mb21 - The Transmission Gallery

The UK UHF transmitter network evolved from planning and negotiations at the ITU conference held in Stockholm from 26^th May to 23^rd June 1961. The plan is commonly abbreviated ST61. The UK delegation submitted requests for 4 allocations at 195 sites. 64 sites with ERPs from 5 to 1000 kW and 131, 1kW sites. All with horizontal polarisation.

The ST61 plan was based on standardised 8 MHz wide channels from 470 - 958 MHz with the channels numbered from 21 - 81, using the 625-line standard. However the ST61 plan only allocated UHF channels up to channel 69, and only for transmitting stations with ERPs above 10 kW. In the UK and many other countries, there were restrictions on the use of channels 35 - 37, due to existing or planned radio navigation systems, and channel 38 is reserved for radio astronomy. The UK broadcasters were allocated the use of 44 UHF channels. 14 in UHF band IV, channels 21 - 34, and 30 in UHF band V, channels 39 - 68.

With 44 UHF channels available, the UK submission was based on 11 standard channel groups of which 10 of the groups were to be used at the 64 high power main stations.

21	25	28	32
23	27	31	33
22	24	26	30
34	40	42	44
41	43	45	47
46	48	50	52
54	56	58	60
59	61	63	65
62	64	66	68
51	53	55	57
33	39	49	67

The French delegation was planning for a three programme network and proposed the use of these standard 15 channel groups.

21	24	27
22	25	28
23	26	29
30	33	36
31	34	37
32	35	38
39	42	45
40	43	46
41	44	47
48	51	54
49	52	55
50	53	56
57	60	63
58	61	64
59	62	65

It seems likely that to ease planning between the UK and France, the UK modified their channel groups such that three of the four UK allocations were the same as a standard French group.

This reduced the number of standard UK channel groups to nine and gives us the familiar UK analogue channel groupings.

21	24	27	31
22	25	28	32
23	26	29	33
39	42	45	49
40	43	46	50
41	44	47	51
53	57	60	63
54	58	61	64
55	59	62	65

These are the details of the 64 Main stations. (Variations from the ST61 plan are in red lettering)

1 Kirkcudbrightshire Lat/Long 55.07, -3.83	1	2	3	4	ERP
Requested	21	25	28	32	100 kW
ST61 Allocation	41	44	47	51	100 kW
143 Cambret Hill	41	44	47	51	16 kW. In service from 1977 as site number 137.21

2 South Yorks Lat/Long 53.62, -1.67	1	2	3	4	ERP
Requested	21	25	28	32	1000 kW directional
ST61 Allocation	41	44	47	51	1000 kW non directional
104 Emley Moor	41	44	47	51	1000 kW directional. In service from 1966

3 Anglesey Lat/Long 51.37, -2.52	1	2	3	4	ERP
Requested	21	25	28	32	100 kW
ST61 Allocation	53	57	60	63	100 kW
118 Llanddona	53	57	60	63	100 kW directional. In service from 1967

4 Bristol Lat/Long 51.37, -2.52	1	2	3	4	ERP
Requested	21	25	28	32	500 kW
ST61 Allocation	54	58	61	64	500 kW
110 Mendip	54	58	61	64	500 kW. In service from 1969

5 Guernsey Lat/Long 49.43, -2.58	1	2	3	4	ERP
Requested	21	25	28	32	20 kW
ST61 Allocation	48	52	54	56	20 kW
Les Touillets	48	52	54	56	2 kW. In service from 1976

6 Fermanagh Lat/Long 54.42, -7.48	1	2	3	4	ERP
Requested	21	25	28	32	100 kW
ST61 Allocation	22	25	28	32	100 kW
151 Brougher Mountain	22	25	28	32	100 kW. In service from 1978

7 South East Kent Lat/Long 51.12, 1.25	1	2	3	4	ERP
Requested	21	25	28	32	100 kW directional
ST61 Allocation	50	53	56	68	100 kW directional
113 Dover	50	53	56	66 [1]	100 kW directional. In service from 1967. Channels 50/53/56 form a standard French group.

