Final Report of the Canadian 2200 metre Amateur Radio Experiments
Contributors: J. Allen VY1JA J. Craig VO1NA and S. McDonald VE7SL
This document is for the sole use of
Since preparations for WARC79, radio amateurs have sought authorization to experiment on long waves, having been relegated to MF and above since the early part of the 20th century. Success was finally realised almost 3 decades later when, following the lead set earlier by the Canadian delegation, a world-wide amateur allocation of 2.1 kHz between 135.7 and 137.8 kHz was approved at WRC07.
The allocation of this band is a domestic matter and up to the
individual administrations. The purpose
of this report is to provide documentation in support of a Canadian allocation
for Radio Amateurs of Canada in their deliberations with Industry
The three reports deal with different locations and geography, spanning
coast to coast to coast: British Colombia,
Despite the close contact maintained with the regional IC office and the use transmitter powers of up to 1.2 kW, there were no reports at all of any interference to other services in the bands. In addition, some of the portions of the reports deal directly with coupling of LF to the power grids and methods of mitigating this effect. Again, there were no reports of interference to any control and monitoring apparatus associated with the power grids.
Our results show that practical LF systems can be developed and safely operated by competent amateurs, that LF is a excellent venue for the development of new techniques for transmitting and receiving and that the allocation of Canadian 2200m band will further the cause of amateur radio in Canada. This will ensure a continuance of the international camaraderie and interest in the development of the state of the art within the amateur service in this country and abroad.
J. Craig VO1NA
Report of Experimental Low Frequency Operation
J. Parke Allen, VY1JA
Tel: (867) 633-4249
2200 meter band characteristics:
a. (Primary) Auroral effects on propagation in the near-arctic,
b. (Secondary) Propagation characteristics over mountainous terrain,
c. (Secondary) Practical antenna systems for rural acreage,
d. (Primary) Interference potential with Power Line Carrier systems on 137 kHz.,
The initial purpose was to conduct experiments
with transmission and reception in the frequency range of 135.7 to 137.8 kHz
centred on the items in the first three subject areas noted above. During the course of the experimentation, it
became apparent that station VY1JA is ideally situated for its operator to
examine interference potentials to Power Line Carrier (
The antenna at VY1JA is located near the 138,000 volt transmission line which runs north and south, along the east end of the acreage on which the station is situated. The voltage ends of the low frequency antenna were as close as legally allowed to the power line, which is within approximately 50 feet. The height of the antenna wires was set to match the approximate height of the power line as well. This is a worst case scenario, providing for maximum coupling of an amateur radio signal into the transmission line. Also, as much as possible, VY1JA was set in beacon mode on a 24/7 basis so that the greatest time exposure for interference existed as well.
When experiments were directed toward the first three purposes, the potential for interference with the power system was monitored continuously and would have been controlled if it had become necessary.
The SCADA technician at Yukon Energy
Corporation (YEC), Robert Burrell, was kept informed of the experiments, exact
frequency of operation and the modes involved.
During all 137 kHz. experiments, no signal was detected in the
Progress, Plans and Notes:
In the first year of experiments, the antenna,
a top loaded vertical with an effective height of the capacitance hat of 70
feet was installed using a 110 foot tower and two, 400 foot long capacitance
wires. The antenna was base loaded and
proved effective in reception because of the uncommonly quiet receiving
environment found in the
On the transmitting side, base loading and matching were completed and Robert Burrell at YEC was notified before the initial transmissions were made using a test power level approximately –10dB below the level allowed by the experiment permit. After establishing non-interference at this level, the power company was notified and the power level was moved up to the operational range and kept within 3 dB of the license limit. Several frequencies were used within the allowed spectrum and while most of the experiments were very narrow bandwidth due to their slow speed, wider bandwidth signals from 15 WPM Morse code contacts with southern BC produced no signs of interference as well.
Careful observance of possible effects on the
This experiment contributes to the growing base
of knowledge with results of one-way and two-way communications during varying
levels of auroral activity which occurs in the mountainous terrain north of
For several years before being given initial permission to begin LF experiments, I had been conducting personal and unpublished HF and MF experiments concerned with propagation during times of varying Auroral activity, observing the propensity toward an observable increase in one-way propagation and loss of east-west propagation in the near-arctic on HF, increasing in effect as frequencies are lowered into the MF range. This had included total loss reception at southern stations of the near-arctic transmitted signal, while the signal received in the near-arctic from the southern transmitters were reasonably strong. One of the purposes of this experiment was to continue experimentation into the LF range to see if the disparity between received signal levels continued to increase with decreasing frequency, in the LF range.
