Monday, July 8, 2019

Castlebar 4 days Walking Festival 2019



Steve EI5DD, and Tom EI2GP, assisted with the communications for the 30 km rambles during the Castlbar International 4 Days walking Festival from the 4th to the 7th of July. We have been assisting with this event since 1992. There were over 260 international ramblers participating. There were twice that number participating in the Road Walks but we were not involved in that section.

The Marshals Organisers and Medical personnel were issued with PMR 446 radio equipment. The PMR 446 radio equipment allowed the Marshals, Walk Leaders, Medical and First Aid personnel to communicate with each other throughout the 30 Km Rambles over boggy terrain and in the hills. Steve, EI5DD, "Ground Control", was also in touch via the same system and also with Tom EI2GP who was using 2 metre Equipment which had wider coverage to the ground station. It was via the 2 metre system that any additional assistance could be summoned as this would be free of any other traffic. 

There were four different routes:

Day 1 - Letterkeen Loop
Day 2 - Achill Island 
Day 3 - Mulranny
Day 4 - A Scenic "Roady" walk through the Castlbar Countryside


As can be seen, the weather conditions were variable but never severe and any rain was only a light and misty. The conditions for walking were perfect and it was not too hot. There were many different walking terrains making it an interesting walk and provided many challenges walking across bog and hill. .

The APRS map of the 4 days is shown below. The Letterkeen Loop did not show up too well as it was situated well behind hills and out of range of almost everything. Our Communications worked well but there was a contingency plan if additional help were required.


The map below shows the entire travels of EI5DD for the 4 days plus travel to and from the event.


In conclusion, the event was very enjoyable from both our perspective and that of the walkers. Our radio equipment functioned perfectly. The Marshals, First Aid and Medical personnel learned radio procedure very quickly and were really proficient throughout the event. They would put some radio amateurs to shame! The liaison between the two systems was excellent and all equipment worked perfectly. We always try to introduce something new to events in which we participate but this particular event cannot be improved beyond its current format.

Tuesday, June 25, 2019

DV-Mega DVStick 30

Operation of Internet Radio has been discussed in the posts about the Inrico TM-7 and the RT-4 Radio. The DV-Mega DVStick 30 offers another system to experience both DMR and D-star Radio by simply plugging the device into a computer and running Blue DV by PA7LIM.  The DV-Mega DVStick 30 is available from CombiTronics for 95 Euro.


The DVMEGA DVstick-30 contains a codec by the manufacturer DVSI, the AMBE-3000©. This is a state-of-the-art codec chip, which supports various encoding systems. The DVstick-30 with suitable software can operate different systems like DMR or D-Star and in the future, may also operate with other systems as the software is developed.

A suitable software for use with the DVstick-30 is Blue DV by PA7LIM. This software is available for many platforms like Windows, some IOS versions (Ipad, Iphone) and Linux, and with suitable hardware (OTG capable) even on Android and IOS. Either the internal mic/speaker system in the computer or an external USB headset may be used. PTT keying is done via button defined by the software.


Before operating the system it is necessary to set up the program with personal details and server details for both DMR and D-Star.

The Set-up Screen is shown below


General Settings:

1) Call sign
2) Com Port
3) Can enter your Lat Lon
.
D-Star Settings

Change the Default reflector to your preference DCS 049 I is used in Ireland and has a lot of Northern Ireland Activity on it

DMR Settings

1) Your DMR ID
2) DMR Type - we use BM in Ireland      can be set to DMR PLUS
3) DMR Master - BM_IRELAND_2721
4) Password - passw0rd

IF DMR + is selected
1) Master - Phoenix F
2) Default Reflector - 4400 UK calling channel - Phoenix is not used in Ireland

Fusion only works on the receive side at present

AMBE

1) Tick the AMBE box
2) Select the correct port
3) Select the speed that works best - try the highest first
4) Kill Timer - 3 mins

Click on save and go to the operating Screen

Click on AMBE to select Microphone and Speaker

Select Serial to enable the DVMEGA DVstick-30

Select DMR and the system will default to the BM Server and Reflector selected


Use the slide on the bottom Right hand side for PTT or designate the Space Bar as PTT.

To change Reflector or Talk Group insert the number in the box arrowed. Note that the slider to the right of the Reflector/Talk Group Box selects P for Private Call or G for Group Call.

One of the advantages of this system, is that it is possible to select a Talk Group on screen to sample the activity on it. If there is nothing another can be selected on screen. This makes it easy to find the active Talk Groups without having to go to the trouble of programming the radio and then finding that the Talk Group has little to no activity on it.

The same applies to D-Star as the system un-links and re-links to the new Reflector when selected selected.

