Sunday, March 1, 2020

ICOM IC-7100 Review

The ICOM IC-7100 is, by no means, a new transceiver having made its debut on the American market around 2013. The radio comes in two parts, the control head and the main body connected by a controller cable. The microphone connects into the control head as does the speaker or headphones. A contrast from other units where the mic connects into the body which is located in the boot of the car reqiring a long extension cable to the driver's position. It ticks all the boxes power wise with 100W o/p from HF to 50MHZ, 50W on 70 MHZ, 50W on 144 MHz and 35W on 70cms. The 5 MHz band as also available. 
The ICOM IC-7100 was purchased for operation from the car or portable outings as it covered HF through 6 metres, 4 metres, 2 metres and 70cms. A bonus was the fact that D-star was available on all bands. Whilst the control head was a little odd with a touch screen tilted at 45 degrees a suitable mount was found for the dashboard of the car. The length of the control cable was long enough to mount the main body of the radio in the boot of the car.

All functions of the radio are controlled by a combination of button presses and the use of the touch screen. The angled screen was unique at the time and the appearance probably put many off the purchse of this radio. It should be noted that this radio has fully functional VFO A and VFO B and can also work on split frequency. The fact that this radio has the D-Star facility on all bands from HF - UHF is a major plus point in its favour.

The body of the radio has one antenna socket for the HF - 70 MHz bands and a second for 144 and 432 MHz. There are data sockets to interface a TNC, a data modes interface, and CI-V commands for remote operation. An external auto tuner may be connected and controlled by the “TUNE” button on the control head.

Like all radios, it is wise to read the manual although, if one has used an ICOM ID-5100, the D-Star operation is similar. All the functions are accessible through the touch screen menus and buttons. If one has never used D-Star before, operation will be a headache if the manual is not consulted. It is not difficult to operate with a little light reading.

The receive side is excellent and the NR and DSP functions are impressive making it possible to bring weak signals out of the noise and the Noise Blanker is effective also. The audio from the IC-7100’s own speaker is good but is naturally enhanced by using a larger external speaker.

Data modes are of interest and it was easy to interface the transceiver to a Signalink USB connected to the DM780 program supplied with Ham Radio Deluxe or the FL-Digi Program. There are many other Data Mode programs available. 

Good reports have been received on both HF and VHF even with the processor added in whilst using SSB. Having used the AOR9000MKII Digital voice modem on previous models of ICOM transceivers, it was easy enough to interface the same through an adaptor cable. This was only tried as one or two in our locality have the AOR system and, as yet, no facilities for D-Star.

It was good to have the facility to communicate on SSB as well as FM on the bands above 30 MHz. SSB, FM and D-star modes all give good crisp and clear reception.

It was noted, from watching YouTube videos, that the audio from the IC-7100 was slightly better than the new IC-9700.

By adding an external GPS, it is possible to send information via DPRS derived from the external unit when in D-Star mode. In GPS mode it is possible to receive data from other users and their position will show up on screen if selected.

The unit has ample memory facilities, and, like other D-Star Radios, it is possible to load a repeater list into the unit which is easy to access. It is easier to program this radio via the RT systems software than try to do so via the touchscreen. Software did not come with the unit and had to be purchased as an extra. Its value will be appreciated.

Interface to rig control/logging program is possible via the CI-V remote control socket. Ham Radio Deluxe is in use in the shack and there was no difficulty setting up the parameters for the IC-7100. There is no Bluetooth facility on this transceiver, but it is easy build an interface to take transmit the audio to and from the headset to the radio with an additional PTT extension. Drive safe Bluetooth units appear on E-Bay occasionally. To comply with the law, it should be used whilst mobile.

An Auto ATU can be controlled by pressing the “TUNE” button on the control head. Whilst ICOM produce their own model, there are many others available for a lesser price and the mAT-180H is one such ATU. This unit can operate at power levels up to 120 Watts over a range of 1.8 – 54 MHz. The ATU will tune coax fed antennas or wire antennas. It should be noted that Mobile whips for HF should be tuned to resonance rather than reliance on an inline tuner. The in-line tuner is more useful for portable operation.

Remote Base operation is possible using the RS-BA1 software.  It is possible to use the IC-7100 in the shack, or at a remote location via the keyboard of a laptop or P.C. Most functions and modes can be controlled via the remote software including interference rejection and I.F. filter settings. Provided there is internet access, it is possible to operate from any location.

