NEWS AND LINKS
Work continues to fill in the gaps in the material on this site - please visit regularly to stay up to date on progress. And of course, there wouldn't be a News page without YOUR news and comments - keep them coming! News items initially posted here will be incorporated into other pages later if appropriate. News more than about a year old can be found on the News Archive page, accessible from this page. Also on this page: links to sites of those who have helped, and to other sites of interest.
30 November 2018: Three more Davey receivers from Down Under
I first came across Davey's book Fun With Radio back in 1968 from the local library. My dad had bought me an Arrow crystal radio made in Japan (the one with the sliding ferrite rod coil) but it had fallen down the back stairs one night and some wires had busted off the coil. Given the choice of buying a new one or fixing the current one, I marched off to the library and brought home Davey's book!
I fixed that one up and, a year later (aged 9), built my first "home made" set. I used a cork fishing reel for the coil former and an old dual gang tuner cap scrounged from a neighbour's discarded 5-valve set. Diodes came from the back of old black-and-white TV sets, and my first earphone came from an old 400AT telephone.
It took a while to weed out the pops, clicks and 50-cycle hum, but perseverance finally paid off with pretty clear reception of all six Newcastle (New South Wales) AM stations.
I wanted to add an amplifier to it, but we couldn't get those OC series transistors where I lived, so I had to abandon that idea. The cost of them back in the late 1960s would have been too high back then, but as time and events would have it, I've been able to fulfill one of my childhood dreams some 50 years later with at least some genuine parts.
Austin has sent a picture (top left) of the set that fulfilled that dream. It is the crystal detector plus one-transistor design from Chapter 3 of Davey's Fun with Transistors, 1st edition, 1964. He writes:
I've kept to the original layout as much as possible. I managed to snag a few OC44/45 and OC71 germanium transistors around 14 years ago, and then lost track of them. But they turned up last year, so I was able to do this reproduction. Extras in the way of capacitors and diodes from the period came from a recycle shop here in Brisbane called Reverse Garbage, along with some really old valve parts and tuner caps.
This set performs reasonably well, despite its looks, as it was designed back in the post war years probably when London had very few radio transmitters, so selectivity wasn't a big issue. It employs the famous "Davey" crystal set coil wound on a ferrite rod with 65 turns and 2 taps for antenna and detector connections. Using a fresh 9 volt Alkaline battery and my old Brown's "F" series 4kΩ headphones, the likes of 4BH (882kHz) and 4BC (1116 kHz) come booming in, as does 4RPH (1296kHz).
The tuning capacitor is a 365pf model from the American Xtal Set Society (XSS) and cost around $13.00 at the time of purchase some 6 years ago. The diode is a Russian made "D18".
Austin has also sent pictures (right and bottom left) of two sets inspired by Chapter 6 of Davey's last book, Fun with Silicon Chips in Modern Radio (published 1981), in which he describes receivers using the then widely available Ferranti ZN414 chip. The chip needs ancillary components (coil, tuning capacitor etc) in order to form a complete receiver. These components and their arrangement were specified by Ferranti and, with their permission, Davey used this information as the starting point for his own experiements with the ZN414, making suggestions for construction, coils, other substitute components and layout. The ZN414 is long out of production, as also is its later "clone", the MK484 (manufacturer unknown). Austin tells me that the latest "clone of a clone" is the TA7642 (Toshiba) which has identical pinouts to the MK chip.
Austin's first receiver (right) uses the MK484 chip, and is built into a thin plywood panel with a base from an unused rat trap as a kind of "foot" which provides stability.
The other set (bottom left), built inside a plastic ABS box, contains a real ZN414 metal can chip. Austin writes:
You can imagine my surprise and joy when it arrived in the mail 5 years ago from an American friend! My ZN414 receiver can DX all the way to Emerald ABC on 1548kHz in the early hours of the morning as it has a quality ferrite rod and winding.
If I have got the right Emerald (in north Queensland), it's about 400 miles from Austin's home. My thanks to him for sending pictures of these receivers. All three now appear on the YOUR DAVEY SETS page.
|Other recent news||News up to around a year old follows. Please see News Archive page for older items, including those relating to Gilbert Davey's death in April 2011.|
30 November 2018
Another Studio ‘E’ set
on the way?
Mick Baldwin wrote to say that he remembered watching the Studio ‘E’
At the time my parents would not let me play with 90 volts so I never did make this radio!
