Over the years, the Galway VHF Group has provided
communications for many local events such as Hill walks, Car Rally’s, Cycle
Races, Rowing events held on the River Corrib, Sailing Club Regattas, and
Marathon events.
From each of these, it was necessary to adopt specific
communication suited to the location and type of event. Connemara is a
predominantly boggy area covering granite rock. Some areas of Connemara actually seem to attenuate VHF signals. In stark contrast, the Burren, the
South of Galway, is a bare sparsely covered limestone region. Neither areas have
trees to hang antennas from.
The Connemara Ultra Marathon and the Galway Walking Club
events take place in a mountainous area and in valleys. To communicate
efficiently in such areas requires the use of HF radio equipment.
We rely totally on "Groundwave Communications" to
pass messages from point to point in Connemara. The area has been researched
over the years and the characteristics of the area have been well documented.
One area yields a low signal strength, but 99% yields good signal levels. HF
operation is operated from mobiles and these refer to a Base Station generally
located at the Maam Community Centre. 2 metres (VHF), or 70 CMS, (UHF) are employed for
local communication around the Base Station e.g. to standby mobile operators. 4 metres (Low-Band VHF) can provide better results
APRS Operation
APRS is widely used during these events. We make no apology for
using APRS Droid via the Cellular Network why introduce more headaches when
there is an efficient system already in place! The area is well covered by Vodafone 4g
Cellular. Why re-invent the wheel? Adapt, Adopt and improve!
APRS allows us to show up on a visual display and reduces
unnecessary communication, from Base, seeking the location of mobile stations.
Nothing worse than repetitive location checks during an event.
From research using the APRS System coverage, we ascertained that the
use of a Multimode Hotspot could be used in the car making
it possible to utilize the Digital Network throughout the area. Not only the
Digital network but also internet radio using Teamspeak or Zello.
DPRS (The Digital version of APRS) can be utilized if working through a Hotspot or through a Digital Gateway or Repeater and between individual stations point to point
DPRS (The Digital version of APRS) can be utilized if working through a Hotspot or through a Digital Gateway or Repeater and between individual stations point to point
HF Operation
Groundwave on 80 metres
Our HF Radio network generally employs 3750 KHz on USB.
Strange to use USB? Generally, the UK operators seem oblivious to any weaker
signals on the frequency and swamp our operation with interference. As they are all on LSB we seldom experience too much QRM if we use USB.
Well, occasionally a debate occurs where a station is good enough to inform us
that we are on USB - Time Wasters!
NVIS on 5 MHz
There is ongoing research into the use of 5 MHz NVIS for our
operations. For fixed stations in Connemara, 5 MHz does work well. Mobile
stations are less effective. Some commercial antennas are available but there
are expensive and generally utilized by the Military or International Aid
organisations. a combination of Fixed stations and mobile stations does work as
there is always a slight NVIS component from an inefficient mobile whip. This
is very much a "work in progress".
Top Band Operation
This had been tried in the past. Top band antennas are very
cumbersome and not really suited to mobile operation. Even a triple mag-mount will not tolerate
the use of a Top Band whip operating from a mobile at speed. The difference
between Top band and 80 metre Ground Wave was not greatly noticeable in the Connemara
area.
10 metres
If CB can work over distance, there is no reason why 10
metres will not. Galway City to Tuam resulted in a good S9 signal, on 10 metres FM, so it is a
player. More work could be done in this area although not a priority. At this point we are close to VHF
characteristics so exercise caution. Rigorous tests would be advisable
Operating from a mountain top
Operation during hill walks makes it possible to communicate from peak to peak between checkpoints using VHF or UHF Radio. At least one of the checkpoint location will have a clear view to ground level allowing a rely to the net controller. One has to bear in mind that operating from a hilltop may not give a clear view to the valley below making it necessary to move towards the edge of a plateau to do so. A portable HF rig such as an FT817 with a MP-1 super antenna has been used with great success for such communications. Ensure that there is a good earth or radial system employed. Bear in mind that excessive chit chat will have to be kept to a minimum as a portable power supply will only give a specific amount to transmission time.
