_ _ .  _ . . .  . . . _  _  .  . . . .
G B 3 Edge Hill
 _ _ .  _ . . .  . . . _  _  .  . . . .

The Amateur Radio Repeater on Edge Hill in the South Midlands (UK) operating on the 70cms channel of RB8. 

June 2013 : major engineering improvements; 'new' Tait T/RX for increased ERP and CTCSS access (A = 67Hz)

Silver Jubilee : Saturday 18 January 2014

A recording of some Day-1 usage - click . Paul, G4OHB explains : 

In honour of the impending Silver Jubilee next Saturday, I’ve managed to transfer to MP3 the ancient cassette on which was recorded the very first hour of EH’s life:  1200 – 1300 on 18.01.1989.  This was an off-air recording made on a timer-operated cassette deck at my flat in Moseley.  The MP3 version has been edited down to about 34 minutes, to excise silences and various bits of QRM.  It is now stored in my Dropbox and may be accessed via the link.
G4OHB and G8CQH are both featured of course!  John G4VOZ/M managed to be the first station to call through.  He became a regular user, but hasn’t been heard for years now so I assume he has moved to another area.  At one point he announces on the output that the old SU8 simplex channel is now officially designated as RB8.
Although he was parked somewhere east of Northampton at the time, he was received loud and clear in Moseley, demonstrating what a good location I had there!
Other stations taking part include Arthur G8PNC (on a handheld in S B’ham), Roger G4OCO/M (who installed the mains feed to our cabinet) and Steve G8PYT who built the original logic.  The callsign was faster than our current one and was issued every 4min 16sec, which we probably wouldn’t tolerate now, but of course at that time we were keen to advertise the box’s presence!  This logic developed a fault many years ago and was returned to Steve for repair, but has never been seen again!  However, by then we had replaced it with the present CAIRO logic.
Rather poignantly, there are two stations on this recording who sadly are now silent keys: Jack G5UM (east of Leicester) and John G3CUN (S B’ham).
Both were well-known and very popular 70cm enthusiasts.
I hope you enjoy this little slice of history, 73 Paul

_ _ .  _ . . .  . . . _  _  .  . . . .

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 Procom diplexer and a cavity filter for single-aerial-working ;

ERP = 18W

LOGIC = "Logic-8" Module

Access =  CTCSS  Tone A (67.0 Hz) 

(but also 0.5 Secs (approx.) of 1750Hz Tone-Burst,  if preferred)

Beacon Callsign Period = 10 mins (approx.) ;   Timeout = 10 mins (approx.) 


Engineering : Clive G0CHO (RF),  Peter G8CQH (Logic (CAIRO), Treasurer & Web)

Installation: Steve G6MMD (Antenna),  Ian G0EDT (Closedown)

_ _ .  _ . . .  . . . _  _  .  . . . .

This Repeater (and its UPS) is housed in two secure cabinets, 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 grain-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 now with an almost totally uncluttered horizon.
(There may still be just a small "null" on the M40 alongside Banbury?)

Tatits and UPS
_ _ .    _ . . .   . . . _    .    . . . .

GB3EH is implemented with two Tait transceivers in the upper cabinet; one for the Rx duty and the other for Tx.

(In the event of a fault, they may be swapped over.)

Together, they are controlled by the CAIRO-8 Logic module which is fixed to the upper cabinet door panel.

The diplexer and cavity RF filters can be seen behind and to the left side of the Taits, respectively.

The lower cabinet houses the Repeater's 12V leisure battery and UPS charger module.

For more 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.

Site History : 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!)

before antenna rise

after antenna raise

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.

GB3EH Users' Page