Whilst this is a computer based system, it does provide good access into the D-Star and DMR networks with Yaesu Fusion to follow at some stage. There are plenty of avenues for experimentation here.

The The DV-Mega DVStick 30 does provide a quick and easy way to rapid cycle through,  select and test out Talk Groups and D-Star Reflectors prior to programming them permanently into a radio. The DV Stick also serves a good system to monitor D-Star and DMR Reflectors and Talk Groups.

What does the DVMEGA DVstick-30 do and how ?

All digital modes in ham radio require a voice codec (coder/decoder aka vocoder (voice codec)). The purpose of a codec is the transformation of voice into a digital data stream and vice versa, from digital information to analogue voice. During this transformation much happens inside the codec than just an analog/digital conversion. The goal is to reduce the data rate as much as possible, because this will require less bandwidth in the limited radio spectrum. This is achieved by reducing and compressing voice in various ways, on the analog and digital side. These procedures are quite elaborate and hard to develop and therefore well protected by patents.  

Since the digital ham radio systems borrow technology from commercial systems, the codec definitions have been adopted. Although there are free open source codecs available, these free codecs are not compatible with commercial systems because they use different protocols. Every digital radio for D-Star, DMR, P25, C4FM, NXDN etc contains such a codec chip as a component of the radio. All radios need such a a codec chip to transform the digital data into analog and vice versa. This is exactly what the DVMEGA DVstick-30 does.

The benefit of such a 'radio less' application in ham radio is the possibility to stay in touch with the friends at home when traveling without a radio, or where no suitable digital repeaters are nearby. The requirements for the Internet data rate are, thanks to the capable codec chip, quite low, usually an ISDN line with 64 kbps is absolutely sufficient.

Saturday, June 22, 2019

Which DMR Radio?

The Galway DMR Network will be up and running shortly giving superb coverage of the county. This network will be primarily using the 70cms band with the exception of the Multi mode Digital Gateway on 2 metres. Consideration should also be given to the fact that there are still Analog Repeaters in existence. 

All of the DMR equipment available can be programmed with analog FM simplex and Repeater channels in addition to the DMR channels. UHF handhelds are available for less then £100.00 from Ebay and many of the Chinese outlets. It is possible to purchase dual band handhelds which will, naturally cost a little more but are probably worth looking into. Even second hand radios are worth looking into provided that they are in good working order.

Bear in mind that handhelds have their limitations! Galway city is well covered by the EI7RHD repeater and the use of High power and the set top antenna will guarantee smooth operation. Low power operation is possible in the City as the Repeater has a good saturation coverage. Connecting the handheld to an external antenna on the mobile is possible. The colinear on the roof of the house will give impressive results. Remember the weak signal handling of Digital Radio will effectively give a greater distance before the signal degrades. Point to point simplex operation is possible on Digital Radio and has often been used on AREN type operations.

Mobile radios running low power, with the ability to run high power of 25 watts or greater, will make life easier whilst driving through the countryside. Roaming facilities are available on some radios and operation similar to Cellular networks is possible. Some handhelds will allow this facility. There are special Linear amplifiers available for use with DMR systems. Be aware of the fact that they have to be designed specifically for use on DMR. Off the shelf Linear amps for Analog FM will >>NOT<< work. Some say that the GPS transmit facility is a great idea, but it is not necessary and wastes battery. In the end it will, undoubtedly, be turned off all the time for this reason.

From a Galway area perspective, the following radios are discussed as most operators have them and Code Plug Programming can be shared around. If you buy an obscure brand of DMR radio the Code Plug will have to be programmed from scratch by you alone!

The following Radios come with good recommendation.

Tytera MD-380 

The Tytera MD-380 is a reasonably priced single band Radio and can be purchased for less than 100 Euro. Many become available on EBay as their owners probably upgrade to dual bander. Code plugs are available locally for this Radio.

The transmit voice quality is very good and very stable without warble. The receive audio quality is also excellent. Programming is easy enough as can be seen from the "Getting Started with DMR". As can be seen, there are very little controls to worry about once the radio is fully programmed.

Tytera MD-390 UV

The Tytera MD-390 UV is a dual band radio with very good quality TX/RX audio and as easy to operate as the MD-380. This model may have GPS facilities but the addition of GPS only adds to the cost - buy one without GPS!



This radio is easy to program. It will cost a little more for the dual band facility but is still good value for money.

There are other Tytera Dual Band Handhelds and these would be equally as easy to program.

Anytone 868 UV/878UV

The Anytone 868 UV is an excellent radio with good quality audio on Transmit and Receive. It is easy enough to program and operate. There are code plugs available locally. This radio retails for approx £139.00  and is good value for money.


