Rowridge transmitting station

Rowridge

The Rowridge transmitting station
Rowridge transmitting station (Isle of Wight)
Mast height	149.6 metres (491 ft)
Coordinates	50°40′35″N1°22′07″W / 50.676389°N 1.368611°W / 50.676389; -1.368611
Grid reference	SZ447865
BBC region	BBC South
ITV region	Southern (1969–1981) TVS (1982–1992) ITV Meridian (1993–present)
Local TV service	That's Solent

The Rowridge transmitting station is a facility for FM radio and television transmission at Rowridge on the Isle of Wight in southern England.

It currently has a 172-metre (564 ft) tall guyed mast, owned and operated by Arqiva (previously National Grid Wireless). There is a smaller tower on the site belonging to British Telecom. Prior to Digital Switchover (DSO) the station broadcast with a power of 250 kW (ERP) for FM radio, 500 kW for analogue television, and 20 kW for digital television. In July 2007, Ofcom confirmed that Rowridge would remain an A Group transmitter at Digital switchover; the digital television transmission signal was then boosted to 200 kW. From March 2018 MUXES 7 & 8 moved out of the A group to channels 55 & 56, though these are due to be turned off between 2020 and 2022.

Rowridge is one of only two main transmitters (the other is the rather smaller transmitter of Rosneath in Scotland) to broadcast its output on both horizontal and vertical polarities. Only the main 6 MUXES are transmitted in vertical polarity. The reason for this dual polarity transmission is to give a second option to those experiencing co-channel interference from transmitters on the continent.

Analogue Channel 5 was not transmitted from Rowridge but was broadcast (at 10 kW) from Fawley Power Station, with the antenna located on the main chimney. Transmissions all fitted within the A group and were horizontally polarised. On 25 March 2009, Channel 5's analogue signal was turned off from Fawley Power Station, due to the digital switchover in the neighbouring Westcountry region.

Population coverage for the main four analogue channels was about 1.75 million.

History

The station was first built to provide BBC 405-line television coverage for an area including Southampton, Portsmouth, Bournemouth, Dorchester, Chichester, Brighton, Winchester and Salisbury. Sites on the mainland and the Isle of Wight were considered, and three were tested by BBC Research Department.

Construction

A temporary 200 ft lattice mast was built with a main antenna at 175 ft and a reserve antenna lower down. These aerials were directional to enhance the signal northwards and reduce unwanted coverage to the south. ^[1]

It was built by BICC, alongside Pontop Pike (also 500 ft) and North Hessary Tor in Devon (a taller mast).

The ITA wanted to build a mast nearby on Chillerton Down, but in February 1957, the local council rejected the planning proposal, and wanted a joint transmitter, not two. ^[2] The ITA mast was built subsequently in 1958.

On June 17 1963 the local council gave planning permission for a joint ITA-BBC mast, 1,050 ft, for UHF 625 line television. ^[3]

Transmission

Test transmissions were from October 18 1954. ^[4] Television reception would stretch from Somerset to Sussex. Sussex had a previous 'booster' transmitter on Truleigh Hill in Upper Beeding. ^[5]

The service opened on 12 November 1954, bringing television to the area for the first time.

A programme feed was obtained via a Post Office radio link, using refurbished equipment that provided the original picture feed for the Wenvoe Transmitter on the British Telecom Microwave Network. A site for this near Alton, Hampshire was acquired and named after a nearby pub: Golden Pot. Here the TV signal from Alexandra Palace was picked up and relayed via a one-hop 4 GHz microwave link to Rowridge. ^[6]

The microwave link from Hampshire was brought into service on 18 October 1954. Later, the microwave link ran from the Museum telephone exchange in London to Rowridge, using Golden Pot as an intermediate site. ^[7]

A better transmitter would be fitted after a year, which was fitted in May 1956. ^[8] National radio on VHF was to be added by 1957. ^[9]

In 1965 the UHF antenna was added making the total height of the structure 149.6 metres (491 ft). This addition allowed Rowridge to radiate the PAL 625-line transmission that allowed broadcasts in colour and eventually stereo sound, using NICAM.