In conclusion, the IC-7100 is a transceiver that has lasted the test of time and is still in production. It retails at around £950.00. It is an ideal mobile/portable radio as it covers both the HF and VHF bands with outstanding performance in noisy conditions. Using a mount that slots into the CD unit of the car, from Lido Radio Products, it is possible mount the Control Head without drilling holes in the dashboard. This transceiver is still in production and presumably firmware upgrades and minor modifications over time have made it what it is today. Whist the ICOM IC-7100 is not at the hugh end, it does represent good value for money.

Saturday, January 25, 2020

EI2BED Multi-Mode Digital Gateway for the Roscommon Area

Roscommon is on the edge of the Galway DMR Network's coverage area and a reliable signal is only available on higher ground with a clear path to the Abbeyknockmoy area. Paul, EI9HQB, having an interest in DMR, wanted better access for his area and wished to encourage more operators in his area to participate. A Digital Gateway seemed to be the most economical solution. In fact, if more low cost Digital Gateways were placed on air, it would fill in the voids between the larger centres of activity.

What is a Gateway?

A Gateway is a standalone system, allowing access to the network where there is no Repeater available. A gateway is not a Repeater, but rather a device that receives a digital signal and passes it to a DMR, D-Star or C4FM network via the Internet. With DMR, Gateways generally work on a single slot basis, normally on Slot 2, which is more than adequate for general and local use.

The majority of users in Ireland use their local Repeater as a Gateway and seldom repeat in their own area. An Example: you link into Talk Group 2722 on the Gateway, this will retransmt on the majority of Repeaters in the West of Ireland and the South East provided they have Talk Group 2722 set as a Static Talk Group on their Repeater.

What does it do?
  1. Allows access and routing through DMR networks (Brandmeister in Ireland)
  2. Allows access and routing through C4FM networks such as YSF and FCS one can cross-link between YSF or FCS network into Wires-X but cannot access beyond the local Node to which the cross link is attached.
  3. Allows full use of the D-Star Network, REF, DCS, XRF and XLX reflectors
What are the advantages of running a Gateway?

For an Outlay of <300 Euro it is possible to build a Multi-Mode Gateway allowing access to the most commonly used Digital Modes. Whilst it will not act as a Repeater it will allow access into the various Digital Networks and complement the wider infrastructure of Repeaters around the Country. Setting up a VHF Gateway will give wider coverage thereby reducing the number required. The ultimate object is to gain as wide a coverage as possible. This would equate to the older network of Analog EchoLink Gateways.

A 2 metre Gateway Network set up in places such as Cork, Limerick, Kerry, Mullingar, Dublin and Dundalk would provide an excellent service and open up the use of DMR, D-Star and Yaesu's C4FM to a wider area.

Many people ask if the network in Galway is going to expand any further. The answer is a simple NO! The Galway Digital Network is covering Galway and spilling over into neighbouring counties. More than adequate for Galway's needs. Any further expansion will improve the facilities within the current system. It is down to operators in adjacent areas, with no coverage, to add to the infrastructure to benefit their own area.
Building a Gateway


  1. A suitable radio such as 2 metre Tait Data Radio TM8105 Motorola GM350 to name two. VHF is more suited to Gateway operation as it will cover a wider area depending on the height of the location and antenna used.
  2. A STM32_VM Board available from Repeater Builder at this location  >>HERE
  3. Raspberry Pi 3B+ and associated Rpi Power supply
  4. Interconnecting lead with appropriate plugs 
  5. A Cooling Fan is essential to keep the radio cool during prolonged use. 
The Tait Radio will need to be programmed onto an appropriate Digital Simplex frequency. The vendor will generally perform that task if supplied with the desired frequency.
There is very little wiring and it is down to a lead connecting the radio accessory socket to the STM32 Board.

 The Tait Radio

The STM 32 board

 The Raspberry Pi 3 B+

The Software for the Raspberry Pi was downloaded from the Pi-Star site >>HERE

The file required is

Once downloaded unzip and etch the file onto a 16GB SD Card then insert into the Raspberry Pi.

Place the STM32 board on top of the Raspberry Pi, making sure it is seated correctly on the GPIO pins. Connect the Ethernet Connection from the Internet Router and plug in the RPi Power supply.

