Author Archives: VK6LD

Agenda Item – 2M Repeater Replacement Project

** Notice of business at the next WARG meeting 05/11/2007 **
From Will VK6UU

Request that regular business be expedited so a discussion can take place under the following topics.

Note; discussion without cost being part of the discussion (see below*)

1. Does warg intend to replace its existing 2M network in part or full?
2. What are the reasons for the replacement?
3. If so what equipment is to be used for the replacement (control board)?
4. How much replacement equipment is available?
5. Is the replacement equipment suitable?
6. How is this to be achieved (who is to do it)?
7. What is the time frame?
8. Would the REP-200 be a better choice if cost was not an issue?

Further discussion.

Does warg have a longer term strategy once (if) the 2M network is successfully replaced?

Under this question points for discussion.

1. Linking of warg’s repeaters.
2. Any new ideas outside rebuilding and maintaining repeaters.

*Cost could bog the discussion down. I believe warg has ample funds and should use them as members intended, however with my offer to fund the project in part of full, cost need not be mentioned and the discussion focus on the points (and others) raised in this motion.

Comments;

Warg have a long and successful history with the club being formed in the 1970’s and continues today with excellent attendance at meetings and considerable efforts by a range of amateurs to maintain the repeater network. For example work done at the Rolystone site over the past couple of years is to be commended.

However a critical examination of warg’s achievements over its entire history has repeatedly shown the club struggles, despite generous effort and time by many amateurs, to move beyond maintaining its existing network. The number of warg repeaters and linked repeaters is less today than a decade ago.

Why?

My examination of the problem is our efforts are fundamentally due to limitations in building our own 2M repeaters. It is the amateur tradition to build as much as possible and to scrounge and be resourceful, all skills to be commended, but not at the expense of being caught in a going no where situations. Repeaters like the ten & six metre repeater are separate to this due to their singular nature.

Warg should not be struggling to maintain its 2M network but fixing it and building in easy replacement so any repeater failures do not result in these systems being off air for months. If a reliable high quality 2M repeater can be achieved (and it can) warg can then move onto standardising and improving all the other important elements of a repeater installation. The talent and interest is there we just need to organise ourselves so we gain enthusiasm due to success.

Repeater linking (by RF) can be achieved in a better way than at present. Standardisation of linking equipment can be done so wherever a link is required it is plug & play. Hamtronics make a range of UHF RX/TX units ideally suited for linking.

Without a close examination of warg’s situation the club may not be able to make the progress it wants and deserves.

Will
VK6UU
Founding & life member of WARG

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Avon Valley VK6RAV Linking Project

Hello all,

Attached are copies of path profiles from Avon Valley to Roleystone,
kindly done by Milan VK6KTV using the Radio Mobile software.(WARG
members may recall William VK6KWT demonstrating this at a previous
meeting, last year).

The plots may not be 100% accurate (Milan asked me for the key info,
some of the figures I gave him are a bit rubbery, eg: antenna heights
on the Roleystone mast) but provide an interesting picture. The key
conclusion being that a Roleystone-Avon link is feasible, but it is no
picnic – the path loss doesn’t leave much fade margin at all.

According to the plots, a UHF link would need lots of antenna gain,
eg: stacked/bayed yagis, and possibly a low noise preamplifier. A 2m
link has a better path, but would require more complex filtering at
the Avon Valley end to prevent the repeater TX blocking the news RX.

2M RadioMobile Path Analysis 70cm RadioMobile Path Analysis

(Click images to view full size)

I am putting this on the email list to allow some consideration/
discussion prior to the meeting tomorrow (or today…depending on when
you read this..)

My thoughts would be that the results are encouraging enough to
proceced with future experiments on a link path, but we should
expect some effort will be required to engineer a good solution.