During the propagation tests Scott Tilley, at
VE7TIL, and Steve McDonald, at VE7SL, were primary participants, either
monitoring or transmitting while their signals were monitored in
some of the principal observations of propagation at
1. Propagation during periods of higher Auroral activity:
a. North-south path
Auroral activity levels appear to cause or at least coincide with one-way
propagation on north-south paths. This
was true at MF and HF and appears to be true on LF as well. The effect is stronger here (LF) than on
MF. It was displayed primarily with the
stronger signal being the received signal in
b. East-west path
Higher auroral activity levels appear to cause or at least coincide with loss of propagation on east-west paths. This was true at MF and HF, and appears to be accentuated on LF. The east-west paths which are near or under the auroral halo are the most greatly impacted. This meant that signals over the east-west path were often not received at all when auroral activity was greater.
Technical Operation Data:
a. Transmissions were limited to fall between the frequencies of 135.7 and 137.8 kHz, in the 2200 metre band.
b. Emissions outside of this frequency range were suppressed by a minimum of 30db below the fundamental signal.
c. Bandwidth of the transmitted signal was limited to 100Hz or less.
d. Radiated power did not exceed 1 watt ERP, and was kept within -3dB to 0dB of 1 W for the duration of the experiments except for brief testing periods.
e. The license period was from December 2004 to May, 2007
f. The transmitter was operated with care not to interfere with authorized users. Authorization for experimental transmissions was on a secondary user basis. There were no requests from primary users to cease transmission or to change frequency during the period of these experiments.
was taken to watch for possible interference with the Power Line Carrier system
of Yukon Energy Corporation. No LF
amateur signal interference to the
h. Transmissions were identified at the beginning and at least once each half hour with the callsign VY1JA. Often text was sent on Dual Frequency Continuous Wave (DFCW) or on QRSS CW, very slow CW, and with dit lengths up to 120 seconds in length. At these speeds, the callsign was sent at ~12 wpm and the slow text followed.
One-way (beacon) communications were run on a
24/7 basis and reports were solicited and received from
j. Two-way communications were attempted with other licensed experimental stations and resulted in establishing that reliable slow speed communications can take place with stations even on a small city lot, and that reliable communications on Morse code at speeds of approximately 15 wpm are possible on most evenings, during the hours of darkness, between two stations with good transmitting sites.
The antenna was a 30 metre (100 ft) top-loaded "T" with the top hat consisting of a pair of loading wires averaging approximately 120 metres (400 ft) in length. A large variable air-core loading coil “Variometer” was used to tune the antenna against a surface ground-contact radial system. A 1:1 air wound LF balun was used to isolate the transmitter from the antenna system.
The antenna match was checked by using a dual-trace oscilloscope with one input monitoring the current and the other input monitoring voltage at the same spot on the RF feedline to the antenna. It was noted that with the LF antenna being this size, there was very little change in antenna match during changing weather. However, during strong winds, the voltage and current traces would visibly but slightly move away from each other in time with the wind gusts. This is a very interesting thing to see demonstrated.
The exciter was a Kenwood TS45O which had its transmit frequency opened up so that it generated RF on 13.7 MHz. This was fed through a divide by 50 frequency divider, to feed the amplifier with 274 kHz.
When using DFCW, the transmitter was operated on Upper Side Band mode, and fed 1000 and 1015 Hz AF into the microphone from computer software. This produced a 0.15 Hz frequency shift for the DFCW.
Two different amplifiers were used. These were courtesy of Scott (VE7TIL) and Steve (VE7SL).
Scott’s prototype amplifier used a pair of FETs in class-C push-pull operation, and Steve’s transmitter used a single FET amplifier operated in near class E operation. Both of these amplifiers were constructed by their owners and demonstrate that building amateur equipment for LF is not beyond the skills of the average amateur operator.
Transmitting schedules and frequencies were
published via the Internet "LF" RSGB reflector (North
American/European) and via the "LOWFER" reflector (
Articles of interest were sent to popular
amateur magazines such as
Final Report of the
J. Craig VO1NA
Marconi Radio Club of
The start of amateur LF experimentation in
Fig. 1. Photo of 125 watt LF Transmitter
Owing to QRM near 135.83 kHz in
Fig. 2. (Reprinted with permission from July 2005 QST; copyright ARRL.)
