Talk:Time from NPL (MSF)

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—Yamara ✉  17:55, 23 June 2008 (UTC)

Discussion
Is the ERP not 27kW? Ojw 17:49, 12 August 2005 (UTC)

How do "pips" fit in?
The BBC broadcast the pips on the hour, with five short pips followed by one long pip. This implies that the end of the signal is 000001. When there is a leap-second, there are 6 short pips followed by one long. The article, however, states that a leap second will not be apparent from the signal until the next signal 17 (or 18) seconds later. Can someone clarify this in the article? — PhilHibbs | talk 11:05, 10 May 2006 (UTC)
 * Okay, I'm thinking of the Greenwich Time Signal — PhilHibbs | talk 11:07, 10 May 2006 (UTC)

"Rugby clock"
I've attached a ) request to "also known as the Rugby Clock", partly because I've never heard of it (not a good reason – it could be just from general ignorance on my part) and partly because of the timing: it won't be the rugby clock in two weeks' time. If there's no backing I'm thinking of removing it. Observations welcome. --Old Moonraker 08:41, 14 March 2007 (UTC)


 * The phrase "Rugby clock" IS used to refer to the NPL time signal. See:
 * "...use the information to decode the signal from the Rugby Clock, and display hours and minutes on the LED Clock Display" (From a University of Cambridge Computer Laboratory study assignment)
 * "Observers making visual observations in the main referenced their timings directly to the Rugby clock." (Observational report on the 08.06.2004 transit of Venus)
 * But it's true that such users will have to change the name come 01.04.2007 -- to the "Cumbria Clock"? -- Picapica 21:47, 19 March 2007 (UTC)
 * Caught out in general ignorance again! I've reverted the request. The real name will become "The Time From NPL", so it looks like the "time from Cumbria" could be a runner! --Old Moonraker 10:48, 20 March 2007 (UTC)

Removed piece of information

 * Another 'false' derivation, from NPL staff, of the MSF callsign is Mac's Standard Frequency, from James 'Mac' Steele the former head of the NPL time group.

I can't locate a claim of this anywhere online easily; please do help out if you know where it can be reliably referenced from. Splash - tk 21:44, 6 April 2007 (UTC)
 * Better out – little relevance anyway. --Old Moonraker 06:37, 7 April 2007 (UTC)

Removed comparison with WWVB tx frequency
I removed the bit that said that the frequency of 60kHz is the same as that used by WWVB in the US. It's true, but it could--without further qualification--imply to some readers that clocks/watches for one market will work in the other. The protocols used by the two systems are different, so they are not compatible. --DudeGalea 17:14, 17 May 2007 (UTC)
 * Well, only if the reader implies such an incorrect interpretation from perfectly correct facts, which happenstance is 'not our problem'. However, the information was essentially ephemera so can happily fade away. Splash - tk 21:29, 18 May 2007 (UTC)

Reversion of "Unreferenced" etc tags.
This article is adequately referenced, but I am about to add the two specific  requests made by the poster of the tag (and replacing a dead link in the process—thanks for that). Complaining that the article is restricted to UK topics is moot, given that it's about a UK government agency, and this tag also removed. Some circular links, i.e. links to this article page, also removed. Please, before going on a tagging spree, register your complaints on the talk page first. You may find that the points have already been taken care of!--Old Moonraker (talk) 10:20, 26 May 2008 (UTC)

Transmitter size?
I can't actually remember how I ended up reading this article, but this sentence strikes me as odd:

"Whilst at Rugby, the transmitter used 70 kW of mains power and generated 60 kW of radio frequency power. The 180m high antenna was T-shaped and 500m across at its top." Is the antenna really half a kilometre across at the top?! I find it unlikely... AnthonyUK (talk) 22:18, 4 July 2008 (UTC)
 * Seems so! The aerial was "T"-shaped, but it was supported by two masts. Extract from here: The aerial system consists of twelve...masts...spaced at quarter mile intervals...The two masts nearest the buildings...support a ‘T’ type cage aerial. The upright of the "T" was suspended from the middle of the span. See also T-aerial. --Old Moonraker (talk) 13:56, 5 July 2008 (UTC)

How sound the signal?
A sound of the signal in an AM receiver capable of receiving its frequency


 * The way I understand it, the demodulated signal has no audible content. Because of the on-off nature of the signal, a typical receiver might generate a clicking sound at each transition but how this sounds would depend on the electronics of the receiver. --Roly (talk) 16:19, 14 February 2013 (UTC)

Signal strength in London
If anyone can find a reference something like this can be added to the article, can't as it stands as it's Original Research.

