Ropey Radio Reception?

[Neil WyattModerator @neilwyatt]

In my experience it's often the stations that are ropier than the reception!

I have my radio tuned to Radio 4 on FM and Planet Rock on DAB as it's easier to switch between reception modes than change channels.

Why can't they make a radio with a 'tuner knob' that allows a quick scan through the channels rather than a pair of fiddly push-buttons?

Neil

[martin perman 1Participant @martinperman1]

Neil,

I have a Roberts solarDAB which has FM and DAB, all stations are on a tuner knob also a Blaupunkt CD/Radio and DAB/FM are also on a tuner knob

Martin P

Edited By martin perman on 07/05/2021 12:00:15

Edited By martin perman on 07/05/2021 12:01:58

[SamsarandaParticipant @samsaranda]

Tv and radio reception can both be problematic, I live near the coast in East Sussex and the most powerful transmitter to tune to is the Heathfield transmitter, ideal because it’s on a hill. One of my neighbours has a ginormous Birch tree in his garden, which unfortunately is in direct line of sight between my house and the Heathfield transmitter, reception from that transmitter is ok in winter but once the tree is in leaf reception descends to unwatchable on our tv. Solution is retune the house aerial to another transmitter, well there is one at Hastings but the power output is so feeble because the French bleat on about interference their side of the channel so the transmitter gives only a very poor signal. Solution in the end was to go for Sky for tv, wasn’t happy doing that but at least the tv is watchable but at a price.

Going back to the old pirate radio days, in 1967 we used to listen to Radio Caroline when we were on guard on the airfield at RAF Sharjah, now part of the UAE. It could only be picked up for about an hour before dawn as the temperature changes in the atmosphere facilitated the signal skipping. Dave W

[Graham TitmanParticipant @grahamtitman81812]

My Dab radios will not work in the workshop when the inverter is in use so no planet rock in the workshop

[Grindstone CowboyParticipant @grindstonecowboy]

Posted by Dave Halford on 07/05/2021 11:07:26:

….. which on a good hot summer night could pull Caroline into Birmingham if only for a wobbly hour or so.

Ah, those were the days!

Rob

[Nigel Graham 2Participant @nigelgraham2]

Bazyle –

I'm afraid that desire in some quarters to make the inherently simple as complicated and awkward as possible for no discernible advantage, is all too common now, and my experience with my DAB radio is very much in that class.

Even my bedside analogue FM radio/clock is a paper-weight for its own instruction leaflet. For setting the alarm is a black art I have not yet mastered, and I hope the ears are burning on whoever designed the volume-control. It operates in several-dB steps rather than by smooth progression. Only just audible on the lowest step, it's loud enough on Step 2 for me to worry about disturbing my neighbour beyond a party wall offering almost no acoustic insulation.

'

Thank you Ega!

'

Martin –

A) You cannot "assume" others have WiFi. I don't – I have neither need nor wish for it

B) Alexa? I would not touch her, nor any of her eavesdropping ilk, with a barge-mouse. Using a PC on-line is bad enough.

C) Why add even more electronics just to select a radio station, when the problem is signal quality external to the radio receiver?

'

Russell –

I'm impressed by that precision they claim, but an ordinary second is near enough and I don't have anything Android.

'

One point I didn't make is that when my neighbour's back door is open I can hear her radio, usually on Radio Four, and the reception is fine even when mine tuned to the same station is falling off. I don't know if she listens on a DAB radio or to the Long Wave broadcast though.

It is very much local to an area within my house, and it is signal quality, not quantity, that suffers. The sound does not fade much but becomes very distorted. It does appear a more Summer than Winter – or maybe daylight – effect. The deterioration is less marked in the front room, and even less on the workshop radio.

[BaldricParticipant @baldric]

Posted by John Haine on 07/05/2021 11:31:34

DAB can't fix this problem because it simply transmits the audio stream in which the pips are embedded. Until someone develops a negative delay line it's a laws of physics problem. There may be time signals embedded in the DAB multiplex but receivers don't seem to use them if so. (Actually there are only a few DAB chipsets so not much variation in the low level capability between sets.)

About 14 years ago I was involved with a project associated with BBC radio, there were plans to insert the PIPs early in to the digital feeds, but I believe it was dropped as not only is it going to depend on the transmission medium (FM/DAB/Freeview/Freesat/sky), but also what the receiver does with it. At about the same time listening to radio via the internet was becoming more wide-spread, that added a whole host of other variations. There is also the route the signal takes to an FM transmitter, that will probably be digital, with minimum delay, I used to here on my radio it switch from one transmitter to another as there was a small repeat of part of a word.

If you want accurate time I would suggest PC time, if set from an external source, or AM/FM radio.

Also of note there was talk of stopping the analogue transmissions, but I am not sure what happened to that proposal.