It will be seen from the schematic, Fig. 2, that this is a class E
design. This was coupled to a wire aerial
about 150m long with a maximum height of 25 m using matching and tuning coils
including a variometer. The initial
reception of the slow speed CW signals in
To explore the utility of LF in local communications, a supplemental
request for authorisation was made to operate a second station. VO1MRC was commissioned and operated by
VO1HP. The first Canadian LF contact to
be completed without computer assistance was between VO1MRC and VO1NA. This showed that a practical LF communications
system could be established in a typical suburban residential lot. Further work
by VE7SL and VY1JA increased the distance of the Canadian record for conventional
CW to over 1000 km. Reliable
transatlantic reception of the
The destruction of the 25m mast during a severe wind and sleet storm
in 2005 resulted in an opportunity to test more modest aerial systems. It was found that a wire about 100m long and
only 1.5 metres high could be deployed to produce readable signals in
To overcome the reduction in signal strength, a commercial amplifier
was shipped from the
Fig 3 Decca amp and power supply, right. Litz helix coils and tuning apparatus left and centre. Note the fire extinguisher.
Transpacific tests were conducted with ZM2E in an effort to link the
antipodes by amateur LF. Although this did not result in a globe spanning
transmission or reception at this end, there were significant developments in
computer interfacing, software development and transmitter control in producing
the FSK transmissions. An interesting display of blue fireworks and symphony of
buzzing, pops and bangs were heard one night when high winds blew the aerial
wire against the supporting tower. This
was easily repaired and the Decca amp was completely unharmed, having a
protection feature. The estimated peak
aerial voltage was in excess of 12 kV during this high power operation.
Finally, fully audible CW signals from our station were again recorded in
“DE VO1NA” in DFCW (FSK) with a 0.1 Hz shift.
Final 2200m transmission from
Results of Antenna experiments:
The antenna design experiments involved the development of tuning circuitry and instrumentation. Tuning and matching followed standard LF practice whereby the aerial reactance was estimated and tuned using an inductance. Matching was less of an issue as the resistive components were generally of the order of 50 ohms and only marginal increases in the aerial current could be obtained by matching the resistive component. It was found that with care the antenna could be tuned using the aerial current, although this created certain problems with class E transmitter stages. Under these circumstances, an SWR bridge was necessary. A commercial amplifier could be tuned using the aerial current and the instrumentation on the amplifier.
Long wire antennas were tried. These consisted of wires 100m long and at heights ranging from 10 to 25 metres. It was found that reliable transatlantic reception at 100 watts output was possible for a 100m wire at 25 metres and for 1000 watts for a wire at 10 metres. Under favourable conditions, transatlantic reception at much lower power levels was possible.
Because any practical LF antenna will have a very low radiation resistance, the importance of adequate earthing cannot be overstated. This is compounded by the LF RF taking the path of least resistance which will be the AC domestic power grid if a poor station ground is used. It was shown that this can be largely eliminated by decoupling the transmitter ground connection and using an adequate RF ground at the station. These results were obtained by taking measurements with a directional antenna at a place where the AC lines were aligned parallel and perpendicular to the transmitter about 5 km away to the east of the station. At this location the mains lines run south then east. Because these lengths of power line were very nearly the same distance from the transmitter, we would expect the variation in the field strength to be seen under the east lines the south lines. If there was a significant amount of power line-LF coupling, we would expect that the orientation of the receive antenna maximum signal strength to follow that of the lines. In fact, the orientation of the receive antenna was independent of the mains lines and a good null was obtained at both locations. This means that there was very little LF RF on the power lines, in contrast with earlier experiments when the mains ground connection was used.
Additional experimentation was undertaken to improve radiation efficiency. The far end of the wire aerial was raised from 3 m by attaching it to a newly installed 10m tower. The aerial current increased from 1.0 to 1.2 amps by this small change. Efforts to improve the efficiency by extending the ground system have been largely inconclusive at the present. A radiation anomaly observed earlier has not been observed since and it appears as if the antenna is essentially omni-directional as expected.
On the subject of the mains electrical system, it was noted that the keying of the LF transmitter caused a voltage drop in the domestic electric power of several volts. The electric company was notified of the difficulty which was mitigated by installing a new 7.2 kV pole transformer at the power drop to the station. The LF experiment thus contributed indirectly to the power company’s objective to meet the standard specifications of domestic power supply.
Figure 6: New 7.2kV:234V 10kVA pole transformer.
Signals can be received at levels below the audible threshold by
using Fourier transforms of the received audio via a computer sound card. While this lowered the bandwidth, it also
lowered the rate at which messages could be sent. In general, speeds of 0.04 WPM were used for
transatlantic communications during favourable conditions, normal Morse could
be copied by ear and the
As a result of reception experiments, knowledge was gained about low noise receiving antennas, preamps and reception techniques, including digital signal processing.
