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Another visit to the repeater site, resulted in MT being off air for 2 1/2 hours as SH was removed with its integral power unit which also charges the batteries. Another SH has been fitted, see picky 1312, pictured here while being built with the yet to be fitted GB7IV duplexers.
This repeater has the M0XIX logic inside it , and this logic has some special features:

Time out is ( as per also on GB3SU ) is 4 minutes after which your over is marked with time out pips to let everyone know you have timed out,.. total time out is 8 minutes, if you rabbit on that long SH will chuck you out and close down. This feature is to prevent jammed PTT holding the repeater open for hours, this same feature exits in SU also, that's the way We ( G8IPG has ) have programmed them.

SH sends a distinctive "double bleep" at the end of each over, and access. However and but, should we have a power fail, then instead of the double bleep the Repeater will send a "B" in Morse ( _...),! at the end of an over, this repeater is a stop gap machine, ... the revised and yet to be fitted repeater will have a modification to the CWID to indicate loss of AC power, which will be a double B being sent in the CWID the first one being the code for 71.9Hz CTCSS, and the second being "Were running on batteries!"


SH is running on a stop gap PSU too, to which were thankful to Chris G8BAL, this goes to show a little " maas " switch mode 22Amp PSU force cooed by a fan, can run our repeaters for 1& 1/2 hours continuous transmit when push comes to shove ! If there is any doubt in the capability of these little wonders we doubt no more. We understand Nevada flogs them.
The temporary GB3SH is built from two ex PMR service converted Tait TM8510 transceivers, they generate the CWID, which is also sent with the CTCSS in encode, we cant do much about that, however once again this rule only applies to this stop gap unit.

Also fitted was a beefed up battery charging unit, which will enable faster recovery time when We have a fail to battery event.

GB3 SU picky 1421, taken of the fitted unit and its logic, in the rack, was also changed out this visit, a pair of Tait UHF TM8110 which have been in service for around 3 years total, was replaced by a rare brand new old stock 1U height Eclipse Repeater, a lot of time was spent on this unit by both Andy G4MYS and Alan G8IPG, who unlocked its secrets,...this is driven by a brand new old stock commercial logic a ""Zetron 38A" which has been programmed with a similar behavioral patterns as SH, the end of over, however is followed by Pips. A number of pips at the end of an over, unless its due to send its callsign which is every 15 minutes, and is rather fast, in this way by listening to the speed of the CWID you will be able to tell which one has beaconed. ( SU is fast , SH is slow ) Otherwise 3 to 5 pips will be send the exact number is down to what "state" the logic is in, normally its 4. Thus in normal use you will get 4 pips or a callsign at the end of an over. Once again this SU is not a permanent replacement, We have removed the other one to upgrade its Logic to the M0XIX type with its expanded facilities including the Running off batteries alert! The CWID is sent without CTCSS when its in beacon alone mode, this is because on a commercial repeater the CWID is generated in the logic if required ( in the USA ) not the transmitter unit as
The repeater removed will be upgraded with the M0XIX logic, we will then use the best behaving repeaters on air and keep standby units ready for action.
Our thanks is extended for his patience with us, and his knowledge of microchip abilities to David M0XIX
For metal bashing and soldering Andy G4MYS
For programming the most awkward 1980s designed logic and excellent RF knowledge Alan G8IPG
it is of course team effort the whole thing does not come together without the efforts of many, and we thank you all for donations and gifts.

Weather camera..As a result of all the unplugging the mains we lost the camera output for some time as this takes up to 12 hours for some unexplained reason to re emerge after a power loss, we are looking into power this with battery back up.

That Tv aerial you'll recall We removed the fallen TV aerial from the roof, the pickys here explain

Picky 1424 is the installed aerials as is 6 June, The disused top aerial is what remains is still up, the middle and front section of the failed aerial, below is an upside down TV aerial the one in use, its normal to fit the cable connector to the top of the boom, thus keeping rain out!

Picky 1428 is the fallen section, we were interested to show you the fractured boom which is the failure point

and the amazing amount of rust on the aerial connections, picky 1426.

We checked over all the masts wall mountings on site, ours & SCC, and all appear well after the long winter and its winds.

We were blessed with good views today a cruise vessel P&O Iona Ocean Terminal is in the old docks picky 1418

02/06/2021 THANK YOU

Thank you to Geoff G4ICD of RF Comms supporting the S.H.R.G.