The Raspberry Pi and STM 32 board fitted nicely into "AVID Minidrive" case which had a low current 12V power supply and a 5A 5V power supply. Just perfect to drive the cooling fan for the Raspberry Pi. It was only necessary to run in the Ethernet cable and the connection from the Tait Radio to the Raspberry Pi. 

The Raspberry Pi will boot up and run the Pi-Star Software.

The software has to be configure with the Station parameters such as Call sign, DMR ID, frequency, Name of the controller, and the various modes in use with their appropriate servers filled in. 

A screen that appear like this is a good indication that all is connecting to the appropriate servers.
The next task is to connect the STM32  Board to the Radio, ensure that a dummy load is connected to the radio. It is now possible to set up the audio levels on the STM32 Board from the radio to the controller and from the controller to the radio.

The setup is covered on an excellent video from >>HERE 

Further information covered >>HERE

Following a few minutes watching YouTube videos, the system was powered up and all the relevant LEDs were lighting. A DMR transmission was made on the Gateway frequencyand the pot (1) was turned clockwise until the clip LED (2) lit and then backed off until it extinguished.

This is the perfect setting for the DMR Levels. It is unnecessary to touch the Pots either side of the D connector. A call was put out on C4FM. I was daft enough to say I was seeking a signal report as I was setting up a gateway. Naturally no replys were forthcoming. Pressing the "X" button to activate the room selection resulted in an instantaneous reaction and a list of rooms appeared on the screen of the FT2D. CQ-UK was selected and a brief call was made resulting in excellent quality audio in both directions. D-Star could not be tested as the registration process was not completed but another 24 hours would see this happen.

The Radio was put into a purpose built unit with a cooling fan to prevent the radio from overheating with constant use. The Raspberry Pi and STM Board were mounted in an old Disk Drive case. which had a power supply built in to give 5v and 12v. Handy for powering the Pi and also the Cooling Fan. The Pi does tend to run hot so it was essential to keep the core temperature below 40 Degrees C.

Tuning up could have been faster if more attention was paid to the video on the Repeater Builder site. It was Rickie MI5DAW who clarified the sequence of events. It then only took 20 minutes to get the DMR peaked to perfection and 5 minuted to re-tweak C4FM and D-Star.

Some excellent QSOs were made on D-Star, DMR and C4FM.

The theoretical coverage the Multi-Mode Gateway is shown below:

The Roscommon area will be well covered by this system and this will,  indeed, encourage more to go on air. The Roscommon system will increase the Galway System's coverage.

So one week on, the EI2BED Multi-Mode Digital Gateway is working perfectly since a minor reduction of TX level on hte DMR side. Plenty of activity is noted coming through the Gateway although Paul, EI9HQB, seems to be the only operator in his area operating the system. You can lead a horse to water but ....... See a sample copy of activity from the dashboard below.

Final checks were performed on C4FM and all sounded well. D-Star was fine on installation but we had nobody to test in the Roscommon area. It was working very well on the bench so is presumed ok. All having been tested, the Gateway is now under the full control of Paul EI9HQB.

Should anyone travel to the Galway area they will find that the coverage does spill over into adjacent counties.                                  

Wednesday, January 1, 2020

EI7AKR Service Resumed Following Severe Storm

The Storm ravaging the country around the 17th of December took its toll on the EI7AKR Repeater installation. Not only the EI7AKR Repeater antenna but the equipment belonging to the Internet provider, who allows us to use his site. The pole supporting the Internet equipment, seen in the centre of the picture, came down completely damaging the larger panel antennas and also the smaller ones seen at the top of the mast. Martin, the site owner, sent out a mail with picures to show the damage to our system as below. So severe were the winds, that the guy wires had been ripped of both masts on the occasion.

EI5DD was in the UK and unable to do anything about this and so a mail was sent via the VHF Group Mailing system. The period leading up to Christmas is a bad time for anyone but, allowing for the festivities to take priority, a group was co-ordinated by Gerry, EI8DRB, tasked with the job of obtaining a new pole and reassembling the antenna system. 

Following a group E-mailing, a small group were brought together to repair the system on the 28th of December with an early start.

Fortunately there was little damage apart from the pole being severely bent and, if left, it would have collapsed destroying the antenna in the process.

The Repairs involved the removal of the APRS antenna, and the Repeater antenna, and substitution of the the pole for a new, heavy duty pole, and then hoisting the whole lot into the air.

