GB3JB - 2m Analogue FM - RV63 - 145.7875 Mhz - 145.1875 Mhz - 103.5 hz ctcss.
GB7JB - 70cm DMR - DVU37 - 439.4625 Mhz - 430.4625 Mhz - Colour Code 1 - Slot 1 "Local" TG9 - Slot 2 "SW Cluster" TG950

Antenna Upgrades

Hi ​All,

GB3JB and GB7JB were both switched off at approx., 9:05 this morning, Sunday 14th June.

The weather held, and the wind was not to gusty. Therefore, Steve M6BPP and he's colleague Ian, were able to remove the original GB3JB antenna, which was damaged, and install the replacement / new antenna systems.

Three in all. A NEW GB3JB antenna, the GB7JB antennas, and the NEW GB3USK 23cm beacon antennas.

​Lots of hard work and effort, for which I am very grateful​.

The 23cm beacon antennas are fine, with a VSWR of <1.4:1

The GB7JB antenna, is also fine, with a VSWR of <1.2:1


However, the GB3JB system has a problem. It is exhibiting a VSWR of >7:1.

Yesterday, when I went to the site, to check that everything was ready, and tested both antennas, just to make sure everything was still OK for today, it was ! Exhibiting a VSWR of <1.2:1

Our considered opinion is that during the lifting and installation of the assembly, the coax / "N" plug assemble at the base of the 2m antenna, has been stressed and the inner pin has probably been pulled back from making a connection to the inner of the "N" socket, on the base of the antenna.

​Unfortunately, this is not going to be a quick fix​, as a significant amount of today's installation will have to be undone and dis-assembled, to re-terminate the "N" plug.

The main issue being that the fixing arrangement for the 2m antenna is not to the side of the support mast, but actually a slide fit to the inside diameter of the the support mast. Therefore the connection point is some 25cm down inside the support mast.

I have spoken to Steve, M6BPP, prior to sending this e-mail, and he is now trying to arrange a date when they will be able to come back to the site. He is hoping that he can fit something in, over the next two weeks.

So I'm sorry folks, but GB3JB is off-air for the next few weeks.


With regard to GB7JB, which returned to service at approx., 5:07 pm today.

The received signal strength at my QTH has significantly improved, compared with the 13ft temporary installation. It was generally fluctuating between S3 and S5 on the meter, and very occasionally peaking up to an S7.

Having been monitoring the signal over the last 3 hours, I can report that it is a steady S7 with regular peaks up to S9.

In terms of accessing the system, I could not raise it on 5 watts, and the signal was very broken up and marginal, when using 25 watts. Now I can bring the box up consistently with 5 watts.

Also, having had a listen around to some of the analogue 70cm repeaters, prior to switching GB7JB back on, I can also report that all the systems that had previously been checked, were a couple of "S" units stronger, with the antenna in it's new position.


With Regard to GB3USK 23cm Beacon.

​At this moment in time we are waiting ​for any feedback what so ever, from ETCC, as to what progress if any, has been made with regard to the NoV for the 23cm beacon.

Despite several requests, no information as to the specific progress of the 4.1 month old application has been forthcoming, other than that indicated on the ETCC web site, where it is listed simply under "VETTING".

Not very informative.

We appreciate that there are various vested interests, in that 23cm is not a "primary allocation" as far as Amateur Radio is concerned. However, it cannot be that difficult to keep track of exactly who is currently dealing with any specific application, how long they have had it, and feedback any concerns that they may have.

This is the same pigeon hole in which the application for GB3UGR the 4m beacon, is sitting. 4m is also not a "primary allocation" as far as Amateur Radio is concerned.


​So there you are folks. Up to date with today's success​ and disaster, as well as the current status of the beacon applications.


​Cheers & 73's
Dave, G3ZXX.