8 Shetland Lat/Long 60.12, -1.1	1	2	3	4	ERP
Requested	23	27	31	33	100 kW
ST61 Allocation	32	34	45	49	100 kW
Bressay	22	25	28	32	10 kW vertical. In service from 1976

9 East Lothian Lat/Long 55.97, -2.78	1	2	3	4	ERP
Requested	23	27	31	33	250 kW
ST61 Allocation	21	24	27	31	250 kW
147 Craigkelly	21	24	27	31	100 kW. In service from 1969

10 North Lancs Lat/Long 54.2, -3.17	1	2	3	4	ERP
Requested	23	27	31	33	100 kW
ST61 Allocation	40	43	46	56	100 kW
Lancaster	21	24	27	31	10 kW vertical. This ITA publication from 1969 lists Lancaster using the ST61 allocated channels with horizontal polarisation

11 Huntingdon Lat/Long 52.47, 0.03	1	2	3	4	ERP
Requested	23	27	31	33	1000 kW directional
ST61 Allocation	21	24	27	31	1000 kW non directional
124 Sandy Heath	21	24	27	31	1000 kW directional. In service from 1969

12 Carmarthenshire Lat/Long 51.75, -4.15	1	2	3	4	ERP
Requested	23	27	31	33	100 kW
ST61 Allocation	53	57	60	63	100 kW
119 Carmel	53	57	60	63	100 kW. In service from 1971

13 Isle of Wight Lat/Long 50.68, -1.37	1	2	3	4	ERP
Requested	23	27	31	33	500 kW directional
ST61 Allocation	21	24	31	41	500 kW directional
108 Rowridge	21	24	27 [1]	31	500 kW directional. In service from 1966. The ST61 allocations may explain why BBC2 used ch24, rather than the usual ch27.

14 Durham Lat/Long 54.87, -1.77	1	2	3	4	ERP
Requested	22	24	26	30	500 kW directional
ST61 Allocation	54	58	61	64	500 kW non directional
109 Pontop Pike	54	58	61	64	500 kW. In service from 1966

15 Staffordshire Lat/Long 52.97, -2.33	1	2	3	4	ERP
Requested	22	24	26	30	100 kW
ST61 Allocation	23	26	29	33	100 kW
121 The Wrekin	23	26	29	33	100 kW. In service from 1975

16 London Lat/Long 51.42, -0.07	1	2	3	4	ERP
Requested	22	24	26	30	1000 kW directional
ST61 Allocation	23	26	30	33	1000 kW non directional
101 Crystal Palace	23	26	30	33	1000 kW. In service from 1964

17 East Devon Lat/Long 50.82, -3.1	1	2	3	4	ERP
Requested	22	24	26	30	250 kW directional
ST61 Allocation	23	26	29	33	250 kW non directional
132 Stockland Hill	23	26	29	33	250 kW. In service from 1971

18 Belfast Lat/Long 54.6, -6.02	1	2	3	4	ERP
Requested	22	24	26	30	500 kW
ST61 Allocation	21	24	27	31	500 kW
107 Divis	21	24	27	31	500 kW. In service from 1967

19 Banff Lat/Long 57.62, -2.97	1	2	3	4	ERP
Requested	34	40	42	44	100 kW
ST61 Allocation	23	26	29	33	100 kW
153 Knock More	23	26	29	33	100 kW. In service from 1974

20 Lanarkshire Lat/Long 55.85, -3.82	1	2	3	4	ERP
Requested	34	40	42	44	500 kW
ST61 Allocation	40	43	46	50	500 kW
105 Black Hill	40	43	46	50	500 kW. In service from 1966

21 North Yorks Lat/Long 54.4, -1.2	1	2	3	4	ERP
Requested	34	40	42	44	500 kW
ST61 Allocation	23	26	29	33	500 kW
116 Bilsdale	23	26	29	33	500 kW. In service from 1969

22 Birmingham Lat/Long 52.52, -1.95	1	2	3	4	ERP
Requested	34	40	42	44	1000 kW directional
ST61 Allocation	40	43	46	50	1000 kW non directional
102 Sutton Coldfield	40	43	46	50	1000 kW. In service from 1964

23 Pembrokeshire Lat/Long 51.95, -4.78	1	2	3	4	ERP
Requested	34	40	42	44	100 kW
ST61 Allocation	40	43	46	50	100 kW
129 Presely	40	43	46	50	100 kW. In service from 1973

24 East Sussex Lat/Long 50.88, 0.53	1	2	3	4	ERP
Requested	34	40	42	44	100 kW directional
ST61 Allocations	49	52	64	67	100 kW non directional
139 Heathfield	49	52	64	67	100 kW. In service from 1970

25 Londonderry Lat/Long 55, -7.37	1	2	3	4	ERP
Requested	34	40	42	44	100 kW
ST61 Allocation	41	44	47	51	100 kW
Londonderry	41	44	47	51	3.2 kW vertical. In service from 1970

26 Kincardine Lat/Long 57, -2.38	1	2	3	4	ERP
Requested	41	43	45	47	500 kW
ST61 Allocation	22	25	28	32	500 kW
112 Durris	22	25	28	32	500 kW. In service from 1967

