Author Archives: VK6LD

D-Star Progress/Update – 15 April 2008

VK6RWN: Brief Status Update

  • Power on
  • Feedline installed
  • Lightning arrestors ready
  • Racks installed
  • DSL installed
  • Server awaiting final config changes
  • UPS awaiting batts
  • PSU ready
  • 2m Filters being tuned
  • 70cm Filters being tuned
  • Antennas TBA (awaiting further discussions amongst all DSTAR groups)
  • WIA license waiting

In terms of physical work required, I believe that most of it could be knocked over in a weekend with a few helping hands. Perhaps if we can have some more people volunteering for some tasks, we can speed things along. food for thought.




Long weekend produces more favourable VHF troppo conditions along the West Coast

Favourable troppo conditions leading up to the Labor Day Long Weekend of 1, 2 & 3 March 2008 produced more VHF DX 2m contacts into the north-west coastal areas.

At 1800LT on Friday 29th February 2008 conditions allowed contact into VK6RAP whilst mobile 20kms south of Dongara all the way through till approx 30kms from Geraldton whilst travelling along the Brand Hwy. Contacts were made with both Danny ? VK6FZUK (Mobile) and Joseph – VK6AAO (Mobile). VK6RAP returned a signal varying between S2 & S9 for the QSO?s with total distances ranging between 360 ? 400kms whilst mobile.

A trough lying along the West Coast was responsible for the favourable conditions and can be seen the Hepburn Tropo Charts. (Click to see)

73?s, Duncan ? VK6GHZ


D-Star contacts in Melbourne

I was in Melbourne for a couple of days this week and was fortunate enough to loan a D-Star equipped handheld from Duncan VK6GHZ for the trip.

I configured the handheld before heading to Melbourne from the instructions on the Australian D-Star website. (Recommended) . I am usually the type that can take a radio straight from the box and start operating it, hardly having to read the user manual. I am afraid that with the D-Star radio this wasn’t possible and I had refer to the manual on more than one occasion! Once the D-Star was setup for the first time I could put the manual away, but there are certainly more functions in it than I was able to use.

I fired up the radio after checking into my accommodation in Kensington (Approx 5kms from the Melbourne CBD) and did some listening around.

Quite a bit of activity was heard on 70cm repeaters and simplex frequencies. QSO’s were also heard on 2m & 6m from around Melbourne.

With a slight bit of trepidation I put a call out on the VK3RWN D-Star repeater. No CW identification, courtesy tone reset pips, unsquelched mute noise or even a reply call came back.

I called on the repeater a second time, listening to the output on my other handheld and could hear the repeater transmitting. I was also looking at the display of the D-Star handheld and watched ‘VK3RWN’ scroll across the display.

The speaker then came alive and VK3BMX responded to my CQ call. His callsign scrolled across the handheld display and we had a short contact. The audio was crisp & clear even on the handheld speaker and sounded slightly ‘nasally’.

The repeater was quite good signal strength even inside the QTH I was staying at. I did some quick experiments with the transceiver horizontal at floor level to get the signal level quite low and the digital audio not decoding cleanly (garbling) or what the locals call ‘R2-D2’.

When using the repeater, a four (4) second gap between transmissions must be left between transmissions for the system to reset (No PTT machine gunners!). This can slowdown a QSO a bit, but according the D-Star gurus this is needed to reset the system correctly after each over.

The D-Star repeater would be quite disconcerting to the local repeater ‘kerchunker’ – No CW idents, no timeout reset pips, unsquelched mute noise or your rig speaker popping open to keep the crowds entertained from this baby. Worse still for the kerchunker is that your callsign scrolls across the screen of everyone that is QRV on the repeater as well as being logged and visible on internet.

From my further observations later, I would estimate that the digital decode became garbled down around what you would expect to hear from a station with a S1-S3 signal level in the analogue FM world. As would be expected, the D-Star didn’t decode down into the noise, but a low signal sounding so clear would certainly be a welcome suprise to most FM users!

The next day I had a couple of more contacts on the VK3RWN repeater to gain an impression of the system. I also took the handheld portable around the streets of Kensington for a brief test. Mobile flutter or picket fencing becomes a thing of the past with D-Star, but garbled decodes and R2-D2 come into play. I guess that where you might lose half a word or a word on mobile flutter, I found on D-Star that it became one or two words until the decode could resume.

