A Radio Question Of The Terrestrial Kind

Mossy Monk

i am sure i asked this in here before but i can't find it, anyway.....

i have a VHF aerial on my roof which used to be for RTÉ on the VHF band. it is currently horizontal. i have it plugged into the back of my Hi-Fi and it is giving me crystal clear reception on Radio 1, 2FM, RnaG, Lyric FM, WLR, Beat and South East Radio. it also gives ok reception on Red FM on 105.7. i am getting weak reception on stations like 96FM (96.1) Radio Kerry (97.0) and a few more. reception is much better in the car but i don't want to sit in the car if i want to listen to them. how much of a difference would i notice if i was to change my aerial to vertical polarity. i'm going to do this while the weather is fine

lawhec

Mossy, assuming this is an old RTÉ Aerial that was used for the old Dungarvan VHF TV service, it isn't the right aerial to be used for FM radio as they use two seperate parts of the airwaves, albeit not too far apart. Aligning the aerial vertically with the elements vertically westwards for 96FM and R.Kerry may help your reception of these channels - there's no harm in trying. Though if it is less than satisfactory you may have to get a proper Band II aerial.

Mossy Monk

it was used for RTÉ1 and Network 2. i only want to be able to hear them clearly. i'm not looking for RDS or any of that. the weather is poor today so i'll have to wait until tomorrow. using the VHF aerial instead of the piece of wire that i have already makes a huge difference so i am optimistic

Mike 1972

Switching to vertical should improve reception but you really should be using a proper FM band 2 (87-108 Mhz )aerial

VHF Band 3 TV aerials are designed to cover 174-230MHz (i.e. frequencies tice those used for radio) while they will have some response on Band 2 a proper 3 element FM aerial will give better reception than an 8 element TV one

rlogue

I've often wondered why there are very few rooftop FM Aerials in Ireland - occasionally you will see a horizontally polarised FM Aerial pointed at the North or Wales but I've only ever seen one vertically polarised FM aerial in the Republic, and that was on a house in a huge dip in the middle of Drogheda.

Here in London rooftop FM aerials are very common, not on every house, but on a fair few all the same.

watty

o Lack of folks selling them
o Reluctance of Irish to spend money on Radio
o Ironically though the UHF TV network is horrid, at 100MHz the Radio TX locations aren't so bad.
o Most of Irish Radio is vertical, meaning dripping, trailing wire on hifi works better and whip aerials work better
o Londoners care more about the HiFi quality for Radio?

I'm amazed how many "halos" have gone up in last year, esp. since in most cases a piece of wire hanging in attic works better.

"Halo" is an omni for horizontal. It has negative gain on horizontal compared with a 1/4 wave whip or a vertical folded dipole for vertical. And MUCH lower gain for most of the Irish signals which are vertical

Go figure.

I'm toying with pointing a couple of Log Periodics at Strabane and see If I get DAB. In Patrickswell Limerick. Am I mad Richard?

Richard

Originally posted by watty

I'm toying with pointing a couple of Log Periodics at Strabane and see If I get DAB. In Patrickswell Limerick. Am I mad Richard?

I'm not the Richard you asked - but I'll answer anyway.

I'd be really interested to hear if you could get DAB. Though of course you'd only get the following:

Classic FM
Prime Time
3C Cool Country
Cool Fm
Downtown Radio
Q102.9
BBC Radio Ulster
Belfast Citybeat

Have you tried getting DTT from Brougher?

watty

Don't have a DTT or DAB RX yet.

Still, a few of those arn't on Sky Sat.

I'll see can I get Analog TV and Radio first. I am getting the 144MHz GIWT repeater just outside Strabane and had brief Dungannon/Portadown contacts again last night.

Getting a 2 or 3 second sharp fade every minute or two from Athlone town contacts last night though. (We talking on 10Watt two way FM radio on 145MHz) .

If anyone interested it is OK (legal) to listen on a scanner etc. If anyone *Madly* interested there are Clubs (optional) and Exam (not hard) for TX lincense access.

Bands Without morse:
50MHz, 70MHz, 145MHz, 430MHz, 1250 MHz, 2.4GHz, 5.6Ghz and 10GHz, plus some even higher ones.

With additional 5wpm morse exam:
137KHz, and various "spot" Short Wave (HF) from 1.8MHz to 30MHz (Highest might be 28MHz)

"Modes" include Speech, Fax, Data, Slow TV (about 20 sec per frame on a PC), and AM or FM "real" TV.

rlogue

Hi Watty,

This is probably getting off topic but I built myself a homebrew MW reciever based on the "Moorabbin MW Reciever" plans on the Internet.