27 Cumberland Lat/Long 54.75, -2.38	1	2	3	4	ERP
Requested	41	43	45	47	500 kW
ST61 Allocation	22	25	28	32	500 kW
137 Caldbeck	28	30 [2]	32	34 [2]	500 kW. In service from 1971
165 Sandale	22	67			500/126 kW. In service from 1979

28 East Lincs Lat/Long 53.45, -0.3	1	2	3	4	ERP
Requested	41	43	45	47	500 kW
ST61 Allocation	22	25	28	32	500 kW
120 Belmont	22	25	28	32	500 kW. In service from 1966

29 Caernarvonshire Lat/Long 52.87, -4.52	1	2	3	4	ERP
Requested	41	43	45	47	100 kW
ST61 Allocation	41	44	47	51	100 kW
144 Arfon	41	44	47	51	3.5 kW vertical. In service from 1975 as site number 118.06

30 Hampshire Lat/Long 51.32, -1.25	1	2	3	4	ERP
Requested	41	43	45	47	250 kW
ST61 Allocation	39	42	45	68	250 kW
126 Hannington	39	42	45	66 [1]	250 kW. In service from 1970

31 East Cornwall Lat/Long 50.52, -4.43	1	2	3	4	ERP
Requested	41	43	45	47	500 kW directional
ST61 Allocation	22	25	28	32	500 kW non directional
131 Caradon Hill	22	25	28	32	500 kW. In service from 1969

32 Jersey Lat/Long 49.22, -2.1	1	2	3	4	ERP
Requested	41	43	45	47	20 kW
ST61 Allocation	41	44	47	51	20 kW
128 Fremont Point	41	44	47	51	20 kW. In service from 1976

33 Armagh Lat/Long 54.23, -6.6	1	2	3	4	ERP
Requested	41	43	45	47	20 kW
ST61 Allocation	54	58	61	64	20 kW
Never built					Allocation used at Camlough from April 2000.

34 Lewis Lat/Long 58.18, -6.58	1	2	3	4	ERP
Requested	46	48	50	52	100 kW
ST61 Allocation	23	26	29	33	100 kW
154 Eitshal	23	26	29	33	100 kW. In service from 1976

35 Orkney Lat/Long 58.92, -2.93	1	2	3	4	ERP
Requested	46	48	50	52	100 kW
ST61 Allocation	40	43	46	50	100 kW
134 Keelylang Hill	40	43	46	50	100 kW. In service from 1975

36 Northumberland Lat/Long 55.55, -2.12	1	2	3	4	ERP
Requested	46	48	50	52	100 kW
ST61 Allocation	39	42	45	49	100 kW
155 Chatton	39	42	45	49	100 kW. In service from 1974

37 South Lancs Lat/Long 53.63, -2.52	1	2	3	4	ERP
Requested	46	48	50	52	500 kW
ST61 Allocation	55	59	62	65	500 kW
103 Winter Hill	55	59	62	65	500 kW. In service from 1965

38 Suffolk Lat/Long 52.12, 0.95	1	2	3	4	ERP
Requested	46	48	50	52	250 kW
ST61 Allocation	41	44	47	51	250 kW
115 Sudbury	41	44	47	51	250 kW. In service from 1968

39 South Wales Lat/Long 51.45, -3.4	1	2	3	4	ERP
Requested	46	48	50	52	500 kW
ST61 Allocation	41	44	47	51	500 kW
106 Wenvoe	41	44	47	51	500 kW. In service from 1965

40 Dumbarton Lat/Long 56, -4.63	1	2	3	4	ERP
Requested	46	48	50	52	50 kW
ST61 Allocation	54	58	61	64	50 kW
122 Rosneath	54	58	61	64	10 kW vertical. In service from 1976 as site number 152.11. The change to vertical polarisation was due to concerns about tidal fading in the service area. [3]

41 Inverness Lat/Long 57.63, -4.07	1	2	3	4	ERP
Requested	54	56	58	60	100 kW
ST61 Allocation	39	42	45	49	100 kW
156 Rosemarkie	39	42	45	49	100 kW. In service from 1970

42 Ayrshire Lat/Long 55.57, -4.3	1	2	3	4	ERP
Requested	54	56	58	60	100 kW
ST61 Allocation	23	26	29	33	100 kW
152 Darvel	23	26	29	33	100 kW. In service from 1972

43 West Yorks Lat/Long 54.13, -2.25	1	2	3	4	ERP
Requested	54	56	58	60	100 kW
ST61 Allocation	21	24	27	31	100 kW
Never Built