The Anytone 878 UV is almost the same as the Anytone 868 UV but has the addition of GPS and Roaming facilities. It will cost £179.00. It hardly seems worth paying extra for the GPS version but it is the more recent model. It has since been updated to have blue tooth headset compatibility. It will cost more as a result. The display is different but with recent firmware updates, the Anytone 868 UV will look exactly the same. 


Both Radios come with the accessories shown. Both radios have exactly the same feel and operation. Both Radios come highly recommended.

Linear Amp 2- 5 watts > 25 - 40 Watts

It is possible to increase the power out put by adding a liner amplifier in line. The B-Tech A lead is supplied to plug into the Speaker mic socket on the side of the handheld. Plug the Speaker Mic into the front of the unit and connect the mobile antenna to the output and a lead from the handheld antenna socket to the Linear amp. A comrprehensive review may be found  >>HERE

Be sure to state which set the liner is going to be used with. Some sets have a different configuration of the Speaker Mic plug. Aengus EI4ABB uses one of these and reports excellent results whilst mobile. 

Tbe B-Tech Linear amp is suitable for Fusion and D-Star modes,  so it would be a useful addition. The linear amplifier retails for around £100.00 but surf the Internet for a good price.

Tytera MD-9600

The Tytera MD-9600 VHF - UHF mobile transceiver operates in both Analog FM and DMR mode in the bands 136 - 174 MHz and 420 - 480 MHz. RF transmit power  is between 46 - 50 Watts. This Set has been reviewed in an earlier post. The Audio Quality is excellent on both Transmit and Receive. It is easy enough to program and if one has a Tytera Dual Band Handheld the program from the handheld can be pulled across into the MD9600 Code Plug with ease.
This Radio is easy to program and use. The MD 9600 retails around £239.00 and is ideal for mobile operation. There is a GPS option but this is really a waste of money. A more detailed review of this radio may be found >>HERE

Motorola DM4600 Series Mobile Radio

The Motorola MOTOTRBO™ DM4600 was designed for the commercial radio market being ETSI DMR Standard Compliant and delivering really high class audio on both transmit and receive. It is packed with features, many of which one would not use in the general day to day amateur use. There are two versions available which operate on either UHF or VHF with either a high power 45 watt version or low power 25 watt version. The DM4600 may be programmed on both DMR and Analog FM. Whilst these transceivers and their accessories do not come cheap, they are well worth the money. It is unlikely that one would need to try any other radio after purchasing the DM4600.



There is a comprehensive review of the Motorola DM 4600 >> HERE

Prices of this set can vary amongst suppliers but may be around £470.00 on average. Whilst the CPS Software seems to be complex, this radio is very easy to program  one a little experience has been gained with other radios.

Whilst this is only a small selection of popular radios, these are the systems widely used in Galway. There will be a lecture and workshop on CPS programming held in the Autumn. Code plug clinics would be considered to ensure everyone gets good value from their Radio. 

Hotspots

If you don't have a DMR Repeater or Gateway system within you locality, consider a Hotspot. There are many available such as the Shark RF openspot 1 or Openspot 2.  

The Openspot systems are very easy to set up and use. The DVMega is another alternative. Both systems allow all Digital Modes to be operated and are the equivalent of a personal Multi mode Gateway.

In conclusion, one does not have to spend huge sums of money to get started and maybe the Mono band UHF handheld will be sufficient to 'dip the toe into the water'. Having tried the system with an inexpensive system, decisions can be made as to whether DMR is for you.

Outlined in this post are Radios in use locally. There are many more but from a starters point of view, those listed will have you on the air quickly. So many choices!


Monday, June 17, 2019

Galway DMR Network


Work is almost complete on the equipment for the Galway DMR Repeater network. The Antennas should arrive shortly and the Software License upgrades will complete the outstanding work. The Licenses are in the process of approval from ComReg and once the paperwork is through we will be ready to place the equipment on site.

Hytera RD985D repeaters will be installed at each site with battery backup in the event of power outage. The Repeaters will be connected into the Brandmeister Ireland Network.


