Full Freeview on the Hemel Hempstead (Hertfordshire, England) transmitter
Brian Butterworth first published this on - UK Free TV
Google map | Bing map | Google Earth | 51.729,-0.426 or 51°43'43"N 0°25'34"W | HP3 8SA |
The symbol shows the location of the Hemel Hempstead (Hertfordshire, England) transmitter which serves 74,000 homes. The bright green areas shown where the signal from this transmitter is strong, dark green areas are poorer signals. Those parts shown in yellow may have interference on the same frequency from other masts.
This transmitter has no current reported problems
The BBC and Digital UK report there are no faults or engineering work on the Hemel Hempstead (Hertfordshire, England) transmitter._______
Digital television services are broadcast on a multiplexes (or Mux) where many stations occupy a single broadcast frequency, as shown below.
64QAM 8K 3/4 27.1Mb/s DVB-T MPEG2
H/V: aerial position (horizontal or vertical)
The Hemel Hempstead (Hertfordshire, England) mast is a public service broadcasting (PSB) transmitter, it does not provide these commercial (COM) channels: .
If you want to watch these channels, your aerial must point to one of the 80 Full service Freeview transmitters. For more information see the will there ever be more services on the Freeview Light transmitters? page.
Which Freeview channels does the Hemel Hempstead transmitter broadcast?
If you have any kind of Freeview fault, follow this Freeview reset procedure first.Digital television services are broadcast on a multiplexes (or Mux) where many stations occupy a single broadcast frequency, as shown below.
64QAM 8K 3/4 27.1Mb/s DVB-T MPEG2
H/V: aerial position (horizontal or vertical)
The Hemel Hempstead (Hertfordshire, England) mast is a public service broadcasting (PSB) transmitter, it does not provide these commercial (COM) channels: .
If you want to watch these channels, your aerial must point to one of the 80 Full service Freeview transmitters. For more information see the will there ever be more services on the Freeview Light transmitters? page.
Which BBC and ITV regional news can I watch from the Hemel Hempstead transmitter?
BBC London 4.9m homes 18.4%
from London W1A 1AA, 30km southeast (138°)
to BBC London region - 55 masts.
ITV London News 4.9m homes 18.4%
from London WC1X 8XZ, 31km southeast (135°)
to ITV London region - 55 masts.
How will the Hemel Hempstead (Hertfordshire, England) transmission frequencies change over time?
1984-97 | 1997-98 | 1998-2012 | 2012-13 | 18 Apr 2018 | |||||
B E T | B E T | B E T | E T | K T | |||||
C29 | ArqB | ||||||||
C31 | ArqA | ||||||||
C34 | _local | ||||||||
C37 | SDN | ||||||||
C40 | BBCA | ||||||||
C41 | ITVwaves | ITVwaves | ITVwaves | D3+4 | |||||
C42 | _local | ||||||||
C43 | D3+4 | ||||||||
C44 | BBC2waves | BBC2waves | BBC2waves | BBCA | |||||
C46 | BBCB | ||||||||
C47 | C4waves | C4waves | C4waves | BBCB | |||||
C50tv_off | SDN | ||||||||
C51tv_off | BBC1waves | BBC1waves | BBC1waves | ||||||
C55tv_off | ArqB | ||||||||
C59tv_off | ArqA |
tv_off Being removed from Freeview (for 5G use) after November 2020 / June 2022 - more
Table shows multiplexes names see this article;
green background for transmission frequencies
Notes: + and - denote 166kHz offset; aerial group are shown as A B C/D E K W T
waves denotes analogue; digital switchover was 4 Apr 12 and 18 Apr 12.
How do the old analogue and currrent digital signal levels compare?
Analogue 1-4 | 10kW | |
SDN, ARQA, ARQB, BBCA, D3+4, BBCB | (-7dB) 2kW | |
Mux 1*, Mux 2*, Mux A*, Mux B* | (-14dB) 400W | |
Mux C*, Mux D* | (-17dB) 200W |
Local transmitter maps
Hemel Hempstead Freeview Hemel Hempstead DAB Crystal Palace TV region BBC London LondonWhich companies have run the Channel 3 services in the Crystal Palace transmitter area
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Monday, 23 January 2012
Ray McConnell: Answer is both as there's two transmitters!
Hemel Hempstead Town is a low power relay located on the top of the former Kodak building:
mb21 - The Transmission Gallery
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The radiation pattern shown above for Hemel Hempstead has three nodes on it.