Fixed Location Operation
It is possible to put up a single fibreglass pole with an Inverted-Vee antenna from most portable locations. if all else fails one can use a random wire tuner to tune a length of wire taped vertically on the Fibreglass pole. Often, the use of fixed portable stations will produce good results on HF. This will depend on whether the operation demands a fixed checkpoint operation as opposed to a mobile operation where competitors are being followed.
Operating from a mountain top
Operation during hill walks makes it possible to communicate from peak to peak between checkpoints using VHF or UHF Radio. At least one of the checkpoint location will have a clear view to ground level allowing a rely to the net controller. One has to bear in mind that operating from a hilltop may not give a clear view to the valley below making it necessary to move towards the edge of a plateau to do so. A portable HF rig such as an FT817 with a MP-1 super antenna has been used with great success for such communications. Ensure that there is a good earth or radial system employed. Bear in mind that excessive chit chat will have to be kept to a minimum as a portable power supply will only give a specific amount to transmission time.
Fixed Location Operation
It is possible to put up a single fibreglass pole with an Inverted-Vee antenna from most portable locations. if all else fails one can use a random wire tuner to tune a length of wire taped vertically on the Fibreglass pole. Often, the use of fixed portable stations will produce good results on HF. This will depend on whether the operation demands a fixed checkpoint operation as opposed to a mobile operation where competitors are being followed.
VHF Operation
VHF is absolutely no use in Connemara for realistic mobile
operations. The maximum distance from base to mobile is 7 Km using the
"popular" 2-metre band. Mobile to mobile is even less. It is possible
to place a mobile on a high spot to cover an area, but it would be a waste of
active personnel if one was to place multiple relays in the area.
70 MHz (4 metres)
70 MHz does provide useful communications throughout a
cycling event where there is no base station involved and there is basically a
convoy of stations dotted throughout the long line of cyclists. A Net Controller can quite reasonably be deployed in the middle of a long stretch of cyclists. Those at the
leading end and at the rear can generally refer to the Net Controller or relay through the group if necessary. It is
possible to amalgamate a 4-metre network by referring them back to Control via
a HF input.
Digital Operation
The Digital Voice Modes may be operated on a point to point as
with any VHF/UHF mode. The use of a Hotspot will obviously extend the range
provided that there is a Cellular Network in the area. Best to research this
beforehand. Huge distances may be covered using DMR, D-Star or C4FM. Some say it
is not "real" radio but if it works don't knock it.
What happens if the cellular network becomes overloaded in the area? Connemara? Hello!
Seriously, we do have a secondary system if all else fails.
What happens if the cellular network becomes overloaded in the area? Connemara? Hello!
Seriously, we do have a secondary system if all else fails.
Point to Point Operations
The Galway Regatta requires point to point operation between
the Results Centre and the Start and Finish lines. DMR, C4FM and D-Star are ideally
suited using either VHF of UHF. Indeed, Analog NBFM will suffice so we have
moved with the times.
Repeater Operation
Repeaters do provide an excellent medium for communication,
however, should only be used as a last resort. Whilst they can link stations
over a wide area, they are the "weakest link". Use a reliable point
to point system such as HF before considering a Repeater. If the repeater is a
primary communication system and it develops a fault there may not be back up
readily available. The proverbial will hit the fan. Always expect the unexpected!
Operation in the Burren
It has been noted that VHF and UHF tend to work quite favourably around the Burren limestone terrain. The VHF signals tend to "bounce" around the area due to reflections. Whilst operating from Kinvara, it was possible to work the Limerick Radio Club's UHF Repeater despite appearing to be well shielded by limestone hills. Obviously, HF would be employed whilst operating in the area but 70MHz and 144 MHz give surprising results.
During one event it was possible to make a transmission from the Burren to Dublin on 3650KHz with a reasonable signal exchange using a pro-am mobile whip for antenna 80 metres.