Brandmeister_EI Network map


Inishbofin Island - EJ7IBD
  
Frequency   430.475 IP  :  439.475 OP            Power 40 Watts     Colour code 1

Antenna  CDF450-ARRAY –    Directional   4 Stack   7.5 dBd  Down Tilt Standard

Abbeyknockmoy - EI7AKR

Frequency   430.825 OP  :  438.425 IP           Power 40 Watts     Colour Code 1

Antenna CDF450-ARRAY  - Omni-directional  4 Stack  6.5 dBd  Down Tilt Standard

Galway City - EI7RHD

Frequency   430.450 IP  :  439.450 OP          Power 40 Watts      Colour Code  1

Antenna Omni-directional 4 x 5/8 colinear  9 dBd

Loughrea - EI7LRD

Frequency   430.500 IP  :  439.500 OP         Power 40 Watts       Colour Code 1

Antenna CDF450-ARRAY  - Omni-directional  4 Stack  6.5 dBd  Down Tilt Standard

Roaming facilities on the Galway Digital Network will be possible.

Each Repeater will have TG 2722, TG2723 and TG 2724 set as Static Talk Groups on Time Slot  2.

Time Slot 1 is used for International Calling & TG9 Local

Time Slot 2 is used for Local EI, GI and UK talkgroups and for general chat & TG9 Local

On Time Slot 1 or Time Slot 2, TG 9 will enable calls to be made via the Repeater but not routed through the network. Two separate QSOs can take place simultaneously on the DMR Repeater. In fact, whilst Time Slot 1 is active for International  contacts, local UK and Irish contacts can take place on Time Slot 2 at the same time.

The Multi-mode Digital Gateway is situated at the Galway City site operating on 144.850 MHz. This unit operates on Time Slot 2 only. It is currently running on DMR, D-Star and Fusion. P25 and NXDN could be set up at some future date.

Finally, we acknowledge the assistance from Rory McGuirk, Radio Security Products,  for  securing the Firmware Upgrade and Licenses for the Hyterea Repeaters and taking the time to talk us through the upgrade process. Radio Security Products are main dealers for Hytera Equipment.

Free downloadable Data Card on the Galway Digital Radio Group Facebook Page in the files section.

Tuesday, June 11, 2019

Getting Started with DMR

Having read the comparison between the various modes of Digital Radio, DMR will undoubtedly stand out as the best value for money considering the price of basic Chinese manufactured equipment such as Anytone, Tytera, Retevis and Aluence. In Ireland, DMR seems to have become the more popular of the modes available at present. A Tytera dual band DMR Radio can be picked up for very reasonable money on Ebay. In the Galway Area a UHF single band Handheld will suffice with the coverage of the Local Repeater EI7RHD and proposed expansion of the network with three additional Repeaters.

The DMR radio is not operable straight out of the box and needs programming which does tend to be a stumbling block to some operators. This program is referred to as a Code Plug. In many cases. somebody will have written a comprehensive Code Plug for their area which may be of use. A Code Plug written for  the South Eastern area of Ireland will not suit the West of Ireland as the Repeaters or Gateways will be on different frequencies. If one is using a personal Hotspot it will be possible to program many channels for use on a simplex digital frequency from which the Hotspot will operate. As the infrastructure expands around Ireland it will be possible to program an All Ireland  code plug.

Initial programming does not have to be complex. Start by programming just the three Irish channels. If no difficulties are encountered it is possible to expand the Code Plug to encompass UK and follow on by adding International channels.

Terminology

A few basic terms need to be understood before proceeding to th programming of the Radio.

Time Slot

DMR uses Two-slot Time Division Multiple Access (TDMA) allowing two channels in 12.5 kHz of bandwidth using the AMBE+2 proprietary codec (or vocoder, voice encoder). “Spectrum efficiency of 6.25 kHz” is often used  although ‘it really uses 12.5 kHz, half the time.’ An illustration of the difference between an Analog signal and a DMR TDMA signal is shown below.


As there are two time slots it is possible to hold two conversations at the same time - One on Time Slot 1 and the other on Time Slot 2. Effectively this is the equivalent of having two repeaters on the one site but only using one TX/RX, one set of cavity filters and one antenna.

A user can only access one time slot at a time. Two Talk Groups cannot be accessed on the same Time Slot simultaneously. Each Time Slot occupies the signal for less than 30ms at a time. Within a 60ms window on a repeater: Time Slot 1 is transmitted for 27.5ms, then a gap of 2.5ms, Time Slot 2 is transmitted for 27.5ms, another 2.5ms gap, and then repeats with Time Slot 1. As there is slight latency in the demodulation of the DMR signal, the human ear will not  detect that small of a gap in audio. A repeater transmits both time slots even though one channel is in use and the other idle. This cuts down on the on/off keying of the repeater. User radios, on the other hand, transmit for 27.5ms each 60ms window. This results in extended life of the handheld battery. 