Regional reception experiments (up to 500 km) showed that LF was
often more reliable than HF. Several
instances of day time reception were noted during beacon reception experiments
at sea at distances where HF or 160m ground wave would be too weak and at a
range where the sky wave could not be received.
Although some amateurs in
There have been several developments as a result of this experiment. Much has been learnt about digital signal processing, direct digital synthesis, and specialised weak signal reception techniques including loop and active receiving antennas. Experimental modes using slow speed CW and FSK were developed and successfully used to establish 2-way LF communication. Class E LF transmitter designs with Hexfets were explored along with high stability carrier generation and calibration against atomic standards. Much was learnt about preamps, transmitting aerials, methods of tuning transmitting aerials and the effects of environmental variability on antenna properties. Methods of effective maintenance of antennas in harsh environments have been developed. We have also learnt much of propagation at local and transatlantic scales.
In addition, there has been much international camaraderie and recognition of Canadian amateurs in the forefront of experimentation and innovation. There is much room for additional work such as accurate LF field strength measurements and more quantitative results for power line coupling.
These experiments have shown that is not difficult for amateurs to
make meaningful use of 2200m in typical back yard scenarios, with aid of
sophisticated computer programs and assistance from established experimenters.
Practical LF communications systems have been developed and used by amateurs in
The LF experiment in
The author acknowledges the assistance and encouragement of VE3IQ
and VE3PU and the late VA3LK, and VE3OT, VE7SL, and many members of the Marconi
Radio Club of Newfoundland and to other VO amateurs who provided signal reports
and expressed interest. W1
Appendix 1: Experimental Proposals
Title: Antenna design and propagation characteristics on the 2200 metre band.
Author: J. Craig VO1NA, Experiment Coordinator
Phone (709) 772-6015
To conduct experiments with transmission and reception in the frequency range of
135.7 to 137.8 kHz with an aim to better understand understand: i) design and optimisation of LF transmitting and receiving aerials and associated measuring apparatus ii) the characteristics of propagation in the LF portion of the spectrum
Since the Washington Convention in 1927,
radio amateurs have been required to constrain their transmissions to 200
metres and down. As a result, there has
beenvery little experimentation in the wavelengths longer than 200 metres by
amateur radio operators. Over a decade
ago, some amateurs in
be discovered about transmission, propagation and apparatus design on this band.
This experiment will augment the findings of the previous investigators and provide an opportunity to promote to the technical aspects of amateur radio and interest in low frequency experimentation.
A transmitter will be used to work CW (A1A) and FSK (F1B) between the frequencies of 135.7 and 137.8 kHz. Emissions outside this range will be suppressed by at least 30 dB. The bandwidth of the emissions will be 100 Hz or less. A 25 metre high tower or 100 metre wire will be used as a transmitting aerial. A variety of tuning and grounding systems will be tried to optimise the efficiency of the aerial. The radiated power will be limited to 1.0 Watt ERP.
The transmitter will operate on the
basis of non-interference to authorised users by transmitting the call sign
VO1NA in Morse code at regular intervals of about 4 times a minute. This call sign has been assigned to the
author. Morse code at much slower speeds
will also be sent. Signal reports will
be solicited from other radio amateurs.
Communications will be attempted with other authorised stations
including radio amateurs in
The transmit frequencies will be monitored when the transmitter is off the air. If we receive a request to stop sending, we will comply or change frequency, as required. It is understood that any authorisation will be on a secondary basis.
The operation will be publicised world-wide by Radio Amateurs of Canada bulletins and by the Marconi radio Club of Newfoundland. Periodic updates will be posted to the MRCN (VO1MRC) web page.
Details of the experimental transmitter,
antenna and tuner along with reception reports will be will be submitted to the
Title: Short range LF communication experiments.
Author: J. Craig VO1NA
To develop and evaluate an amateur radio
LF communication system at ranges of up to 300 km in
Amateur experimentation on LF has been conducted in many countries around the world. A world wide LF allocation has been placed on the agenda for the next WRC in 2007 by Canadian representatives.
Very little 2 way communications have
been conducted on 2200 metres within
The use of the VO1MRC call sign for this
project has been approved by the Marconi Radio Club. The transmitter will constructed and
installed under the direction of the author.
Communication will be attempted with the fixed LF station VO1NA from different
sites. The parameters of the operation will
be as per the original authorisation for VO1NA dated
Appendix 2 Bibliography of LF Canadian
(This is not a complete listing.)
