Things you always wanted to know the answer to [Vol. 5]

[Strangely Brown]

48k said:

Strangely Brown said:

48k said:

Theoretically the FM, AM and LW will be closest to the correct time, assuming all other things being equal (eg. FM, AM, LW and DAB transmitters all receiving the same signal at the same time).

In my house the "nearest real time" to "farthest from real time" order is :

Analogue Radio
Radio via Sky satellite
Radio via Freesat
DAB
Computer / internet

???

In my house the computer is easily the "nearest to real time". Timekeeping with ntp is probably about as close as anyone needs outside of some specialised fields.

Analogue radio is next followed by TV and the farthest being DAB.
The current time is...

You're not reading the question / understanding the context.

We're not talking about NTP or how accurate a computer is, we're talking about listening to pips on a radio programme.

When I listen to a radio programme stream via computer, it's easily the most "behind" of all of the above.

Yes I am and do. When I hear the pips on a DAB radio compared to the time on the computer or phone it (the radio) is usually behind. That would not matter whether I was listening to the "radio" on DAB or a streaming service on the computer. The computer or phone would be more accurate.

[Strangely Brown]

bodhi said:

audi321 said:

When compared to what though...........What I'm trying to get at is how you know that your phone is most accurate. Someone else has said the internet is the least accurate of all the sources, yet surely your phone is getting the time from the internet, and you are saying it's the most accurate.

Two different things - the clock on your phone syncs from a central server and is basically about as accurate as you can get. Internet radio streams normally involved a delay, so when the 8 o clock news comes on Internet radio, it's usually a couple of minutes behind.

^^This.

ntp uses, ultimately, a stratum 0 time source which is usually a satellite or atomic clock. The time is then cascaded down through stratum 1,2 etc. The time difference is accommodated and adjusted accordingly. The delay in transmission for DAB or streaming services is not so will necessarily lag.

[Clockwork Cupcake]

Strangely Brown said:

Yes I am and do. When I hear the pips on a DAB radio compared to the time on the computer or phone it (the radio) is usually behind. That would not matter whether I was listening to the "radio" on DAB or a streaming service on the computer. The computer or phone would be more accurate.

That wasn't the question though. The question was about propagation delay not accuracy.

If I watch the F1 on my Sky Box but also fire it up on my tablet with Sky Go, the latter is around half a lap behind the former.

Same happens with DAB and internet radio.

NTP is different as it adjusts for propagation delay, and also wasn't part of the original question.

As an aside, GPS probably has both the least propagation delay and also great accuracy, because every GPS sat has an onboard atomic clock and broadcasts that time, and your GPS device actually relies on the propagation delay to triangulate its position and thus derives a consensus time.

[Nethybridge]

Watching car reviews, I wonder how the car cargo space volume is calulated,
and why litres are sometimes used even though
as any fule kno the litre isn't a base SI unit.

[Alickadoo]

Alickadoo said:

I have radios in various rooms in my house.

Some are set to FM, some AM, some DAB, some Long wave and so on. You get the picture, I am sure.

The eight o'clock pips have just gone on the BBC. Which radio is giving the most accurate time?

Having asked the original question and read all the answers, it seems the most logical answer is :-

Whichever device gives the pips first. Logically the authorities (BBC?) are not going to transmit the signal before, say, 8o'clock, then whatever the first device to transmit the pips is the one that that is the most accurate.

There you go, I have answered my own question - I think.

[48k]

Strangely Brown said:

48k said:

Strangely Brown said:

48k said:

Theoretically the FM, AM and LW will be closest to the correct time, assuming all other things being equal (eg. FM, AM, LW and DAB transmitters all receiving the same signal at the same time).

In my house the "nearest real time" to "farthest from real time" order is :

Analogue Radio
Radio via Sky satellite
Radio via Freesat
DAB
Computer / internet

???

In my house the computer is easily the "nearest to real time". Timekeeping with ntp is probably about as close as anyone needs outside of some specialised fields.

Analogue radio is next followed by TV and the farthest being DAB.
The current time is...

You're not reading the question / understanding the context.

We're not talking about NTP or how accurate a computer is, we're talking about listening to pips on a radio programme.

When I listen to a radio programme stream via computer, it's easily the most "behind" of all of the above.