Talk Groups (TGs) - A way for groups of users to be separated on each time slot, without distracting or disrupting other users, is to use Talk Groups. The radio stays muted until the assigned Talk Group appears on the frequency, then it will unmute or activate for that transmission.
.
Ham radio Talk Groups can be created for any purpose and usually fall into the categories of Wide area (worldwide), Regional or for a particular purpose or group. In Ireland TG 2722 is a Calling Channel, TG 2723 is a Chat Channel and TG 2724 is a bridge between DMR and Yaesu Fusion. TG 2724 is connected into YSF Ireland allowing those on Yaesu Fusion to communicate with DMR users. The UK has a number of Talk Groups, UK Call, three Chat TGs and a number of Regional TGs.

TG 91 is a worldwide Talk Group monitored all over the world. Europe has a specific English speaking TG amongst others, the United States has a Nationwide call TG and also many regional TGs for each call sign area. 

In Ireland we tend to allocate Time Slot 1 to International Talk Groups and Time Slot 2 to our Domestic TGs and UK. Bear in mind, that calling on International TGs may come out on many Repeaters at once so do request that a longer QSO is conducted on Time Slot 2 on a "chat" TG.

TG 9 is a talk group assigned for non specific use. If calling another station point to point, the use of TG 9 will be a common meeting point. If used via a repeater, the Repeater will behave like a normal voice repeater and just relay the up-link. Any other Talk Group will be routed through the network to its destination. An example, TG 2722 would route through the whole network for a general call. 

Static TGs - A static Talk Group is a talk group programmed onto the Repeater on a specific time slot. If a call should be made on this TG, then it will be automatically relayed through the repeater. Sveral Static Talk Groups may be programmed onto a repeater. International TGs would be programmed to TG 1 and Domestic and UK TGs on Slot 2.

Dynamic or User Access (UA) TGs - Dynamic TGs are those selected by the user. These are pre-programmed into the Radio. On pressing the PTT they will automatically routed through the network. If one selects another Dynamic TG, the Repeater will disconnect from the one previously used and connect to the newly selected TG. If a Dynamic TG has not seen any use for 15 minutes, it will automatically disconnect from the network.

Reflectors - are similar to D-Star or IRLP reflectors,  where nodes are connected in a round table type configuration. When one station transmits, their signal is transmitted by all other connected nodes. So far, these sound like Talk Groups. The difference is reflectors are available worldwide and repeater users have to specifically link and unlink a reflector. This means only repeaters and hotspots connected to that reflector are tied up during transmissions and not thousands of repeaters on world-wide Talk Groups. 

A Reflector has a 4-digit ID that begins with a 4, as in 4xxx. Reflectors are only available on Time Slot 2 via the Brandmeister system. To disconnect from a Reflector on keys in 4000. Reflectors may be programmed into a memory bank. Brandmeister have this ability. Some reflectors are cross-patched to Talk Groups on Brandmeister so either the reflector or Talk Group ID can be used. Reflectors are seldom used on Brandmeister because of the availability of all Talk Groups to all repeaters and hotspots on the network. However, reflectors still serve the intended purpose if a station isn’t in range of a Brandmeister repeater.

Contacts - There are three call types in DMR: Group Call, Private Call, and All-Call. Each is a contact within the radio. A Group Call is a transmission from one radio to a group of radios. These instantly link-up dynamic Talk Groups when PTT is pressed.

An example of a Group Call would be TG 2722 (Ireland Calling Channel) When the PTT is pressed, any radio linked into and listening on TG 2722 will unmute and the call will be heard.

A Private Call may be initiated from one radio to another using the Radio user's ID point to point or via the network. If the radio called has used the network the call will be routed to the last known Gateway or Repeater - a little like D-Star! Private Calls are discouraged on the network as they can tie up a Time Slot or even break into an existing QSO on the destination Repeater. A Private call may only be returned if the originator's ID is programmed into the destination radio.

All Call is a facility used by a supervisor on commercial systems and will result in the call being heard by ALL users on the given time slot. This is NOT used under any circumstances on an Amateur Network for obvious reasons.

Getting Started

It is necessary to register for a DM ID number which is your personal ID and this will link to your call sign and name. Registration for a DMR ID may be obtained  >> Here.

Follow the instructions and have a PDF copy of the front page of the license to upload completing the registration process. The ID is issued within 24 hours. Follow the steps below and programming will become second nature. Rome wasn't built in a day, and neither will your code plug!

The order in which programming is done is as follows:

1) Contacts
2) Channels
3) Zones
4) Placement of Channels in Zones

The programming software for an individual radio is down-loadable from the manufacturer's website, or on a disc supplied with the radio. In this brief tutorial, it is the Tytera MD-380 or clones such as Retevis or Zastone handhelds programming described.

