Coaxial aerial feeder question - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Panrock · 29th Sep 2018, 8:42 pm

Here's the coax and aerial plug from a 1937 Marconiphone television, working at the outlandishly high frequency of 45 MHz. I'd love to learn more about this connector, by the way.

Steve

emeritus · 29th Sep 2018, 11:39 pm

Concentric plugs of essentially the same configuration (but presumably bigger) for use with conventional flex were available in the Edwardian era as alternatives to the more common range of 2-pin plugs where a polarized connector was required: the attached scan is from the GEC catalogue for 1910-11. A plug of essentially the same configuration is used on the charger of my wife's electric bike.

Refugee · 30th Sep 2018, 1:30 am

Coaxial connectors are also used in the bases of jug kettles.

dtvmcdonald · 30th Sep 2018, 2:53 am

Quote:

Originally Posted by G6Tanuki

I'd bet on some of the first-generation AI/Gunlaying gear from the late-1930s.

From memory, coax was really not a big thing in the first-generation pre-WWII TV sets, which seemed to use flat- or twisted-twin cable for preference.

I have a Marconi 702. I believe it used coax. Mine has the original coax
inside, but had a non-functional unoriginal coax connecter installed
on the back. I replaced it with a modern US standard one.

Most interesting tidbit: the coax insulation was gutta-percha!

G4YVM David · 30th Sep 2018, 6:48 am

That Edwardian advert is most fascinating because it gives the weights in kilos. I wonder why it does that (esp as no dimensions are given in mm)?
David

Skywave · 30th Sep 2018, 11:50 am

Quote:

Originally Posted by stevehertz

I have a theory that everything vibrates, and in doing so takes the path of least resistance.

Everything has a natural frequency. If an item is subjected to an external stimulus at that frequency - voila! resonance! The Tacoma Narrows bridge disaster springs to mind.

Al.

Skywave · 30th Sep 2018, 5:58 pm

Re: post 25.
Might be so that a buyer could calculate postage costs.

Al.

emeritus · 1st Oct 2018, 2:37 pm

I assume that metric dimensions were provided with export in mind. I only have two of the four volumes of that catalogue, and both UK and Metric dimensions are quoted for pretty well every product. The parts I have do not include anything about general conditions such as shipping for export. I seem to recall reading that the Indian railways used the metric, not imperial, units for calculating freight shipping charges from an early date, given the existence of so many local weights and measures.

I note that it does list "American Edison Screw lampholders", with the caption "These lampholders are specially adapted for use in Canada, the South American states, and other Countries where the Edison screw thread is universal", so export to countries using the metric system was clearly contemplated. (The American version was externally different from the UK version, lacking the UK's ceramic skirt, and seems to have been provided with clamping grub screws to prevent accidental dismantling).

G4YVM David · 1st Oct 2018, 2:55 pm

Aye well thats my query...only metric weight was given, not dimensions.

Anyway, it was a long time ago...

29th Sep 2018, 8:42 pm	#21
Panrock Nonode Join Date: Feb 2005 Location: Worcestershire, UK. Posts: 2,535	Re: Coaxial aerial feeder question Here's the coax and aerial plug from a 1937 Marconiphone television, working at the outlandishly high frequency of 45 MHz. I'd love to learn more about this connector, by the way. Steve Attached Thumbnails

29th Sep 2018, 11:39 pm	#22
emeritus Dekatron Join Date: Jan 2012 Location: Brentwood, Essex, UK. Posts: 5,349	Re: Coaxial aerial feeder question Concentric plugs of essentially the same configuration (but presumably bigger) for use with conventional flex were available in the Edwardian era as alternatives to the more common range of 2-pin plugs where a polarized connector was required: the attached scan is from the GEC catalogue for 1910-11. A plug of essentially the same configuration is used on the charger of my wife's electric bike. Attached Thumbnails Last edited by emeritus; 29th Sep 2018 at 11:48 pm.

30th Sep 2018, 1:30 am	#23
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,554	Re: Coaxial aerial feeder question Coaxial connectors are also used in the bases of jug kettles.

30th Sep 2018, 6:48 am	#25
G4YVM David Heptode Join Date: May 2014 Location: Salisbury, Wiltshire, UK. Posts: 998	Re: Coaxial aerial feeder question That Edwardian advert is most fascinating because it gives the weights in kilos. I wonder why it does that (esp as no dimensions are given in mm)? David

30th Sep 2018, 5:58 pm	#27
Skywave Rest in Peace Join Date: Jun 2006 Location: Chard, South Somerset, UK. Posts: 7,457	Re: Coaxial aerial feeder question Re: post 25. Might be so that a buyer could calculate postage costs. Al.

1st Oct 2018, 2:37 pm	#28
emeritus Dekatron Join Date: Jan 2012 Location: Brentwood, Essex, UK. Posts: 5,349	Re: Coaxial aerial feeder question I assume that metric dimensions were provided with export in mind. I only have two of the four volumes of that catalogue, and both UK and Metric dimensions are quoted for pretty well every product. The parts I have do not include anything about general conditions such as shipping for export. I seem to recall reading that the Indian railways used the metric, not imperial, units for calculating freight shipping charges from an early date, given the existence of so many local weights and measures. I note that it does list "American Edison Screw lampholders", with the caption "These lampholders are specially adapted for use in Canada, the South American states, and other Countries where the Edison screw thread is universal", so export to countries using the metric system was clearly contemplated. (The American version was externally different from the UK version, lacking the UK's ceramic skirt, and seems to have been provided with clamping grub screws to prevent accidental dismantling).

1st Oct 2018, 2:55 pm	#29
G4YVM David Heptode Join Date: May 2014 Location: Salisbury, Wiltshire, UK. Posts: 998	Re: Coaxial aerial feeder question Aye well thats my query...only metric weight was given, not dimensions. Anyway, it was a long time ago...