I found your web site looking for designs for a tuning coil with reaction, saw the Studio ‘E’, and decided to construct this as I have lots of DL and DF valves to hand, as well as bases. I had no coil, so wanted to recreate it as far as possible, and set about winding a copy of the Teletron coil winding for medium wave only. The tuned winding is easy to calculate, as is the aerial coupling, but feedback is a little more tricky. But from your design for a large coil that works as a Teletron coil I was able to wind a close lookalike to the original - I will send pics of construction stages.
As for wander sockets, I decided to use 4mm sockets. Having taken them apart you are left with metal sockets to mount onto Tufnol plates cut and drilled to the correct size. They look correct though.
I have some orignal tuning caps to use in this build. Most of the hard-to-get parts have been made at home, i.e. coil, LT/HT battery sockets. The only parts I cannot make are the caps - going to try polyvaricons [polyester?] and see how this works - a sort of old modern build!
Several people have shown interest in this receiver. I find most people today have no idea how valves work or how to use them! I will keep in touch with pics.
Thanks for a wonderful web site. Mick.
Thanks for your message and your kind words, Mick. I very much look forward to seeing your pictures when you can send them – of your progress so far, or of the set when you complete it. Good luck with it!
1 July 2018
John Pugh's Studio ‘E’ One-valver
Yet another Studio ‘E’ set -
to my knowledge this brings the total to four built since the rediscovery of the BBC
leaflet. John Pugh has sent me pictures of his nicely made set. He writes:
This is my attempt at recreating a long past memory. Unfortunately, the coil is a Repanco DRR2 - I still cannot find the Teletron! Other parts came from my junk box - sorry, I mean items in stock. The Jackson caps are original, as is the valve, a DAF96.
The set is powered by an AA cell for LT, and a mains “Battery Eliminator” for HT of 64 volts. It works fine, although there is a distinct lack of MW stations now. Like your comment on your own set, reaction control is a little deficient at the LF end. Please keep up your good work on your website.
Thanks to John for sending his pictures, which now appear on the YOUR DAVEY SETS page. He may not have found the Teletron coil (keep looking!), but he has found some genuine wander sockets – very hard to find these days. I wouldn’t mind betting that quite a few Studio ‘E’ sets were built with the Repanco coil and a wavechange switch – other coils were available in 1957, including the Repanco. This coil has no aerial winding, but does have a long-wave winding. John has shorted out the long-wave winding (blue to black) with a view to an experiment later. Intriguing - I look forward to hearing about this.
9 May 2018
News from Down Under
Hello Les, It is good to see you active again with the site. As it
turns out, we just had a meeting of the Crystal Set and TRF Constructors Group at
my place recently. The Group is a sub-group of the Historical Wireless Society
of South East Queensland. http://www.hws.org.au/.
One of the sets that we played with was the Two Valve Set of mine that is featured on
your site. It aroused considerable interest, and a number of members left
with all the construction details. I was able to introduce about 10 members
to Gilbert Davey and your site. The meeting also fired up my desire to build
more Davey sets.
As an aside, have you noticed the incredible prices that are being asked for Fun with . . . books on the web? I have at least one and sometimes two different editions of each of Davey’s books. I thank my lucky stars that I bought them when prices were sensible. All the best, Dan Bedford, Brisbane, Australia.
PS: I notice that Graeme Zimmer (Zim) follows your activities and has enlightened you about the AM MW radio situation downunder. [See below.] Zim is a wiz with the ultra hi-tech computer radio wizardry!
Thanks for your message, Dan. I’m enjoying looking at the Historical Wireless Society web site – some fantastic looking sets on there! Well done for spreading the word about GWD and my site at your meeting! I look forward to hearing about any new Davey sets you or your co-members decide to build.
Yes, the prices of Davey’s books have certainly gone way up – I often wonder if my site is the cause of it??!
You obviously know of Graeme Zimmer – have the two of you met? He often gives very helpful and informative comments on the web site.
Yes, I know Graeme but only in this cyber world. We communicate and share PDFs of old radio books from time to time.
Thanks to Dan for this news - stand by for some new Davey sets from Oz!
19 April 2018
A workmanlike one-valver
In August 2017, Peter Munro from near Melbourne,
Australia, sent me pictures of his very workmanlike Davey one-valver.
This now appears on the
YOUR DAVEY SETS page. Peter wrote:
In 1979, I wanted to build a one-valve radio, but I was advised to build a one-transistor radio. About ten years ago I came across Fun With Electronics at a book sale, and built the one-valve radio a few years ago. I recently pulled it out again to replace the regeneration capacitor I had stolen. I don’t know why I used 90 volts HT.