I also joined in on a local net one evening where a number of stations discussed D-Star and assisted each other with their D-Star experiences and helping others through problems or issues. I could also see that some operators had their name or the radio they were using in ‘My Info’, but this information is limited to 4 alphanumeric characters.

I also made a few recordings of QSO’s that took place on the repeater to listen to the action. (MP3 format)

QSO 1 (3.9mb)

QSO 2 (2.9MB)

QSO 3 (4.6MB)

QSO 4 (4.6MB)

In summary, it was quite exciting to use this new mode. The communications are exceptionally clear and all the possibilities for sending voice and data over our bands seems endless. I imagine this comes with every new innovation in amateur radio, be it SSB, FM, repeaters, satellites, packet radio, IRLP or Echolink.

The cost of new equipment seems quite reasonable and the add on D-Star capability for some older models is also good to see. Hopefully in time other manufacturers of equipment will also have D-Star equipment available in the market to spurn competition and innovation.

Australia has been very lucky to have Icom & the WIA support the provisioning of D-Star repeaters in several states. Due to the high costs of purchasing and maintaining a D-Star repeater it is unlikely and unfortunate that we will not see use spread outside of the metropolitan areas in the near future.





More coastal ducting into Geraldton

Early this evening (27/12/07 1830hrs) conditions again improved and two-way contacts were made between Christie – VK6XCJ, Mick – VK6YXL and Jon – VK6NOW utilising VK6RAP (Roleystone). Jon was able to hear the input signal at around S0-S1 / R5 with Jon’s input signal being copied at S1 / R5 in Geraldton.

Contact was also established with Barry – VK6HX utilising VK6RMW (Mt William) that was a strong S5-S6 signal into Geraldton. Barry indicated he could hear he input signal at S0 / R5 and Barry’s input signal could be heard at S1 / R5 in Geraldton – a simplex distance in excess of 500kms.

Duncan – VK6MHZ


VK6RSR heard in the Mid West Region of WA

Today (27/12/07) at 0830hrs, VK6RSR (Simplex Repeater, Perth) was heard in the Geraldton / Greenough area whilst mobile on the Brand Highway (375km). Signal strength peaked at S5 and the repeater was easily accessible on its input / output frequency of 147.225MHz. Unfortunately no stations were worked via the repeater although a number of calls were made.

Also, VK6RAP (Roleystone), VK6RLM (Lesmurdie) and VK6RTH (Tic Hill) could be heard and worked with signal strengths varying between S5-S9. QSO?s were made with both Joseph ? VK6AAO and Martin ? VK6MJS (both homebase) via VK6RLM. Both stations were readable on simplex around S2-S3. VK6RCW (Morse Beacon) was also audible at times (S1-S2) from its home in Orange Grove.

Included below is a MSL Pressure Chart and William Hepburn?s Tropo Forecast indicating the deep trough centred down the West Coast giving rise to the rare conditions today.

Duncan – VK6MHZ

Hepburn Charts Link

BOM Synoptic Charts Link?

MSL Pressure Chart


Hepburn Chart



VK6RSR Repeater On Air

Simplex (Parrot) Repeater VK6RSR, a combined project between VK6GHZ Duncan & VK6JRC Rob, has recently been licensed and placed on-air.

VK6RSR is co-located with VK6RVP (70cms Repeater) and VK6RVP-1 (APRS Digipeater) in Leonard Street, Victoria Park and provides coverage to the Perth Metropolitan Area.

To access VK6RSR, transceivers should be set to Simplex Mode (no repeater offset required) with 147.225MHz being set for the operating frequency. 30 seconds of record time is available ? please pause for 2 seconds before talking.

VK6RSR serves a number of purposes which include the following:

  • Antenna Testing;
  • Alignment of Transceivers and Receivers;
  • Modulation Checking;
  • Path Loss Measurement;
  • Alternative Calling Frequency for those not wishing to utilise main Perth repeater frequencies; and
  • Brief repeater capabilities for those stations unable to maintain Simplex contact.

Photos can be seen here.

