European 6M Repeater Operational Status

 

European 6M Repeaters
Status
as at: 29-Jun-98


  • GB3AE - IO71PR - Tenby, Dyfed
  • GB3AM - IO91QP - Amersham, Bucks
  • GB3EF - JO02PB - Martlesham, Suffolk
  • GB3FX - IO91OF - Farnham, Surrey
  • GB3HF - JO00HV - Hastings, East Sussex
  • GB3HX - IO93BP - Huddersfield, W. Yorks
  • GB3PX - IO92XA - Barkway, Herts
  • GB3PD - IO9OKT - Portsmouth, Hants
  • GB3RR - IO93JA - Hucknall, Notts
  • GB3UM - IO92IQ - Markfield, Leics
  • OH3RTR - KP11WK - Tampere, Finland

    "GB3HF latest news ..."

    Progress with GB3HF is slow, but there is a feeling with all concerned that better to do it this way than act in haste! There are two major outstanding issues; firstly, there has been some delay in getting the antenna installed. This has been due to a "rethink" regarding precisely where on the building to mount it. The original view was that it could be simply sat on top of an existing mast, but I think now they've seen the size of it, the boys have decided against that one!

    Secondly, having installed one of those "cheap" duplexers made from Heliax (tm) at Portsmouth, both myself and our filter guru (Jon, G4MDC) have been of the opinion that this design could be substantially improved upon. While the TX<->RX isloation of the GB3PD duplexer is "okay" (at around 75 dB), it doesn't lend itself to running "full power", so progress on the GB3HF duplexer has slowed a little while this rethink is under way.

    G4NAO has made some more of those cute little PCB's that I've taken to using as 6M repeater controllers; G4MDC has converted yet another Tait TX unit, and I've done the receiver. We're working on the duplexer, and provided Martin can get something done about the antenna, it should be "all systems go" for the forthcoming Sporadic E season on the south coast. Rather them than me!

    Given the current (business and personal) workloads of all concerned, it's difficult to see now how GB3HF can be brought on line much before September, but of course if an opportunity presents itself, it'll be seized upon, no doubt!


    "GB3PD status ..."

    Our intial suspicions regarding the use of the "white stick" antenna (shared with GB3PC, 2M repeater) were absolutely on the money. The remarks I made about using these things for repeater service in my October 1994 briefing paper (was it really that long ago?) all proved to be correct.

    The fundamental issue is that the angle of radiation from these things is considerably greater than zero, so most of the energy is spread upwards at an angle of about 18 degrees above the horizon. Which is pretty useless for an installation on a high site ... John (G0WEH) has therefore designed and constructed a dual-band omnidirectional "J-Pole", and this was installed on the building during the early part of May. Shortly afterwards the receiver developed what looked to be an intermittent fault, so I trudged down there again with a spare.

    With the new receiver installed, all of the talkthrough levels had to be reset, and it took some considerable amount of time to get this anything like right. Have you ever tried doing work like that in a sauna disguised as a lift motor room? Anyway, it's done now, and general opinion seems to be that 'PD is a lot better all round. We'll see ...

    "GB3AM current status ..."

    Eventually the replacement element for the folded dipole surfaced from the manufacturers, and a spate of particularly nasty weather meant that this sat around waiting to be installed for quite a long period of time.

    Finally, the weather broke, and one Saturday in May Mark (G8AWO) and myself managed to get on site and replace it. The good news is that it didn't change the service area AT ALL, but at least now we have the comfort of knowing that the antenna is once again at "DC" potential, which ought to give us better protection from all of those nasty lightning bursts that seem to target the Chilterns.

    I now have a modified Notice of Variation for GB3AM to permit digital voice announcements to be made. I'v had it for a month or so, but I am undecided whether to implement it at this time or not. The major concern I have is that the Radiocommunications Agencey have seen fit to dictate not only the nature of the messages but the precise wording of them. Frankly, they're not much use, so I'm not sure I'll be bothered until someone sees sense and allows them to be changed.

    All that aside, GB3AM is performing entirely to expectations, and as a rseult I am loathe to do more than my monthly on-site inspection of the parameters right now. We'll see ...

    "GB3AE Update"

    After what seems like an eternity, the guys at GB3AE (Tenby) have finally received their authority to install the repeater. I think that they will still have some way to go before they're ready, and I'll see what we can do at this end to make their lives a little easier.

    We did send them the raw materials to make a Heliax (tm) duplexer, but I don't know how they're getting on with it. I also suspect that we ought to finish our modifications to the deisgn as a matter of some urgency and share our findings with them!

    Watch this page for regular updates!
     

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    Webmaster: Iain Philipps, G0RDI

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    Last updated:- 29 June 1998