The set has a Vernier dial and can tune from at least Spectrum Radio at 558 kHz (100 on the dial) down to Capital Gold on 1548 (20 on the dial). It's a regenerative reciever so it's a little more powerful than the average tranny - I've picked up OK RTE Radio 1 on the set at night.

I'd like to listen to any amateur transmissions in the 160 metre band - but I'm wondering how many turns my coil needs. Right now 50 turns pretty much gives me the MW broadcast band, but I don't want to lose the lower MW frequencies.

Is the 160 metre band all that active? I've asked on the uk.amateur.radio newsgroup but just got a load of crap in response.

rlogue

Watty, I think you'll struggle to get DAB from Strabane as far south as Limerick.

Having said that, if the tropo conditions are good for 144 MHz then you're in with a chance.

lawhec

Brougher Mountain carries the same DAB services on the same block (12d) as Strabane. Although Brougher is closer to sea level than Strabane but if ye still fancy yer chances...

byte

I didn't realise Brougher was transmitting DAB! For some reason, I thought Divis was the only Tx in NI transmitting DAB! :rolleyes:

I currently have a Halo FM aerial but it's just sitting under the hifi! I haven't bothered to install it outside yet, due to my slippy roof, so when I do make the effort, I intend to use a proper directional antenna. I must try putting the halo in the attic though to see if I get an improvement on BBC R1, which currenly isn't very good in Stereo

Thank God for satellite!;)

watty

Originally posted by rlogue
Hi Watty,

This is probably getting off topic but I built myself a homebrew MW reciever based on the "Moorabbin MW Reciever" plans on the Internet.

I'd like to listen to any amateur transmissions in the 160 metre band - but I'm wondering how many turns my coil needs. Right now 50 turns pretty much gives me the MW broadcast band, but I don't want to lose the lower MW frequencies.

I mess with 144MHz , and up so I don't know about how active.

Unfortuneatly a regen rx is a small transmitter! I'd recomend a second coil and tuning capictor with FET (2n3819) as a RF pre-amp and put the regenerative receiver in a tin so screen it.

In theory a regenerative receiver can demodulate SSB, CW is less likely. 160 may be mostly CW (morse). In practice you'd be lucky. Have a go..

A two way switch and tap coil at 1/4 and 1/2 turns to change "band" may work..


Long ago I built a little VHF regen reciever to run on one AAA "pen" cell. A plastic straw with a ferrite slug, coil length air space and cut off brass screw in it slides in /out to give a massive tuning range the tuning scale is on the straw. 2MHz is about 3mm movement. Does VHF broadcast and Air band. Might even even go up to 146MHz. Minature volume /on off Fits in a matchbox.

I also did a TRF LF/MF receiver to fit in matchbox with no on/off runs for about 3 months! A switch changes between LW and MW with fixed tuning for R4 and RTE. Vary volume by rotation of receiver!

Anyone intersted PM me for schematics.

Last night was fine for HF /SW but poor for VHF. Far too damp and humid. Signal from Tuam in Galway a bit rough. Nothing audiable at all from Norn Iron.

Richard

Originally posted by byte
I didn't realise Brougher was transmitting DAB! For some reason, I thought Divis was the only Tx in NI transmitting DAB! :rolleyes:

Actually, I didn't know that Strabane broadcast DAB! After doing a bit of looking around, I found this:
http://www.wohnort.demon.co.uk/DAB/ukloc.html#NIreland

So apparently, SCORE Digital broadcasts from "Black Mountain, Colinward, Londonderry, Strabane, Limavady and Brougher Mountain".

AFAIK, the BBC only broadcasts DAB from Divis.

Where is Colinward?

Richard

There is also some information on "L-Band allocations" for the Republic, whatever these are:

http://www.wohnort.demon.co.uk/DAB/irlband.html

watty

L-Band is totally impractical for portable Radio. It is up in the GHz.

They have simlar allocations in UK where they do have DAB on BandIII but not on L-Band. Only some of the mose expensive DAB units in UK can even receive L-Band

Approx bands
Ku Band 10 to 12GHz (satellite)
C Band 3.5GHz to 4.5 GHz (3500MHz to 4500MHz) Satellite
MMDS 2.5GHz = 2500MHz
Wifi, video Senders 2400MHz

L-Band 1500 MHz to 1600MHz

Security TV links 1400 MHz
Amatuer TV 1300MHz

Wireless stock control etc 890 MHz

TV is 470 MHz to 890MHz

RF Remote control 433 MHz

Hyperband 280MHz to 450MHz (cable etc)