Data Communications
Another method of communication from point to point via the keyboard. This can be standard Radio Teletype or better still an error-correcting mode such as Amtor, Pactor, but more importantly, Olivia and MT-63 THOR and THROB. PICCOLO and COQUELET are efficient modes of error-free Data transmission which work under low signal conditions often being almost inaudible on reception. Such operation is seldom used unless there is a requirement to send large amounts of text messages from point to point. File transfer is also possible using these systems. D-Rats is an interesting program for Data handling via the D-Star network and is designed for Emergency Communication. D-Star, C4FM and DMR have a provision for sending short messages although seldom used. One has to mention WinMor/Winlink is another system but we really have not found a practical use for it yet.
Brief experimentation has been done using the P25 mode and results are impressive. There is a clarity peculiar to this mode, not achievable by the popular three. NXDN has not been tried yet but it is on the cards.
ALE (Automatic Link Establishment)
ALE has been tried over some long international paths and is a superb way of guaranteeing a path between stations over a long distance but requires multi-band operation. We have it working via a TransWorld TW7000 radio system. It is of little practical use for our "semi-local" operations. Nice to have it under the belt all the same.
SSTV Operation
If we really wanted to be "Joe 90s", it is simple to send Slow Scan TV Pictures either on VHF or HF. There are limitations to the quality but it is sufficient for most purposes. Believe it or not, the Israeli Army used the Kenwood handheld SSTV camera mic, the VCH-1 in the not too distant past. This was proven by the sale of 10 units via E-Bay A High Resolution still picture may ne be transmitted via EasyPal on VHF or HF and picture transmission is possible via D-Star or C4FM. Handheld Mic/SSTV Cams are available for Analog use. To date, this is only a diversion and we have not found any practical use for such a system. It is available and can be employed where necessary.
Fast Scan Live TV
There is no problem sending Live TV pictures via VHF or UHF. Digital techniques have been tried and successful. As with SSTV, image transmission is an unnecessary distraction. It is available, has been found to work.
Satellite Communication
Since the introduction of the CQ-100 geostationary satellite, this can be a new and interesting system for transmission over long distances and obstructed path. It is possible to connect several static points via the satellite. It is easy enough to set up and is only of benefit where the stations in question are static as Fixed Portable Base Stations. Sub nets can operate and refer back to the Base who can then relay to another Base beyond an obstructed view. This has been tried, it works and it is extravagant and O.T.T. for the type of work we do. Never let it be said that we have not tested it and found a use for it. FSTV transmissions are also possible through this system although not tested as yet. Digital Voice transmissions such as the AOR OFDM, D-Star and C4FM also work well via this system. DMR is not possible - end of story!
PMR 446 Operation
Operation in the Burren
It has been noted that VHF and UHF tend to work quite favourably around the Burren limestone terrain. The VHF signals tend to "bounce" around the area due to reflections. Whilst operating from Kinvara, it was possible to work the Limerick Radio Club's UHF Repeater despite appearing to be well shielded by limestone hills. Obviously, HF would be employed whilst operating in the area but 70MHz and 144 MHz give surprising results.
During one event it was possible to make a transmission from the Burren to Dublin on 3650KHz with a reasonable signal exchange using a pro-am mobile whip for antenna 80 metres.
Data Communications
Another method of communication from point to point via the keyboard. This can be standard Radio Teletype or better still an error-correcting mode such as Amtor, Pactor, but more importantly, Olivia and MT-63 THOR and THROB. PICCOLO and COQUELET are efficient modes of error-free Data transmission which work under low signal conditions often being almost inaudible on reception. Such operation is seldom used unless there is a requirement to send large amounts of text messages from point to point. File transfer is also possible using these systems. D-Rats is an interesting program for Data handling via the D-Star network and is designed for Emergency Communication. D-Star, C4FM and DMR have a provision for sending short messages although seldom used. One has to mention WinMor/Winlink is another system but we really have not found a practical use for it yet.