Check out his page, we have just bought over 4000 cores any many top grade materials at silly prices WWW.RFCOMMS.CO.UK

G4MYS onbehalf of the group

Radio Spectrum
New proposals to help people boost mobile signals indoors

People struggling for a mobile signal indoors will be able to buy a wider range of 'mobile repeaters' under new proposals published by Ofcom today.
Indoor mobile repeaters are devices used to boost a mobile signal and are typically used in residential properties. They can help people and businesses who struggle to get good mobile reception indoors.

In 2018 we authorised the use of mobile repeaters, so long as they met certain technical requirements. We are now proposing to amend those requirements, to extend the range of devices that people would be able to purchase legally. This would provide more choice for people who are looking to boost their indoor mobile signal and potentially bring down the cost of devices.

We are also consulting on proposals to help make it easier for people to see which devices meet the technical requirements and are therefore legal to purchase. This would help to prevent people buying illegal devices, which could cause harmful interference with other wireless equipment.
The consultation closes at 5pm on 28 July 2021.

02/06/2021 Radio Spectrum
New licence condition for spectrum licensees confirmed

Ofcom has today confirmed a new licence condition that now applies to the vast majority of spectrum licensees.
The changes mean most licensees will need to take action to ensure their equipment operates within international guidelines on electromagnetic fields (EMF) for the protection of the general public. Most licensees will also need to keep records demonstrating their compliance.

Following the publication of our policy statement on EMF in October 2020, we wrote to licensees in March this year to inform them of our proposals. We have considered licensees' feedback carefully and made some changes to the new licence condition and guidance documents. Today we have published full details of our final decision on the licence condition.

We have also published guidance on what licensees should do and how long they have to ensure compliance - this is dependent on the frequencies they are using. Our EMF compliance flowchart tells licensees whether or not they need to take action and, if they do, what action is needed.

A simplified version of the full guidance and specific advice for holders of amateur, ship radio and aeronautical licences will be published next month.
We will shortly be writing to affected licensees to inform them of our final decision and provide a replacement/update for their current licence.


Alan and Andy have been back to the repeater site with the intention to rid GB3SU of the QRM from GB7MT once and for all time, the result of this visit was plenty of test tones on GB3SU from the test set as they tried various filter configurations on GB3SU and GB7MT. Basically whatever was tried did not really improve the situation. In the process GB7MT was put back on its 4 stack UHF dipole array, and this made the situation worse, so its back on the GB7IV colinear!

We fitted a "circulator" to the transmitter of the effected repeater: GB3SU,
A circulator is a passive, non- reciprocal three ( or four-port ) device that only allows RF signal to exit through the port directly after the one it entered. "Ports" are where Coaxial cable or coaxial couplers connect to the device. For a three-port circulator, a signal applied to port 1 only comes out of port 2; a signal applied to port 2 only comes out of port 3; a signal applied to port 3 only comes out of port 1, and so on, therefore form our point of view the circulator acts as a one way street!

While it may seem a little crazy to fit a filter to the transmitter of the effected repeater,.. one would think rightly so that filters need to go on the effected receiver, one needs to bear in mind that RF will also go down into the transmitter of nearby repeaters ,.. in here.. the transmitter of GB3SU.. whether it is transmitting or not, the high powered unwanted RF can cause problems by "mixing" inside the transmitter, and it was this signal we were seeking to reduce., So we fitted a circulator, the drawing explains what happens. In this drawing Port 1 is connected to GB3SU Transmitter, and port 2 is connected to the coax which goes to the duplexer. Port 3 is connected to a 50 Ohm dummy load rated at the same power or more then the transmitter. Thus any RF entering down from the duplexer on port 2 is dumped by the Circulator in to the dummy load on port 3. In this mode its known as an Isolator. The working of Circulators are not covered in the RAE, and you can see why normally we have no use for such a devise, they are big enough to sit on the palm of your hand, are heavy for size and at UHF around 5MHz wide, they also need careful tuning, however very important is not to drop them as they contain ferrite material.

The circulator has not cured the problem completely to the frustration of our lads, and the users, no doubt, however the Lads will go up gain with other parts to try and work out where the problems is and how to cure it!

