD - 335, located in Chapleau, Ontario.

'YLD' runs just 100W into a 100' vertical but is well-heard throughout North America and many parts of Europe under the right conditions. Listen for its upper-sideband CW identifier (with your receiver in the CW mode) on 335.415 kHz.

Summer lightning storms may provide additional listening challenges but today's lightning map of North America looks surprisingly quiet ... maybe we will get lucky. It can't however, be any worse than last month's CLE, where widespread lightning was reported by almost every participant.!

courtesy: http://thunderstorm.vaisala.com/explorer.html

If you are interested in building a system for the new (U.S.) 630m band, the CLE will give you the chance to test out your MF receiving capabilities and compare against what others in your area might be hearing.

When tuning for NDBs, put your receiver in the CW mode and listen for the NDB's CW identifier, repeated every few seconds. Listen for U.S. NDB identifiers approximately 1 kHz higher or lower than the published transmitted frequency since these beacons are modulated with a 1020 Hz tone approximately.

For example, 'AA' near Fargo, ND, transmits on 365 kHz and its upper sideband CW identifier is tuned at 366.025 kHz while its lower sideband CW ident can be tuned at 363.946 kHz. Its USB tone is actually 1025 Hz while its LSB tone is 1054 Hz.

Often, one sideband will be much stronger than the other so if you don't hear the first one, try listening on the other sideband.

Canadian NDBs normally have an USB tone only, usually very close to 400 Hz. They also have a long dash (keydown) following the CW identifier.

All NDBs heard in North America will be listed in the RNA database (updated daily) while those heard in Europe may be found in the REU database. Beacons heard outside of these regions will be found in the RWW database.

From CLE organizer Brian Keyte, G3SIA, comes the details:


Hello all

Here are the full details for this weekend's co-ordinated listening event.
It is open to everyone including CLE new-comers:

Days: Friday 22 June - Monday 25 June
Times: Start and end at midday, your LOCAL time
Range: 335.0 - 349.9 kHz

Wherever you are, please join us and log the NDBs that you can positively
identify that are listed in this busy frequency range (it includes 335.0 kHz
but not 350 kHz) plus any UNIDs that you come across there.

Send your CLE log to the List, preferably as a plain text email
(not in an attachment) with "CLE233 - FINAL Logs" at the start of its
subject line.

Please show on EVERY LINE of your log:
# The date ( e.g. 2018-06-22 or just the day no. 22 ) and UTC
(the day changes at 00:00 UTC).
# kHz (the beacon's nominal published frequency, if you know it)
# The Call Ident.

Show those main items FIRST on each line, before other optional details
such as Location, Distance, Offsets, Cycle time, etc.
If you send any incomplete logs to the List during the event, please also
send your 'FINAL', complete one.
Please always make your log interesting to everyone by showing your
own location and brief details of the receiver and aerial(s), etc., that
you were using.

We will send the usual 'Any More Logs?' email at about 17:00 UTC on
Tuesday so that you can check that your log has been found OK.
Do make sure that your log has arrived on the List at the very latest
by 08:00 UTC on Wednesday 27th June.
We hope to complete making the combined results on that day.

You can check on all CLE-related information from the CLE Page
http://www.ndblist.info/cle.htm
It includes a link to seeklists for the Event from the Rxx Database.

Good listening
Brian
----------------------------------------------------------
From: Brian Keyte G3SIA ndbcle'at'gmail.com
Location: Surrey, SE England (CLE coordinator)
----------------------------------------------------------

(REMINDER: You could use any one remote receiver for your loggings,
stating the location and owner - with their permission if required.
A remote listener may NOT also use another receiver, whether local
or remote, to obtain further loggings for the same CLE). 
-------------------------------------------------------------------

So I'm driving to work this morning; and when you commute to work every day, you get a real good chance to look at the behinds of cars that are in front of you.  As I come to a red light and come to a stop, I notice the car in front of me has one of those vinyl decals on his rear window.  It looked like this - but you have to picture in your mind's eye that this was all surrounded by the entire darkness (blackness) of his tinted rear window.

Over the past few years, the Reverse Beacon Network (RBN) has been utilized by thousands of amateurs to gauge the performance of their antenna systems, to check propagation or to compare their station's antenna performance against another nearby amateur's system.