Reprinted with permission from July 2005 QST; copyright ARRL.
"Long Wave Experimenting in
Papers were published by L. Kayser VA3LK on the first Canadian LF QSO in July 2000 with VE3OT and the first LF transatlantic QSO of Feb. 2001 and also the work of VE1ZJ/VE1ZZ.
"A progress report of experiments
on 2200m by the Marconi radio club of
"Update on experiments on 2200
metres" J. Craig
"First Western Canadian Contact on
2200metres" S. McDonald and
"Progress Report on LF
Experimentation in NL" J. Craig, R. Dodge and R. Peet. Sept/Oct 2004
"Experimental LF QSO in
"Transatlantic Reception of QRP
1600 Metre Signal" J.Craig and A. Melia and H. Wolff. p 13
"The Transatlantic on 2200 Meters" J. Craig and A. Melia. QST 89, no. 7 Jul 2005.
"Getting started on 2200m" By
S. McDonald. Jul/Aug 2005
"A West Coast LF Adventure" S.
McDonald. Jan/Feb 2006.
"Modernising the XH100
Receiver" J Craig
Summaries in "Around the
Corner" (p 10
Long Wave low frequency work. Jul/Aug 2003
2-way transatlantic QSO from NL Sept/Oct 2003
More news on propagation on 2km band p 9 May/June 2004
Conventional CW LF QSO p 7 Nov/Dec 2004
LF experimentation by radio amateurs Jan/Feb 2006
Another Transatlantic 2200m QSO Mar/Apr 2006
Canada US LF cross-band QSO (VE7SL) QSO Mar/Apr 2006
LF experimentation by radio amateurs Jan/Feb 2006
Reports in Club Newsletters
Poldhu ARC Newsletter June 2005
Long Wave Club of
News Articles in National Journals.
QST p 84 Feb 2005 with photo of antenna/25m tower, VO1NA on 137.777 kHz.
Rad Com LF Column June 2004 VO - UK QSOs,
regular reception in
Rad Com Apr 2006: Reception of 5 WPM CW from VO1NA in Eu. More transatlantic contacts on 2200m
Rad Com LF Column Feb 2008 p 30. Transatlatic 1600m.
27 May 2003
The Marconi Radio Club of Newfoundland is promoting interest in long wave low frequency work on 136 kHz
ARRL Online Bulletins and newsletters
www.arrl.org/news/stories/2003/05/29/101/ (as above)
Three North American LF signals received
Experimental Licensees Moving Low-Frequency Agenda
www.arrl.org/news/stories/2003/05/29/101/ NL Club promoting LF
RSGB LF Group Reflector
LWCA Group Reflector
"VE7SL - 2200m EXPERIMENTAL OPERATIONS REPORT"
Station Operator: Steve McDonald
There were two subjects of this experimental licence:
1) To observe the propagation characteristics of amateur 2200m signals into and over mountainous terrain.
2) To test typical small-lot LF antenna systems capable of communicating on 2200m.
In order to gather information for either of the two objectives, it was first necessary to build a complete station that was capable of transmitting on 2200m at 'typical' amateur power levels, as well as receiving signals in this somewhat challenging part of the radio spectrum. Once a capable transmit / receive platform was developed, it was intended that as much two-way communications as might be possible under the limited terms of the licence would be undertaken as well as numerous one-way (beaconing) tests should be implemented.
The first year of the
licence period was taken up with the construction of suitable equipment that
could be used for the tests (APPENDIX A). After building a number of
European-designed transmitters, I settled upon one utilizing a single
Before and during the licence period, numerous receiving antenna systems were employed, consisting mainly of loops, both passive and tuned. As well as using a short active whip antenna, the main transmitting antenna was also employed for receiving.
Two different transmitting antennas were utilized during the licence period.
For much of the
licence period, there were no other nearby stations with which to conduct
two-way tests. The nearest other experimental licensee was Mitch Powell
Scott was able to
make two separate radio / camping trips into mountainous areas to the east of
Early in the propagation testing, it became apparent that although propagation into mountainous terrain would be challenging, propagation over the mountains would be relatively easy.
On the evening of
The secondary objective of the experimental licence application, observing the effectiveness of simple 'backyard' LF antenna systems, began with the above tests in August, 2004. It should be noted that any amateur antenna systems (especially those confined to typical domestic lots) will be extremely inefficient on 2200m. A normal 'minimal standard' quarter-wave vertical radiator would need to be over 1600' high on 2200m to achieve a nominal radiation efficiency of 50%. As well, at these frequencies, horizontal radiators are almost completely ineffective as they suffer from very large ground absorption losses as a result of ground-proximity coupling. Anything less than a 1600' vertical on 2200m results in an immediate and severe degradation of radiation efficiency!