I suggest a good first step would be to find & prepare a length of
LDF-450 cable (we have stocks of s/hand at Hillview) with suitable
connectors, ready to install to the VK6RAV mast at the same time the
problem antenna is changed, etc. Once the feeder is in place &
suitably weatherproofed a variety of antenna/RX system combinations
can be tried to see what works. Of course if a trial link antenna is
ready to go at the same time as the feeder, all the better. However,
if not I would still prioritise the feeder installation in the short
term – it’s a much simpler matter to climb a tower & swap antennas on
an existing feeder than to also have to run the feeder from scratch.

One other point I should make is that due to existing commitments I am
unlikely to have time in the near future to devote to much of the work
for this project. I suspect many of WARG’s techo “usual suspects” are
similarly committed.

So, calling all hitherto non-techo WARG members, whether old-timers,
newcomers &/or newly licensed: over to you, were you thinking of
volunteering for a WARG project? Could this be the one? Come to the
meeting, discuss it further, put your hand up to be part of the team.
Us techos are not going to drop you in it – any questions you want
answered, any support you want, we will be there to guide the way. But
us small group of usual suspects can’t do all of the work by
ourselves. We need you to join us. Don’t think it all looks too hard.
(As I keep telling everyone: if I can do it, it can’t be that hard).
Sometimes it will be hard, but it is not impossible and you will learn
heaps. As you learn your confidence will grow, and at the end of the
day have the satisfaction of knowing you are helping develop our
repeater network & keep it running.

See you at the meeting!

BR & 73,

Anthony VK6AXB

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Roleystone (VK6RAP) Working Bee

Quick update on the weekend’s working bee at VK6RAP.

Thanks to the following who attended on either or both of the days:
Danny VK6FZUK; Dennis VK6KAD; Heath VK3TWO/6; Neil VK6BDO; Peter
VK6PMY; William VK6KWT; plus myself. Thanks also to Danny & Heath
for donations of cable tray offcuts, etc.

The aim of the working bee was to replace the various old
interconnecting coax, leads with new double-screened low-loss coax
leads, and to tidy the racks & check/remount the various cavity
filters/cables more securely. This was achieved for the voice
repeater systems and associated cavity filters, however time ran out
before we could complete work on the cabling associated with the
packet systems. (The existing packet coax cabling is not too bad
though, should be OK for now).

On Saturday VK6’s AXB / BDO / FZUK attended and made new cabling for
the 70cm repeater and remounted its filters in the rack. Work was
begun on remounting the 2m filters. The 70cm filters/diplexer were
swept using WARG’s newly-acquired IFR1500 instrument, which proved
itself versatile & easy to use in practice.

On Sunday VK6’s AXB / BDO / KAD / KWT / PMY / & VK3TWO attended.
Remounting of the filters in the racks was completed. New cabling was
made for the 2m voice repeater, news link, & 6m voice repeater
(antenna feed). The remaining filters & 2m diplexer were swept with
the IFR. Lengths of donated cable tray were mounted to the walls to
tidy & secure antenna feeder cables & the like. At the conclusion of
the job the racks & hut floor were vacuumed/dusted, and the hut given
a general tidy up.

resize-of-vk6rap_cabletray.jpg

On-air tests & monitoring of the news broadcast links indicates all
systems are working well, however if anyone is experiencing the
contrary, please make a report and let us know ASAP!

I have taken a few photos which I will try & bring to the meeting,
also I will send some to Rob for inclusion on the WARG website as
appropriate.

Future work ideas (in rough priority order):

Reinforce saggy floor under batteries

Acquire & install cable ladder/support system between mast & hut to
replace existing old/inadequate catenary support

Complete work on interior cables

Fix water ingress near door to prevent floor swelling/rotting near entry

The 2m to 6m/70 cm news link system should also be monitored and
future work considered if the startup delay (or other problems)
become worse or re-occur.

I can make more of a report at the meeting if needs be.

BR & 73,
Anthony VK6AXB

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VK6RBP International Beacon

Some troubles were reported with the NCDXF International Beacon at Roleystone on Saturday 29 September 2007.

A visit to the site by Cliff VK6LZ and interested observers that day found that the beacon was shutting down on the 17 metre (18MHz) transmission cycle and resetting the transceiver.