Brief experimentation has been done using the P25 mode and results are impressive. There is a clarity peculiar to this mode, not achievable by the popular three. NXDN has not been tried yet but it is on the cards.
ALE (Automatic Link Establishment)
ALE has been tried over some long international paths and is a superb way of guaranteeing a path between stations over a long distance but requires multi-band operation. We have it working via a TransWorld TW7000 radio system. It is of little practical use for our "semi-local" operations. Nice to have it under the belt all the same.
SSTV Operation
If we really wanted to be "Joe 90s", it is simple to send Slow Scan TV Pictures either on VHF or HF. There are limitations to the quality but it is sufficient for most purposes. Believe it or not, the Israeli Army used the Kenwood handheld SSTV camera mic, the VCH-1 in the not too distant past. This was proven by the sale of 10 units via E-Bay A High Resolution still picture may ne be transmitted via EasyPal on VHF or HF and picture transmission is possible via D-Star or C4FM. Handheld Mic/SSTV Cams are available for Analog use. To date, this is only a diversion and we have not found any practical use for such a system. It is available and can be employed where necessary.
Fast Scan Live TV
There is no problem sending Live TV pictures via VHF or UHF. Digital techniques have been tried and successful. As with SSTV, image transmission is an unnecessary distraction. It is available, has been found to work.
Satellite Communication
Since the introduction of the CQ-100 geostationary satellite, this can be a new and interesting system for transmission over long distances and obstructed path. It is possible to connect several static points via the satellite. It is easy enough to set up and is only of benefit where the stations in question are static as Fixed Portable Base Stations. Sub nets can operate and refer back to the Base who can then relay to another Base beyond an obstructed view. This has been tried, it works and it is extravagant and O.T.T. for the type of work we do. Never let it be said that we have not tested it and found a use for it. FSTV transmissions are also possible through this system although not tested as yet. Digital Voice transmissions such as the AOR OFDM, D-Star and C4FM also work well via this system. DMR is not possible - end of story!
PMR 446 Operation
It is often necessary to have communication with the organisers of an event or a direct link to Emergency services. PMR 446 equipment is generally more than adequate for this purpose. Considerable distances can be covered by PMR 446 gear if there is a clear path. Often used from one end of a valley to the other. This at least enables the organisers to send a message throughout the network if there are any changes in circumstances. Sadly it is not possible for non-licensed personnel to use Amateur Radio equipment due to licensing issues.
The Black Box
Where practical, we utilize a "Black Box" recording system on our nets. This records the communications on our channels and is normally established at Net Control. If there is ever an enquiry into an incident or, if we wish to review and hold a "post mortem" on the day's activity, we can refer back over the communications for the day. It has been a vital system and has actually saved the mornings results during a boat race when their computer crashed. Of course, we also had accurate paper logs to back this. During the lunch break, it was possible to manually recalculate the semi-finals and finals for the afternoon and nobody was any the wiser. It also settled a dispute where the decision of an organiser was contested. What had been picked up in the background of an over gave an accurate account of what had been said rather than the misinterpretation by the claimant.
In Conclusion
There is no doubt that any area, in which useful communications are to be used, should be well researched beforehand so that no surprises result therefrom. HF, VHF and UHF all have their attributes. Whilst HF is not the most popular area on which to operate, it does offer superior results where the operation covers a wide area. The one major advantage is that it reduces the number of personnel required and also reduces the need to relay messages. It is possible to run a VHF net in a localised area and connect with another isolated VHF via an HF link. The distances could be from one side of the country to the other or just simply between two isolated areas normally shadowed by mountains preventing VHF communications.
It doesn't stop here as there are still many other systems that can be used and ongoing research is taking place. We do, however, try to keep the operation simple. By adding too much "tech" one is open to failure.
We have been operating such systems since the 1980s and there is always something new to test and operate. Where possible we include new technology but not to the point where it makes the operation cumbersome.