As, can be seen on the photographs, the conditions on the hilltop were none to pleasant with very muddy conditions and a copious amount of cow sh*t underfoot. The weather conditions were also very cold and windy on site. Not pleasant working conditions to say the least.

The pole was finally placed upright and secured and guyed once again. Hopefully this will last throughout the winter. The repeater was switched on and normal service was resumed. Reports from Roscommon, by EI9HQB, confirmed that the signal was at normal strengths in his area proving that the antenna was working perfectly.

Finally Special thanks to Martin List-Petersen, Gerry EI8DRB, Andrew EI3FEB, and John EI1EM for their assistance at such short notice.

In keeping with our mission statement, we strive to keep our systems on air with minimum down time where possible. Our Repeater was out of Service for 10 days.

Thursday, November 21, 2019

The C4FM Wires-X System

By accessing the local Wires-X Gateway on the dedicated system, EI2SHD, located in Lower Salthill or on the Galway Fusion Repeater, EI2TBR, it is possible to enjoy high-quality QSOs and news function including overseas stations via the Internet.

As shown above, there are numerous possibilities from a C4FM transceiver following a very simple access operation. Once initiated it is simple to navigate by following the on-screen instructions.

Using the C4FM transceiver, and accessible node can be found easily.

1) Press the "DX" key. This will send a search signal to the Wires-X Node

This will result in the Identity of the Node appearing on screen. A message "Search and Direct" will appear. Select that and then select all.

Scroll through the list of Nodes available and select the desired area. Next to the Node name in the list there will be a figure which denotes the number of Nodes connected to it. See Below

Select the Node from the list and wait for it to connect. 

Once the node is connected this screen will appear

It is possible to select news items from the screen or press back to place a general call and chat through the system.

So to summarise the following operations can be performed via a Wires-X Node on a Gateway or Via a Repeater fitted with a Wires-X system.

The News facility is fairly basic but nevertheless makes it possible to leave messages or general text items for others to view. It is further possible to upload pictures on this system.

A Node to which you connect may have one or many more Nodes connected to it in a similar fashion to D-Star or DMR Reflectors. Place a call into the Node and it will come out on many other systems connected.

There is always plenty of activity on CQ-UK and, after 9 pm, many Australian stations connect into the UK Node. Normally there are over 20 Nodes connected. America-Link has a huge number of Nodes connected at any one time and would be another good place to initiate a few calls.

The local Galway Fusion Repeater has Wires-X fitted and will allow plenty of scope to use the news and messaging facility between the two stations.

The Wires-X node consists of a Yaesu FTM100D and HRi200 modem. These are interfaced to a computer which runs the Wires-X node Software.

The Node Software runs continuously on the computer. The EI2SHD node is connected into CQ-UK which is further linked to between 19 and 30 other nodes depending on the time of day. Of particular interest is the link to XRF 925A which is a bridge to D-Star. This is also linked to a "Peanut" app which is an Internet radio system.

The screen of a Wires-X node is shown below

It is from this screen that the parameters of the Wires-X node can be set up. The purple bar indicates all the Nodes connected to CQ-UK and which the system is currently connected to. There are a wealth of Nodes that one can connect to located all over the world. America link probably holds the largest collection of Nodes and usually numbers around 110 Nodes. The ALLJA-CQ-Room tends to be the next most populated. CQ-UK tends to be the best Node for semi local contacts.

EI2TBR is connected to CQ-IRELAND which links to DMR TG2724 and is a good location for the occasional EI calls. If you are reading this from outside of Ireland do give a call on TG2724 or CQ-IRELAND if you would like to get an EI contact.

The EI2GCD Mulit-Mode Gateway runs C4FM and is linked to CQ IRL via the IRL Bridge which also links to Brandmeister TG 2724.

EI2SHD the Wires-X Gateway, located in Salthill, is linked to Wires-X Node CQ-UK, This is Node is quite active both day and night.

The Map below show locations of Wires-X Nodes in Ireland. Sadly this mode is under utilised to date. There are two private Wires-X Nodes showing on the map in Donegal and Kilkenny. There is a 70cm Repeater located on Woodcock Hill, Limerick but this has no connection into the Wires-X system. Multi-Mode Digital Repeaters in the Waterford area can run C4FM and have the facility to operate on the YSF or FCS system. If Programmed to YSF-IRELAND an output on CQ-IRELAND will be possible and if Programmed to FCS-004 it is possible to exit on CQ-UK.