The first antenna tested was a short 30' vertical wire, employing a three-wire top hat to increase radiation efficiency. The top-hat, which was centered on the vertical radiator, was approximately 50' in length. In order to achieve resonance on 2200m, a large loading-coil of approximately 3mH was required. In addition, the antenna was fed against a small ground system consisting of approximately forty buried radials, each about 40' in length. With the 90W transmitter used in combination with this antenna system, the ERP was estimated to be less than 100mw.
It should be noted that calculated ERP and actual measured ERP are usually quite different, with actual ERP usually being less than theoretical values. As well, measuring actual ERP requires specialized instrumentation not readily available to amateurs. It would seem that, for this reason alone, limitations on power levels for amateurs operating on 2200m would be better if specified as DC POWER INPUT (W) or RF POWER OUTPUT (W) as is done on all other amateur bands. Measurement and enforcement of ERP levels is a much more challenging and time-consuming task compared to measuring DC power levels.
The second antenna tested was a larger version of antenna #1. This antenna consisted of a 60' vertical wire connected to the center of a three-wire top hat, approximately 100' in length. This antenna was run parallel to and suspended over the beach very close to the ocean. The antenna used the same buried radial system and required about 2mH of inductance to resonate on 2200m. This antenna was run exclusively with a new home built transmitter utilizing a pair of switching FET's and capable of developing approximately 500W of output power resulting in an estimated ERP of around 500mw.
After installing the
new system, it quickly became evident how easily 2200m signals would propagate
via sky wave on a regular basis. On most nights of normal (undisturbed)
propagation, the beacon test signal was easily seen in the central
A number of different receiving antenna systems were employed throughout the test period. These consisted of a large 10' resonant air-core passive loop, a shielded single-turn amplified broadband loop, a 30" active whip antenna and transmitting antenna #2. All of the antennas performed well. The best performer was transmitting antenna #2, followed closely by the 10' tuned loop. In noisy city locations, I suspect that the loop antennas would provide a superior signal-to-noise ratio compared with the transmitting vertical because of their null-steering capabilities. The small 30" active whip proved to be an amazingly good performer for such a small footprint and when positioned in a quiet area of the backyard would be an effective receiving antenna for routine work on 2200m.
During the licence period, many hundreds of hours were spent transmitting in the beaconing mode (at high power) and at no time was there any interference to primary users evident or brought to my attention. It would appear, from personal experience, that amateur LF operations can co-exist with the primary users of the 2200m band without conflict. It should also be noted that the reciprocal would also appear to be true in that no interference from primary users was noted during any of the experimental operations.
From the limited testing conducted specifically on propagating signals into mountainous terrain via ground wave propagation, it would appear that this is a difficult task when using power levels and antenna systems that might typically be found in amateur installations. Propagation via sky wave during the hours of darkness, into and over mountainous terrain, appears to be relatively easy.
Again, from the limited amount of time conducting antenna tests, it would appear that even though a typical backyard LF antenna system would, by necessity, have an extremely poor radiation efficiency, worthwhile results can be realized from such a system.
With very few
During the term of
the licence one important objective was to keep as many amateurs in
TRANSMITTER #1 - 100W OUTPUT
This is the transmitter built for tests
Shown below is my 2200m experimental station, located on
transmitter, in the lower right corner, is my homebuilt version of the "LF
Half-Kilowatt" designed by Scott, VE7TIL. My original signal source
utilized a 4040 (binary counter) IC as a 2200kHz crystal oscillator driving a
4060 IC in a divide-by-8 configuration to produce a low-level signal at 275kHz.
This has since been replaced by a homebrew
The panel above the transmitter contains two rack-mounted low-voltage power supplies strapped in parallel to run the transmitter, along with a small 12V / 5V supply for the IC's and fans.
The top panel houses my homebuilt 500W reflected power meter. It is an LF version of the Drake power meter. The lower left corner houses the scope which constantly monitors the transmitting antenna tuning.
Both antenna CURRENT and antenna VOLTAGE are monitored. This allows easy tuning for resonance as well as making any matching adjustments with the loading coil very easy. The impedance of the antenna can be observed as well as its inductive or capacitive characteristics. It is fascinating to watch changes in the scope pattern while the antenna blows in the wind!
The Scope Match was homebuilt from plans by MØMBU and is shown in the 'LF Experimenter's Handbook' (G3LDO).
