DAB workshop reception

[Mick HenshallParticipant @mickhenshall99321]

Thanks Nick, hadn't thought of auto standby, done as you suggested and all seems good,thanks again

Mick

[michael howarth 1Participant @michaelhowarth1]

Posted by Nick Hughes on 09/01/2016 16:14:24:

DAB ok in the Home, workshop and the car for me.

Mick H, connect the freeview box to your TV (so that you can see the menu) and disable the Auto Off/Sleep setting, then return it to your workshop.

Nick.

Not sure what you mean by that Nick. My problem is with a radio receiver not a TV or am I missing your point?

I took the radio upstairs in the house this evening to give it a trial and it seems to work OK there, but as the problem is intermittent anyway, it doesn't prove anything one way or the other. I think I might try a simple single wire aerial extension tomorrow and get it up as high as possible in the workshop before I start getting too adventurous with an additional outside aerial.

Mick

[Mick HenshallParticipant @mickhenshall99321]

To Mick H, may be some confusion here-see my post about freeview box turning itself off, I think Nick's post may have been reply to me, I may be mistaken but his suggestion works for me,

Mick

[jason udallParticipant @jasonudall57142]

Baz…
Re digital yagi..really ?

My comment was the fact that all the antenna theory I remember dealt with analogue e/m waves…cant see where a “digital” wave form propagates other than as a fourier series…of analogue…..but hay…what ever.

Maybe I just didn’t get the joke

Edited By jason udall on 09/01/2016 20:43:08

[jason udallParticipant @jasonudall57142]

We are all wavefronts on this bus

[Johnboy25Participant @johnboy25]

Sounds like you could do with a home made Ground Plane aerial. I won't bore you with the theory but it's all out there on t'internet… The Sony manual or again a search on t'internet might help you determine the aerial impedance to get the maximum power transfer from the aerial into the radio.There are several 'common' impedances – 75ohm, 300ohm or 600ohm which may cause a problem in the design consideration of an aerial.

If your in a really bad reception area – you could go for Internet radio that's is if you don't mind installing a laptop or PC in the workshop with a WiFi connection or hard wiring to you broadband modem. Just a thought.

I'm using my Daughters discarded FM radio. I not a fan of DAB. A DAB radio has a much higher power consumption so in a power cut situation it will run batteries much faster than 'good old' FM! 

John

[Mike PooleParticipant @mikepoole82104]

I suspect that broadcast type radio may die out in favour of digitally streamed media from the Internet. I use a SONOS speaker to listen to Internet radio and the variety of stations is remarkable. I also stream music from my NAS drive where I have stored all my music ripped from my CDs. Subscription services such as Spotify are also available. The shear amount of choice should find something to please everybody. DAB will only deliver a limited number of stations but the Internet has a station for every niche listener imaginable.

Mike

[KWILParticipant @kwil]

As it is only 2 parallel pins perhaps it is intended for a 300 ohm twin flat feeder connection. Finding a matching line socket to plug in will be the main problem. Contact Sony (or Sony dealer)?

[SillyOldDufferModerator @sillyoldduffer]

You might try moving the radio around to see if you can find a good spot for it. This works because internal reflections inside the room will be either reinforcing or cancelling each other out. It's very unpredictable because the indoor RF environment is very complicated: people are mobile reflectors and there are wires, pipes and lumps of metal all over the place.

Your radio might be a bit deaf, especially if it's an older model. The £20 radio I recently got from Tesco for my workshop is much more sensitive than my somewhat expensive brand-name bedroom clock-radio.

An outside antenna in the clear will always out-perform an indoor antenna. The simple rule is to get the antenna as high and as far away from the house as you can. Indoor antennas only work if the local signal strength happens to be high.

DAB is a VHF system (170 – 220MHz vertically polarised) so a home-made dipole would consist of two rods (or wires) each about 0.65m long, arranged up and down. Or you could buy a folded dipole like this.

The placement of your TV antenna is a good guide to where a DAB antenna should go, but lower down will probably be OK.

The hard part looks to be that weird connector. I've never seen anything like that on a radio before but it might be one of these.

Ideally the antenna and radio should be impedance matched to each other and the transmission line (Coax or ribbon) This can get quite complicated if you are rolling your own, but I wouldn't worry too much about it unless the radio still doesn't work after you've tried it – a crude outdoor lash-up might well be "good enough".

It's slack terminology, but a "digital" antenna is simply one optimised to receive the frequencies digital TV signals are transmitted on. It might be necessary to install one if your old antenna happened not to work well enough after switch-over. Analogue and digital signals were introduced on different frequencies in the same band so that they wouldn't interfere with each other. Unlucky people sometimes found the digital signal was just outside their old antenna's bandwidth, or that reception was marginal anyway.

