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UHF repeater relocated

Peter VK5BE, Andrew VK5VKC, Colin VK5DK and Leith VK5FLAR installed the UHF repeater (439.825/434.825) at The Bluff on Sunday 24/5/20. The unit is now running off mains power.

The antennas are temporarily placed at this time until tower issues are resolved. In the meantime there are much improved signals, especially to the NW. Well done fellas. There was quite a lot of activity testing the repeater this afternoon. Not as good in Mt Gambier as expected – it’s a long way away, but still usable mobile. David VK5HDW had usable signals mobile in Millicent.

2 metre repeater in left cabinet, 439 MHz repeater in right cabinet with 2M backup battery. The Portland link will require some re-arrangement to go in the left hand cabinet.
The workers (Leith, Col, Andrew), with Peter as photographer
UHF antenna in temporary position

Low voltage detect

The LVD for the Mt Eckersley repeater is now finished and working ready for installation in the VK3RSW cabinet.

The device makes use of a solid state relay. A microprocessor looks after the management of voltages. If the battery voltage falls below 11.9 volts the relay turns off and does not turn on again until the battery voltage exceeds 12.7V (80% charge) for 100 minutes. The timer ensures the battery is in good condition before the repeater is used.

The normal on range is from 13.8V (fully charged) to 11.9V (20% charge).

The device was home brewed and software program written in the VK5DJ shack.

LVD for VK3RSW (photo off centre to stop reflections)

Update from Portland

Report #1            Team visit 17/05/2020

                                VK3HJV; VK3HAQ; VK3FJET; VK3VET

  1. The outside of the container is in good condition. The rear (original) door is welded shut and it was decided not to remove the weld. At the roller door end there is rust damage at the very bottom LHS looking in. This damage is below the level of the floor but it might be prudent to repair it before the new floor is laid. The roof is in good condition.

  2. In a phone call to Gus before we went out, he suggested that we clad the outside rather than patch and paint. We thought that this was a very good suggestion as it will provide an air insulation gap as well as remove the need to patch and paint the exterior. We may be able to source some second hand zinc alum cladding either free (Gus and or VK3LTL). David has suggested using 90*45mm treated pine for batons, cut to length an screwed/bolted to the container to hold the cladding.

  3. David suggested that the roof slope from 200mm down to 100mm across the length/width of the container and again zinc alum the clad. He noted that the slope needs to be either pointing downhill or towards the clad and sealed end of the container.

  4. The old floor has been almost removed. David and Paul did all the hard work, and it was hard, as the flooring was heavy duty ply and screwed into steel bearers. Some of the steel bearers are damaged and rusted away from the support side frame. We will need to put some bracing in to help support the new floor. The new floor will most likely be heavy duty waterproof chipboard. David and I are hopefully heading out there this Friday to finish removal of the floor.

  5. In the preliminary phone call to Gus I mentioned getting the container up the hill when it is ready. He will organise a flat bed tilt tray and is going to take it up the gravel road through his neighbour’s property. This is the road access to the Telstra/Optus set up. He is prepared to cut his fence to allow access for the truck/trailer. This removes the hazard of getting the container up a very steep and slippery hill.

  6. We had some discussions (whilst enjoying the view from the top of the hill) about how the seat and bold the container into position. David had a great suggestion which involves 4 raised concrete pads to sit the container on and bolted or welded lugs to the container which will attach to the pads.

  7. David and I will draw up a materials list this Friday (time permitting) and then we can see how much we can scrounge without spending money.

Denis VK3VET

View from Mt Eckersley

VK5ROH down

On Sunday, May 17th, a team comprising of Peter VK5BE, Colin VK5DK, Andrew VK5VKC, and Andrew VK5MAS fully dismantled the 70cm repeater from the Crouch Street North water tower site in Mount Gambier.

This included the repeater and link equipment rack, all coax feeders and power cables, antennas, and solar panels.

As a result, the VK5ROH repeater will be off the air until further notice, for hopefully only a week or so.

The 70cm repeater will now be re-built using mains power in lieu of solar power, plus will no longer be linked to the 2m repeater VK5RSE at Mount Graham, once it is re-installed in our new facility at The Bluff.

Improved IRLP and Echo-Link facilities will also be added later.

Initially we’ll retain the off air feed from the clubrooms but a wifi link is highly likely. WiFi will be a significant upgrade by allowing us to put the IRLP/Echolink node at The Bluff. We await some work to be done at the Gambier Electronics site.

VK5RSE at Mount Graham still remains on air as a stand alone 2m repeater.

Report by Peter VK5BE on behalf of the repeater committee

Mt Eckersley Frequencies

We have received notification from ACMA that our frequencies for the new Mt Eckersley repeater will be 146.875 MHz TX (user receive) and 146.275 MHz RX (user TX).

The link frequency will be 449.875 MHz but users won’t need to worry about that.

John VK5DJ
Repeater coordinator

Naracoorte fence removed

The Naracoorte fence has been removed, not only does this tidy up the site but it also means that the Council people who tidy the whole site can also mow closer to the the repeater site – with the exception around the tower. I guess we’ll look to the NARC to poison regularly.

This will be great for the repeater maintenance team as they will no longer have to wear pith helmets when entering the area.

 

Mt Eckersley Cabinet now in Mt Gambier

Thanks to Brian VK5VI for arranging the cabinet and President Peter for getting it from the VK5RHO site.

