GB3JB Update

Saturday 28th May 2022 @ 1719 UTC

The following is the text of a blanket email, issued to the 155 registered list members, earlier this afternoon.

Hi All.

As most will be aware, the introduction of GB3JB has had quite an impact on SWC activity levels.

As I have previously reported, I have had QSO’s with almost 30 new users in the last month.

A significant number, using GB3JB.

Obviously being on 2m, the coverage of GB3JB from up on top of it’s hill top, near Mere, is significantly greater than that of the old GB7JB on 70cm installation, on the same site.

Thus, there is significant overlap, in Yellow, of the GB3JB coverage with that of a number of the existing 70cm Cluster repeaters.

This was of course expected, with the hope that it would encourage greater mobile use, across the Cluster. Which it appears to be doing.

All very good so far ….. YES ? ……….. Well, there is always a ‘However’.

As the keeper of GB3JB I feel that I must remind users that there is a Slot 1.

Many users of the Cluster are used to working each other across the Cluster, using different 70cm repeaters. Which is absolutely what the Cluster is there for. To provide that communications capability.

So now we get to that ‘However’ …..

If your QSO, irrespective of how many members, is only using GB3JB, can I respectfully request that having established the QSO, via Slot 2, that you all QSY to Slot 1.

This will free up Slot 2 on all the 70cm repeaters in the Cluster, for other users, as well as slot 2 on GB3JB, for cross-repeater, across-clusters, cross-band activity.

If all in the QSO can all work each other via, Slot 2 on GB3JB, you can all also work each other via Slot 1 on GB3JB.

Staying on Slot 2 of GB3JB when it is un-necessary, locks up the entire Cluster System, which could be being used by others.

So please be prepared to QSY to Slot 1, on GB3JB, if it will not effect any members of your ongoing QSO, to do so.

I will put my hand up at this point and say that I have been guilty of previously not thinking about this issue.

I do hope that the logic of the above, makes sense to you all.

The last thing that we want, is for the GB3JB activity to have a negative impact on the existing Cluster activity.

Cheers & 73 Dave, G3ZXX.

GB3JB Update

Sunday 15th May 2022 @ 1042 UTC

The change from analogue FM to TDMA DMR, and linking to the South West Cluster, is to date proving to be very successful.

The 30 or so responses to the ETCC news and my ‘blanket’ updates etc., have been overwhelmingly in favour of the change. Only one disgruntled individual.

In the last two weeks, I have added 20 new Cluster users call signs to my contacts list, and I am aware of at least 6 individuals who have purchased NEW dual-band DMR radio’s, several specifically for mobile use.

Other long time users, are also reporting increased activity, and making new contacts.

Interestingly, I have also received communications from several individuals who are considering the possibilities of setting up a SWC DMR repeater in their area of the South West.

My thanks to all who have provided support and encouragement during this process of change and development.

If anyone is struggling with a code plug, please let me know. I have been busy writing code plugs for different radios, over the last couple of weeks, and may well be able to assist. If I can’t, I probably know someone who can.

On Saturday 30th April 2022

The NEW GB3JB Became Operational.

With effect from approx., 1:30 pm on Saturday 30th April 2022, GB3JB became fully operational. A day earlier than planned.

At this time, 6:00pm, 30th, Cross-Cluster contacts have been made via GB7BS, GB7EW, GB7JB, GB7SD and GB7SP.

Several 2m GB3JB DMR QSO’s have also been made. The most impressive being with 50mW from Wincanton and 1 watts from Andover. Both with loft antennas, and lots of building and large hills in the way. Absolutely no background noise, no drop-outs, crystal clear QSO’s.

GB3JB Back On Air - In Beacon Mode

GB3JB came back on air, at approx., noon on 26th April 2022.

With the help of Ian G0GRI and Frank G8PCB, we re-installed the turbine with it’s new generating hub assembly, which appears to be operating OK. Al be it, not generating much energy as the wind was quite calm on site, at the time.

We also installed the DR3000 DMR repeater system. No change in frequencies, so exactly the same as the old FM GB3JB, and operating at 14 dBw erp, via the same cavity, coax, and antenna system.

Still waiting for the data SIM, for the 3G router to arrive. Hence, beacon mode.

It beacons, in digital mode, every 5 minutes. On every 3rd consecutive ident, i.e. every 15 minutes, it also adds an analogue FM ident, in Morse, to the end of the digital ident.

Obviously, if you are listening on an Analogue FM radio, with the ctcss turned off, then the digital ident will sound like a ‘rasping’ noise, which lasts about 2 seconds. The added analogue FM ident will be in the clear.