On running the program this is the first screen that will appear


If the set is a UHF handheld, this is the basic information see. Attach the programming lead supplied with the radio to the computer and then switch the radio on. Look along the toolbar of the program ans to the right of the disc symbol there is a picture of a handheld radio with an white arrow pointing to the left. Click on this and anything programmed into the radio will be downloaded to the program on screen. Normally, there is one channel as an example already in place. The view shown is the Basic Information which is the first item in the menu.

General Settings

Click on General Settings and the following screen will appear


Look at the positions highlighted by the red arrows. The Radio Name is your Call sign and this is typed in Capital Letters. The Radio ID  menus the DMR registration number assigned to your call sign. The two boxes shown at the bottom right of the screen can contain in Line 1 - your name and Line 2 - your call sign. These may be left blank as they will not affect the operation of the radio. Best to leave all of the other settings alone until a greater understanding of the radio is realized.

Contacts

On the menu, click on Digital Contacts and this screen will pop up


Click "add" at the bottom of the screen. Enter the name of the contact in the "Contact Name" box - it is possible to replace the words "Contact 1" with the name required/ Click on Call type and three options will be available on the drop down menu. Most Talk Groups will be Group calls, whilst individual call signs will be Private Calls. Enter a contact here which may be a Talk Group, Reflector or an Individual.

Any number of contacts can be added to this box for future use

To program a channel the layout would be as follows:

No    Contact Name        Call Type       Call ID

1          Ireland Call           Group            2722

2          Ireland Chat         Group            2723

3          YSF Ireland          Group            2724

4             EI4ALE               Private          12345

A complete list of individual Talk Groups may be found >> Here

Ireland Call is the Irish calling channel. It is a Talk Group and will be a Group Call so all can hear that call when it is made. 2722 is the DMR ID of that Talk Group. EI4ALE is a Private Call so when the call is made it will be only directed to that individual. On completion of the contacts screen, the next task is to assign channels.

Channels

From the menu, select "Channels" and the following screen will appear


All of the positions with red arrows need to be filled in the following order

Channel Name - From our Example above, this one can be named Ireland Calling Channel
Channel Mode - Generally defaults the Digital, if not the drop down menu will allow selection
Frequency - Your Choice of Frequency for the RX and TX frequencies. The same if simplex.
Contact Name - Click on the down arrow and all of the contacts will be displayed. Choose The Ireland Call Channel
Colour Code - Can be any number 1 -15. generally set to 1 unless otherwise required
Repeater Slot - Can be set to 1 or 2. On repeaters, International contacts on Slot 1 local on Slot 2
TOT (S) -  Set to 180 secs as all networks time out after 3 mins
Power -  Set to low power if using a local Hotspot or High for a Repeater

If it is planned to use the Radio with a Hotspot such as an OpenSpot or DVMega, program the simplex frequency of the device you wish to use.

It is possible to program Analog Channels for Repeaters or Simplex use. CTCSS tones can be included on Analog Channels.

Zones

With earlier set there were a maximum of 16 zones where 16 channels could be stored in each. This equates to about 256 channels. This allows one to sort specific areas into a common Zone. A Zone could be Ireland and UK contacts where all Irish and UK channels could be stored, Another could store USA channels and so on.

Zones may be selected from the menu. Click on Zone 1 in The menu and the screen shown will appear. This Zone can be renamed relevant to the channels therein. Click on Zones several times and more will be added.


Click on Zone 1 in the menu and the screen shown will appear. This Zone can be renamed by back spacing over Zone 1and giving a relevant name for the channels contained therein.

To add channels to the Zone, the available channels will be shown in the Left hand column. Click on a channel in the list as in channel 2 in the diagram which is highlighted. Click the add button in the centre of the box and the channel will be transferred into the Zone on the right hand side as a channel member.

In the case of the Tytera MD-380 there are only 16 Zones available for programming with channel members.

Now SAVE THE PROGRAM to the computer before transferring the code plug into the Radio. It is generally best to program a few channels and try them out before adding more. Program local channels first and then move on to outside the country.

Most DMR Radios follow this protocol. It may seem laborious in the beginning but it becomes second nature after a few tries. It is really no different to using Chirp to program Analog Radios.

Operation of DMR

Once fully programmed, switch on the radio, select the Zone with the desired contact contained therein. Press the PTT and put out a call. It is normally wise to call on a calling channel such as Ireland Call or UK Call. From there one can move to a chat channel. A more complex Code Plug will have channels allocated for use on Hotspots, Gateways and Repeaters depending on the equipment in the locality.