The solar charger will be mounted at the top on the non removable back of the cabinet. Below this will be the repeater for Mt Eckersley which will be on 19″ mounting holes. The cabinet is quite wide so the right hand side of the 19″ mount is on a bar that is fastened from top to the horizontal bar. This leaves about 200mm gap at the right for limited access.

Peter plans to cut an access port in the rear of the cabinet behind the repeater. Normally this will have a covering plate attached by bolts with captive nuts. The cover will maintain the vermin proofing. Rear access to plugs, antenna connections etc is necessary as Tait equipment is quite heavy and difficult to remove from the cabinet if only one person is present.

In the lower section will be placed the 4-6 cavities (until we have tested we won’t know how many we’ll need) and the battery.

We are still waiting on the allocation of frequencies although the callsign VK3RSW has been confirmed.

The VK3RSW cabinet

Portland repeater hut

Update Portland and SW Radio Group

With the very generous help from Andrew (VK3LTL) the “shack” has been delivered to Mt Eckersley. David (VK3HAQ) went out to assist Gus McLean (the very generous owner of the property) and Andrew with the unloading. And to Paul (VK3HJV) for his assistance with thoughts, ideas and comms. Between David, Paul and Andrew we have a very potent core.

The container is in good condition but will need a little bit of maintenance to the floor. This may involve replacing what appears to be marine ply or putting a false floor over the top with steel bearers and waterproof chipboard. We will most likely need to silicon seal the normal container doors (which we don’t use as this converted 20 footer has a roller door at the usable end) as there appears to be a little moisture getting in at that end. Inspection was made difficult because of the inclement weather today. A further inspection will be made as soon as the weather clears. Because of the social distancing laws there will be only one person per visit permitted and so we will draw up a roster of jobs and anyone wishing to volunteer can do so. There may be some work needed on the outside but only a light sand back and some paint.

The staging will be something like 1. Get it here; 2. Get it ready to go up the hill; 3. Prepare the site; 4. Get the shack and tower to site and on the same day dig and pour the footings, including the tower. (this operation will require a week of no rain and light winds and will only be possible when social distancing rules end); 5. Set up the solar panels and test (David is a qualified electrician – thanks again David); 6. SERG to set up and test the equipment.

There is no rush at this time as cross border travel restrictions would mean the team from VK5 would have to self-isolate for 14 days when they returned home. It is likely to be at least 90 days before this restriction is lifted. In the words of Suetonius “festina lente”.

Attached are some images. If you have any questions let me know.

The Portland Team

Hut on the trailer hired by SERG and behind Andrew’s car ready for transport
This view gives a better idea of how it looks

Here’s a further update post from Denis VK3VET

Greetings all. In discussion with the local team and with the consent of Peter Becker and SERG we are suspending travel to Mt Eckersley until travel restrictions are lifted in Victoria. This will not impede any further planning which needs to occur. For those outside VK3 this state imposes a $1652 fine on individuals caught travelling/being away from home in breach of the rules. For those with legal minds I have just read a letter to published in Science Magazine that suggests that country by country travel restrictions such as we have violate international laws (to which this country is a signatory). In a separate post see a small piece about pets and the virus also from Science.

Progress report: Radio gear for Mt Eckersley Repeater

The repeater controller at The Bluff (Mt Gambier end) only has capacity for one repeater and two RF linking ports. The links were occupied (one to Mt Benson [Kingston ] and the other to Naracoorte) a solution was needed to supply a third RF link to Mt Eckersley.

The simplest solution was to take one link (that to Mt Benson) and split it into two with one going on to Mt Benson and the other to Mt Eckersley.

This required a new sub-controller to be designed and built.

The sub-controller would have most of the facilities of the main controller but control would be completely separate from the main via DTMF tones with a separate code access.

The sub-controller was designed and after much checking and consultation boards were ordered and supplied. One board has been populated with components and John 5DJ has preliminary software working. This is most encouraging as PCB design is always fraught with mistakes but fortunately so far all seems to be satisfactory.

Brian 5VI has been occupied building the hardware component of the project.

Fortunately we have a spare almost completed RF subrack on hand and all that is required is some additional wiring. This will be the main component housed at The Bluff end of the link. It will have the two RF links (to Mt Benson and Mt Eckersley) and the sub-controller module. Both RF links will be Tait T85x Series II (synthesised) modules).

For the Mt Eckersley site the RF equipment will be housed in one 19″ subrack and will contain the RF link (to The Bluff), the local repeater, and the repeater controller. All radio gear is modular and should a fault occur a replacement module can easily be fitted and the faulty module returned for repair. This will almost always eliminate the need to carry test gear to site.

To reduce site power consumption all RF equipment will be of the Tait crystal-locked variety although provision will be made to replace with synthesised equipment in emergency cases.

Current status is the Mt Eckersley radio subrack is being manufactured, is work-in-progress.

We have sourced a vermin-proof lockable cabinet which will house all radio, duplexer cavities, and battery-charging equipment and which will be available once travel restrictions are lifted.

Brian and John

VK5VI/VK5DJ

5th April 2020

The new sub-controller board to be placed at the Bluff. Left lower plug to existing controller, Portland connector above and then Mt Benson. Small OLED display on right to indicate status of ports.