Transponder Net.

Due to the relocation of the link to the GB3NS Repeater in Surrey, the Transponder Net is currently suspended. Look for its return soon! It is an “ordered” Net, check-ins are taken in advance and the rotation follows the order of check-in.


North Surrey Repeater Group Information

The NS repeaters are now operational from a Ridge-top site near Caterham, Surrey on the North Downs with a new equipment line up.
GB3NS (Analogue) Simoco TSF2025
Normal operating Frequencies
Channel DVU54
TX freq 439.675MHz RX freq 430.675MHz CTCSS 82.5Hz
Time out – 180 seconds
Logic is ID-O-Matic Mk 3 kit which sends a K in Morse on carrier drop
Locator – IO91WG
Echo-link access via Trevor G7ELZ remains available on the Analogue machine.
GB7NS (Digital) Motorola DR 3000

Normal operating Frequencies

Channel DVU13

TX freq 439.1625MHz RX freq 430.1625MHz

DMR is a digital mode which uses TDMA technology. This allows for either two voice channels at the same time or one voice and one data channel. Slot 1 and Slot 2 are the respective audio channels available within a 12.5 KHz channel spacing.

It now requires a Colour Code set as 3, not 1 as previous, it is also now connected onto the DMARC network via the Internet.

Talk groups (TG) should be set as 9, for local repeater communications using slot 2

Also on slot 2, with a TG of 235 will communicate with all UK repeaters set up to allow this.
TG 8 will be used later as a London Roam Function.
Slot 1 is used for international
TG1 being World Wide and brings up all DMARC connected repeaters around the world, this being over 300 units, active in 18 countries and expanding at a very fast rate.
TG 2 is used for European base stations being accessed.
TG 3 brings up North American units.
TG All call should no longer be used.

You will also need to leave a two second pause before PTT back on a active channel to allow the network to keep up with the connections of multiple repeaters around the world.

The coupling of the two units onto the same antenna, has reduced the power output to just under half the power that was available on the duel mode unit, but now there can be two digital and a analogue conversation, all going on at the same time.
History of GB3NS

Due to loss of original site the repeater was moved to a local commercial site on 15th December 2011, after some initial aerial changes the repeater provided good coverage to it’s original service area. MB7NS was co-sited and provided better service than previously probably due to increased aerial height. because of a change in the site owners building requirement the repeater was turned off on 4th June 2012.

The repeater was then sited at a temporary location in IO91vh providing some coverage of the London and North Surrey Areas.

Operating Frequency – 70.3875 MHz

MB7NS continues to operate form the temporary site.

Unfortunately it will not be possible to move MB7NS to the same site because of other commercial units operating on adjacent frequencies. There is a possibility to relocate MB7NS to an alternative North Downs site, in the meantime it continues to operate from an emergency site. There is still the possibility of developing MB7NS into a full repeater, however this will not happen until Ofcom have finished new band allocations, where additional frequencies in low band may become available to allow this to happen.

MB7NS uses a Motorola GM900 mobile using ADS-SR1 Simplex Repeater module. Carrier squelch operation, which will record signal for up to 120 seconds, or carrier drop if before, and then replays recorded message after 2 seconds drop of input signal.

Callsign / beacon, voice every 5 minutes, Morse Ident every 5 minutes.

Power output 10 Watts ERP


The group also provide and maintain GB3SEE microwave propagation beacons located at Reigate Hill IO91vg, radiating 1W ERP on 10,368.850 MHz & 1W on 24048.960MHz.

These are now Frequency locked and operating reliably.

10 GHz beacon has been heard by OZ1FF at 733 Km JO45bo

Best DX on 24 GHz Beacon is 123 Km to G4BEL JO02bi

Propagation Reports on any of the above are most welcome email


Author: CVRC

Crescenta Valley Radio Club is an organization over half a century old. Our members are amateur radio operators who share interests in radio and service to our community. Members help new members starting the hobby as well as helping other members with technical and operational problems of getting on the air. We keep ourselves up to date with the technological changes by inviting expert speakers to our meetings. CVRC closely supports GEARS (Glendale Emergency Auxiliary Radio). Many members are in both organizations and have provided communications for an emergency at Glendale Memorial Hospital, and with Cruise Night, the Montrose Christmas Parade, and various local themed running events. We meet once a month on the second Thursday of the month at USC Verdugo Hills Hospital at 7:00PM. Every Sunday we hold two nets. On our 445.680 repeater, we hold the No Chit Chat net at 7:50PM, and at 8:00PM, we switch to our 146.025 repeater for the Whats Going On Net. Both repeaters are located on top of Mount Thom and share use the city's antenna tower. Their power is backed up by both batteries and an emergency generator. We have several annual events. In June, we participate in the National Field Day by setting up several stations in Verdugo Park and operating completely "off the grid". Every August we have a barbecue in Crescenta Valley Park with a Fox Hunt activity where the members try to locate a hidden transmitter. When December comes around we come together for a traditional holiday dinner.

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