Please click HERE to go to our NEW web site.

These pages are no longer being updated.

Please also note that the "Contact Us" e-mail address, shown here is no longer available.


SITE LAST UPDATED ON: Thursday, 12/03/2015 @ 01:37 UTC.

DVU37 - Output 439.4625 MHz - Input 430.4625 MHz.

GB7JB is funded solely by donations from its' users and supporters. There is no club or group to join and no annual membership fee. We rely totally on your good will.

The system is located in South Wiltshire, in IO81vc, co-sited with GB3JB, and provides coverage across South Wiltshire, South Somerset and North Dorset.

GB7JB is a 70 cm Digital voice repeater, based on DMR TDMA Mototrbo technology.
It provides TWO simultaneous channels. One is for local chatting, whilst the other is connected to the Regional Cluster / Network.

Wednesday, 1 April 2015

New Web Site ....

Hi All.

There is a NEW "JB" web site.

It combines data from this and the previous GB3JB web site, plus additional information and resources.

On the NEW site you will find all the relevant information relating to "JB" Repeaters, as well as other repeaters and beacons that are installed at the "JB" site.

The new site also includes information relating to the 70cm SW Cluster and DMR technology.

This site, along with the original GB3JB site will continue to run in parallel for the next couple of weeks, so as to give individuals time to make the change to their links / favourites etc.

A further very significant change is the closure of the original e-mail contact addresses: gb3jb.repeater@gmail.comand

These addresses have been closed for the purposes of communication, as a result of the significant amount of SPAM mail that has started to arrive, over the last couple of months.

Any communications sent to either of the above address, will be automatically deleted by the e-mail server, upon arrival.

These original e-mail addresses are now only valid for the purpose of making donations, to the relevant repeaters PayPal account.

You will note that there is now a "Contact Us" page, associated with the NEW web sites Navigation. This page contains a Form, for communicating with either myself or the Treasurer.

"Blanket" update e-mails will still be sent out, as previously, but unless specifically specified, they will be from a "NOREPLY" e-mail address, but will include a link to the "Contact Us" form.

Any communications sent to the "NOREPLY" address, will also be automatically deleted by the e-mail server, upon arrival.

This change may be inconvenient to some, but not as inconvenient has having to filter all the JUNK that has started to appear in the repeater in boxes.

Please feel free to make any constructive comments via the "Contact Us" form.

Please only use the NEW web site, from now onward.

Cheers & 73's
Dave, G3ZXX.

Thursday, 12 March 2015

GB7JB Operational.

Hi All,

GB7JB, became operational at approx., 4pm local time today, 11th March 2015.

It is running at full ERP into the planned antenna, which is currently in a temporary position, approx., 15 feet agl.  The site being approx., 745 feet asl.

We are awaiting the final installation of the antenna on the tower.  I will of course keep you up to date with developments.

Signal strength and activity reports will be much appreciated, via:

The operational characteristics are as follows:
  • Channel / Frequency:  DVU37 - Output 439.4625 Mhz - Input 430.4625 Mhz
  • Mode:  DMR - TDMA
  • Slot 1: Local Coverage - Talk Group 9 - Colour Code 1
  • Slot 2: Regional Cluster - Talk Group 950 - Colour Code 1

The Regional Cluster also includes GB7AA, GB7BS, GB7DR, GB7SD.  All 5 repeaters are inter-linked.

To the left of this posting, you will see computer predicted coverage maps for both GB7JB and the Regional Cluster.

I would like to convey my thanks to all the individuals and clubs, that so willingly donated towards the GB7JB project, as well as those who have provided both technical and moral support.  GB7JB is on air thanks to your enthusiastic support and encouragement.

Thank you.

We still have a little way to go, but I think I can safely say, we are 90% there.

As some of you will know, I have been slowly upgrading the site CCTV system.  This is now more or less complete, with an additional 4 cameras and an upgraded storage / live audio and video streaming system having been installed.

This work is being carried out in conjunction with the site owner, who is spending a not inconsiderable amount on upgrading the facility, to include new structural security measures.

Cheers & 73's
Dave, G3ZXX.

Thursday, 26 February 2015

Nearly There ... Well Almost.

Hi All,

All the component parts of the GB7JB system have been available for about a week now.

However, as you may or may not already know, from the e-mail updates, the 'cherry picker' that was used to install the existing GB3JB system, is no longer available.

Therefore, there will be an obvious delay in getting the GB7JB system on the air, because it's not that simple to install the antenna, without a 'cherry picker'.

Several options are being considered, as follows:

  • I have had several offers from individuals, to climb the tower and install the system, subject to a site inspection and risk assessment, etc.  However, bearing in mind the antenna system is quite cumbersome, this is not my personally preferred method. Safety first.
  • I am also investigating the hiring of a 'cherry picker'.

This latter option is proving to not be as simple as it sounds.