Band III is 175MHz to 280MHz

Marine 156MHz
Amatuer 145MHz
Airports 136MHz

Radio 87.5 to 108 MHz

Mobile 60 to 80 MHz

Short Wave 1.8MHz to 28MHz

MW 0.500MHz to 1.6MHz

LW 0.180 to 0.3 MHz

LF 138 KHz = 0.138MHz

VLF Rugby atomic clock radio signal 60 KHz = 0.06MHz

Mossy Monk

i finished off the aerial tonight and i am picking up a lot of stations with RDS. i am surprised by the quality of the BBC radio reception. Radio 2 for example is coming in on 3 different frequencies with 88.1 being the best (perfect as it happens). it is probably the weather that's doing all of this but Alex Lester never sounded so good:)

watty

Yes the Mullaganish (co. Cork) Amatuer Radio repeater picking up Devon, Cornwall and Anglesea at Weekend. Also folks in Waterford getting Cornwall/ St Ives. (I can link to Mullaganish repeater fine).


One poor Deven soul new to Amatuer radio couldn't understand why his "Newport / Gwent" repeater had all these Irish accents and call signs. We explained that under "lift" condtions sometimes at 20 to 30 mile distant station will fade and you receive a different further station (100 to 1000 miles) on the same channel instead.

I wasn't getting anymuch north or east from here nr Limerick City, but I was able to talk direct to Waterford out on the headland to west on coast with about 10W each way.

Athlone stations and me with them occasionally perfect but with sharp fades to noise lasting a second or two every minute or so. (Quite a long overland path for only 10W on VHF).

watty

Originally posted by Mossy Monk
i finished off the aerial tonight and i am picking up a lot of stations with RDS. i am surprised by the quality of the BBC radio reception. Radio 2 for example is coming in on 3 different frequencies with 88.1 being the best (perfect as it happens). it is probably the weather that's doing all of this but Alex Lester never sounded so good:)

Yes many places in Ireland a "Good" chimney mounted VHF aerial will give you more stations and better quality than some DAB users have in UK.

I used to listen to Manx Radio on VHF/FM and Galway pirate stations in 1970s with good quality in Co. Antrim 25 miles noth Belfast with home made attic aerial made out piece of coax hanging from roof and four radial pieces on the rafters.

Richard

Originally posted by Mossy Monk
i finished off the aerial tonight and i am picking up a lot of stations with RDS. i am surprised by the quality of the BBC radio reception. Radio 2 for example is coming in on 3 different frequencies with 88.1 being the best (perfect as it happens). it is probably the weather that's doing all of this but Alex Lester never sounded so good:)

The weather may have had something to with it - I was on a beach in east Wexford yesterday and was able to pick up 8 mobile networks on my phone (Voda UK/IRL, O2 UK/IRL, Meteor, T-Mobile, Orange and Manx Telecom). I wasn't able to select any of the UK/IOM networks since I believe that if you are too far from the transmitter, it doesn't work - i.e. if the radio signal takes too long to go between the mobile and the base station.

Richard

Originally posted by watty

I wasn't getting anymuch north or east from here nr Limerick City,

I believe the weather wasn't so good that direction!

Mike 1972

Id say the main reason for few people in Ireland having outdoor FM aerials is widespread public ignorance.

When you buy something like a midi system in a shop even though it has an aerial input nobody tells you that you should use an outdoor aerial (OK the instruction book may or may not mention it but few people read instruction manuals as theyre usually written in gobbdelygook)

Most people just assume the pice of wire (Or even the AM loop) that comes with the set is the aerial they should be using.

RTE's refusal to publish technical information on their website only adds to this (The Beeb's website on the other hand has a load of useful info although some of the stuff relating to polorisation is not applicable to Ireland) In most electrical shops dont even stock FM aerials and requests for one attract blank looks (or occasionally they try and sell you one of those useless circular halo ones)

Mike 1972

Id say the main reason for few people in Ireland having outdoor FM aerials is widespread public ignorance.

When you buy something like a midi system in a shop even though it has an aerial input nobody tells you that you should use an outdoor aerial (OK the instruction book may or may not mention it but few people read instruction manuals as theyre usually written in gobbdelygook)

Most people just assume the pice of wire (Or even the AM loop) that comes with the set is the aerial they should be using.

RTE's refusal to publish technical information on their website only adds to this (The Beeb's website on the other hand has a load of useful info although some of the stuff relating to polorisation is not applicable to Ireland) In most electrical shops dont even stock FM aerials and requests for one attract blank looks (or occasionally they try and sell you one of those useless circular halo ones)

lawhec

i am surprised by the quality of the BBC radio reception. Radio 2 for example is coming in on 3 different frequencies with 88.1 being the best (perfect as it happens).