For a more in depth view of the Wires-X system Click >>>Here<<<< for the manual.

Friday, November 15, 2019

Reception of Digital Radio on the RTL SDR Receiver

Scanner receivers and are often limited in the areas they can receive. The availability of cheapish Baofeng radios also opened up access to areas of spectrum but again, coverage was limited. In many cases commercial users have either migrated to digital systems or have moved to the UHF spectrum and employed digital modes of operation in that area.
With this in mind, the RTL2832U + R820T2SDR was purchased as it covers a spectrum from 25 MHz to 1.7 GHz and covers 100 KHz to 30MHz. A package shown below cost only £20.00. The Hack RF SDR would be considered at a later date if initial work on the RTL SDR proved favourable.

The RTL SDR radio is wholly dependant on Software to make it function and there are many variations. There are many programs available, but SDR Sharp was the first program tried. Nowadays, the programs are almost ready to go following installation. It is important to install the USB Driver for he SDR dongle before it will function with the software. There is plenty of documentation on YouTube to assist with the set up so installation was simple. 

The Broadcast band was the first area to test. The miniature antenna was sure to pick up a good range of signals to test the reception and quality. All of the parameters of the receiver are software selectable so bandwidth and gain are important for reception of wide band FM signals.

SDR Sharp was tried initially as it was easy to set up and gave good results straight away with the miniature antenna supplied. This is an excellent program for everyday use on HF, VHF and UHF. It was easy to install and once the driver program Zadig had been run, it required very little to set up.

The next area to test was the Amateur bands. The likelyhood or receiving an amateur transmission on VHF or UHF can be pretty slim in Galway By removing the antenna from the SDR receiver, it was possible to receive low power transmissions from the Handheld on both VHF and UHF. Kerchunking the local repeater produced some brief signals.
HF reception was possible but the miniature antenna was really not sufficient to make any impact. By connecting a longer length of wire, signals started to appear. An arbitrary length of wire with 9:1 transformer would produce better results. SSB and AM signals were clear and of reasonable quality. Data Modes such as RTTY, PSK were easily received but there are probably software packages to resolve them from a SDR radio. Not really a priority.
Digital Radio signals were of more importance but SDR Sharp requires plug ins and virtual audio cable and an additional plug in DSD. When these plugins are added in it is possible to decode a wide range of digital voice modes.

Another program, SDRangel was more complex with all of the facilities to decode digital voice signals. Provided that the USB driver has been installed, SDR Angel will work immediately after installation.

To start up, it is necessary to select the device connected, in this case the RTL SDR, and the reception of Digital Voice transmissions is done via the DSD Demodulator.
For the purpose of initial tests, the SDR radio was set up to receive the output of the hotspot. The hotspot was able to receive DMR, D-Star and C4FM on their respective active channels. 

The Screen shots for the various modes are shown below:
DMR operation

In the DMR mode it may be necessary to tune slightly offset from the centre frequency to decode DMR transmissions. The audio was amazingly clear and the DMR ID appeared on the line just above the constellation graphic. It may be necessary to adjust the tuning very slightly but the waterfall display and the constellation graphic will assist. 

D-Star Operation

D-Star signals were easy enough to tune. Note the Shape on the constellation graph. If centred as shown, the D-Star signal will become audible. It may be necessary to fine tune the frequency offset very slightly to ensure that the tuning is centred. Again the signals are very clear.

C4FM Operation

C4FM signals were easy to tune and fine tuning was facilitated by observation of the constellation graphic. Once the signal is centred, the audio became clear.

The next test will be to hook in a more resonant VHF/UHF colinear to the SDR receiver. 

The SDR receiver has many uses:

Full coverage from 100KHz to 1.7GHZ with no gaps.
Broadcast Radio - Reception on HF and VHF 
Decoding RDS signals
DAB Radio Reception
Scanner Receiver 
Air Traffic
Marine Traffic
Public Services  
Decoding Unencrypted Digital Voice - DMR, D-Star, C4FM, P25
Decoding Pager POCSAG/FLEX traffic

Reception and decoding of GPS Signals

Reception of Automatic Dependant Surveillance - Broadcast Mode -S Transponders which broadcast altitude and location information to air traffic controllers. With the appropriate software, these signals can be can be used to produce a "radar" like display on the computer. ADS-B receiver systems can retail for over £200.00. 