Regards,

Dave

Edited By SillyOldDuffer on 09/01/2016 23:02:34

[BazyleParticipant @bazyle]

Broadcast radio will survive for cars. It will become digital rather than analogue and once digital it is a moot point whether it is a radio signal or an internet stream. Digital TV is already like that. So your Netflix and BBC are both digital just different modulation schemes but will converge in a couple or 3 years.

Jason, I thought you were joking 'cos of the smilie so made a silly response. The actual answer is that digital signals are wider bandwidth so the elements of a digital aerial are made wider to blur the exact distance between elements and hence wavelength they are optimised for. That gives the salesman a reason to say you need a new one though mostly only affects reception for TV aerials.

[jason udallParticipant @jasonudall57142]

Thanks Bazyle.

So the digital bit applies to the wider channel bw..
Mmm
New to me but been out of antennas since fss at uni

[michael howarth 1Participant @michaelhowarth1]

Loads of information there and thank you for it gents. I shall work through it bit by bit to try and get a result. There have been a couple of suggestions based on the internet but our internet connection varies between 2 or 3 Mbits and is pretty much hopeless at connecting to radio.

Mick

[martin perman 1Participant @martinperman1]

If you have wireless internet within your house or an ethernet connection you can get Internet radio's which would give give you worldwide programmes. Just type internet radio.

Martin P

[Johnboy25Participant @johnboy25]

 

Re. By the way any one know how a digital yagi is supposed to work? 

We'll be getting into the realms of Log-periodic aerials soon so keep your hat on – it may get a bit heavy! 

​P.S. How do I stop these B****y  hieroglyphics when using tHis iPad?

​

Edited By Johnboy25 on 10/01/2016 09:18:23

[Michael GilliganParticipant @michaelgilligan61133]

I suspect that there are much better options than this genuine Sony item.

**LINK**

MichaelG.

.

P.S. … Given what we know about vertical polarisation; the instructions here seem confused.

Edited By Michael Gilligan on 10/01/2016 10:03:47

[Johnboy25Participant @johnboy25]

Mmm.. If there is continuity between the pins it will be 300 ohm impedance but if it's open circuit it will be 600 ohm… If that's any help!

Edited By Johnboy25 on 10/01/2016 09:58:21

[Les Jones 1Participant @lesjones1]

I think Johnboy25 is correct that the impedence of that antenna connector is probably 300 ohms (Check the specification information in the radio manual.) It is very unlikely you will have the equipment to measure the impedence at 230 Mhz (DAB radio frequency.) The DC resistance will not be 300 ohms. To match it correctly to 75 ohm coax you should really use a balun transformer but it should work without but there will be some attenuation of the signal.

Les.

[Johnboy25Participant @johnboy25]

Yes I agree with your observation Les. I was referring to impedance as opposed to DC resistance.👍😀

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Les Jones 1 on 10/01/2016 10:54:04:

I think Johnboy25 is correct that the impedence of that antenna connector is probably 300 ohms (Check the specification information in the radio manual.)

.

Les,

I posted a link to the 'instructions' earlier … they appear to be silent on such technicalities.

… Maybe there is a proper manual somewhere.

MichaelG.

[Anonymous]

Posted by Les Jones 1 on 10/01/2016 10:54:04:

I think Johnboy25 is correct that the impedence of that antenna connector is probably 300 ohms

Most likely given that the theoretical impedance of a folded dipole is around 292 ohms.

Andrew

[Johnboy25Participant @johnboy25]

300 ohm being the nominal impedance for a folded dipole – if you like to look at the theory a little more in depth take a look at

http://www.vias.org/radioanteng/radio_antenna_engineering_03_09.html

[Nick HughesParticipant @nickhughes97026]

Posted by Mick Henshall on 09/01/2016 20:27:46:

To Mick H, may be some confusion here-see my post about freeview box turning itself off, I think Nick's post may have been reply to me, I may be mistaken but his suggestion works for me,

Mick

Ahh, I didn't realise that there was a Mick H involved in this thread (I must start to read all threads from the start),

so apologies for the confusion caused.

Nick.

[Mick HenshallParticipant @mickhenshall99321]

No worries Nick, would have replied earlier but I bin listening to the radio!

Mick

[Russell EberhardtParticipant @russelleberhardt48058]

If you have an internet connection in your shed the easiest way to get LBC would be: **LINK**

It's just one of 30,000 stations available on that site!

Russell.

[michael howarth 1Participant @michaelhowarth1]

Russell, works brilliantly indoors. Unfortunately no internet in shed…..as yet! Things may change.

Mick

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