44 Norfolk Lat/Long 52.6, 1.17	1	2	3	4	ERP
Requested	54	56	58	60	250 kW
ST61 Allocation	55	59	62	65	250 kW
114 Tacolneston	55	59	62	65	250 kW. In service from 1967

45 Herefordshire Lat/Long 51.87, -2.48	1	2	3	4	ERP
Requested	54	56	58	60	100 kW
ST61 Allocation	22	25	28	32	100 kW
149 Ridge Hill	22	25	28	32	100 kW. In service from 1972

46 South Devon Lat/Long 50.57, -3.5	1	2	3	4	ERP
Requested	54	56	58	60	100 kW directional
ST61 Allocation	53	57	60	63	100 kW non directional
136 Beacon Hill	53	57	60	63	100 kW directional. In service from 1973

47 West Sussex Lat/Long 50.88, -0.25	1	2	3	4	ERP
Requested	54	56	58	60	100 kW directional
ST61 Allocation	27	55	58	66	100 kW non directional
125 Midhurst	55	58	61 [1]	68 [1]	100 kW. In service from 1972

48 Buchan Lat/Long 57.53, -2.23	1	2	3	4	ERP
Requested	59	61	63	65	50 kW
ST61 Allocation	41	44	47	51	50 kW
Never built					Allocation used at Rosehearty with vertical polarisation at 2 kW.

49 Selkirkshire Lat/Long 55.55, -2.78	1	2	3	4	ERP
Requested	59	61	63	65	50 kW
ST61 Allocation	55	59	62	65	50 kW
161 Selkirk	55	59	62	65	50 kW. In service from 1972

50 Flintshire Lat/Long 53.28, -3.38	1	2	3	4	ERP
Requested	59	61	63	65	100 kW
ST61 Allocation	39	42	45	49	100 kW
145 Moel-y-Parc	42	45	49	52	100 kW. In service from 1969. Channel 39 not used to protect radio astronomy in channel 38 at nearby Jodrell Bank

51 Northamptonshire Lat/Long 52.07, -1.03	1	2	3	4	ERP
Requested	59	61	63	65	500 kW
ST61 Allocation	53	57	60	63	500 kW
117 Oxford	53	57	60	63	500 kW. In service from 1968

52 North Devon Lat/Long 51.12, -3.78	1	2	3	4	ERP
Requested	59	61	63	65	100 kW
ST61 Allocation	55	59	62	65	100 kW
138 Huntshaw Cross	55	59	62	65	100 kW. In service from 1973

53 North Antrim Lat/Long 55.02, -6.45	1	2	3	4	ERP
Requested	59	61	63	65	100 kW
ST61 Allocation	55	59	62	65	100 kW
130 Limavady	55	59	62	65	100 kW. In service from 1970

54 East Yorks Lat/Long 54.07, -0.75	1	2	3	4	ERP
Requested	59	61	63	65	100 kW
ST61 Allocation	53	57	60	63	100 kW
Never built					Allocation used at Oliver's Mount

55 Caithness Lat/Long 58.4, -3.12	1	2	3	4	ERP
Requested	62	64	66	68	100 kW
ST61 Allocation	21	24	27	31	100 kW
148 Rumster Forest	21	24	27	31	100 kW. In service from 1973

56 Perthshire Lat/Long 56.45, -3.25	1	2	3	4	ERP
Requested	62	64	66	68	100 kW
ST61 Allocation	53	57	60	63	100 kW
123 Angus	53	57	60	63	100 kW. In service from 1969

57 Nottinghamshire Lat/Long 52.87, -1.03	1	2	3	4	ERP
Requested	62	64	66	68	250 kW
ST61 Allocation	54	58	61	64	250 kW
111 Waltham	54	58	61	64	250 kW. In service from 1968

58 Cardiganshire Lat/Long 52.3, -4.02	1	2	3	4	ERP
Requested	62	64	66	68	100 kW
ST61 Allocation	21	24	27	31	100 kW
135 Blaenplwyf	21	24	27	31	100 kW. In service from 1970

59 Dorset Lat/Long 50.85, -2.3	1	2	3	4	ERP
Requested	62	64	66	68	100 kW
ST61 Allocation	40	43	50	67	100 kW
133 Never built					Location is close to the Winterbourne Stickland relay which used the allocation 40/43/46/50 at 1kW vertical.