The beacon was shutdown until a site visit on Monday 2 October 2007 by Anthony VK6AXB, Dennis VK6KAD & Heath VK3TWO/6.? Tests found that the power supply for the beacon transceiver was faulty. It was removed for repair and a backup power supply was fitted to the beacon and returned to service.

Thanks to all who attended.

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Katanning (VK6RAW) Site Visit

Bevan VK6VX and myself made a site visit to the Katanning repeater site out at Fairfield on Monday 17 September 2007.

We inspected the site, our equipment in the rack and the antennas on the tower. We removed all of the equipment from the rack (repeater, link transceiver, packet TNC & user port transceivers) & cleaned up around the rack as it had become home & haven for rodents. They obviously liked the warm heatsinks of the radios and the PC as these were well & truly stained. They have also enjoyed feasting on the interconnecting packet/data cables and even the plastic foam on the front of the FM828’s!

The repeater was replaced with the FM814/815 unit that we acquired from the Geraldton ARG last year was installed. The cavity duplexer no longer appears to be at the site (They were in a picture taken 8-10 years ago) and the repeater has been running on split antennas. There were 7 unmarked coax cables running to the amateur rack in the hut and 7 amateur antennas up on the tower. We were able to narrow the VHF from the UHF antennas by the use of a VSWR meter, but where they sit on the tower will be a job for another day! In the end, we picked the two VHF antennas that had the best S meter readings from VK6RMS & VK6RAA repeaters and plugged them into the repeater.

The old repeater and packet gear was loaded into Bevan’s van and we left the site around 2.00pm. On the way home I was able to trigger the repeater with 300mW around Tambellup (35km) and it is full scale into my home QTH on the collinear (approx 60km). Bevan is able to key the repeater from his QTH at Kendenup, about 80km and I have keyed the repeater just before Mt Barker, about 95km, and out at Frankland, about 60km.

I have sorted through the gear brought back from the site. Some just had to go to the tip and from the other stuff that is salvagable I will have to check with Gary VK6GS what belongs to him and what is WARG equipment.

The next job will be to remove some the antennas from the tower that aren’t being used any longer, use what antennas we can for the voice repeater, otherwise work towards replacing the antennas & coax feeders that need it.

Bevan has all the tickets, accreditations & permissions to climb the tower, but we will probably be needing the services of a second climber for safety and support. We hope to arrange this over the next few months.

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Roleystone (VK6RAP) Site Update

Hi All,

Anthony here, gradually getting back on deck. A quick update on my visit to Roleystone site a few days ago, plus a few other things:

Firstly, I will be unable to attend the WARG meeting this Monday coming, please put me down as an apology. I should be on the net this Sunday; my contributions there and via this email will have to suffice as a technical report in my absence from the meeting.

Roleystone: following the net last Sunday 26th when problems with VK6RAP 2m RX performance were widely reported, I was able to attend the site after work on Tuesday 28th. I checked for intermod/interference but did not note anything specific at the time. I then opened & checked all coax connectors in line with the repeater diplexer/TX filters/RX filter & preamp – I tightened two connectors which were somewhat loose on their coax, and cleaned others as required. Antenna SWR was also checked and no problems were noted. At the conclusion of this work on air checks with VK6’s MRS/CS/PMY & others seemed to indicate the repeater performance was improved, and to date I have seen no reports to the contrary. (Please let me know ASAP if there are still problems – some urgent investigations/repairs may be possible before Sunday’s news broadcast).

This is very much an interim fix – the poor state of some coax interconnecting leads at Roleystone has been discussed before, and I have previously mentioned the desirability of upgrading all these cables (using RG214 double-screened low-loss coax, we have a qty of this kindly donated by VK6MS) and tidying/re-mounting the various cavity filters in the repeater rack. As more problems could occur or be worsened due to the continuing poor state of these cables, I suggest this work be organised sooner rather than later – although not immediately, as we need to obtain connectors for the RG214 and do a little pre-planning. I suggest we aim to organise a working bee in late September/early October, would appreciate any comments people have on this proposal, what times you are available, etc. (I still have to confirm my availability for these weekends, on-call work schedule could interfere…)

News TX: just before Hamfest I repaired a WIA news TX (which I got from Dennis) and returned it to Neil. It tested OK on my bench, but I see a reference in the August minutes that there is still a problem with it, maybe I overlooked something? I am happy to take the unit back for another look, unless the problem has been solved already? if anyone has more info on this, please let me know.

