Bernard Lovell Actually!

[flyingtech55]

Originally Posted by Bazz4CQJ

I have become increasingly uncertain about the accuracy and reliability of TV science programmes, even on the Beeb.

I'd have said particularly the BBC. Basically, if it doesn't appeal directly to the 'disadvantaged' and can't be physically measured in terms of 'double decker buses' or 'football pitches' then the BBC aren't interested. If your intellect exceeds that of an amoeba or similar single celled organism then you are obviously 'privileged' and not part of the BBC's target audience.

Just my opinion...

Tim

[paulsherwin]

Last warning people: on topic or the thread is closed.

[flyingtech55]

Sorry....

[ms660]

Luv the Radar CRT bopper in the opening shots....Anyone recognise the 'scope/display unit along side it?

EDIT: Got it, Marconi TF1104, TV Sweep Generator (mag page 41):

http://www.americanradiohistory.com/...ni-1961-06.pdf

Lawrence.

[dave walsh]

I presume you thought that was appropriate and in period then Lawrence?
While I'm here, perhaps I should say [for accuracy] that the first few words of my original post should have read ONLY 10%...which gives the emphasis I'd intended!

I'm just about to watch tonight's Strange Signals but any comments on that will be in a new thread to comply with the rules.

[ms660]

Originally Posted by dave walsh

I presume you thought that was appropriate and in period then Lawrence?

Not really.

Lawrence.

[LeakyGrid]

It always amazed me that such a huge structure could be mounted and steered so precisely. It is on an alt-azimuth mount of course, not an equatorial, which means that the two axes have to be driven at a constantly varying rate to track a given point in the sky. Once a reference point had been established, its position was worked out by integrating the motor speeds against time.

The drive speeds for tracking, or for moving to another point, were worked out by analogue computers using servos for the trig functions (I'm a bit vague about this now). It makes me wonder whether anyone is interested in analogue computing these days.

I was working at Ferranti's sometime in the 1960s when they were given the job of converting the system from analogue to digital, presumably because of their experience with process control computers (the Argos range). A special console was designed to enable the astronomers to specify their observing programs much as they did before, but to produce digital programs.

Roger

[Radio Wrangler]

And the original servoamplifiers were 'Ward-Leonard sets'

I suppose they had magslips as indicators and repeaters? The resoluton could be quite high if they were mounted on drive pinions rather than on the main thing itself... and backlash was attended to.

David

[Hartley118]

It's well-known that when Bernard Lovell began his work at Jodrell Bank in 1945, he used ex-military radar equipment. I can relate to that - just like for so many of us, WW2 gear was the catalyst for his technical progress. I guess that was even before the advent of Lisle St and Tottenham Court Road!

What I've never managed to find is any information on the actual ex-WD kit that was used at Jodrell. For example, did it include those 45Mc/s IF strips full of VR65s and VR91s that some of us turned into TV sets? Does anyone know more?

Martin

[dave walsh]

The books I referred to show the building of the telescope with photos but I don't have them with me. Getting hold of the Gun Machinery for free was probaly the key to it being built at all. He certainly had a full complement of [redundant] portable War Time Radar Tracking gear [mounted on vehicles or trailers] for the Meteor Research, so a lot of gear familiar to enthusiasts would have been involved.

This was all "planted" on Manchester University's Botanical Research acres down in Cheshire which was considered to be an ideal "quiet zone" radio wise then. When the main railway line next door was electrified [in 68 I think or maybe later] they got around any potential problems technically [easier than moving the Dish I suppose ]

I understand that in later years, JB continued to to use the good old BBC B computers for positioning the bowl long after they had fallen out of general use... on the simple basis that they still did the job very well!
My friend, who was a technician at Christie's Cancer Hospital, said the BBC machines were kept on there in a similar way for timing the administration of treatments because of their proven reliability.

Dave W
Bexhill


12-40
Having researched the books [there's a lot re Sir Bernard] I've mis-remembered a little. I have got three [maybe four] in hardback but the first "The Story of Jodrell Bank" is from 1968 [not the eighties] and describes the initial construction. The second "Out of the Zenith [a great title] covers 1957-70. I'm sure the was a third as well. I've had them in pride of place on the shelf up in Rammy for years.

[SteveCG]

Martin,

I don't think JB used the Pye IF strip - or shall we say, there seems to be precious little evidence left if they did. However Cambridge Radio-Astronomy definitely did. Many years ago I saw them in a museum display out that the Lord's Bridge Obeserving site. And I think 45 Mc/s was still used as an receiver IF frequency for later telescopes. An interesting frequency to stick with, given that Channel B1 TV was quite watchable in Cambridge!

[SteveCG]

Re: post no. 29

Martin,

In the book,

Unseen Cosmos: The Universe in Radio by Francis Graham-Smith (2013)

There is a picture of the radar at the JB site but no model name is given.

Perhaps a scan of the scientific papers published by Lovell just after the war might just give a clue?

[dave walsh]

Further to the link between Jodrell Bank and the Parkes Observatory [made by David, in post 3] Parkes opens an article in this week's Observer The New Review 28/5/17 "From A Galaxy Far, Far, Away" re 'fast radio bursts'. There's a photo as well.

Dave W

[McMurdo]

I'm jolly interested in exactly how Jodrell Bank was made to work from day 1, and can find little historical technical details on the web; particularly in the 'humdrum' aspect of its servo tracking controls. I went a couple of years ago: you can walk over the tunnel that connects the dish to the control room, and walk around the dish as it's moving. It was tracking when I was there, it moved very, very slowly for most of the time and then every few minutes sped up to a walking pace for say 5 seconds, then went back to a crawl. The main visitor centre is rather child-orientated and techno-phobic

[Brigham]

Unfortunately, a lot of 'visitor centres' are like this. Not surprising, when so many national museums are similarly arranged.