The transmitter is connected and matched to the antenna system by a large antenna loading coil. The loading coil was salvaged from a local ndb transmitter and is extremely rugged.
It is air-wound, on ceramic spacers, with #12 copper wire for a total inductance of 2.8mH. My antenna requires only 2.0mH to resonate at 137kHz so the antenna is tapped down on the coil. A homebuilt variometer, between the loading coil and antenna, is used for fine-tuning the system to resonance.
The variometer is a 'variable inductor', with an inner rotating coil connected in series with the outside coil. Rotating the inside coil changes the overall inductance plus/minus 300uH approximately.
The transmitting antenna system (ANTENNA
#2) is a 'Marconi T' 3-wire flatop. One end is attached near the top of a 100'
Balsam tree while the other end attaches to my neighbor's Fir tree. Spacing on
the top wires is 1m, with an overall length of approximately 30m. The antenna runs
parallel to the ocean beach on the eastern shore of
Papers were published by L. Kayser VA3LK on the first Canadian LF QSO and the first LF transatlantic QSO of Feb. 2001.
report of experiments on 2200m by the MRCN " J. Craig
experiments on 2200 metres" J. Craig
Canadian Contact on 2200metres" S.
on LF Experimentation in NL" J.
Craig, R. Dodge and R. Peet
"The Transatlantic on 2200meters" J. Craig and A. Melia. QST 89, no. 7 Jul 2005.
on 2200m" By S. Mcdonald. Jul/Aug
"A West Coast LF
Adventure" S. McDonald. Jan/Feb
Assorted summaries in
-Around the corner p 10 Long Wave low frequency work. tca jul/aur 2003
-Around the corner p 10 Another ta 2200m qso tca mar/apr 2006.
-Around the corner p
-Around the world p 10 lf experimentation by radio amateurs. tca jan/feb 2006.
-Several News items reporting on LF in VO land in QST, Rad Com.
example: -news on p 84 feb 2005 qst. with photo of antenna/25m tower at vo1na on 137.777 khz.
Transatlantic Reception of QRP 1600 Metre Signal J.Craig and A Melia and
H. Wolff. p 13
Experimental LF QSO
2004 - Initial testing of the LF station (~ 90W) was
followed by a two-way QSO on 2200m with Scott, VE7TIL, in
few nights of beaconing turned up several encouraging screen captures. The
first was received from Steve, AA7U, in
OCTOBER, 2004 - My first crossband QSO was with John, VE7BDQ, located in Tsawwassen, B.C. John was using a homebuilt converter for receiving on LF, while transmitting on 80m CW. John's receive antenna was a large coil and tuning capacitor located outside in the backyard! He now has a new 8' loop antenna for LF work.
2004 - In late November, extensive antenna renovations were
completed to the 3-wire flatop when the antenna was lengthened and raised much
higher. As well, the new 500W transmitter was completed and ready to go. The
first overnight test on December 4th and 5th resulted in several encouraging
signal reports as well as a new crossband QSO with Roger, KØMVJ, near
Roger initially reported that my QRSS30 signals were very strong and that I should go to QRSS10. He then reported that the QRSS10 signal was 'easy copy' and that I should speed up to QRSS3. It turned out that QRSS3 was a little too weak so I went back to QRSS10. The capture below shows the difference between the two speeds.
Bryce, KIØLE, also in
That same night and the following night,
screen captures were received from Jay, W1VD, in
Again on both nights, Mitch, VE3OT near
QRSS3 beacon signal as received in
After our crossband QSO, I let the LF
beacon run all night at 50 watts output. Jay reported that the 50W signal was
also good copy in
Jay is in CP20kw, approximately 1000 miles to the north.
Dexter, W4DEX in
Not to be outdone by his neighbor (W3
W1VD in CT again reported hearing the beacon, indicating best reception from 0515 EST until sunrise fadeout.
The ARRL Letter
Vol. 23, No. 29
* First western
Canada LF QSO reported:
reportedly completed the first western Canadian contact on the 2200 meter
band on July 10. McDonald said the contact between the two stations on
137.754 kHz spanned a distance of approximately 50 km (about 31 miles).