Mt William: Mac VK6MM has advised he has fitted a temporary Yagi antenna to Mt William to get the digipeater back on air (following the failure of the main repeater antenna, the main digi antenna was swapped to the voice repeater to keep it on air). Also note the problem with Mt William is not simply finding a climber – the Mt William mast has a large antenna/cable load, and the whole structure is aging to the point where there is an increased risk of structural failure – anyone proposing to climb Mt William would have to have sufficient experience to weigh up the risks to their own safety – makes it a tricky problem to solve, we need to investigate further and see what is possible. Mac is the one most familiar with the site.

WARG test equipment (the IFR1500) – last I heard, VK6XRE had our newly obtained communications service monitor? (If not please let me know where it might be). It would be useful for the Roleystone working bee proposed above, to enable checking of cavity filter/diplexer tuning. I would like to have it for a short time beforehand to refresh my memory of IFR operation. I can collect it if required, with a bit of notice beforehand. Please let me know.

There are a number of other things I promised to do before I went away – if they aren’t mentioned here, I haven’t done them yet! Watch this space for more info…

BR & 73,
Anthony VK6AXB

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Cataby (VK6RCT) Site

The Cataby 2m repeater on 147.200 appears to be off the air. It has been like this since about 3 weeks ago, and it coincided with some rather hefty weather they had up here.

I’m up here once a week – and am happy to go up and have a look. I have access to a 4WD through work, and it’s only about 10km away from the accomodation I stay in each Wednesday night.

If anyone has keys it would be appreciated if I could somehow grab them.

Alternatively, if anyone else wants to come up and have a look, feel free to do so!

73? Blake
VK6FBNZ

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Tic Hill Site Visit

21.08.07??? Visit was arranged with the Quarry Owners for 10 AM

Those in attendance were Cliff VK6LZ, Geoff VK6NX, Max VK6XME, and Don VK6DUK.

We met the new Quarry Manager Cliff Kelly and explained the Group and the History of Tic Hill.??? He was most co-operative and interested.??? (We also left a cake for the staff morning tea)

He escorted us to the site, this was necessary as we had to sign the Visitor?s book at the main office and Safety rules dictate that visitors are escorted through the mine workings.

In the event we were unable to gain entry to the Radio Bunker due to a vandalised top padlock which could not be removed.

22.08.07??? We were again escorted to ?Ticky? by Cliff Kelly who stayed to see what was installed inside out of interest.

Those in attendance were Cliff VK6LZ, and Don VK6DUK.

The faulty padlock was removed (courtesy of angle grinder and generator supplied by Don)

The six large 500 aHr wet cell batteries each measured 2.25 Volts, but as expected the electrolyte was at minimum level since last top up was February 2006 when batteries were installed, these were topped up with commercial distilled water to maximum and took 22 litres.

In the process a Power lead had to be loosened to allow access to the filler cap which resulted in the 70cm repeater powering down.??? It was decided not to power it up again until next visit so as to allow the batteries to recharge.???? Vaseline was applied to all connectors.

The 4WD club?s (car) battery was also checked and found to be below plate level so was also topped up from distilled water already on site.

A supply of 60 Litres of Distilled water was taken to the site, which leaves 38 litres for future top ups.

It was noted that the Solar Panels were providing 4 to 6 amps on an overcast day but that the regulator green LED was only illuminated weakly, it was decided to leave the spare regulator on site and do the change over on the next visit as time was moving on.

The two meter repeater VK6RTH which had audio problems was removed for service.

The Bunker was cleaned up, a new padlock was fitted to the top of the outside gate, and the site was vacated at 13.45 hours.