Plane plotter is an inexpensive commercially produced application that can be used with an RTL SDR Dongle as shown below

AIS Reception of Marine traffic similar to the ADS-B

Monitoring Meteor Scatter
Radio Astronomy

Spectrum analyser 

Panadaptor to sweep the receiver I.F. showing Waterfall display of adjacent channels. Ideal for spotting activity on a quiet band. One could spend fortunes on a unit manufactured for a specific radio but despite all of the frills and facilities, the basis of the unit is an SDR receiver module.

Triangulation of transmitter locations

and so much more ........

All of the above can be performed for just £20.00. However, it is planned to get a more expensive Hack RF system which has the capability to transmit 30mW throughout its coverage up to 2 GHz. The RTL is one of the less sophisticated SDR systems available but is an excellent starting point for experimentation. 

SDRangel is a little more complex with the plugins as an integral part of the program. It is not really designed for the beginner, however, there are plenty of YouTube videos describing the set up and uses of the program. It would be advisable to watch them first. Using one of the simpler SDR programs will give a good insight into SDR Radio before moving on to SDRangel.

If Digital Radio is not the primary interest, try SDR Sharp or Windows Consol V 3.0. There are many more on offer and all basically perform the same task so the choice really should be the one that suits the task. SDR Sharp is a useful program for Panadaptor use when monitoring the I.F. of a transceiver.

Thursday, November 14, 2019

Radioddity GD-73A Review

Measuring a mere 115mm x 50mm x 32mm, the palm sized Radioddity GD-73A is a fantastic little radio, ideal for operating via a household Hotspot or into a local Repeater. It is a fully functional Tier II DMR Radio running power levels of 0.5 Watts or 2 Watts.

What is in the box

The Radio comes complete with a charging/programming lead which has a standard USB plug on one end and a mini USB on the other, an earpiece with mic and PTT, Battery and USB Charger and 2600mAH Li-Ion battery pack.

The 2600mAH battery provides sufficient power to afford 16 Hours of continuous use or 48 hours on standby. 

It is possible to store 1024 channels in 64 Zones containing 16 channels in each.  

The stability is            +/- 1.0 ppm,
Channel Spacing        12.5 KHz
Modulation                 11K0F2E (Narrow FM)
                                      7K60FXD   12.5 KHz (Data only)
                                      7K0FXE     12.5 KHz (Data & Voice)
Vocoder                       AMBE+2TM 
Modualtion BER         ≤ 5%
Analog Sensitivity      0.35uV/-116 dBM (20dB SINAD)
                                      0.22 uV/-120 dBm (Typical)
Digital Senstivity       0.3uV/-117.4 dBm (BER 1%)
                                      0.22uV/-110 dBm (BER 5%)
Power O/P                   Low 0.5 W High 2.0 W

The unit will need Firmware upgrading to V1.04 and the accompanying CPS Software. After download ensure that the Firmware upgrading software is run as "administrator". It pays to read the extended manual supplied with the software download. Much time was wasted before this was noted.

Once the Firmware is upgraded it is possible to program the radio. 

The CPS is reasonably simple and conforms to other CPS software. After filling in the general settings with Callsign and DMR I/D, Enter Digital Contacts (Name and TG). Next program channels, and then create a Zone for the respective channels. It is necessary to place channels into a receive list otherwise transmission is possible but reception will not occur. Save the CPS and then load into the transceiver. SIMPLE!

Step 1

Fill in the DMR Radio Field with your call sign and the Radio I.D. with your DMR ID. Ensure that TX Time Out is set to 180 seconds as the components of the network time out beyond 3 mins (180 seconds).

Step 2

Enter Talk Groups that you wish to use. Give each on a Name and it will be a Group Call and the Call ID is the Talk Group designated number as shown below.

Step 3

Assign the Channels and their parameters by filling in the following area for each channel.

Step 4

Assign the channels to a Zone. This locates channels into one bank where they can be selected via up down keys.

Step 5

Fill channels into Receive Group list e.g all Local channels are placed into the EI and UK Receive Group List. 

That completes the programming. Bear in mind that 64 Zones may be programmed with 16 channels in each one. That is a total of 1024. This leaves plenty of scope.

Always save your Code Plug before upgrading the firmware as it may be necessary to reload after the upgrade.

Wot no Keypad? you may ask, but with channels programmed into the device already, the keyboard is seldom used. Programmable buttons P1 and P2 may be assigned to allow navigation and selection of channels in various Zones also selection of High or Low power may be programed to these keys.

