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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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20th Oct 2018, 6:52 pm | #1 |
Nonode
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 2,052
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Band II: tropospheric lift
Quite a few distant stations coming in today, consistent with the settled high-pressure area. Here in my workshop (North Worcestershire), I'm enjoying listening to SAM-FM in almost noise-free stereo (South Coast service on 106.00 MHz - Chillerton Down, 4kW e.r.p.) plus several French-speaking stations. As the evening progresses, there may be enough signal level to trigger RDS information on some of the continental ones
Nice to be able to resume a previous hobby! Guy
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20th Oct 2018, 7:40 pm | #2 |
Nonode
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 2,052
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Re: Band II: tropospheric lift
France Culture, 91.50 MHz.
These signal levels - and the rapidity with which they have increased in the last hour - are indicative of a temperature inversion layer forming, leading to a ducting effect. Usually I can (just) hear Wrotham Radio 3 on this frequency.
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20th Oct 2018, 8:39 pm | #3 |
Nonode
Join Date: Jul 2010
Location: Folkestone, Kent, UK.
Posts: 2,172
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Re: Band II: tropospheric lift
Hi Guy,
your gain is our loss! France being just across the way from here, the viewable 'fine weather' TV channels have disappeared! Coincidently, so has the MUX with Quest and Horror |
20th Oct 2018, 9:59 pm | #4 |
Nonode
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 2,052
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Re: Band II: tropospheric lift
Blimey. That's quite something ...
Last time I saw evidence of significant tropo at UHF was at Holme Moss in the early '80s; one dayshift we were getting perfectly decoded teletext from a West German station - mind you, we did have a pretty good receiving antenna on a fairly decent mast and no local obstructions to the signal path As I write (21:50) most of the high strength French FM stations have faded. It'll be interesting to see if there is anything around tomorrow morning. Cheers Guy (edit: re. post #2, that frequency is not Wrotham Radio 3 which lives at 91.3 ... memory error )
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"What a depressingly stupid machine." [Marvin: HHGTTG] Last edited by Nymrod121; 20th Oct 2018 at 10:09 pm. Reason: edit re WRT |
20th Oct 2018, 10:49 pm | #5 |
Hexode
Join Date: Jul 2009
Location: Wokingham, Berkshire, UK.
Posts: 437
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Re: Band II: tropospheric lift
About this time of year "Sporadic E" raises its head.
60ish years ago I was living in W London in a block of flats and my FM aerial was a dipole hanging out the window. A very English voice was saying the weather over the Harz mountains was going to be fine tomorrow. Next day I realised it was BFBS Koln. That one transmission got me going on FM DXing. Still do it when I get the chance. This evening was good - lots of French stations. Have a Fuba 8 element yagi on a rotator about 10 metres up, and just above that a halo as a sort of general search aerial, both fed into a Magnum Dynalab MD100. John Last edited by John Caswell; 20th Oct 2018 at 10:49 pm. Reason: typo |
21st Oct 2018, 8:47 am | #6 |
Nonode
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 2,052
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Re: Band II: tropospheric lift
Yes, the Fuba "UKA Stereo 8" has always been my favourite
I finally got "Sam FM" on the (Woolworths!) FM/DAB receiver display last thing yesterday - and it locked/displayed immediately this morning, which is a 'first' for me... Cheers Guy |
23rd Oct 2018, 1:39 am | #7 |
Dekatron
Join Date: May 2006
Location: Invercargill, New Zealand
Posts: 3,458
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Re: Band II: tropospheric lift
About nine years ago in the 08 Outlander I had for work, several Canberra FM stations were coming in loud and clear for a few hours, around town and on the way home - not bad for a little stubby aerial on the vehicle roof, and stations 2000 km away!
Haven't really struck it that good since then, and my band II yagi (homebrew, cutting down the old band I & III TV aerial when they turned off analogue) is pointing the wrong way - pretty much due north towards Mid Dome. |
23rd Oct 2018, 10:09 am | #8 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,967
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Re: Band II: tropospheric lift
It's not unusual to receive French and Spanish FM stations when there's a big high pressure system to the south, but 2k km reception would be a very rare event.
https://www.metoffice.gov.uk/public/...ime=1540209600 |
23rd Oct 2018, 11:02 am | #9 |
Dekatron
Join Date: Jul 2008
Location: Charmouth, Dorset, UK.
Posts: 3,601
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Re: Band II: tropospheric lift
The 2m amateur band is full of French stations this morning, never heard so many.