There is a significant cost implication, around £430 inc delivery and VAT, for the day (!).  Plus, there is also a HSE requirement for the operator to be IPAF qualified for specifically operating 'cherry pickers', or as they seem to call them Mobile Articulated Boom Lifting equipment.

The further implication of this is that either the hire company has to provide a qualified operator, at around £250 per day, or I (or someone) will have to go on a training course that costs about £185.

If there is anyone out there who has the relevant IPAF qualification, I'd love to hear from you.  At least that would save some of the un-anticipated cost.

If there is anyone out there who has a 'cherry picker', I'd really, really, really love to hear from you.

So, that is the current situation.

Sorry folk's, I'm not going to get it on air by the end of February.

Cheers & 73's
Dave, G3ZXX.

Wednesday, 11 February 2015

It's Arrived ...

Hi All,

Just a quickie to advise that the DR3000 repeater unit has arrived, and that it is currently being programmed and tested, by Chris, G6WHI.

Cheers & 73's
Dave, G3ZXX.

Friday, 6 February 2015

Repeater Hardware, Funds & Talks

Hi All,


The Motorola DR3000 Repeater unit has now been ordered.

Still aiming to get GB7JB on air by the end of this month.

Although, as you can see, not all the pledged donations are in yet, 4 to go, I have gone ahead and ordered the unit on the assumption that the remaining pledges will be honoured in the not too distant future.


We have now received £1,530 of the £1,600 of pledged donations, from 35 of the 39 individuals who made pledges.

Make your donations payable to:

If you don't select either the "friends and family" or "Donation" option, we have to pay a quite significant fee, and thus ​we ​do not get your full donation, as has happened in a couple of cases.

As per earlier e-mails, if you wish to pay by cheque, please send your donation to:

GB7JB Repeater.
c/o Mr. P. Hillman, M0ACD

BA8 0JH.

The following is very important, for donations by cheque.

Please ensure that your cheque is made payable to “GB3JB Repeater”. That's GB3JB Repeater”.

Also ensure that your NameCallsign and e-mail address and that it is a donation for GB7JB are all very clearly printed on the reverse of your cheque.

An acknowledgement of your donation will be sent to you via e-mail.

Do NOT send cash under any circumstances.

​Talks / Presentations.

This weeks two events, at the Andover and Trowbridge Clubs, were very well received, with much interest and support being offered by those present.

The demonstration of the equipment / technology, which involved the use of 4 different radios from different manufacturers, went down very well indeed, and dispelled many individuals concerns about audio reproduction and quality.

I personally enjoyed the events, and thank the Clubs for the opportunity outline the project, and clarify / answer the many questions and issues raised by their members, regarding the technology, as well as GB7JB and the Regional Cluster/Network.

I must thank the two clubs for the hospitality shown to me, and the very positive outcomes from the evenings.

I have been asked to do the talk / presentation for the RSGB (Bristol Group), and this will take place on Monday 27th April.

There is also the possibility of giving the talk / presentation at the Taunton Club.

If any other groups or clubs would like the me to come along, then send me an e-mail.  I will be only too pleased to oblige.
Cheers & 73's
Dave, G3ZXX.

Saturday, 10 January 2015

Donations ......

Hi All,

Just a quick update on the Donations, front.

Had a few more come in, as can be seen from the image below.

Otherwise we have to pay fees, and do not get your full donation.

Make your donations payable to:

As previously indicated, the pledged donations do not have to be in until the end of January.

I'd really like them all in by the 31st, so that I can get the order placed for the repeater on Monday 2nd February.

Once again, thanks to all those who pledged a donation.

If you did not make a pledge, then that's not a problem ... Don't be shy ... You can still make a donation, and it will be very graciously received.

Of course if you are debating how much you should donate, just remember, no amount is too LARGE.

Cheers & 73's
Dave, G3ZXX

Sunday, 4 January 2015

Donations ......

No it's OK ... Don't Panic ...

But as I'd actually had a few donation come in, I thought that I'd produce another 'thermometer' to indicate how the donations were coming along.

As you can see, I've had a few pledges honoured already.  Thanks folks.

Don't forget to select either the "friends and family" or "Donation" option. Otherwise we have to pay fees, and do not get your full donation.

Make your donations payable to:

Still not got the Bank account sorted .... As soon as I get the details, I'll let everyone know.

As previously indicated, the pledged donations do not have to be in until the end of January.

I'd really like them all in by the 31st, so that I can get the order placed for the repeater on Monday 2nd February.

Once again, thanks to all those who pledged a donation.

If you did not make a pledge, then that's not a problem ... Don't be shy ... You can still make a donation, and it will be very graciously received.

Of course if you are debating how much you should donate, just remember, no amount is too LARGE.

I hope you all had a great Christmas and New Year ... so far ... Let's hope 2015 turns out to be good for everyone.

Cheers & 73's
Dave, G3ZXX