As the repeater has only just been placed on-air, coverage reports from around the Perth Metro Area and beyond would be welcomed and can be emailed to Duncan (VK6GHZ)

Feedback on any technical difficulties experienced can also be directed via email to this address.

VK6RSR is proudly supported by VK Batteries.


D-Star -v- Analogue FM

Adrian VK6TUX has released an MP3 recording of some comparison tests he has conducted between D-Star and analogue FM on 2m/145MHz over a 40km path.

Adrian writes: “Done with VK6AWO Steve. We found DV mode to have good readability after FM analogue contact was lost. The lack of noise or interference(esp near power lines etc) is spooky & unusual for radio transmission, and is a big plus for the mode. All other files associated with the test are at files section of;

VK6TUX D-Star -v- Analogus FM Test MP3 (1.5MB)

IC-PCR2500 screenshot showing DV text (203kB)


D-Star Brochures

Heath (VK3TWO/6) has located several Icom brochures on the D-Star system and D-Star capable radios.

The documents are in PDF format and rather large, so please be mindful if you are on a dial-up connection or have a low monthly download quota.

D-Star System Introduction (600kB)

D-Star System Overview (2.8MB)

Icom IC-2200H (322kB)

Icom IC-2820H (636kB)

Icom IC-91AD Handheld (690kB)

Icom ID-800H (502kB)

Icom IC-V82 & IC-U82 Handheld (784kB)

Icom V-82 (Review QST 2005) (418kB)

Documents are provided for the information of WARG members. All documents are copyright by Icom & QST/ARRL and remain the property of Icom & QST/ARRL respectively.


D-Star Working Group

The West Australian Repeater Group (WARG) have established a D-Star Working Group.

Members are:

Phil Sutherland – VK6KPS

Danny Ainsworth – VK6FZUK

Anthony Benbow – VK6AXB

Eddie Saunders – VK6ZSE (WIA TAC representitve)

Heath Walder – VK3TWO/6


2M Repeater – Hamtronics Links

Thank those of you who have replied to the idea of rebuilding our repeater network sing equipment like the Hamtronics REP-200.

The point was made that we would be best to perhaps buy one or two and see just ow well they work.

Hamtronics have been making amateur repeaters and many other amateur products or at least two decades. The REP-200 is a proven and very reliable repeater. Do a search on the web and you will find endless information about the REP-200 along with user comments. I see little point in using the argument of only buy one or two to see how they work. However for the total skeptics this may be required.

What we do need to be sure of is the functionality of the repeater in terms of linking and the way we use repeaters in VK6, such as WIA news broadcasts. Remember these repeaters are set up for the American amateur, but they are
used all round the World.

What we should understand is what does warg see as its future? Is it just doing the same building repeaters over and over hoping to come up with the repeater of all repeaters? Is it so in the process of building replacement repeaters, amateurs
become involved and learn? This was one of the reasons touted a couple of decades ago and it did not work.

Now stop rolling your eyes and saying that was then (at least two Iraqi wars ago) and now is now. Getting a significant number of amateurs involved in building replacement repeaters can happen but the odds are against you. This is due
to logistics of getting people together on a regular basis over a long period of time. It can be done but it requires a very dedicated one or two people with the time to organise this to happen. Busselton, Tic Hill & Cataby are examples of
where it did happen but you need that special person of persons to drive the project.

The projects mentioned were largely due to Jill Weaver VK6YL being that special person who did much of this organisation.

However the Hamtronics repeaters built from the kit form is a much easier group project that could happen. Building 10 repeaters from X commercial equipment very unlikely.

The point;

The reason for my renewed interest in what warg is moving towards doing, replacing the existing 2M repeaters with modified X commercial equipment, I firmly believe will not work to the extent we all would hope.

Money seems to be the main argument against the REP-200 concept. Warg has been a very successful club for over 3 decades and it is only of recent with the donation from the VK6WIA that it has become well off. For most of wargs existence the club only had a few dollars at best. What better way to spend the windfall from the WIA than spend it on an investment in the future and then move on to doing more than just re-building repeaters.

I will find out the exact total cost from Hamtronics for the cost of 10 completly built and tested and the cost of the 10 kits.

Links to sites on the Hamtronics Repeaters

Hamtronics REP-200

Repeater Builders Website

Why a Hamtronics Repeater?