For those not familiar with the RBN, it is the opposite of a network of 'on-air beacons' and consists of a network of 'on-air receivers', usually SDRs, that automatically skim a wide range of frequencies within the CW bands and report back what they hear, along with a definitive signal strength report ... all posted immediately back to a central website where you can read the data from the various stations that have heard your signal. Calling 'CQ' or sending a few 'TEST de' signals, followed by your call sign, will trigger the desired network response.

I have recently been testing a new 40m antenna, an inverted-V dipole at 80', against my long-used half-sloper, but have been using a different online receiver network to make my real-time comparisons ... the KiwiSDR receivers, mentioned in previous blogs. I'll have more to report about the new antenna and its performance in an upcoming blog, once everything is finished and the antenna is fully optimized.


When it comes to real-time 'A-B' antenna comparisons, I found the KiwiSDR network much more interesting and informative than using the RBN. If hard data is what you want, then the RBN will provide it, but not in the same real-time, 'A-B' style that the Kiwis can offer. Once set up so that the two antennas may be fast switched, 'A-B' style, you can actually hear the difference immediately, with your own ears, as if sitting at the online receiver hundreds or even thousands of miles away. By sending a continuous series of dashes while switching between antennas, the comparison can be strikingly obvious, as the propagation variances experienced in an RBN comparison are no longer a factor. One might argue that using longer RBN comparisons, averaging the signal strength over a period of minutes, may yield a truer picture of antenna performance ... but this method lets you hear the second-by-second differences as they happen.
 
My antenna testing is not yet complete, as much of the initial time was spent trying to determine which online receivers were suitably quiet enough to utilize. Many of them were rejected for being far too noisy to be useful while many others were found to be ideally quiet. I am slowly working my way through the list!

So far, I have been able to listen to my transmitted signal and compare the two 40m antennas on numerous receivers from coast to coast, both near and far, as well as into the Caribbean and South America. I have found the best power to use is between 1 and 5 watts, as making the signal intentionally weak at the receiver end makes subtle differences of just a few db easier to detect.

The gathering comparisons are fascinating as often the signal strengths between my two antennas are very different. Often the sloper and the inverted-V are neck and neck, while in different directions or at different distances, one or the other is a clear winner. On many far-off receivers, I was easily able to detect my signal with all power controls set to '0' with no indication of any output showing on my meters, a rather surprising observation and another reminder of how RF just loves to radiate ... even at very low levels!

If you want to try this yourself and can quickly switch antennas 'A-B' style, here are the direct links to a few of the receivers that I have found to work very well so far ... with low noise levels and no man-made crud, while listening on 40m.

KA7U SDR - Idaho

K1RA/KW4VA - Virginia

W0AY - Montana

K2SDR - New Jersey

G8JNJ - England

K2ZN - New York

WA2ZKD - New York 

KD4HSO - Kansas

VE6JY - Alberta

W3SWL - Pennsylvania

N6GN - Colorado

N8DTT/6 - California

VE6JW - Alberta 

Kingwood - Texas

TWR - Bonaire

EA8DGL - Canary Islands

Wellbrook ALA1530LNP - Southern Finland

NO2CW - Florida

Pardinho - Brazil

I will continue to update this list as more receivers are tested ... now back to some outdoor antenna tweeking!

YEK - 329kHz courtesy: www.ve3gop.com/

This coming weekend will see another monthly CLE challenge. This time the hunting grounds will be 320.0 - 334.9 kHz.

 

For those unfamiliar with this monthly activity, a 'CLE' is a 'Co-ordinated Listening Event', as NDB DXers around the world focus their listening time on one small slice of the NDB spectrum.

 


A nice challenge in this one is to hear the Arviat NDB, located in Nunavut on the western shores of Hudson Bay. 

'YEK', on 329 kHz runs 500W into a 100' vertical and it's well-heard throughout North America and many parts of Europe under the right conditions. Listen for its upper-sideband CW identifier (with your receiver in the CW mode) on 329.421 kHz.

Propagation has been very good on the MF band recently but at this time of the year, good listening is often hampered by a lot of lightning activity. Hopefully that will not be the case this coming weekend but today's map shows what we may be up against!

courtesy: http://thunderstorm.vaisala.com/explorer.html

If you are interested in building a system for the new (U.S.) 630m band, the CLE will give you the chance to test out your MF receiving capabilities and compare against what others in your area might be hearing.

