Wireless World 1969

[Steve Anderson]

Gents,

For years I have been trying to get a copy of an item published in the UK magazine 'Wireless World'. It was in 1969 regarding the re-vamping of an oscilloscope, somewhere around the middle of the year I think. It was based on a 5CP1 tube.

If anyone has this I would love a copy in any format possible, a scan or photocopy, any means at your disposal. I will reimburse if there are any costs involved.

Thanks in advance.

Steve A.

[Viewmaster]

Steve, cannot directly help as my large collection of WWs ends at 1945.

But if no success on this forum you might try joining this British wireless/TV/etc forum and putting a request in.......
http://www.vintage-radio.net/forum/

There is a section for service info and service data here for example......
http://www.vintage-radio.net/forum/foru ... y.php?f=23

and vintage test gear here.......
http://www.vintage-radio.net/forum/foru ... y.php?f=36

Good luck.
Albert.

[chris_vk3aml]

Steve,

Give me a few days - this is a busy week - but the RMIT University here in Melbourne has a very good collection of "Wireless World" back to about 1932, and the State Library of Victoria has it back to 1912 or thereabouts, when it was called "The Marconigraph". The RMIT set are easy of access and photostats are cheap, at around 8 cents/page. I'd be only too willing to scan these and post them if I can find the article. The State Library set goes back further, but photostats are up around 25 cents per page and their library staff are right bastards for preventing you from photostatting at the proverbial drop of a hat.

In the meantime, if you're interested in running electrostatically deflected CRT's in television service I can recommend a few books in my own collection, and if you can locate copies on e-bay or elsewhere, I really suggest that they're worth obtaining in spite of their age:

(1) "Time Bases" by O S Puckle (Chapman and Hall Ltd., London, 2nd Edition 1952). This classical text is a much-enlarged (388 pps) version of the original edition from 1943 (204 pps). The second edition, much to be preferred, includes great detail on the linearisation of time bases and the proper running of various types of CRT.

(2) "Typical Oscilloscope Circuitry" by Tektronix, Inc., Beaverton, Oregon, published by Tektronix, 1966, revised edition. Includes much information on broadbanded deflection amplifiers and final-generation thermionic (valve) oscilloscopes.

(3) As a source for the voltages etc of various electrostatic CRT's available via surplus sources, I can thoroughly recommend:
"International Radio Tube Encyclopaedia" by Bernard B Babani, London, Bernard's (Publishers) Limited, 3rd edition, 1959, about 1000 pps.
Two particularly relevant sections are the exhaustive coverage of "Cathode Ray Tubes" (pps 326-357) and "Photo Tubes" (pps 360-369). If sufficient interest is indicated I would be happy to scan and post the CRT section of the book - about 31 pages.

I'm not sure if this is the sort of thing you're after, Steve, but I'm guessing that it is.

One favorite "trick" in running CRT's with electrostatic deflection is to use push-pull drive on the deflection plates, connecting those plates directly to the anodes of the push-pull valves driving them. You then float the cathode/grid/heaters at negative EHT and have the final anode near earth potential. Alternatively, if you have a third (post-deflection) anode, you have that at positive EHT (usually about 2KV+), the deflection plates down near earth potential, and the cathode at negative EHT (usually about -2KV).

The use of push-pull deflection is greatly to be preferred to single-ended working, as it minimises astigmatism resulting from the aggregate shift of the sum DC potential of the plates in relation to the electron gun.

The modulating potential is then applied to the cathode and grid of the CRT through two large-ish high voltage isolating caps. Alternatively, an opto-coupler can be used to couple video information to the CRT grid.

Hoping that this isn't superfluous information,

Chris Long VK3AML.

[Steve Anderson]

Albert, Chris,

Thanks for both your responses. Chris, I can just recall the library at RMIT it was 1975 the last time I was there! I was at RMIT from 1972 to 1975. If and when you have the time and happen to be there please see if you can find that article.

The reason that I'm keen to find a copy (in any format) is that it's the article that got me interested in CRTs at the age of 13. I read it, and re-read it time and time and time again. Within weeks this interest was further bolstered when my father took me to his factory one Saturday morning and one of the technicians demonstrated a scope to me.

I am somewhat of a tube-head but for some unknown reason CRTs just 'do it' for me. (No smart remarks guys).

Thanks for the suggestion regarding the differential deflection drive and that's exactly what I going to use in the display/monitor currently under construction. Much like the DG7-32 item in the thread 'HD NBTV?' Except this time it will be tubes and not semiconductors.

I was having a tidy-up recently and came across a whole batch of EF91s (6AM6/CV4014) that I forgot I had. These are described as RF pentodes, so I looked up the datasheets I had for them and one made a passing reference for use in triode mode. But the data was scant.