Yes I am and do. When I hear the pips on a DAB radio compared to the time on the computer or phone it (the radio) is usually behind. That would not matter whether I was listening to the "radio" on DAB or a streaming service on the computer. The computer or phone would be more accurate.

No, you're not comprehending what is being asked and what the answers are saying.

The question was about propogation delay when hearing pips on a radio programme.

I responded regarding what I hear in my house.

Out of: listening to a radio programme on my analogue radio, listening to a radio programme on my DAB radio, listening to a radio programme on my Sky box or listening to a radio programme on my computer, the stream on my computer is most behind.

Having a geek fest about NTP is bugger all to do with the question that was asked or my answer which you took issue with. Effectively which ever one your hear the pips on first is the most accurate. In my house, that's not the computer.

[trackdemon]

Always wanted to know: why does almost every post on PH turn into bickering and oneupmanship about who's more right/cleverer?

[WrekinCrew]

Alickadoo said:

Having asked the original question and read all the answers, it seems the most logical answer is :-

Whichever device gives the pips first. Logically the authorities (BBC?) are not going to transmit the signal before, say, 8o'clock, then whatever the first device to transmit the pips is the one that that is the most accurate.

There you go, I have answered my own question - I think.

That's exactly what I said two hours earlier. Are you browsing PH via DAB?

[bodhi]

48k said:

No, you're not comprehending what is being asked and what the answers are saying.

The question was about propogation delay when hearing pips on a radio programme.

I responded regarding what I hear in my house.

Out of: listening to a radio programme on my analogue radio, listening to a radio programme on my DAB radio, listening to a radio programme on my Sky box or listening to a radio programme on my computer, the stream on my computer is most behind.

Having a geek fest about NTP is bugger all to do with the question that was asked or my answer which you took issue with. Effectively which ever one your hear the pips on first is the most accurate. In my house, that's not the computer.

How would you measure which is closest to real time without a known accurate time to compare it to?

That's where NTP comes in, and is entirely relevant to the discussion.

So put yer handbag away.

[v9]

trackdemon said:

Always wanted to know: why does almost every post on PH turn into bickering and oneupmanship about who's more right/cleverer?

A basic principle pertaining to all living organisms is the desire, conscious or not, to pass on their genetic material to subsequent generations. Both intellectual prowess and being perceived as superior to others increases the chances of successful propagation of said genes.
TLDR: to get sex.

[borcy]

Why do pensioners have conversations in the middle of the pavement?

[48k]

bodhi said:

48k said:

No, you're not comprehending what is being asked and what the answers are saying.

The question was about propogation delay when hearing pips on a radio programme.

I responded regarding what I hear in my house.

Out of: listening to a radio programme on my analogue radio, listening to a radio programme on my DAB radio, listening to a radio programme on my Sky box or listening to a radio programme on my computer, the stream on my computer is most behind.

Having a geek fest about NTP is bugger all to do with the question that was asked or my answer which you took issue with. Effectively which ever one your hear the pips on first is the most accurate. In my house, that's not the computer.

How would you measure which is closest to real time without a known accurate time to compare it to?

That's where NTP comes in, and is entirely relevant to the discussion.

So put yer handbag away.

The OP doesn't have to measure. NTP is entirely irrelevant. In fact if you scroll up he already answered his own question. Whichever one he hears first is most accurate.

[Clockwork Cupcake]

An OP: Why does the sun rise in the East?
PersonA: The sun is a big firey ball in the sky
PersonB: That's not what the OP asked!
PersonA: It is very important to the discussion.
PersonC: Actually it is a star, and runs on nuclear fusion
PersonD: How does that contradict what PersonA said? It merely adds to it. But also doesn't answer the OP's question
PersonE: It's due to the way the Earth rotates
The OP: Thanks! That answers my question
PersonA and PersonC continue to bang on about their answers which weren't actually to do with what the OP asked.

Other persons then tell CC that she is taking the piss with her analogy and actually NTP is also relevant to solar radiation. Which, ironically, has nothing to do with why the sun rises in the East.

[droopsnoot]

48k said:

Strangely Brown said:

48k said:

Strangely Brown said:

48k said:

Theoretically the FM, AM and LW will be closest to the correct time, assuming all other things being equal (eg. FM, AM, LW and DAB transmitters all receiving the same signal at the same time).

