Category Archives: Heard on Air

Heard on Air

Fremantle (VK6RFM) has a new antenna.

The Fremantle repeater VK6RFM now has it’s new antenna installed thanks to Bob VK6KW.

Coverage and Signal reports so far show a significant increas in the repeaters coverage compared to the temporary discone antenna.

Some have reported that the signal is better than the previous repeater location, whilst others have reported that it’s slightly lower. This is to be expected as it’s physically in a different geographical location, as well as using a new antenna with different gain and radiation pattern.

We plan to do some more testing/tweaking on the Cavity Filters to improve on the repeaters performance.

Please let us know any signal/coverage reports.

Echo/IRLP is also back online. It was ofline for a short period as the Echo/IRLP ‘node’ couldn’t access the repeater with it’s temporary antenna.


Perth-Geraldton site propagation testing

Xmas/New Years period will see a week of propagation testing from potential site ~345m HASL up in the hills about 170km south of Geraldton, 75km north of Cateby. Temporary equipment including APRS 145.175 and VK6RLM 146.750 repeater will be running from the site from 26th Dec 2010 till ~2nd/3rd Jan2011. APRS will consist of a Digipeater and frequent beaconing (25W & 50W). Equipment will be powered by 120W solar panel, with antenna mounted on a 15m mast. Keep an ear out on both frequencies and let us know on warg @ if you hear anything.


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



VK6RAP Roleystone worked

146.700 VK6RAP repeater is audible down here at Cranbrook this morning for most of the news broadcast.? (Approx 320kms)

Unfortunately the signal is up & down so I don’t know if I was getting through or not and it is frustrating when everyone is so quick on the mic PTT in the callbacks to give me a chance of getting in at the right time!