Peter |
23rd Oct 2018, 1:00 pm | #10 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,577
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Re: Band II: tropospheric lift
According to the Hepburn tropo forecast that tropo event down in the south west / over the Bay of Biscay is due to get even stronger before it finally starts to wane on Thursday 25th October (2018, for anyone reading this next year). I wish we could get a really stonking good tropo lift up here over the North Sea for once but they seem few and far between nowadays.
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23rd Oct 2018, 6:07 pm | #11 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,108
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Re: Band II: tropospheric lift
The atmospherics closer to ground level here, were very unusual on Saturday 20th. Normally i can hear traffic noise from the main road regardless of wind direction, but on the afternoon of the 20th there was total hush despite a favourable breeze, it was like being in one of those little villages in the cotswolds. I can only assume that thermal layers had formed and damped everything.
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23rd Oct 2018, 6:49 pm | #12 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
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Re: Band II: tropospheric lift
My normal way of detecting a tropo lift is when Classic-FM starts going a bit 'fizzy' - then I start tuning around to see what I can hear!
I don't have ant 2M "DX-type" antennas here [living in a RF-hollow I can't even hear any repeaters on my mobile installation so never bothered putting up a permament 2M antenna]. Perhaps I should head for somewhere high with my little 2-ele ZL-Special portable antenna and the FT897D to see what is up? |
23rd Oct 2018, 7:53 pm | #13 |
Octode
Join Date: Feb 2018
Location: Southampton, Hampshire, UK.
Posts: 1,063
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Re: Band II: tropospheric lift
This evening Spirit Radio on 549 kHz from ROI is coming in quite clear in the Southampton area. This frequency is normally occupied by Algeria.
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23rd Oct 2018, 9:01 pm | #14 | |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,577
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Re: Band II: tropospheric lift
Quote:
Just to get an idea of the situation over the south west at the moment, have a look at the north west europe tropo map here:- http://www.dxinfocentre.com/tropo_nwe.html When you land on the page it is showing the tropo situation as I write this, 23/10/2018. That enormous blob of yellow and red over the south west is not normally there. It's a fairly high end event. You can advance the forecast about 6 hours at a time by single left clicking on the map itself. It's a very useful resource. |
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23rd Oct 2018, 9:30 pm | #15 |
Octode
Join Date: Feb 2018
Location: Southampton, Hampshire, UK.
Posts: 1,063
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Re: Band II: tropospheric lift
Great website, thank you. I must listen out for those elusive FM stations. Many years ago I once experienced meteor scatter DX on FM and a couple of years ago suddenly heard French FM stations one summer morning. Some had RDS too.
I think the improved MW reception at present is because of the solar minimum and winter combined together. |
23rd Oct 2018, 9:48 pm | #16 | |
Nonode
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 2,052
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Re: Band II: tropospheric lift
Quote:
During the mid-'60s - early '70s, Austin H. Uden wrote regularly in HFN/RR ('FM Diary') about enhanced VHF/FM propagation (hence my recent request in the 'FS/W' section for back-issues). Guy
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24th Oct 2018, 1:44 pm | #17 |
Dekatron
Join Date: Jul 2008
Location: Charmouth, Dorset, UK.
Posts: 3,601
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Re: Band II: tropospheric lift
We had a PMR for many years, until mobile phones became affordable, we had a Westminster base station in the hall which was permanently on and virtually noise free with the squelch open as it had an independent IF gain control, don't know why they didn't all do it. Anyway as soon as conditions at around 80 - 90 mhz came up we got eastern European radio stations coming in. Very good early warning system.
Peter |
25th Oct 2018, 9:49 am | #18 |
Nonode
Join Date: Jan 2004
Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area.
Posts: 2,967
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Re: Band II: tropospheric lift
Very good conditions last night. Whist driving home from work our Radio 2 signal on 89.90 was getting knocked about by a strong French signal also on 89.90 from the French Rennes transmitter. The car radios RDS settled on Rowridge 88.50 instead. I was also picking up very clearly all the other Rowridge signals plus Wave and Sam FM from Chillerton Down.
This morning conditions seem to favour a more south to south westerly direction with French signals heard from Brest, and Cherbourg with the BBC Nationals, plus Classic FM, romping in from North Hessary Tor.
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25th Oct 2018, 12:04 pm | #19 |
Nonode
Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 2,052
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Re: Band II: tropospheric lift
Good stuff
I spent a couple of hours in the wprkshop last night and had wall-to-wall noise-free stereo programme from 'France Bleu Armorique' on 103.1 MHz (Rennes). The RDS service identifier locked straight away as the signal level was very good - pic herewith. AtB Guy |
25th Oct 2018, 1:01 pm | #20 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,577
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Re: Band II: tropospheric lift
Was this also affecting 4 metres / 70Mhz, did anyone notice? I'm never sure if Tropo effects extend down that far.
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