Baldric.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Baldric on 08/05/2021 09:07:27:

Posted by John Haine on 07/05/2021 11:31:34

DAB can't fix this problem because it simply transmits the audio stream in which the pips are embedded. Until someone develops a negative delay line it's a laws of physics problem. There may be time signals embedded in the DAB multiplex but receivers don't seem to use them if so. (Actually there are only a few DAB chipsets so not much variation in the low level capability between sets.)

About 14 years ago I was involved with a project associated with BBC radio, there were plans to insert the PIPs early in to the digital feeds, but I believe it was dropped as not only is it going to depend on the transmission medium (FM/DAB/Freeview/Freesat/sky), but also what the receiver does with it. At about the same time listening to radio via the internet was becoming more wide-spread, that added a whole host of other variations. There is also the route the signal takes to an FM transmitter, that will probably be digital, with minimum delay, I used to here on my radio it switch from one transmitter to another as there was a small repeat of part of a word.

If you want accurate time I would suggest PC time, if set from an external source, or AM/FM radio.

…

Baldric.

All my DAB radios can display accurate date-time read from timestamps on the packets and – unlike the audio pips – the time is correcy. Unfortunately none of the radios make it easy to display time – it flashes up briefly when the radio first connects, but then hides deep behind a wall of mysterious sub-menu options, along with plex, frequency, data rate and other techy information.

My guess is time's hidden because DAB radios all use the same display module for cheapness, and it isn't big enough to show time as well as station information. My beside clock/alarm uses digital time to set the clock and adjust Saving Time, but other than that it's invisible. So while it knows accurate time, the pips are wrong.

It's part of the inherent cussedness of things!

Dave

[HowiParticipant @howi]

there are more dinosaurs on this site than in the natural history museum

[SamsarandaParticipant @samsaranda]

Without the Dinosaurs this site probably wouldn’t exist, proud to be among them. 🦕. Dave W

[Frances IoMParticipant @francesiom58905]

it required a collision with a large meteorite to wipe them out ( + most of rest of life) so they were pretty well adapted to their world

[duncan webster 1Participant @duncanwebster1]

Posted by Samsaranda on 07/05/2021 12:20:47:

….. reception from that transmitter is ok in winter but once the tree is in leaf reception descends to unwatchable on our tv. Solution is retune the house aerial to another transmitter,…….

I had the same problem with trees in summer, bought a Freesat receiver and dish, no more problems, loads more rubbish to watch, lots of radio stations, no monthly fee.

I've tried DAB radio in the workshop, fine until SWMBO has the same station on a different receiver in the next room, they are then out of synch which makes it difficult to hear properly. I'll keep my FM wirelesses until they finally give up the ghost

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, my elder sister used to listen to Radio Caroline. +1 for Freesat.

Regards Nick.

[noel shelleyParticipant @noelshelley55608]

DAB was more about money than any goodwill towards the listening public. The fact that FM is still running is that DAB has shortcomings, and the government can't communicate with many of us due to NO or a poor signal. Once the analogue signal goes the channels that come free will be sold off for a fortune ! PROGRESS or CHANGE ? Noel

[duncan webster 1Participant @duncanwebster1]

When I was still a wage slave they brought in the culture of continuous change. When I asked if they really meant continuous improvement, they said no, so we would change it even if it didn't get better. I reckon it's because change creates the illusion of progress.

[SillyOldDufferModerator @sillyoldduffer]

Posted by noel shelley on 08/05/2021 13:53:30:

DAB was more about money than any goodwill towards the listening public. The fact that FM is still running is that DAB has shortcomings, and the government can't communicate with many of us due to NO or a poor signal. Once the analogue signal goes the channels that come free will be sold off for a fortune ! PROGRESS or CHANGE ? Noel

Can't disagree with that: DAB is a mix of positive and negative features. DAB happens to be more reliable in my house than FM, and it makes it easier to find more stations. The positives outweigh the negatives here. Not everyone is so lucky.

But I fear time is running out for all terrestrial services. Whilst we dinosaurs might be happy with AM, FM and DAB, the young folk are deserting all of them droves. They prefer to listen and watch programmes delivered on demand as internet services, whether by cable, broadband, wifi, or the mobile telephone network. Sooner or later, not enough people will be using DAB to make it worth maintaining, and it too will go the way of the Quill Pen.

Another thought: Has anyone timed how late the pips are on FreeSat? In addition to the delays that stuff pips up on DAB, the satellite is in geostationary orbit 23000 miles up, which I reckon adds another quarter second delay.

The answer to Nigel's problem is easy: put up a decent external antenna!

Dave

[ChrisHParticipant @chrish]

Ah – Radio Luxembury and Radio Caroline – that brings back memories and dates me at the same time.

As a young student in 1964 I and a few friends lived in rented a semi-basement flat in Plymouth, I had a good old valve radio, but Luxemburg was hard to pull in, very faint.

Then I realised that the phone line that had been put in when the previous married tennants were 'expecting' and needed a phone for the babys arrival was still in place, the handset had gone but the line was in place.

Eureka! Aerial lead from radio was promptly connected to the phone line and now I had a really effective radio aerial of how ever long it was! Didn't look – didn't dare, anyway at that age, who cared!

