AREG News: September Meeting – Power Supplies

AREG’s next meeting is this coming Friday the 15th September at the Reedbeds Community Hall, Phelps Court Fulham, doors opening at 7:45 pm.

This coming meeting will be another in AREG’s Amateur Radio Beginners Series and the topic for this evening will be, Power Supplies.

Matthew, VK5ZM, will take people through the basics of power supplies, what their characteristics are and what do people need to look out for when selecting a power supply for Amateur Radio use. He will also discuss the pros and cons of Linear vs Switchmode and what makes a good or bad power supply.

AREG Repeater News:

We have noticed that VK5RSB 70cm appears to be dropping coverage. Our fault investigation team will take a look at our earliest opportunity but we suspect a problem with the antenna feeder or connectors. Also the VK5RWN D-STAR repeater is suffering from reduced performance due to mechanical issues with the antenna mounts. Plans are well underway to make repairs at both sites, which we hope will be completed in October.

Contesting news:

AREG is again making plans to mount a portable DX Contest Station for the Oceania DX Contest in October. This will be a QRO Multi-Multi station this year operating from a new site north of Adelaide. We hope to see other VK5’s get involved in this contest this year too, as it is your one opportunity to have the DX stations around the world pointing their antennas our way looking for us! The OCDX SSB contest is being held on the weekend of October 7th and 8th.

In DX News:

AREG wishes Grant VK5GR good luck in his activation of Niue starting next week. Grant should be heard across VK signing as E6AG, Echo 6 Alpha Golf, from September 14th through until September 25th on most HF bands. So keep a lookout for Grant and Grant, goodluck with your operations.

2017/18 Subscriptions now Due

Finally, all AREG members should note that their subscriptions are due for 2017/18. It is a great time to be a member of AREG and this year will be big, with the club turning 20 years old next July – who would have thought! Look out for some special activities throughout 2018 marking the occasion.

So remember folks, come along to AREG’s next meeting, it is this coming Friday evening, everyone is most welcome.

After the formal events, a light supper of tea, coffee and cake will be available whilst you can mingle, review and discuss the topics of the day.

 

VK5RWN DSTAR Repeater Damaged – Repairs Pending

In the wild weather over the past few weeks the VK5RWN repeater system has sustained some structural damage.  The original tower section is currently bent at a rather alarming angle and will require replacement.

In the past few days we have had our repair crew up there to shore up the tower section and make temporary repairs until a more permanent solution can be found.

There is still internet connectivity to the site and the D-Star repeater is still operational for the time being.   Users may find that the coverage of the repeater is somewhat disturbed however.

In the coming weeks the antenna system will need to be upgraded, so there will most likely be a prolonged period where the system will be off air while repairs are being made.

VK5RSB Maintenance Day – Battery Backup & 6m Antenna

Since the statewide power blackout last year, AREG has been assembling replacement parts for the battery backup system on our VK5RSB repeater system. Now that this last weekends excitement is over, I am now able to compile and present a detailed report on the working bee at the VK5RSB repeater site at Summertown.

Working bee members,

  • Ben VK5BB
  • Colin VK5ACE
  • Paul VK5BX
  • Adrian VK5ZBR
  • Rod VK5UDX (both Rod and Adrian were on an official task at the site in their employment but were able to spend time assisting at the site)
  • David VK5MDF (invited visitor from NERC)

The aim of the working bee was to replace the cavities on the 23cm repeater, reinstate the battery backup system for the 70cm repeater (disconnected several years ago when the repeater was replaced with one requiring 24v input) and install (finally) the permanent replacement 6m repeater antenna (delayed multiple times in the past due to weather).

Work completed successfully included

23cm Repeater:

  • 23cm duplexer fine tuned (thanks to Paul VK5BX and his Specan/tracking generator)
  • the old 23cm removed and the new one fitted, tested into the antenna and live on air, all good

70cm Repeater

  • the 12 volt to 28 volt inverter installed into rack and wired in,
  • RF power out of 70cm when on battery backup has been set to 30 watts (normally 75 watts whilst mains power is active)
  • repeater tested on battery backup, draws just on 8 amps and puts a “beep” every 60 seconds to identify unit running on battery backup.
  • whilst on site, Paul took the opportunity to “Sweep” the VK5RSB 70cm antenna, return loss was good BUT it was identified that there IS a problem, a ringing or ripple on the return loss sweep, possibly due to a faulty connection in the line. We believe that the problem is most likely the coax connector on the top end of the LDF 450 coax, as this was not serviced or replaced when we changed and fitted the new antenna a couple of years back.This means another working bee, when the weather for working at the top of the tower is conducive.

6m Repeater

  • during the above work activities, Adrian and Rod were able to swap out the old 6m repeater antenna and install the new antenna. Once the new antenna was connected, a return loss sweep was done and all looked very good.
  • with the the 6m repeater reconnected to the antenna, it was still “going nuts” keying up very regularly on “spurious” Checks of the spectrum could not identify any specific signals the could be causing this other than the high noise floor. So Adrian wound the mute setting a bit higher and this fixed the regular intermittent keying of the repeater. (subsequent observations and reports are that the 6m repeater seems to be working very well and is generally quite when not being worked)

A big thank you to everyone who contributed to the work at VK5RSB. I am sure it will improve service for all amateurs in the greater Adelaide Metropolitan area.

VK5RSB Repeater Extended Outages

Photo of downed powerlines courtesy ABC News

AREG’s VK5RSB Summertown repeaters  have been off air since Tuesday evening’s violent storm which has taken out power lines that feed the site. The restoration work according to SAPN is still progressing. The latest estimate for restoration is now 1.00pm today (31st December)..

We apologies for the outage on these major Adelaide repeater services, and are looking to see what can be done to reinstate the battery backup at the site which has failed.

VK5RWN Internet connectivity re-established.

wncdstar_logoFollowing up from the previous report that VK5RWN D-STAR system was off line due to site mains power failure.

Well the power came back on last night, 13 July 2016, but the internet connectivity did not?

A site visit this morning, 14 July 2016, identified that the POE power supply had died.

This is one of those little Blue QSKJ inverter modules that lifted the 12 volts to 16 volts to feed the router switch and the Ubiquiti WiFi unit up the tower. The faulty unit was replaced with a loan unit.

With the POE PS restored, connectivity was re-established and all is now good. Confirmed that the VK5RWN D-STAR system was fully operational and reporting to the respective D-STAR reporting sites.

Feedback on VK5RWN’s performance and operation may be sent to AREG, vk5arg@wia.org.au or the D-STAR Systems Administrator, Ben VK5BB, vk5bb@wia.org.au

VK5RWN D*STAR Repeaters OFFLINE – Mains Failure

During the wild weather in Adelaide over wncdstar_logothe past 48hrs, VK5RWN’s mains power was lost. Batteries held the site up for a while, but due to the extended nature of the outage these have now been exhausted.

AREG is monitoring for the mains power to be restored and will bring the system back online as soon as we can.

VK5RWN D*STAR 23cm 128kbit Data port in hibernation

wncdstar_logoThe Amateur Radio Experimenter’s Group wishes to advise that the 1299.700MHz 128kbit/s port of the VK5RWN D*STAR node has been placed into “hibernation”. In the entire life of the repeater this port has been accessed 3 times, and so rather than continuing to pay to keep it active it has been switched off. The equipment remains installed however so if you do desire to experiment with this aspect of D*STAR it will be a simple matter of contacting the club, and we can go and re-enable it for you. (This is to help further combat the $1000+ power bill the club foots to run this site each year).

Regards – The AREG Committee