I have two very large MSF clocks with hands and two small travel clocks with digital display, in London. Before the relocation of MSF they all worked. Since then the large clocks work exactly as before, always right, but the small clocks most of the time don't have a signal and of course drift over the months and don't handle the summertime change. In fact virtually every time I look they've got no signal, but once I noticed that an alarm that had been drifting was right again; I checked and both clocks had signal, but lost it soon after. I'd guess the physically small size leads to an insufficient antenna. I note that Maplin's MSF clocks are both large, though Argos sells smaller ones too, and user feedback suggests that they usually work OK, I'd expect that receiver sensitivity has had to improve, as reception certainly hasn't. Also possibly clocks sold now may be using the German signal, which may be stronger.

The practical implication is that older MSF clocks may not work in some places; they should be discarded or used as non-radio-controlled rather than have time wasted on them. Possibly bad or iffy reception could be expected even with newer clocks in some places. I personally wouldn't buy a new clock unless I was sure I could return it, or an older second-hand clock. Pol098 (talk) 09:40, 2 November 2011 (UTC)
 * You are right: using a blog post as a source isn't good enough. A tag, making the same request as above, added. FWIW, my original Junghans is as erratic after the move as it was before, but it is not well positioned. --Old Moonraker (talk) 10:09, 2 November 2011 (UTC)

Fast time code
I seem to remember, there used to be a fast code, at the beginning of each minute, which encoded the whole time within one second. I can't remember the format or it's location. I see no mention of this in the description. Is this code still there or has it been discontinued? Or is my memory failing me yet again. --Roly (talk) 16:11, 14 February 2013 (UTC)
 * Your memory is fine: there certainly was a fast time code, but according to this NPL FAQ it was removed in October 1998. Wellset (talk) 12:08, 13 April 2018 (UTC)


 * Thanks for that confirmation and link. I've added a mention of it under "protocol". --Roly (talk) 13:04, 13 April 2018 (UTC)

Removed reference to GMT
GMT is an ambiguous term with different meanings in civil and astronomical useage so I've removed the reference to it and replaced it with UT1 which is the correct, unambiguous term to use. 101.98.248.252 (talk) 13:52, 30 March 2016 (UTC)

External links modified
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 * Corrected formatting/usage for http://www.clockco.co.uk/documents/msf.pdf
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AstroLynx thinks referenced statements are wrong.
AstroLynx claims I have introduced incorrect statements into the article. He does not say what he objects to, just asks me to discuss on the talk page. So if he does have valid criticism he can


 * point to the passage which he says is incorrect


 * explain why he thinks it is incorrect.


 * IP, please sign your postings so that everyone knows who you are. In your edit you claim that the NPL time signals are a "very close approximation (within 0.9 second) to the United Kingdom's official timescale", while the NPL links clearly indicate that it is the official civil timescale of the UK. AstroLynx (talk) 09:08, 5 April 2016 (UTC)

The NPL reference states

"The time at which summer time begins and ends is given in the relevant EU Directive and UK Statutory Instrument as 1 a.m. Greenwich Mean Time (GMT)."

The NPL claim about the importance of their transmissions is in a self - published source which is unlikely to have been through peer review. It does not override British or Community law and directives. 217.44.223.15 (talk) 18:41, 27 April 2016 (UTC)

Polarisation
What is the polarisation of the transmitted signal: vertical or horizontal magnetic field?--178.106.99.31 (talk) 23:04, 19 May 2016 (UTC)
 * The polarisation is usually taken to be that of the electric field, which is vertical. The magnetic field is perpendicular to both the electric field and the direction of propagation, so it's horizontal. Harumphy (talk) 07:37, 20 May 2016 (UTC)

"bit A" vs. "the A bit"
I confess I'm not certain what the difference is. If you'd said "the A bits", that would have been something. FWIW, that entire sentence was moved unmodified from its previous location, where it has been sitting happily for the last 10 years. 71.41.210.146 (talk) 16:32, 4 January 2017 (UTC)


 * I meant to write "the A bits"; perhaps I was thrown off by the close proximity of two occurrences of the string "the A bit". I fixed it. Jc3s5h (talk) 17:56, 4 January 2017 (UTC)

Semi-protected edit request on 18 March 2017
In the "NPLTFS" reference, defined at the start of, add the parameters July 2007 and TAF001v06. 71.41.210.146 (talk) 18:30, 18 March 2017 (UTC)
 * Yes check.svg Done Gulumeemee (talk) 03:03, 19 March 2017 (UTC)

Absolute versus coordinated time
Hi, something interesting. The GPS's in space are synced to ground stations so in theory the clocks are *slightly* off wrt these due to relativity however the satellites agree via software and the relative path length + added offsets help determine location. This is compensated for in GPS receiver firmware to prevent drift over time but what would be involved in actually determining time with reference to Planet Earth? Obviously relativistic acceleration much over 1% light speed would be noticeable and result in an (IIRC) 1 second per month absolute drift. Its not a problem yet but once we start going much out of Earth orbit the problem will become noticeable. IIRC the Mars delay depends on orbits etc and varies throughout the calendar year but periodically can be as low as 20 light minutes. — Preceding unsigned comment added by 88.81.137.12 (talk) 15:39, 6 March 2021 (UTC)