This suggests that you were either picking up the Sandale TX in Cumbria, or the North Hessay Tor TX in Devon (probalby more likely looking at the reports above). What is it like now?

I was on a beach in east Wexford yesterday and was able to pick up 8 mobile networks on my phone (Voda UK/IRL, O2 UK/IRL, Meteor, T-Mobile, Orange and Manx Telecom). I wasn't able to select any of the UK/IOM networks since I believe that if you are too far from the transmitter, it doesn't work - i.e. if the radio signal takes too long to go between the mobile and the base station.

Hold on. You got a signal for Meteor?:eek:

In all seriousnes, you're right - you can't properly "use" a base station which is more than 35km approx from where you are as it cannot "handshake" fast enough.

Mossy Monk

Originally posted by Northern Correspondent
This suggests that you were either picking up the Sandale TX in Cumbria, or the North Hessay Tor TX in Devon (probalby more likely looking at the reports above). What is it like now?

it is not as good as it was but Radio 2 is mono with a bit of noise. it is listenable though so i will be definatly going for a proper FM aerial with booster

Mike 1972

http://www.radiowaves.fm/Articles/OutdoorAerials.shtml
(article on outdoor FM aerials)

Watty they DO plan to use L Band for DAB once Band 3 is full. but as you rightly point out its going to take a lot of transmitters (probably cosited with mobile phone transmitters) to achieve decent coverage

rlogue

252 kHz has been active over the last 24 hours with Radio 1.

Here in NW London, the signal is noticeably worse at night, and although reception with my kitchen radio is quite OK, the car radio reception is not great.

Mossy Monk

i must tell my sister who will be pleased by this news

byte

Ah glad to hear 252LW is back in action, just a pity it's Radio 1! Wonder if it's mildly pointless nowadays, especially as a big amount of audio systems only have MW and FM.

I'm probably one of the very few that listened to Teamtalk 252 for the short while it was using that frequency! :rolleyes:

Richard

Originally posted by Northern Correspondent

Hold on. You got a signal for Meteor?:eek:

My girlfriend actually got a Meteor sim recently and the quality is as good as Vodafone anywhere she's used it. For the tarrif she's on it costs 30c/min in the evening to UK mobiles and GB landlines*, which is rather good. Also, if you top up by €20 or more a month, you get a €10 bonus (for the first 10 months only).


*I presume NI landlines called using the '048' prefix are charged at the same rate as ROI landlines, though their literature suggests otherwise.

watty

Well I have Car Radio and Alarm Clock and Russian all band portable and Lidl clock/radio all with LW.

Admittedly the cheapest stuff does not have it. But the point is this is supposed to be a service for Irish follks in UK. Possibly France & Spain too at night. I'll ask a Gibralterian if he gets it, but he has Sky anyway.

lawhec

Originally posted by Richard
My girlfriend actually got a Meteor sim recently and the quality is as good as Vodafone anywhere she's used it. For the tarrif she's on it costs 30c/min in the evening to UK mobiles and GB landlines*, which is rather good. Also, if you top up by €20 or more a month, you get a €10 bonus (for the first 10 months only).


*I presume NI landlines called using the '048' prefix are charged at the same rate as ROI landlines, though their literature suggests otherwise.

To be honest Richard, my tounge was in cheek when I wrote that. I have a meteor SIM card myself, but it's coverage is terrible - there is no reception anywhere in Donegal or in most parts of Monaghan (where I'd porobably use it most often) - though it's fine in Dublin. I have the SIM card mainly for ringing back home, as mentioned above, the 30c rate is rather good. And yes, if you call a NI landline using the 048 prefix it will be charged at the same rate as a landline call in the Republic, as I've successfully done this.

Richard

Originally posted by Northern Correspondent
To be honest Richard, my tounge was in cheek when I wrote that.

I guessed that! For ringing ROI, you may also be interested to know about Kernow Telecom's weekday 07764 27 26 25 service.

It lets you ring LANDLINES in various countries around the world for the price of a call to an Orange mobile. So if you have an Orange mobile yourself, you can ring any landline "down south" as part of your free minutes during the week.

There is more info here:

http://www.kernow-telecom.co.uk/

http://pages.123-reg.co.uk/sjough-43803//kernowtelecom/id4.html

and no, I'm not involved with them, apart from using their service quite a lot!

marclt

Totally off topic I know... but I was on the hill above Fishguard yesterday and the only Irish mobile provider I got was Meteor - strangely enough the only mobile provider my phone could find was Meteor... couldn't get on the network though