"VE7TIL utilized slow-speed CW--QRSS3--mode, while VE7SL used normal CW,"
McDonald said. VE7TIL was running a homebrew transmitter that ran about 1
W output, while VE7SL was using a homebrew crystal-controlled exciter into
a single FET amplifier at 100W output. "Both of us used similar antenna
systems for transmitting--a loaded three-wire flattop T," McDonald said,
and small loop antennas for receiving. McDonald said he hoped their
stimulate more interest in LF in western
information about 136 kHz activity and equipment, visit The VE7SL Radio
The ARRL Letter
Vol. 25, No. 13
* Low-frequency experimenters seek reports, crossband skeds: The next round
of LF transpacific
testing between ZM2E,
VA7LF, S Pender Island, British Columbia, will take place April 3, 4 and 5.
Testing will begin shortly after sunset at VA7LF (approximately 0630 UTC)
and will continue until sunrise (approximately 1400 UTC). The frequency will
be 137.7890 / 137.7886 kHz (0.4 Hz shift) using FSK90. Following a schedule
with VA7LF, ZM2E will
continue with R6L until sunrise in
Reception reports via the reflectors are encouraged, and the VA7LF site will
be Internet equipped. "If we are able to get things set up smoothly, we may
be on the air for testing on Sunday night, April 2," said Steve McDonald,
VE7SL. "Since we will be at our maximum ERP limit, we hope to have some time
available to attempt some crossband HF-LF CW-CW QSOs or QRSS-CW contacts in
our early evening hours (0300-0600 UTC)." Interested stations should contact
McDonald via e-mail, email@example.com
Canadian Team Tries
Again to Contact New
Assisting in this project were Martin MacGregor, VE7MM, and John Gibbs, VE7BDQ.
Using an aluminum tower 40 feet high, we added two 20-foot aluminum sections to the top of the tower, as well as a large 150-foot two wire top hat spaced 10 feet across. Another 25 feet of wire was extended from the base of the antenna over the cliffside, ending just above the beach, where it was matched and fed with 50 ohm coax, for a total of 105 feet. The entire antenna system was brought into resonance on 137 kHz; the big vertical required 1.9 mH of inductance to bring it down to 2200 meters.
Murphy's Law of
propagation was evident all three nights of the test, as the A and K indices
were highly elevated. In addition, there were strong geomagnetic storms and
aurora displays so intense they could be seen in the central
Even with the poor
propagation, VA7LF and ZM2E (
The third morning had
the best results: ZM2E's signal suddenly elevated 25 dB over the noise and
acknowledged our call as a perfect copy of the beacon signal. This was an
invitation to begin a formal contact sequence, but as the sun was starting to
On the third night
just prior to sunset, VA7LF took advantage of the strong groundwave signal and
made a number of crossband contacts, using 160-2200 meters, to
VA7LF has attempted to make this contact since 2004. Although not reaching the goal of a valid contact, we will try again. -- Steve McDonald, VE7SL
The ARRL Letter
Vol. 25, No. 25
authorized to experiment on low frequencies. Perhaps best known as the ham
who most often hands
out the hard-to-work
Allen now is beaconing nightly on 137.574 kHz. On May 25, Allen completed
the first LF QSO from
ERP was likely well below 100 mW," McDonald estimated. He reports Allen's
very slow-speed CW signal was 100-percent copy using ARGO software on the
receiving end. In
enough to copy by ear at normal speeds. Observed McDonald: "At 1000 miles
distance, the initial QSO demonstrates that amateurs can enjoy
inter-provincial or out-of-state CW ragchews on 2200 meters using simple
stations and backyard antenna systems." There's more information on 2200
meter activity in "The VE7SL Radio Notebook" http://www.imagenisp.ca/jsm
The ARRL Letter
Vol. 25, No. 37
* Long-distance CW QSO marks milestone in LF experimentation: Steve
McDonald, VE7SL, and J Allen, VY1JA, are claiming the first long-distance,
low-frequency aural CW contact between two Canadian amateurs. The QSO in the
vicinity of 136 kHz
(2200 meters) between VY1JA in
Territory (CP20) and
place Friday, September 9, at 0705 UTC. The distance between the two
stations is approximately 1000 miles. "It was nice not having to rely on
computers or QRSS [very slow-speed CW] mode to be able to work each other,"
McDonald said. "Copy was 100 percent at both ends with little fading." VY1JA
was running 200 W to a 100-foot top-loaded tower, resonated at 137 KHz,
while VE7SL was running 450 W to a 65-foot wire vertical and three wire
vicinity of 136 kHz. "LF experimental work by Canadian amateurs continues to
demonstrate the suitability of 2200 meters for reliable two-way
communications with simple homemade equipment and without causing
interference to primary users of the band," McDonald concluded. For more
information on 2200
meter activity in
Additional Information: Report
by Scott Tilley VE7TIL submitted to
List of Canadian amateur radio LF milestones compiled by J. Craig.