So I chose 10 random samples and sat down for a day and traced the triode characteristics for them. I must really automate this process, it is tedious. The end result is a very capable differential drive circuit. The results of which follow. Over 100V p/p at each anode (200 differential) and only the third harmonic present at -46bB. There was little difference at 150kHz.

The monitor is still under construction but in time will be the subject of another item for the newsletter, but I will post it here as a pdf first.

As for the other references I will follow them up. Thanks again to the both of you.

Steve A.

[Steve Anderson]

Two particularly relevant sections are the exhaustive coverage of "Cathode Ray Tubes" (pps 326-357) and "Photo Tubes" (pps 360-369). If sufficient interest is indicated I would be happy to scan and post the CRT section of the book - about 31 pages.

I'm not sure if this is the sort of thing you're after, Steve, but I'm guessing that it is.
Chris Long VK3AML.

Chris, just as a follow-up, yes I for one would be interested, but scanning 31 pages will take some time. But as and when you could I would be most grateful.

Steve A.

Chris, as a thought, just scan the first page, I at least might have it already and quite willing to post/e-mail it to others interested.

[Steve Anderson]

Gents,

You know, four years on and I'm still trying to track down the article mentioned in the opening posting.

I've just spent a couple of hours on flea-buy to no avail with the exception that I may have narrowed it down to one of these issues of Wireless World, all 1969...March, April, June or July. I'm fairly certain that it's no later than September '69.

I'm sure there is probably a copy in a British library in London, I curse myself for following it up while I was in the UK last year...and I was commuting into London for work! Idiot!

Steve A.

[Viewmaster]

Gents,

For years I have been trying to get a copy of an item published in the UK magazine 'Wireless World'. It was in 1969 regarding the re-vamping of an oscilloscope, somewhere around the middle of the year I think. It was based on a 5CP1 tube.

Steve A.

This dealer is Bookbarn International on
+44 1761 452178

If phone is expensive from your neck of the woods let me know and I'll phone 'em.
There have 1969 WWs here.......COVERING THE WHOLE YEAR !!
http://www.look4abook.com/index.php

Also.........

Steve, this chap, Geoff Moss, has an article re amplifier taken from a 1969 WW posted on his web site.
Why not contact him and ask if he will sell you/copy his WW ?
His email is on this page
http://www.tcaas.btinternet.co.uk/

This may be an out of date add, but has quite a number of 1969 WW.
Try the phone number in Newport 075072912 (add UK code)
http://www.publicads.co.uk/ads/for-sale ... ml&kID=152

Good luck, Steve, let us know if any good.

[Viewmaster]

Steve these 1969 WWs are for sale on ebay at present. You might be lucky, although not the months you mentioned. Give the sellers an email asking for contents of each or ask if they have any other months stashed away.
Ebay numbers are.......
Feb 310395915453
May 310395915458
Oct 310395915466
Dec 310395915461
Sept 310395915467
Aug 310395915465

[Steve Anderson]

Albert,

Thanks so much for your efforts. but look4abook turned out a bit expensive st 35 quid plus 10 for shipping. OK, it is four hard-bound issues but all I'm looking for is one 4-5 page item to photocopy or scan. Even a ratty old copy for a few quid is fine. Or if someone has a copy but wants to keep it they might be kind enough to copy/scan for me.

The ebay ones I found earlier this morning as well.

There must be thousands of copies stuffed in attics across the UK...

Maybe one day I'll trip across it, and thanks again.

Steve A.

[Klaas Robers]

Steve, I will have a look in the library of Philips Research in Eindhoven (the Nat.Lab.). In the mean time I have access to the library. I am almost sure they had (have still?) a subscription and those magazines were collated to books, one book a year, meters (yards) of books on long shelves. I hope they are still there, in the basement...... It might have been easier to keep them there than to throw them away.

Do you have any clue to the title? That might help me searching.

[Steve Anderson]

Klaas, thanks for the offer, but in the last few days I have received a pristine scan of said item from a chap in the UK.

It appears he has a huge collection of back-issues of WW and for the price of a couple of beers will scan almost anything for you. I did ask if I could post contact information for him here (I did point him in the direction of this forum and the NBTVA web-site), but as yet he hasn't responded.

Thanks to all that have put considerable effort into this search.

My quest is over.

Steve A.

P.S. The 'beer fund' is not compulsory by the way.

[Klaas Robers]

Then you are lucky Steve. I couldn't find Wireless World any more in the current catalogue of the Philips Nat.Lab. library. So happily you have got your scan already.