BBC2 was planned to arrive on November 14 1965 on 625 lines, ^[10] but test transmissions would start on December 18 1965, with full broadcasts from January 16 1966. ^[11]

On the neighbouring ITA mast, the ITA expected colour transmissions by late 1969. ^[12]

On 25 March 2009, Channel 5's analogue signal was turned off from Fawley Power Station. Later on in the day, "existing digital terrestrial TV services moved to new frequencies", due to the digital switchover happening in the region in 2012. ^[13]

Arqiva applied for planning permission to replace the existing 150m (492') mast with one 187m (614') high on 22 May 2009. ^[14]

Channels listed by frequency

Analogue radio

Frequency	kW [15]	Service
88.5 MHz	250	BBC Radio 2
90.7 MHz	250	BBC Radio 3
92.9 MHz	250	BBC Radio 4
96.1 MHz	10	BBC Radio Solent
98.2 MHz	250	BBC Radio 1
100.3 MHz	125	Classic FM

Digital radio

Frequency	Block	kW	Operator
225.648 MHz	12B	5	BBC National DAB

Analogue television

12 November 1954 – 15 January 1966

Frequency	VHF	kW	Service
56.75  MHz	3	100	BBC Television

15 January 1966 – 13 December 1969

Frequency	VHF	UHF	kW	Service
56.75  MHz	3	—	100	BBC1 South
495.25  MHz	—	24	500	BBC2 South

13 December 1969 – 27 December 1969

Frequency	VHF	UHF	kW	Service
56.75  MHz	3	—	100	BBC1 South
495.25  MHz	—	24	500	BBC2 South
519.25  MHz	—	27	500	Southern

27 December 1969 – 4 December 1982

Frequency	VHF	UHF	kW	Service
56.75  MHz	3		100	BBC1 South
495.25  MHz	—	24	500	BBC2 South
519.25  MHz	—	27	500	TVS (Southern until 1982)
551.25  MHz	—	31	500	BBC1

4 December 1982 – 3 January 1985

Frequency	VHF	UHF	kW	Service
56.75  MHz	3	—	100	BBC1 South
471.25  MHz	—	21	500	Channel 4
495.25  MHz	—	24	500	BBC2 South
519.25  MHz	—	27	500	TVS
551.25  MHz	—	31	500	BBC1

3 January 1985 – 15 November 1998

Frequency	UHF	kW	Service
471.25  MHz	21	500	Channel 4
495.25  MHz	24	500	BBC2 South
519.25  MHz	27	500	Meridian (TVS until 1993)
551.25  MHz	31	500	BBC1 South

Analogue and digital television

15 November 1998 – 31 October 2002

Frequency	UHF	kW	Service	System
471.25  MHz	21	500	Channel 4	PAL System I
489.833  MHz	23-	20	BBC (Mux 1)	DVB-T
495.25  MHz	24	500	BBC2 South	PAL System I
513.833  MHz	26-	20	Arqiva (Mux C)	DVB-T
519.25  MHz	27	500	Meridian	PAL System I
530.000  MHz	28	20	Digital 3&4 (Mux 2)	DVB-T
546.000  MHz	30	20	SDN (Mux A)	DVB-T
551.25  MHz	31	500	BBC1 South	PAL System I
562.166  MHz	32+	20	BBC (Mux B)	DVB-T
570.166  MHz	33+	20	Arqiva (Mux D)	DVB-T

31 October 2002 – 24 May 2007

Frequency	UHF	kW	Service	System
471.25  MHz	21	500	Channel 4	PAL System I
489.833  MHz	23-	20	BBC (Mux 1)	DVB-T
495.25  MHz	24	500	BBC2 South	PAL System I
513.833  MHz	26-	20	Arqiva (Mux C)	DVB-T
519.25  MHz	27	500	Meridian	PAL System I
530.000  MHz	28	20	Digital 3&4 (Mux 2)	DVB-T
546.000  MHz	30	20	SDN (Mux A)	DVB-T
551.25  MHz	31	500	BBC1 South	PAL System I
562.166  MHz	32+	20	BBC (Mux B)	DVB-T
570.166  MHz	33+	20	Arqiva (Mux D)	DVB-T
735.25  MHz	54	2	Solent TV	PAL System I

24 May 2007 – 25 March 2009

Frequency	UHF	kW	Service	System
471.25  MHz	21	500	Channel 4	PAL System I
489.833  MHz	23-	20	BBC (Mux 1)	DVB-T
495.25  MHz	24	500	BBC2 South	PAL System I
513.833  MHz	26-	20	Arqiva (Mux C)	DVB-T
519.25  MHz	27	500	Meridian	PAL System I
530.000  MHz	28	20	Digital 3&4 (Mux 2)	DVB-T
546.000  MHz	30	20	SDN (Mux A)	DVB-T
551.25  MHz	31	500	BBC1 South	PAL System I
562.166  MHz	32+	20	BBC (Mux B)	DVB-T
570.166  MHz	33+	20	Arqiva (Mux D)	DVB-T