When tuning for NDBs, put your receiver in the CW mode and listen for the NDB's CW identifier, repeated every few seconds. Listen for U.S. NDB identifiers approximately 1 kHz higher or lower than the published transmitted frequency since these beacons are modulated with a 1020 Hz tone approximately.

For example, 'AA' near Fargo, ND, transmits on 365 kHz and its upper sideband CW identifier is tuned at 366.025 kHz while its lower sideband CW ident can be tuned at 363.946 kHz. Its USB tone is actually 1025 Hz while its LSB tone is 1054 Hz.

Often, one sideband will be much stronger than the other so if you don't hear the first one, try listening on the other sideband.

Canadian NDBs normally have an USB tone only, usually very close to 400 Hz. They also have a long dash (keydown) following the CW identifier.

All NDBs heard in North America will be listed in the RNA database (updated daily) while those heard in Europe may be found in the REU database. Beacons heard outside of these regions will be found in the RWW database.

From CLE organizer Brian Keyte, G3SIA, comes the details:

Hello all

Our next Co-ordinated Listening Event is less than a week away.
It is an ideal one for new listeners as well as for regulars:

Days: Friday 25 May - Monday 28 May
Times: Start and End at midday, your LOCAL time
Range: 320.0 - 334.9 kHz

It's straightforward - just log the NDBs that you can identify having their
nominal frequencies in the range, plus any UNIDs that you come across
there. We last concentrated on these frequencies during CLE216 in
February 2017.

We'll be near the DGPS beacons range and some of us, especially in North
America, may hear a few, but please don't report them in this CLE.

73
Brian
-----------------------------------------------------------------
From: Brian Keyte G3SIA ndbcle'at'gmail.com
Location: Surrey, SE England (CLE coordinator)
-----------------------------------------------------------------

If you are interested in some remote listening - maybe due to local difficulties - you could use any one remote receiver for your loggings, stating its location and with the owner’s permission if required. A remote listener may NOT also use another receiver, local or remote, to make further loggings for the same CLE.

 -------------------------------------------------------------------

Ever since earning my ticket as a teenager back in '63, almost all of my on-air activity has been focused on CW ... I've always loved it.




Back when I first got on the air there were very few amateurs using keyers. Most used bugs and the remainder used hand keys. It was very easy to tune across the band and identify any of the locals just by the sound of their fist ... like snowflakes, no two were the same. The same went for most stations that were very active. DX or otherwise, one could usually tell who it was, long before the call signs were sent.

So much has changed now with the almost exclusive use of electronic keyers and everyone pretty much sounds the same, which is rather unfortunate I think.

Once my interest in building vintage-style vacuum-tube transmitters evolved, my interest in bugs was reactivated and over the years I have purchased a few more.

I'll do everything I can to promote and encourage the use of CW and especially hand-generated CW. That's why I was excited, once again, to read a recent e-mail from W6SFM, posted to several lists that I read, announcing the Bug Roundup!

The Samuel F. Morse Amateur Radio Club, a Sacramento, California based CW enthusiast club wanted a special time to bring bug operators together on the air. 

In the same spirit as ARRL's Straight Key Night, participants are encouraged to make simple, conversational, “chewing-the-fat” QSOs using their bug type key. 

This is an opportunity to exercise, share and exhibit your personalized fist. This is NOT a contest. However, there is a very easy and quick registration form found at https://w6sfm.com/bug-roundup/. 

Once you've optionally registered for the event simply Call "CQ BR" so folks know you are a Bug Roundup Participant. So lets grab that bug, clean those contacts, and let’er fly! We want to hear that “Banana Boat / Lake Erie Swing" or that commercial KPH/WCC quality fist.

Reserve the date! The event begins on Friday May 18th (00:00 UTC) and concludes Sunday May 20th (00:00 UTC)
 
That's 5:00 PM Friday evening until 5 PM Pacific Time Sunday (LOCAL)

For more information, to register your station, and to help assist in spotting, potentially increasing QSOs, an On-line chat window link can be found near the bottom of Bug Roundup home page located at https://w6sfm.com/bug-roundup/ 

We hope to hear you all on the air! 73,

courtesy: arrl.org

Sounds like a fun event and I'll have a tough job deciding on which bug to use but it'll probably be the 'Original' this time out.

Please see if you can squeeze-in a few hours of nice old bug-generated CW as the present digital craze is taking a big bite out of conventional CW activity it seems. Hopefully this is only temporary!