Bear in mind that International contacts should be made on Slot 1 and Local and UK contacts on Slot 2. This will ensure free QRM free operation. Remember that calls made to Talk Group 9 may be used on either Slot as these will only be relayed locally and not routed through the Brandmeister Network.

Galway Facilities

The Galway City DMR Repeater EI7RHD operates on Input 430.450 and Output 439.450. Both Time Slots may be used. TG9 is relayed through the system in the same manner as an Analog Repeater. All Other Talk Groups will be routed through the Brandmeister Network. Talk Groups 2722 Ireland Call, 2723 Ireland Chat and 2724 YSF Ireland are programmed in as Static Talk Groups which means that any activity on any of these Talk Groups will be re-transmitted by the Repeater.

The Galway City simplex Multi-Mode Gateway EI2GCD operates on 144.850. This Gateway only operates on Slot 2. The Gateway is located on the same site as the Repeater. The operation of Busy International Talk Groups on this device is not encouraged as they tend to take over the system preventing other users benefiting from the system. It is ideal for use with Local and Semi-Local Talk Groups. Always Disconnect from busy International Talk Groups after use.

Proposed Expansion

The Galway DMR Network is due to expand with a Repeaters located on Inishbofin Island, Abbeyknockmoy and the Eastern side of Loughrea. This should provide 95% coverage of County Galway with spillover coverage into neighbouring Counties.

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Monday, May 13, 2019

Phase III & Phase IV of the Galway DMR Network Proposal Updated

Recent discussions have taken place regarding the placement of Repeaters to complete the Galway Digital Network. Each of these Repeaters will be running DMR only.

Proposals put to the three Radio Amateurs, involved in the Wireless Internet business, have been productive and greeted with enthusiasm and acclamation. Kind offers of feeder and possibly antenna systems have also been made which will speed up the process.

We await the final Software and firmware upgrades for the Hytera RD 985 Repeaters and also the licensing process to issue. We should have all in place as soon as possible. Minimal bench testing is required to get this system running as the initial programming has already been completed.

Assuming all four Repeaters are installed and running, as anticipated, the following maps reveal the probable coverage for the entirety of Co. Galway and neighbouring Counties such as Mayo, Roscommon, Clare and even touching into areas further afield.

See the coverage maps below:


The locations L - R  -- Inishbofin Island, Galway City, Abbeyknockmoy and Loughrea all situated in Co. Galway.

The illuminated satellite map below shows the coverage with a little more clarity


By implementing Roaming facilities, there would be almost seamless coverage of the County and surrounding areas. All that is required is adjacent areas to place something on the air to cover the South, East and North.

Overlapping coverage from other Repeaters adjacent to the Galway coverage areas would complete the picture. An Example would be the Repeater located on Mount Leinster which would give coverage of the South East and one could roam from Galway coverage into the Southern coverage through this system.

Factoring Mount Leinster's Digital Repeater into the Galway coverages, the net result is shown below


There are supposed to be Repeaters covering Cavan, Dublin and Drogheda that would also complete the picture. Sadly neither Cork, Kerry or Limerick have any interest in setting up a system at present.

Interesting times ahead! Watch this space for updates.

Monday, May 6, 2019

Interested in D-Star?


D-STAR (Digital Smart Technologies for Amateur Radio) is a digital voice and data protocol specification for amateur radio was developed by the JARL and was the first digital radio system designed specifically for Amateur Radio. The D-Star system was in the development stages in the late 1990s before its release in 2004. At the Dayton Hamvention (2004) there were demonstrations of D-Star and the AOR 9000 Digital voice system used on HF.

The advantage of D-Star, like all of the other Digital modes, is that it utilizes less bandwidth and the quality of audio is better than an analog signal at the same signal strength provided that the signal is above the minimum threshold. D-Star has the advantage of a number of years development over the newer Yaesu Fusion System.  
   
D-Star is capable of linking repeaters together locally and through the Internet utilizing call signs for routing of traffic. Servers are linked via TCP/IP utilizing proprietary "gateway" software, available from Icom. This allows amateur radio operators to talk to any other amateurs participating in a particular gateway "trust" environment.    

D-STAR transfers both voice and data via digital encoding over the 2 m (VHF), 70 cm (UHF), and 23 cm (1.2 G)Hz) amateur radio bands. There is also an interlinking radio system for creating links between systems in a local area on 10 GHz, which is valuable to allow emergency communications oriented networks to continue to link in the event of Internet access failure or overload.  