25 March 2009 – 7 March 2012

Frequency	UHF	kW	Service	System
471.25  MHz	21	500	Channel 4	PAL System I
495.25  MHz	24	500	BBC2 South	PAL System I
519.25  MHz	27	500	Meridian	PAL System I
530.166  MHz	28+	20	BBC (Mux B)	DVB-T
545.833  MHz	30-	20	SDN (Mux A)	DVB-T
551.25  MHz	31	500	BBC1 South	PAL System I
562.166  MHz	32+	20	Digital 3&4 (Mux 2)	DVB-T
570.166  MHz	33+	20	Arqiva (Mux D)	DVB-T
578.000  MHz	34	20	BBC (Mux 1)	DVB-T
602.166  MHz	37+	20	Arqiva (Mux C)	DVB-T

7 March 2012 – 21 March 2012

Frequency	UHF	kW		Service	System
		H	V
471.25  MHz	21	500	—	Channel 4	PAL System I
498.000  MHz	24	200	200	BBC A	DVB-T
519.25  MHz	27	500	—	Meridian	PAL System I
530.166  MHz	28+	20	—	BBC (Mux B)	DVB-T
545.833  MHz	30-	20	—	SDN (Mux A)	DVB-T
551.25  MHz	31	500	—	BBC1 South	PAL System I
562.166  MHz	32+	20	—	Digital 3&4 (Mux 2)	DVB-T
570.166  MHz	33+	20	—	Arqiva (Mux D)	DVB-T
602.166  MHz	37+	20	—	Arqiva (Mux C)	DVB-T

Digital television

21 March 2012 – 18 April 2012

Frequency	UHF	kW		Operator	System
		H	V
474.166  MHz	21+	200	200	BBC B	DVB-T2
498.000  MHz	24	200	200	BBC A	DVB-T
522.000  MHz	27	200	200	Digital 3&4	DVB-T
545.833  MHz	30-	50	—	SDN	DVB-T
570.166  MHz	33+	50	—	Arqiva B	DVB-T
602.166  MHz	37+	50	—	Arqiva A	DVB-T

18 April 2012 – present

The commercial multiplexes were situated on their pre-DSO frequencies until 18 April 2012, when they started transmitting at vertical polarisation. ^[16]

Frequency	UHF	kW		Operator	System
		H	V
474.166  MHz	21+	200	200	BBC B	DVB-T2
482.166  MHz	22+	50	200	Arqiva A	DVB-T
498.000  MHz	24	200	200	BBC A	DVB-T
506.000  MHz	25	50	200	SDN	DVB-T
522.000  MHz	27	200	200	Digital 3&4	DVB-T
530.000  MHz	28	50	200	Arqiva B	DVB-T
602.000 MHz	37	10	-	Local Multiplex	DVB-T

See also

• Chillerton Down – a transmission site approximately 2.5 miles (4.0 km) from Rowridge, broadcasting a mix of analogue and digital radio stations not available from Rowridge
• List of masts

References

1. Pawley, Edward. 1972. BBC Engineering 1922 – 1972, p. 377. BBC, London. ISBN   0-563-12127-0.
2. Times Saturday February 23 1957
3. Times Tuesday June 18 1963, page 8
4. Times Saturday October 9 1954
5. Times Wednesday November 10 1954, page 2
6. Times Friday November 12 1954, page 2
7. Kilvington, T. The London—Isle-of-Wight Television Link, Stage One. POEEJ 48 (1):36–38
8. Times Saturday December 17 1955, page 2
9. Times Thursday August 2 1956, page 5
10. Times Wednesday March 24 1965, page 12
11. Times Friday November 12 1965, page 6
12. Times Wednesday February 26 1969, page 5
13. "Isle of Wight County Press – "Stand by for the digital switch"". iwcp.co.uk. Retrieved 11 January 2014.
14. Isle of Wight Planning Application – TCP/23520/R, P/00748/09
15. Radio Listeners Guide 2010
16. "Digital Switchover Transmitter Details – Meridian Region" (PDF). 5 January 2011. Retrieved 26 May 2011.

External links

• Entry for Rowridge transmitting station at the Transmission Gallery
• Freeview on the Rowridge transmitter
• Rowridge Transmitter at thebigtower.com