The repeater was subsequently delivered to Tony VK6YAG for repair.? It was found to have a corroded plug/socket on the audio board which Tony replaced and returned the unit to Cliff VK6LZ at the WARG Meeting.??? (Not sure if anything else was done)

04.09.07 ??? Visit was arranged with the Quarry Owners for 10 AM

Those in attendance were Cliff VK6LZ, Don VK6DUK, Mark VK6UHF, and Eddie VK6KEG.???? After signing the visitor book and giving the Manager a cake for his trouble, we were again escorted to ?Ticky?.

The Battery voltages were checked at 2.2 volts each.? The coax from the cavities was checked at 2 to 1 SWR and the Antenna (Dual Band) was checked at 1.3 to one SWR.

The replacement Solar Regulator was fitted and both LEDs came on, the input from the solar panels was measured at 2 to 5 Amps (the WX was Cloudy and Raining).? It was found that the Power from the batteries was down, this was caused by four of the battery links being loose and required tightening.

The Two metre repeater VK6RTH was refitted and turned on, and an on-air test was carried out with VK6YAG.

The 70 Cm Repeater was then booted up (requires on air DTMF Codes) and tested on-air.

A serious water leak has developed with rain coming down the coax/solar power pipes and running onto the bench – this will have to be addressed on next visit.? (The log book which was in a plastic bag will also need replacing)

Note until we have obtained the required climbing gear, no tower climbing is allowed due to insurance problems.

Cliff VK6LZ

NOTE:? ACCESS TO VK6RTH SITE IS STRICTLY RESTRICTED

The site is designated as a ?MINE SITE? and as such comes under Health & Safety Legislation.??? There are also Insurance Ramifications for both WARG and Hanson.

All visits MUST be co-ordinated with the Quarry Management, and Visitors MUST be signed In and Out in the Visitors book in the HANSON main Toodyay Road Office.

All Visitors must be escorted (Convoy) through the Quarry workings, this means that visits can be made during the Quarry working hours on weekdays only. (No Weekend Access)

In Practice to save calling for an escort we have been allowed to EXIT only, through the old workings and back gate after phoning the manager to sign us out on leaving.? ut beware heavy trucks coming the other way.

Currently access is by Four Wheel Drive only for the last 100 metres due to a large wash-away deep ditch.????? Two Wheel Drives need to be parked at this point.

I have (February 2006 when delivering the batteries) taken my 2 WD over the ?ditch? but it is now much deeper, perhaps we could get permission to fill it in with surrounding large rocks when we have established good relations with the new manager (keep supplying cakes).

DO NOT ?ROCK THE BOAT? BY VISITING UNANNOUCED PARTICULARLY AT WEEK ENDS AS THIS COULD LOOSE US THE SITE

Currently Hanson is experiencing vandals at week ends and after hours, in one recent case, the site security apprehended a group trying to start up some heavy equipment, they are to appear in the Midland Court House shortly.

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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!

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Tic Hill Solar Regulator

The solar panel charging regulator delivered to me earlier this week for repair is now serviceable. The fault was a failed LM317L which is used as a constant current regulator to provide the reference voltage for the 358 op amp which controls the FETs that switch the DC from the panels to the battery. Interestingly, my records indicate that it was the same fault
which caused the failure of a similar Arlec SR712 regulator in 2004. (I think that this one is now in use at either Tic Hill or Cataby).

The 317L (little TO92 case) regulator is now unobtainable but in any case is probably being run a bit hard, so has been replaced in both instances with a full size 317 (TO220 case) heatsinked to the aluminium box. Unlikely to fail again!

Does anyone know what the max amperage output in full sunlight produced by the solar arrays at Tic Hill and Cataby is? The Arlec 712 is limited to 15 amps by the IRF530 switching FETs but could be upgraded if necessary by using more modern and better FETs. However, if the output of the panels is well under 15 A – as I think is the case – then there is no point in changing these devices. Maybe we could discuss on Sunday’s net?

Cheers, 73 Clive VK6CSW.

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