60 North Kent Lat/Long 51.22, 0.8	1	2	3	4	ERP
Requested	62	64	66	68	5 kW
ST61 Allocation	40	43	46	65	100 kW with easterly directional restrictions
158 Bluebell Hill	40	43	46	65	30 kW. In service from 1974

61 Isle of Man Lat/Long 54.13, -4.5	1	2	3	4	ERP
Requested	62	64	66	68	20 kW
ST61 Allocation	30	34	48	52	20 kW
127 Richmond Hill (ITA VHF TV site)					Site not used for UHF TV [2]

62 Wigtown Lat/Long 55.03, -4.8	1	2	3	4	ERP
Requested	51	53	55	57	100 kW
ST61 Allocation	53	57	60	63	100 kW
Never built

63 West Cornwall Lat/Long 50.22, -5.23	1	2	3	4	ERP
Requested	51	53	55	57	100 kW
ST61 Allocation	41	44	47	51	100 kW
141 Redruth	41	44	47	51	100 kW. In service from 1970

64 Argyllshire Lat/Long 56.4, -5.48	1	2	3	4	ERP
Requested	51	53	55	57	20 kW
ST61 Allocation	22	25	28	32	20 kW
Torosay	22	25	28	32	20 kW. Vertical polarisation used. In service from 1976

The above information, and further reading, sourced from these two ITU documents.1238 pages and 186 pages

[1] The Rowridge allocation of channels 21/24/31/41 is a consequence of channel 27 being allocated to West Sussex (Midhurst), which couldn't used channel 61 with a channel 66 allocation, due to the channel n+5 restriction. As channels 66, 67 & 68 are effectively "spare" channels, not part of either a standard UK or French grouping, the solution to "free up" channel 27 for Rowridge, was to swap the fourth allocations at Dover, Hannington and Midhurst. So Dover & Hannington both changed from ch68 to ch66, freeing up ch68 for use at Midhurst. This also permitted Midhurst to use ch61, as there was no longer an n+5 relationship, releasing ch27 for use at Rowridge.

[2] It seems that the change of plan for Cumberland (Caldbeck / Sandale), as well as Isle of Man (Richmond Hill), has much to do with the fact that ITV had a Border region and the BBC didn't, with northern Cumbria part of the BBC Northeast England region and Southwest Scotland part of the BBC Scotland Nation. So effectively two of the Isle of Man allocations (chs 30 & 34), were taken for use at Cumberland to provide 5 available channels for Caldbeck & Sandale to use between them. The ch25 allocation couldn't be used because of the n+5 relationship with ch30. A third Richmond Hill allocation, (ch52) was also now available for use at Moel-y-Parc.

[3] Two BBC Research Department reports (1970/22) and (1973/30), concluded that tidal fading was less severe with vertical polarisation. This is the most likely reason for the change to vertical polarisation at Arfon, Bressay, Rosneath, Londonderry & Torosay, all of which have reception areas where the transmission path crosses tidal water.

21	25	28	32
23	27	31	33
22	24	26	30
34	40	42	44
41	43	45	47
46	48	50	52
54	56	58	60
59	61	63	65
62	64	66	68
51	53	55	57
33	39	49	67

21	24	27
22	25	28
23	26	29
30	33	36
31	34	37
32	35	38
39	42	45
40	43	46
41	44	47
48	51	54
49	52	55
50	53	56
57	60	63
58	61	64
59	62	65

21	24	27	31
22	25	28	32
23	26	29	33
39	42	45	49
40	43	46	50
41	44	47	51
53	57	60	63
54	58	61	64
55	59	62	65

21	25	28	32
23	27	31	33
22	24	26	30
34	40	42	44
41	43	45	47
46	48	50	52
54	56	58	60
59	61	63	65
62	64	66	68
51	53	55	57
33	39	49	67

21	24	27
22	25	28
23	26	29
30	33	36
31	34	37
32	35	38
39	42	45
40	43	46
41	44	47
48	51	54
49	52	55
50	53	56
57	60	63
58	61	64
59	62	65

21	24	27	31
22	25	28	32
23	26	29	33
39	42	45	49
40	43	46	50
41	44	47	51
53	57	60	63
54	58	61	64
55	59	62	65

21	25	28	32
23	27	31	33
22	24	26	30
34	40	42	44
41	43	45	47
46	48	50	52
54	56	58	60
59	61	63	65
62	64	66	68
51	53	55	57
33	39	49	67

21	24	27
22	25	28
23	26	29
30	33	36
31	34	37
32	35	38
39	42	45
40	43	46
41	44	47
48	51	54
49	52	55
50	53	56
57	60	63
58	61	64
59	62	65

21	24	27	31
22	25	28	32
23	26	29	33
39	42	45	49
40	43	46	50
41	44	47	51
53	57	60	63
54	58	61	64
55	59	62	65