They also fitted a circulator to GB3SH to try and rid ourselves of the data QRM from the co sited SCC system, hopefully that will do the trick. We will only find out as the week goes by as We cannot stimulate the SCC transmitter in to operation! ( and rightly so )

The other important work was to test the all brand new GB7IV, this is built form a pair of "New" old stock Motorola GM360 mobile transceivers, they have been fitted in to a 3U 19" rack tray, the idea today was merely to check that they would work together successfully side by side without miss-behaving in a repeater set up. Users were puzzled by the behavior of "GB3SH" as it gave no pips or callsign, and had a squelch tail! - as of course its to be fitted with a Raspberry Pi and other electronics to allow it to become a data repeater on R7, 145.775MHz. We will tell you more as this project progresses.

The other important job was the first one we did, as the wind was low at the at time, as during the last few days we have had storm after storm with high winds cross the United Kingdom since the start of May. On the 3rd of May our on-site weather station recorded a peak wind speed of 72.5 MPH. The following weeks saw high winds for this time of year, Thursday 20th had a speed of 65.1MPH, during all of this an abandoned TV aerial which was left in situ, was unknowingly about to fail, curiously the fitters who put the new one up last year simply cut the coax to it, and connected that coax to the new one further down the domestic aerial mast and left the old one to its own devices. Friday afternoon shortly after 1300 the rear half of that TV aerial fell off!, landing fortunately on the roof, and rolled into view of our weather camera! As the windspeed this morning were low enough for us to access the roof and check our aerials and the others, Alan Recovered the rear half of the aerial before it went any further.

So why had it fallen? This TV aerial is the type which sits on a twin support boom, the clamps on the boom grip the aerial l towards the front, and rear, the rear one is where the aluminum of the boom has fractured and snapped. As to why? The rear section has a 20 element reflector which is also clamped on the the boom, this had worked itself lose and was able to rattle itself back and forth along the boom for around 30mm, Why it was taken out of use? - We will never know but - the F plug aerial connector had no weather proofing!

09/05/2021 SITE VISIT & CHECKS

Alan and Andy made the first visit to the repeater site this weekend and found one little problem which was causing QSB last year, with GB3SH.

Oddly enough only one station, 2E0ZBE reported QSB from GB3SH last summer, and it was noted then that the power level was going up and down, this could be clearly seen form the trace of the Farnham SDR. With gratefull thanks to them for their useful facility.

The cure to this was to plug in the cooling fan Tray DC connector which had fallen out of it's socket, so we now know to screw up those silly D plugs dont we ?!! The reason for the QSB was the PA was getting hot and automatic thermal protection was kicking in and the effect was the Power was being turned down! The fan runs on the transmitting being activated, and it runs on for another 3 minutes, after the tx goes off air.

We refitted the filter which should keep GB7MT out of GB3SU receiver,... all be it not as well as we'd like, Both Alan and Andy have been on the trail of more Narrow notch filters to try and keep one repeater out of another.

Additionally measurements were taken so we can make up new coaxial cables for extra filters for the VHF digital repeater GB7IV, these filters will enable us to test GB7IV at full power hopefully before installation.

While They were on site the winds were reaching 59.9MPH, they watched our aerials from the ground, moving with the wind.


Were sorry to report that there is a failure in the link somewhere which has downed our system.

We have good reason to believe that the problem exists with the Internet supplier who are changing cables and equipment in their network, this may be also associated with a vandalism attack on their equipment in the city centre, on Monday 12th.

We are aware that our camera and weather station went down at 00:07BST on Monday 12th April 2021, at time of writing We have no news at all, of when we can expect a re-connection. GB7MT will operate as normal as it uses a Microwave RF link to GB7PO.


Were pleased to say were back!

Our logging kit records we returned at 1354Local Wednesday afternoon.



Due to Covid restrictions we were unable to do the raffle on the date last year at The Southampton ARC Meeting.

We followed FULL Government Guidelines and held the Prize Draw on the Southampton ARC Zoom Meeting.

Well done to the winners of the prizes and thank you to you who purchased a ticket. The profits made go in to the running of our repeaters.

1st Prize - FT70D (Ticket 356) G8XIX Cheryl

2nd Prize - Alpha Tronix Power Supply (Ticket 351) G7NKZ Keith

3rd Prize - High Power Glass Insulators (Ticket 377) M0VBD Rob

4th Prize - Ceramic Insulators (Ticket 3) G8IPG Alan

Thank you for your support. The Committee



Behavioral Tests were made on Saturday 6th March to establish if our "Sinclair" Canadian built duplexers would work successfully on the 2M band.

