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The Amateur Radio Repeater on Edge Hill in the South Midlands (UK) operating on the 70cms channel of RB8.
_ _ . _ . . . . . . _ _ . . . . . BAND = 70 cms ; Channel = RB8 (RU256); Output = 433.200 MHz , Input = 434.800 MHz
SITE = Edge Hill, Warwickshire, 10 km North of Banbury, UK
NGR = SP 361 457; (OX15 6HR) Locator = IO92FC ; Zone B
ANTENNA = Co-Linear (TS B3301 (Repeater)) with a
Diplexer (Procom) for single-aerial-working ;
ERP = 9.93W (9.96 dBW)
LOGIC = "Logic-8" Module
Access = 0.5 Secs (approx.) of 1750Hz Tone-Burst ; Timeout = 10 mins (approx.)
Beacon Callsign Period = 10 mins (approx.); (CTCSS = A (67.0 Hz)) - not implemented)
KEEPER : Paul G4OHB
Engineering : Clive G0CHO (RF), Peter G8CQH (Logic (CAIRO), Treasurer & Web)
Installation: Steve G6MMD (Antenna), Ian G0EDT (Closedown)
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This Repeater is housed in a secure cabinet attached to a grain-drying barn on the cusp of Sun-Rising Hill. The mast is topped-off with a slender co-linear antenna and rises a modest 15 Metres alongside the large motor-room holding the dryer - some 3-phase motor, that is! The site is totally rural, being only a few yards from the escarpment which falls away sharply to the North. This favours RF penetration into Stratford-upon-Avon (Shakespeare!) and Banbury, and also the M40 Motorway corridor between the two. To the north it reaches the southern outskirts of Birmingham and Solihull including the M42 corridor.Tall and mature broad-leaf trees once surrounded this rural site, leading to some variations between summer and winter coverage. However, almost all such trees were felled (in the Spring of 2001, by the site owner for his own purposes) to leave the antenna with an almost totally uncluttered horizon. (There's just a small "null" on the M40 alongside Banbury.)
The GB3EH RF units (left) are controlled by a Logic module (right) which is compatible with CAIRO-8.
For engineering details please proceed to the Logic-8 sub-site.
To the East, the next land feature of equivalent height is in Russia; being The Urals. Perhaps this fact explains the bitterly cold winds which we often experience each Winter, especially when adjusting the antenna or its guys? But happily, The Castle Inn, is a most authentic English pub only two-minutes' drive away, with its ample servings of traditional ales and meals available on an all-day basis. In the summer, it's a popular area for serious walkers to meander in the balmy afternoon heat, having paused, of course, for their well-deserved libations at the pub, after visiting the Battle Monument Stone on their rise up this dramatic and historically-significant escarpment. But it is equally popular with those who prefer an evening leisure drive for a breath-taking halt in the beer garden to watch the sun sink over Wales.
And - yes! - this is indeed the Edge Hill which is famed for the Battle of 1642 when Charles-I had his well-documented 'set-to' with Oliver Cromwell, at the outset of the Civil War. [Web]
GB3EH coverage maps surveyed then computed by Clive, G0CHO/M before (L) and then after (R) antenna raising on July 17, 2009.
(The redder the better!)
Clive explains his methods:
The meter drive signal of an Icom 3210 was logged on a laptop at 1 second intervals using a PicoScope adapter, the voltage derived from the rig having been previously calibrated at a Stratford Radio Society test equipment evening (thanks to John for bringing the kit along). Simultaneously the location data from a GPS unit was also logged as I drove various routes around the area .This captured data was read into a spreadsheet (up to 2000 lines per route!), invalid readings discarded then scaled and grouped to S-meter levels (all below S3 lumped together). Finally the results were further massaged into a format that could be imported in the Radio Mobile (prediction software) over a map of the area showing the S-meter levels as differing colours. The 'before' readings were taken in early July 2009 and the 'after' readings, in late July/Aug 2009.