Yet the photographs on MB21 show it only has two sets of trough antennas for transmission:
mb21 - The Transmission Gallery
The pre-DSO digital panels (two sets of) can be seen lower down, and they too are pointing in the same direction of the ones used for analogue.
The two sets of antennas on nearly opposite faces explains the coverage map of the analogue signal which spills out much further in two opposite directions:
mb21 - Transmitter Information - Hemel Hempstead (Pimlico)
So is the clover-shaped radiation pattern (above) wrong or has there been subsequent work? Or have I missed something?
MB21 says they understand that there is no plan for the ones shown in the photos to be replaced for DSO.
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Wednesday, 25 January 2012
J
Jim F5:22 PM
Dave Lindsay: The "interim DTT panels" as shown on MB21 appear to me to be located on three sides of the mast - four on the left side, four on the right side, and four at the back (but these are somewhat hidden by the structure).
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Wednesday, 14 March 2012
I
Ian9:52 AM
Berkhamsted
I have recently moved to a house 5 miles north west of the Hemel Hempstead transmitter. On the website it says this is a repeater and I should position my aerial elements vertically. However everyone in this area appears to have their elements positioned horizontally including me! Before I waste time and effort climbing up on the roof is everyone else wrong or am I missing something?
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Ian's: mapI's Freeview map terrainI's terrain plot wavesI's frequency data I's Freeview Detailed Coverage
I
Ian10:13 AM
Berkhamsted
On further investigation - Because I can currently receive HD I wonder if in fact we (and everyone else) are getting our signals fom Crystal Palace which is in approximately the same direction fom here as the HH transmitter. Presumably after 18th April I should reposition to vertical for a really strong signal from HH ?
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Ian's: mapI's Freeview map terrainI's terrain plot wavesI's frequency data I's Freeview Detailed Coverage
K
KMJ,Derby10:26 AM
Ian: The aerial is most likely to be pointing at Crystal Palace (SE). If it points NNE it will be pointing at Sandy Heath which at this time delivers the best signal on five of the muxes. After DSO in London which takes place on 4th and 18th April 2012 your best signal is predicted to be from Crystal Palace, which will transmit at 200kW on each mux. The Hemel Heampstead (2kW) relay is shown as variable on the PSB muxes after switchover, possibly due to interference resulting from sharing frequencies with Hannington COM muxes.
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I
Ian5:28 PM
Berkhamsted
Thanks KMJ Derby, however according to this website the power of the three possible transmiters and distance to me is:
Crystal Palace 20kW - 30.5 miles
Sandy Heath 180kW - 27.2 miles
Hemel Hempstead 400W - 5.3 miles
Using inverse square law to calculate signal strength this means that CP is a little less than twice as strong as HH but CP is only 9% of SH.
So SH would be the optimum signal as long as I could live with Anglia and BBC East!!
If there is an error on this website and CP is actually 200kW as you suggest then SH is still slightly stronger but not much in it but both better than HH.
:-)
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Ian's: mapI's Freeview map terrainI's terrain plot wavesI's frequency data I's Freeview Detailed Coverage
Wednesday, 4 April 2012
B
brian english12:23 PM
Abbots Langley
Crystal Palace/Hemel Hempstead
Has anyone got any idea why as of today BBC4 is listed in two multiplexes and how is my box supposed to tune to it
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brian's: mapB's Freeview map terrainB's terrain plot wavesB's frequency data B's Freeview Detailed Coverage
K
KMJ,Derby1:15 PM
brian english: That is correct, as Mux BBCA after switchover contains all the BBC standard definition TV and radio channels. These were divided between Mux1 (now switched off) and MuxB which has to remain on air as it carries Sky Sports on the pre-switchover configuration of the muxes. When using auto scan Mux BBCA on C23 or C44 will usually be placed in the normal (LCN) positions in the channel list as it is found before MuxB on C28 or C59, the BBC channels in MuxB will then appear as variations in the 800's. If doing a manual tune between the two stages of the switchover it is usual to omit MuxB unless Sky Sports is required.
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B
brian english2:23 PM
Abbots Langley
KMJ - thanks for the info - very enlightening
A couple of the boxes have complained about this and tuning has failed - so I will have to tune the manual way and leave BBCA off my TUTV Sky Sports box for 2 weeks
Whoever the genius was that decided to leave duplicate channels on C59 (pointing at HH not CP) is truly worthy of a Darwin award
link to this comment |
brian's: mapB's Freeview map terrainB's terrain plot wavesB's frequency data B's Freeview Detailed Coverage
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