The image above shows Dave G3ZXX & Frank G8PCB, lowering the turbine mast, ready for re-attaching the turbine.

Ian G0GRI, is shown with Frank, after we re-fitted the turbine.

Ians dog, Summer, was acting as general site supervisor, and ‘responsible adult’ ……

The image opposite, shows the turbine, currently back in it’s original position, plus the full tower arrangement.

We are still considering the ‘How’ and ‘Where’ of the re-positioning and the adding of height above ground level, for the turbine.

We would be very interested to get reports on signal levels and signal to noise ratios.

Subject to the arrival of the SIM card, GB3JB should be fully operational on Sunday 1st May.

Please remember … No donations until further notice.

Please see the Donations page for details.


Saturday 9th April 2022 @ 1437 UTC

We have now been advised by the turbine manufacturer, that the returned ‘generating hub’ is a write-off. As we anticipated.

We have however agreed a good price with them for a new replacement ‘hub’.

Funding has been made available, and we hope the parts should be with us, once the cheque has cleared and the new ‘hub’ delivered. Unfortunately, probably not till sometime after the Easter weekend.

Once received and put back together, the reconstructed turbine will be put back on the site. However, changes are planned with respect to the turbines installation and likely site location.

This will of course delay things a little, but it is hoped to have been completed by the end of April.

Please remember … No donations until further notice.

Please see the Donations page for details.


Thursday 24th March 2022 @ 1150 UTC

Hi Folks. Just a quick update. The relevant parts of the turbine, have been back with the manufacturer for a little over a week now, and we are awaiting their assessment with respect to a repair and cost etc.,

With respect to GB3JB itself, as you should be aware, the TX hardware is dead. However, several options have been considered, and I am hoping to move forward with getting 3JB back on air in due course.

As previously advised, please resist any urges you may have to dip into your piggy-banks, to make any donations to the group, at this time.

Dave, G3ZXX.


Sunday 27th February 2022 @ 1920 UTC

At this time I consider that the state of the Turbine could well be TERMINAL.

My thanks to Frank G8PCB, for coming to the site on Friday pm, to help with lowering the turbine. His assistance was very much appreciated.

If you would like to click this link to the IMAGES web page, I believe that you will have a good idea as to what the issues are.

A picture says a thousand words ……..

My plan is to contact Marlec, to discuss the images, and get their thoughts on the viability of a repair and the costs involved.

Obviously, a repair will be cheaper than buying a new turbine, but as it appears to me at this time, as the casing is damaged, and at least one major part is damaged, the repair cost will relate to a significant proportion of the hardware’s costs.

The only bits to not be replaces would be the main plastic shroud, a piece of tubing, two bridge rectifiers, several bits of wire, and a bracket or two.

More, info as soon as available.

Although, donations are always nice. Please do not make any at this point in time.

Hold back on any enthusiasm that you may be feeling at this time to raid your piggy bank.


Friday 18th February 2022 @ 1655 UTC

At this time I consider the state of the FT-2600m TX unit to be TERMINAL.

After further inspection, rechecking fuses, and simply checking various parts of the circuit from a simply DC prospective with the multi-meter, I decided to attempt a power up whilst doing a factory reset.

Joy it powered up. However, it soon became clear that all was not well.

The smell of something getting hot. Nothing obvious to the touch on the top of the board.

Checked TX on 25 watts output …. The smell of something getting very hot.

Removed main 15A fuse, which was warm to the touch. Put the ammeter in line, pressed PTT and exceeded 10 Amp scale.

At the 5 watt output setting it is taking 62.5 watts @ 13.4 volt supply.

At the 10 watt output setting it is taking 97.8 watts from the 13.4 volt supply.

I have not stripped the board out of the unit. I do not consider it to be worth the effort that is required to do so, at this time.


Thursday 17th February 2022 @ 1412 UTC

Unfortunately the hardware now has some serious issues.

The marine wind turbine has stopped turning. Unfortunately, the wind was much too strong for me to attempt to lower it on my own.

My initial thoughts, based of the previous experience with earlier turbine on the site, is that the bearings have probably failed.

This will have caused the mechanics inside to shift, with the consequence of the winding being significantly damaged and causing everything inside to jam up.

Unfortunately, it will probably turn out to be a write-off. Further inspection is obviously necessary.

Just to add insult to injury, the FT2600m TX is also dead.

There is power going to the unit, all external fuses are OK, as is the on-board fuse. So not very hopeful. Only time and further investigation, will tell.

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