In my house the "nearest real time" to "farthest from real time" order is :

Analogue Radio
Radio via Sky satellite
Radio via Freesat
DAB
Computer / internet

???

In my house the computer is easily the "nearest to real time". Timekeeping with ntp is probably about as close as anyone needs outside of some specialised fields.

Analogue radio is next followed by TV and the farthest being DAB.
The current time is...

You're not reading the question / understanding the context.

We're not talking about NTP or how accurate a computer is, we're talking about listening to pips on a radio programme.

When I listen to a radio programme stream via computer, it's easily the most "behind" of all of the above.

Yes I am and do. When I hear the pips on a DAB radio compared to the time on the computer or phone it (the radio) is usually behind. That would not matter whether I was listening to the "radio" on DAB or a streaming service on the computer. The computer or phone would be more accurate.

No, you're not comprehending what is being asked and what the answers are saying.

The question was about propogation delay when hearing pips on a radio programme.

I responded regarding what I hear in my house.

Out of: listening to a radio programme on my analogue radio, listening to a radio programme on my DAB radio, listening to a radio programme on my Sky box or listening to a radio programme on my computer, the stream on my computer is most behind.

Having a geek fest about NTP is bugger all to do with the question that was asked or my answer which you took issue with. Effectively which ever one your hear the pips on first is the most accurate. In my house, that's not the computer.

This all goes back to the old proverb:

Man with watch always knows time.
Man with two watches never quite certain.

[98elise]

48k said:

bodhi said:

48k said:

No, you're not comprehending what is being asked and what the answers are saying.

The question was about propogation delay when hearing pips on a radio programme.

I responded regarding what I hear in my house.

Out of: listening to a radio programme on my analogue radio, listening to a radio programme on my DAB radio, listening to a radio programme on my Sky box or listening to a radio programme on my computer, the stream on my computer is most behind.

Having a geek fest about NTP is bugger all to do with the question that was asked or my answer which you took issue with. Effectively which ever one your hear the pips on first is the most accurate. In my house, that's not the computer.

How would you measure which is closest to real time without a known accurate time to compare it to?

That's where NTP comes in, and is entirely relevant to the discussion.

So put yer handbag away.

The OP doesn't have to measure. NTP is entirely irrelevant. In fact if you scroll up he already answered his own question. Whichever one he hears first is most accurate.

Agreed. They won't be broadcast ahead of time, so its only a question of what order you hear them.

[valiant]

borcy said:

Why do pensioners have conversations in the middle of the pavement?

Because they keep getting run over when they chat in the middle of the road.

[Roofless Toothless]

borcy said:

Why do pensioners have conversations in the middle of the pavement?

I was walking down the pavement in Naples once and came upon two old boys having an animated conversation, right between a row of parked motor scooters and some old refrigerated cabinets filled with cold cuts of pizza. Nobody could get past, but they were blissfully unaware.

Of course, being English, I found myself tut-tutting and getting all irate, but two young Italian lads, early twenties I suppose, coming the other way, just smiled and ever so gently eased the old boys to one side with a hand on the shoulder and elbow. I don’t think they even noticed, and continued with their discussion. We all filed past, everybody now amused at the situation, and laughing gently.

It made me think. What a typically uptight English reaction I had been guilty of, and how right the young Italians were to show love and respect to their elders, guilty of no more than getting carried away with a vigorous debate.

[Halmyre]

droopsnoot said:

This all goes back to the old proverb:

Man with watch always knows time.
Man with two watches never quite certain.

I have the time written on a piece of paper...

[Alickadoo]

borcy said:

Why do pensioners have conversations in the middle of the pavement?

If they (we) fall over, there is less chance that they (we) will either hit their (our) head on a wall or finish up in the road.

They (we) have to think of these things.

[Alickadoo]

WrekinCrew said:

Alickadoo said:

Having asked the original question and read all the answers, it seems the most logical answer is :-

Whichever device gives the pips first. Logically the authorities (BBC?) are not going to transmit the signal before, say, 8o'clock, then whatever the first device to transmit the pips is the one that that is the most accurate.

There you go, I have answered my own question - I think.

That's exactly what I said two hours earlier. Are you browsing PH via DAB?

I answered my own question, apart from those people who had given me the answer previously.