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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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8th Feb 2021, 8:57 am | #21 | |
Heptode
Join Date: Jul 2016
Location: Portland, Dorset, UK.
Posts: 874
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Re: Vintage Transmitting Valves and Halls.
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There are some more pictures inside Rampisham here, http://www.bbceng.info/Operations/tr...m-pictures.htm |
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8th Feb 2021, 9:08 am | #22 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,901
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Re: Vintage Transmitting Valves and Halls.
Second photo in that link, down the left hand edge shows a stack of racked units, each looking to have a National inc. "Velvet Vernier" dial aka HRO tuning knob.
Now the real HRO one has a right-angle gearbox behind it, driving variable capacitor sections on each side. But I picked up an oddball variant at a rally some years ago. It has an in-line reduction gearbox behind it, and the cover has "Muirhead" cast into it in large, friendly, letters. I've never seen any others like it, but I wonder if I've now seen some in the wild. David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
8th Feb 2021, 9:58 am | #23 |
Octode
Join Date: Oct 2008
Location: Littlehampton, West Sussex, UK.
Posts: 1,465
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Re: Vintage Transmitting Valves and Halls.
I remember seeing a UHF signal generator some years ago with an HRO tuning dial. I tried turning it and it felt just like an HRO but I’ve no idea what what was inside. It was a sizeable unit I recall.
Jim |
8th Feb 2021, 10:15 am | #24 | |
Dekatron
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,687
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Re: Vintage Transmitting Valves and Halls.
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Each sender's 50 Ohm Zo unbalanced output went to their respective Baluns atop the yellow 'climbing frame' visible left background there, behind the Marconi senders, and from there was routed to the outdoor switching matrix, thence to the antennas via 328 Ohm Zo trunk-feeder (boxed-in open wire feeder). I've seen fluorescent lighting within the senders work switched off, and in the crypt at Skelton B. Paul M: when the Germans were installing the AEGs they were very blase about running them up with the doors off, etc... and they wouldn't let the Marconi lads near! We did the grid-box (mod. valve switching unit) course - I did a RMP one and a SK one - with the likes of Tudor Pike and Bill Walker from Marconi, and they were excellent. They gave us a week's course on all aspects. Can't remember any other Marconi names but remember faces.
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