These test followed others where the D Star repeater would not behave and We were seeking a second test to try theory's out.

We tried with an Icom Repeater "GB7IV ", between 0800 & 1130 also Yaesu DR2 " fusion" type repeater, from around 1200 to 1800L and a pair of Tait TM 8110 mobiles which will form a complete standby GB3SH. from 1800 to 1845L

The tests used in D star, C4FM and FM this allowed different modes to be tested and with FM other non digital users could try it should they have wanted.

The tests consisted around attempting to run the transmitters at different power levels, with in the licence limit, to establish if the transmitter was happy and also importantly if any De sence was happeing, in other words if the transmitter was deafening the receiver, It difficult to establish this with the D star repeater as it wont run FM and neither does it have an S or RSSI meter. But what We did find out was that even at 17 watts our limit the D star repeater was happy.

After lunch it was the go of the Yaesu DR2, We put this in to dual mode, and found out how it operates in dual mode configuration. For the record it only sends its CWID on FM, and it will wait for the end of an over to CWID in FM, however when its time to CWID and its idle, even if the previous QSO was in C4FM, it still goes over to FM and sends the CWID. One or two may of had the surprise then of hearing " GB7IV " as a CWID and may of wondered wat's that?! This is when We started to note the desencing issue, while We were playing on FM.

In the evening We tried the Two Taits bearing in mind : We have had them at the repeater site on air behaving impeccably at 17 watts as GB3SH in to the SH duplexers without a hint of problems for several hours.

These Taits also played up when used on the IV channel and the IV duplexers, curiously it was beaconing as " GB3SH" of course,.. and anyone puzzled by finding a "GB7IV" in the afternoon must of wondered how GB3SH had QSYed! and perhaps even better why there was now two of them!

So the conclusion is........
As three different repeaters from 3 different manufacturer's played up shows that the Sinclair duplexers are not up to the job currently.
What to do about it is of course being pondered as We of course do not want to be restricted to 3 watts from the transmitter !

As for why the D-star repeater played up previously, it is just possible that as the twin screened RG214 cables were a very precise 319mm long, this precise measurement is the length of coax links fitted to 145Mhz duplexer cans, it is possible that this alone caused the problem as during tests with the D-star repeater again today it did not misbehave.

So were glad We tried off site as it is more easy to fathom out what is happening when not working in the restrictions, of the repeater site be that the COVID Threat, The cold, it struggled to get above +5C today! And of the dragging all the kit to site in the first place.

We gratefully thank:

2E0TGE 2E0ZBE G4MYS G6DLJ G7AFN G8IPG & M1PVF for working through and help test the repeater system.

Thanks to: ICOM Yaesu and TAIT for some rather good radios to play with!


The Yaesu DR 2 from the tail connections note "callsign" GB7MT on the repeater, and "GB7IV" on the duplexers. The DR2's are dual band so it was no problems to reprogram GB7MT to become GB7IV!

The almost complete standby "GB3SH" on GB7IV channel just before its "go", sitting on top of the on air DR2, the top unit is the monitoring unit showing volts and current drawn, also holds the RSSI or S meter and a convenient " tx test inhibit and normal" switch on the front panel, and the electronics to enable the operating "On Battery " ident to be transmitted. Also fitted a thermal probe on the transmitter heat sink, with its display on the panel, this curiously worked from two 1.5 volt button cells in parallel !


New 145Mhz duplexers work very well !!
New build GB3SH repeater functions well !

We are pleased to say our desire to have a fully spare working VHF FM repeater ( cold standby ) has been built with Tait TM8100 mobiles, built in New Zealand, it's been soak tested in to a dummy load for several days, for thermal reasons, and tested on air, with the logic, a brand new design by M0XIX to our specifications with some features for ease of use and information. For instance when running on battery back up, a special tone will replace the end of over "Beat". This repeater has been tested with our brand new old stock Sinclair Canadian built Duplexer which was aligned to R7, 145.775 Mhz by Richard G4WFR.

The next thing to do is take them to site and air test both of them on our aerials. A date for this has yet to be decided as with everything its COVID dependent.
While the repeater is intended to be a fully spare GB3SH, that we can take over to the site and remove the fitted unit and fit this one with, it will be tested as GB7IV on the IV channel. This will enable us r to find out if We can run two VHF repeaters on the same site at the same time. GB7IV will of course be a data repeater, We want to try both Fusion ( C4FM ) and D-Star, it is however more easy for us to test with FM, and even We have plenty of FM handhelds which are easy to test with!