Luxemburg now pulled in loud and clear, in fact I could trun the volume up to full because of distortion the signal was now so strong. Ripper!

Chris

Edited By ChrisH on 08/05/2021 16:55:47

[Nigel Graham 2Participant @nigelgraham2]

Radio Luxembourg of blessed memory – 1933 – 1992, when the company was dissolved.

' ' ' '

I suppose I could try that DAB radio again, having been deterred by instructions suggesting a needless complexity akin to the spectrum-analysers I used at work…. in fact I think they were easier to use provided you knew what you were using it for.

I have just paused to look more closely at the wireless in the kitchen. It has a telescopic aerial and no socket for a further aerial.

It was on Radio Three and loud and clear. I tuned to Radio Four: ditto. Not brilliant audio quality I don't expect anyway; but ample radio signal. This was so with the aerial erect or closed and folded down to its clips, on both stations. All that happened in the closed state was my shielding the signal to some extent.

The weather? Thick overcast.

[Russell EberhardtParticipant @russelleberhardt48058]

Unfortunately very few FM radios are fitted with a proper aerial socket and the built in whip aerials are woefully inadequate. For best operation a whip aerial should be 1/4 wave, that is about 75 cm, long. The other problem is that in a house the signal will come from multiple paths each with a slightly different delay and interfere with each other. For compact reliable reception a WiFi receiver of some sort is much more reliable and easy to set up.

Russell

[SillyOldDufferModerator @sillyoldduffer]

Posted by Nigel Graham 2 on 08/05/2021 17:18:28:

… just paused to look more closely at the wireless in the kitchen. It has a telescopic aerial and no socket for a further aerial.

… Not brilliant audio quality I don't expect anyway; but ample radio signal. This was so with the aerial erect or closed and folded down to its clips, on both stations. All that happened in the closed state was my shielding the signal to some extent.

The weather? Thick overcast.

A proper plug and socket isn't strictly needed to connect an external antenna. Just wrap a few inches of the coax centre conductor around the base of the telescopic aerial. RF best practice isn't essential – with luck the bodge only has to improve a marginal signal due to the radio being inside the house.

Of course, for best FM reception, go the whole hog. That means putting an antenna high up outside, at least 2 wavelengths away from any nearby structure, maybe a beam aimed carefully at the transmitter, with a pre-amplifier, and connected to a better FM receiver with a proper antenna socket. ega's leaflet covers the ground rather well, and goes so far as to suggest rotating the beam. This contrasts sharply with buying a cheap FM portable and hoping it will work inside a house. Do it properly and the antenna might well cost more than the radio. Much depends on location relative to the transmitter: these don't put down a uniform signal in neat circles. This map shows Mendip's patchy service area. Good signal up several Welsh valleys, and South Dartmoor, but no good for Yeovil, Bristol and Bath, all shielded by high ground.

It's not really possible to tell how strong an FM radio signal is just by listening to it. Radios are fitted with Automatic Gain Control that works hard to maintain the same output whatever the input level. Radios are designed to fool the ear – don't trust it!

AGC fails causing distorted audio when the input is too strong or too weak. Too weak also causes drop outs, where noise intrudes – usually distant weak stations and/or hash. Nigel's symptoms match FM radios demodulating marginally weak signals. I have the same problem: my portable radios work OK in some rooms and are hopeless in others. They all work perfectly in the garden!

Houses are dreadful for radio reception. First the signal arrives mis-phased due to bouncing or diffracting off all the other buildings, hills, trees, lakes, or whatever at ground level between the house and the transmitter. Inside the house it gets worse. Apart from loads of domestic electrical noise, the incoming signal bounces off internal walls, water pipes, electric wiring, metal window-frames, girders, aluminium curtain rails, people, and pretty much anything else bigger than an FM 1/4 wave. What the telescopic aerial gets is a mish-mash depending on a multitude of variables, any of which can alter path lengths causing signal strength to rise and fall mysteriously. Weather can effect FM but it's associated with Sporadic E and Ducting, both relatively unusual. One explanation is folliage. In winter it dies back, which could strengthen subtractive paths; in summer, the subtractive part is weakened.

Russell and I have both suggested the multiple path problem: we're not making it up! The answer is a good antenna. At roof height most things that change path length by bouncing are below the antenna, as is most electric noise.

In communications radio the antenna is the most important part of the system. A high-performance receiver and powerful transmitter connected to a town-centre indoor antenna are easily outperformed by modest equipment connected to an efficient outdoor aerial high up in a good location well clear of obstacles and electrical noise. Most radio amateurs are constrained by their antennas – gardens not big enough, and cluttered take-off due to close neighbours, some of whom run unfiltered VFDs!  Off with their heads!

Dave

 

 

 

 

Edited By SillyOldDuffer on 10/05/2021 11:09:07

[Nigel Graham 2Participant @nigelgraham2]

Thank you for all this information!

The reception's pretty good today…

[Author]

Posts