Leicestershire Repeater GroupProviding a service for all Radio Amateurs |
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Repeaters & Beaconsby the engineering team |
Leicestershire Repeater GroupProviding a service for all Radio Amateurs |
|
Repeaters & Beaconsby the engineering team |
| Located in Charnwood Forest, Leicester.
This shows the details of site equipment. Reports about our beacons and repeaters to Nigel M1NAS - engineering manager. |
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Call sign |
TX Freq. (MHz) | RX Freq. (MHz) | Power | Antenna | Notes |
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145.600 |
145.000 |
25W |
Collinear |
2m NBFM Phone repeater RV48 (R0). 12.5KHz spacing
(enforced by primary user). Reciprocal with 0.18mV mobile running 25W. Single antenna working. 2.5kHz maximum deviation required to use. Greater than 2.5khz peak deviation may cause your signal to drop out of the repeater, audio will sound distorted and will breakthrough with other repeaters on 145.6125MHz Access: CTCSS:
C:77Hz or 1750Hz toneburst |
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| GB3GV | 1318.5 | 1249.0 | 12W | RX: 6dB Alford Slot. TX: Alford Slot (2m below RX ant) |
15 April 2008: Off air due to antenna repairs. Reverts to beacon mode when not in use as a repeater. |
| GB3LE | 433.100 | 434.700 | 25W ERP | Co-linear | 70cm NBFM Phone repeater RU248 (RB4). 12.5KHz
spacing (enforced by primary user). RG213 coax, N-type terminated. |
| GB3LES | 2320.955 | ----- | 10W ERP | Alford slot radiating at 160 degrees | 13cm Microwave Beacon. |
| GB3LEF | 3400.955 | . | 5W ERP | Alford slot radiating at 180 degrees | 9cm Beacon. Status: On air |
| GB3LEX | 10368.955MHz | . | 1W ERP | Slotted Wave guide | 3cm Microwave Beacon |
| GB3UM | 50.740 | 51.240 | 25W | 0dB gain Centre-fed folded dipole |
15 April 2008: low power and 2 antenna working 6m phone repeater, sensitivity: 0.175m V for 12dB SINAD. |
| Beacon News The 2.3, 3.4 and 10 GHz beacons are co-sited, 220metres asl, at Markfield about 8kms north west of Leicester; locator reference IO92IQ,. In 1981 the 10.400GHz, WBFM, beacon GB3LEX became operational and in 1985 was joined by GB3LES on 2320.955MHz. Technical details: GB3LES, is a 2watt transmitter F2 modulated with callsign and QRA locator; ZM24J. The NBFM transmitter comprises a 0.5watt Wood & Douglas source on 386.826 MHz which is filtered and then amplified to an output of approximately 10watts. A retuned Microwave Modules 1296 Varactor multiplier is then used to triple the input and after filtering drives a varactor doubler. The doubler, which is a VHF Comms design by DF7QF, produces, after further filtering, a final output power of approximately 2watts. A 25m length of FHJ50-2 coaxial cable is used to feed the RF to the antenna which is an Alford slot, the performance details of which may found in the Microwave Handbook chapters 14.29, 15.26. The antenna is contained in a 'radome' fashioned from 50mm diameter of gray plastic drainpipe. The transmitter and keyer were built by G4LRT. The Alford slot was built by G3JVL and G3WDG. Originally commissioned in 1981 the transmitter comprised a 200mWatt waveguide cavity Gunn oscillator, tuned to 10400MHz. WBFM modulation was applied via an offset varactor diode mounted in the waveguide cavity. The beacon antenna is 16 slots in one face of a length of full height WG16 (UR90). The slots are equally distributed about the centre line of the broad wall. When the beacon was re-commissioned, following the collapse of the mast with loss of the waveguide feeder, it was updated to be a NBFM transmitter on 10368.955 MHz. The original waveguide slot antenna was re-used and this gives an ERP of 1W with a -3dB beamwidth of ± 90deg on a heading of 180 degrees. The transmitter comprises a 94 MHz source which is amplified and frequency multiplied to produce a filtered output at 3400.955MHz of 1.5Watts. The transmitter has been rebuilt, by G4LRT, using much of the hardware recovered from the Sheffield beacon, GB3UOS. The antenna is a Alford slot in a plastic drainpipe radome. Send comments and reports on beacons to:
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| Home | This page last updated: 16 April 2008
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