We will let you know when We do these tests as we will need as many as possible to engage in QSO's to ensure equipment compatibility with out resorting to using even more filters.




After around five years of trying to get a set of working duplexers for GB7IV, a brand new set has been successfully obtained privately.
This gives us the desired opportunity to run a digital repeater on VHF. Once our engineers can get access to the repeater site, due to COVID restrictions, We will take one of the spare FM GB3SH repeaters and set it up as GB7IV on the GB7IV channel of R7:- 145.775MHz, and basically see if we can get two repeaters to function on one site without problems!

We will need your help with this experiment.
The experiment will use the aerials which we intend to use, as they are already fitted!
We Will of course let you know as to when We will run these tests, as those tests can only go on for a few hours at best, due to licensing, and We will want QSOs to go through both the repeaters at the same time!

You will not need special equipment, for these tests, just a FM transceiver on either the usual GB3SH channel, or a transceiver on 145.775MHz FM, the old GB3PC channel with CTCSS on 71.9 Hz. on transmit.

GB7IV will have CWID with the callsign GB7IV for legal reasons, and your interest, as normally of course GB7 callsigns are only assigned to the digital service. If you would like to help with the purchase of these filters please contact: on info on how to help with this privately funded project.

In addition We are pleased to announce that Richard G4WFR, the keeper of GB7SU and his digital DMR repeater station, which was close to Southampton docks, has joined the SHRG with his repeater:- GB7SU which is currently in West Southampton. The opportunity will be taken, to test to find out how we can successfully run the DMR repeater on our site! Once again We have the capacity aerial wise, and duplexer / filter wise, to run GB7SU from our repeater site hopefully, without interference with a much improved coverage for the DMR users.

We will on our link pages put information on how you too can get operational on DMR, the kit to use, where to get equipment from, and to avoid how to get the radio programmed,and how to obtain the needed
"Digital ID" for which a pdf of your Amateur licence is required

In the meantime keep a watch on this site for more information



Since the Covid outbreak the Southampton ARC holds now a regular get together on Wednesday Evenings at 19:30 on Zoom Meeting.

Very informal chat at times has gone on to almost midnight. But you can come and go as you please. You can hear about the latest repeater news GB3SH, GB3SU, GB7MT & GB7IV

Topics range from projects sharing of information, to subject not radio related but a good chat always!!

Everyone is welcome from Licence to SWL and those interested to take on the courses to become licenced.

Feel free to join us at anytime on a Wednesday evening, You dont have to be in Southampton some of our regular visitors log in from all over UK.... Maybe overseas soon?

For the Zoom access code e-mail Andy G4MYS at


17/01/2021 Amateur Radio history story from the BBC


We are pleased to announce that our GB3SU & GB7MT Broadcastify links are back on and connected up. The GB3SU link has been back on for around 6 days.
They were moved due the pending loss of the needed internet connection at their previous location. The new location is in a high signal area, hopefully this will improve the recovered audio especially on GB3SU, and reduce the QRM on 70cM.

Changes will be made to the aerials used over the next few days, which may interrupt the service for a while esp on GB3SU. Reports are welcome, esp on audio quality which we know is not BBC radio 4 quality to:



The weather station returned online today at 16:00. The Weather Cam is still off line and should return in the next 24 hours



Update: An engineer is on the way today to fix problem in West Southampton

We have lost our Video camera and Weather feed thanks to a fault on internet provider network which occurred at 1101AM on Monday 28th of December, which affected the Millbrook, Maybush and Shirley areas of Southampton.

While the fault in the network has been cleared, it has the effect of this has knocked out our connection to the internet. This fault is a variation on a theme on around 50% of the reason's as to why we lose connection, some of the faults are to do with the linking equipment, all of this as such is is all out of our control. Due to the COVID restrictions We can't go to our site to make our standby alternative arrangements work - frustratingly.

Unfortunately as this is late December, and many are on leave, We seem to have little hope of any any improvement and a return to service of the weather station or a viewable camera until Monday the 4th or later on in the week. However We are pleased to say our internet free link to GB7PO works fine, and this is the reason why we dont use the internet for this link!