What is available - a picture is worth a thousand words


D-Star transfers voice and data by digital encoding over the 2m, 70cm, and 1.2 GHz amateur bands. There is an interlinking radio system for creating links between systems in a local area on 10 GHz which would allow emergency communications oriented systems to continue to link in the event of Internet access failure or overload. See below
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Features

1) Digital Voice Mode through Repeaters and Gateways Internet Access
2) Short Data Message whilst in Digital Voice mode
3) GPS tracking mode whilst in Digital Voice Mode
4) Digital Data Mode via the Internet
5) I.P. camera in Digital Data Mode - watch digital images sent in real-time
6) Point to point direct Digital Voice mode
7) Analog operation direct or via Analog Repeaters or Gateway

Most D-Star operation results from users talking over links to other users connected to reflectors. Reflectors are conference servers. Many Repeaters may be connected to a particular conference server. A transmission on any one of the connected systems is repeated on all of them. There are actually more operators to talk to than just those connected to within the RF distance of ones own local repeater.

Getting Started 
   
It is necessary to register for the D-Star Network. This is simple enough as it is possible to register via Icom UK. Send the following: Name, Call sign, Postcode or location, and email address, to info@icomuk.co.uk. This is probably the easiest way. It is also possible to do it yourself via by Googling D-Star registration. This can have its own problems! Once Registration is complete, it is possible to use the facilities D-Star has to offer.   

Setting up the Radio

As with most radios, it is necessary to set up the date, time, and add your call sign. The GPS may be left on to send out position information but, if it is not required, turn it off so save the battery. Select the desired mode - either analog or DV.
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Facilities

 Simplex Operation


Local Repeater Call



Gateway Repeater Call


 Calling Via a Reflector


Linking to Reflectors

There are a couple of  systems available:

D-PLUS has probably caused the most significant D-Star growth around the world. D-PLUS reflectors are designated REF###x as in REF001C etc.

Two other linking systems have since been written:

DExtra creates XRF reflectors and DCS creates DCS reflectors. They all operate in a similar way.

Linking is relatively easy. Most D-Star Repeaters allow registered users to issue Link and Unlink commands over RF. These commands need to be inserted into the URCall of the radio and then press the PTT. An Example of a Link command to REF001C as follows -- "Place REF001CL" in URCall. Note the first 6 positions are for the name of the reflector as in REF001, the 7th  position is the Band Module, normally A, B, C, D, E,   and the 8th position is the D-Plus command. L is the link command and U is the unlink command. Is is common practice to program the a couple of memories with these commands.

Practical Use of D-Star
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Most D-Star Repeaters are connected to Reflectors. Any Radio Operator registered with D-Star can connect with another Radio Operator beyond the coverage of the local Repeater. Connection to any part of the world is possible with a relatively simple combination of button presses.

D-Star can be used with Digital Access points such as the DVAP, Openspot and DVmega etc.

One of the outstanding features of D-Star is the ability to call another operator without knowing their current location or on which Repeater or Gateway they are located. If an operator has used a Repeater of Gateway in the UK, it is possible to connect to their call sign via one's own Repeater/Gateway and D-Star will automatically route to the last known destination. If should move to another area and use D-Star it will automatically route to the new location.

Facilties Available in Galway

D-Star has been implemented on the Galway Multi-Mode Digital Gateway on 144.850 MHz. Aengus, EI4ABB, has a D-Star Gateway which may be pressed into service on the 70cm band at some future point in time. 

In Conclusion

D-Star has been around since 2004 and many modifications to the system have been made to the operation. D-Star is a System designed specifically for Amateur Radio use and is quite complex as a result. APRS and Digital messaging are possible whilst in QSO and are transmitted simultaneously.

It is not easy to use equipment straight out of the box and reading the manual is essential to derive the best possible use. The basic ID-51E Plus2 manual is 90 pages long and explains the use of the system very well. The advanced D-Star Manual for the ID-51E Plus2 Handheld is literally 400+ pages long and is useful for reference purposes. It would take some time and patience, which we as amateurs don't have, to wade through this manual. We are, however adaptable!

The Nifty E-Z guide to D-Star Operation by Bernie Lafreniere, N6FN, gives an easier tour of the facilities with comprehensive explanations. The Nifty Mini-Manual is also a superb source of reference. In addition, D-Star is well documented on the Internet so there are plenty of resources should difficulties be encountered.

There are over 50,000 D-Star operators so there is no shortage of people to chat with. A number of Worldwide D-Star nets are held and they are well populated. As a starting point, try REF 001C where there is an abundance of activity. Reflector  DCS 049 I will yeild activity from all over Ireland both North and South and REF005C for the London area.

D-Star operation is possible on most amateur bands from 80 metres to 10 GHz

Voice quality is excellent and especially somewhat enhanced since the AMBE+2 chip has been implemented.

Verdict - A steep learning curve but once mastered it becomes second nature.