Operation through the hotspot was simple and just a case of selecting the required Zone followed by selection of the desired channel, using the up down keys, and then PTT to access. For use via the repeater, selection of 2 Watts is an option although in many cases it was possible to use the low power setting.

The 2600mA will give 16 hours of continuous use or 48 hours of standby time which is more than adequate for most operations.

This is a convenient lightweight handheld to slip in a pocket or bag. The GD-73A has been taken on many trips abroad and kept me in touch with Ireland. The audio out is pleasant and, with the volume turned up full, does not show any signs of distortion. 

As with many DMR handhelds there are Firmware upgrades from time to time ensuring that bug fixes and modifications are carried out.  These are carried out following consultation with users on the Radioddity pages. 

Whilst not at the top end of DMR equipment, the GD-73 is more than adequate for the average requirements of any user. Good clear audio is a key factor and this radio will provide that facility. At $80 this radio will not break the bank and yet will provide hours of Service. if one is only using a hotspot why pay any more for a DMR Radio. Sadly, it does not come with a drop in charger but the fact that it can be charged via a mobile phone charger or the laptop USB may be a plus point.

So far anyone who tried out my GD73A were impressed by the ease of operation and programing. Operation through the Repeater network in the Galway area was perfect and a good point to point QSO over 60 Km was possible using 0.5 watts with both stations almost line of sight 

Saturday, October 26, 2019

Phase III - Abbeyknockmoy DMR On Air

On Saturday the 16th of October EI7AKR, the Abbeyknockmoy DMR Repeater was installed on site at Knockroe, Abbeyknockmoy, Co Galway and appeared on air at 16:30.

Sadly, our previous attempt to put the Repeater on air saw a total disintegration of the 4-Stack array and therefore we were unable to switch the equipment on. Radio Structures LTD supplied us with a new antenna, under a 3 year warranty agreement, so our trip on the 26th of October was to install the replacement antenna. 

On this occasion, our team consisted of Aengus, EI4ABB, who was responsible for tuning the cavities into  the antenna system, Steve, EI5DD, who programmed the Repeater along with Tom, EI3ER, Joe EI3IX, and Enda EI3IS who installed the new antenna system.

This site provides the primary coverage of Co. Galway as it is located almost in the middle of the County a superb height and an excellent Radio Horizon in all directions. This will facilitate communications on all roads into and out of Galway.

The antenna system is the same as used for the previous Analog Repeater located at this site. The antenna is an RF Structures Ltd. 4-Stack omni-directional antenna offering 6.5dBD of gain. The antennas are built to withstand the worst of weather conditions and therefore ideal for purpose.

Some Excellent views towards the horizon

The new 4 Stack Omni-directional antenna is pictures above as of 26th October 2019

Aengus, EI4ABB, assisted with the installation and made sure that the Sinclair Cavity Filters matched the Antenna system. Despite perfect tuning at ground level, the impedance of the antenna is seldom exactly that of the dummy reference antenna leading to losses. Often only minor tuning was required to obtain perfection on site into the the 4-Stack array.

Whilst the Cavity Filters were checked, Steve, EI5DD, locked the Network settings into the DMR Repeater and ensured that the connection into the Brandmeister network had established. A quick check followed to ensure that all other settings and levels were correct.

On power up the Repeater appeared up on the Brandmeister Dashboard - great sign that all is well. The power levels were then increased to 40 watts. On Re-boot, there was no indication of desense detected on the receive side. A quick tidy up of cables was performed and finally the remote switching equipment was installed.

A scout around the shack was in order before leaving the site and to make sure that we left nothing behind as we would not be going back to that location for at least another year. 

A check on the Brandmeister Dashboard revealed that all was well so we now have three out of four DMR Repeaters  and one multimode Gateway on site and operational within one year.

The Coverage of the Abbeyknockmoy Repeater is as shown below

Combining the Abbeyknockmoy coverage with the Inishbofin Repeater EJ7IBD, and the Galway Repeater EI7RHD it can be seen that the Network is slowly coming together.

The addition of the Loughrea Repeater EI7LRD will complete the Network. Uniform coverage with saturation of the majority of the County will be possible. This will facilitate Roaming where the user radio can switch between repeaters according to received signal strength. Should one of the Repeaters shut down, for any reason, ample but reduced coverage will still be possible.

We look forward to installing the Loughrea repeater on site in the near future.