Peter's set is based on the version published in Fun with Electronics, 2nd edition, 1972. The home-made coil has aerial, grid (medium wave) and reaction windings. I like the nice chunky brass terminals!
Peter powered the set initially using ten PP3s in a plywood box for HT, and a single 'C' cell for LT. He was a bit disappointed with the set's performance, and thought at first that it may have been because he was using a transformer to drive low-impedance headphones. Trials with a high impedance earphone were no better, with not many stations to be found on medium wave, but Peter intended to try some high-impedance headphones.
These one-valvers usually do very well with a reasonable length of aerial, and Peter's 90-volt supply should have allowed the set to be brought easily to the sensitive point of just failing to oscillate. I wondered whether the posiition in Australia was the same as in the UK, with broadcasters deserting the medium wave band. Following the May 2018 site update, my correspondent Graeme Zimmer (also in Australia) advised that there is still plenty to listen to on medium wave there.
Hi Les, Great to hear from you as always, and nice to read the updates on your site. Just a note on your comments re Peter Munro's set: Unlike Europe, the AM band is still healthy in Australia. Still hundreds of stations on every channel from 531 to 1701 Khz. Regards, Zim VK3GJZ.
Graeme attached a screenshot of the band at night from his software-defined radio, which shows a well-populated band. Also, the time of day can make a great difference on medium-wave.
I told Peter about this, and he has now tried his high-impedance headphones. Results were much better, even with HT reduced to 45 volts, with about five stations coming in. He does, however, have trouble with breakthrough from a Chinese language station 2 kilometers from his home, radiating at 5 kilowatts.
Peter has been hunting for a one-transistor radio circuit to build (as originally advised!), and I gently suggested that simple transistor sets with crystal detector front ends are very unselective, so they can disappoint, compared with a simple one-valver with reaction. Nevertheless, I will be most interested to hear if Peter does build a Davey transistor set.
My apologies to him for the delay in putting his set on to the site. I have recently been able to draw back somewhat from the charity work that has limited my spare time, so I hope it won't be too long before the next update.
Please see News Archive page for news more than about a year old,
including items relating to Gilbert Davey's death in April 2011.
Links to those who have helped:
(Links in this and following
sections were last checked
on 30 NOVEMBER 2018.)
BBC Written Archives Centre
http://www.bbc.co.uk/archive/written.shtml has assisted with documents,
information and copyright permissions on BBC material.
British Library https://www.bl.uk/ is the gateway to the British Library's vast resources. Under "Catalogues and Collections", select "Explore the Main Catalogue". Anyone can use the Catalogues, but you have to sign up as a Reader to see books etc. The catalogues are sometimes awkward to use, but they were the key to much of the information on this site.
Kelly Books http://www.eclipse.co.uk/~lk5092/page2.html Source for two 1950s copies of Radio Times. Many other vintage backnumbers in stock.
Practical Wireless https://www.warnersgroup.co.uk Under their previous owners (PW Publishing Ltd), Practical Wireless published my tribute to Gilbert Davey, and gave me permissions and much help in making available images of his pre-war articles. The magazine is now owned by Warners Group. Their online radio bookstore at https://www.radioenthusiast.co.uk/ handles subscriptions and orders for archived issues (back to 1965) on searchable CDs.
Maurice Woodhead's extensive site http://www.vintageradio.me.uk/ covers circuits, component data, restoration etc. The details of the Teletron HAX coil pointed to the probable identity of my similar 50s-vintage one-valver coil.
UK Vintage Radio Repair and Restoration Forum https://www.vintage-radio.net Hundreds of discussion threads on all aspects of vintage radio and audio. The BBC 1-valver! thread was one important inspiration for this project.
|Other sites for radio and tv - history, restoration, resources:||
Sites marked * have kindly added links to this site - my thanks go to their Webmasters.
https://www.bvws.org.uk/ British Vintage Wireless Society - events, auctions, resources, and a beautifully produced Bulletin for members. The Society also caters for vintage television interests.
https://bvwm.org.uk/index.htm * The British Vintage Wireless and Television Museum, West Dulwich, London. Managed by the British Vintage Wireless Society (see above), the former home of Gerry Wells, obsessive collector and restorer of radios and TVs. A must-see cornucopia of vintage nostalgia.
http://www.vintage-radio.info/ Paul Stenning's archive of component and servicing data, vintage radio documents, and vintage technology books. Currently raises an internet threat warning on my PC.
http://www.earlywireless.com Lorne Clark's site, with good theory pages, and an excellent page on electrical safety.
https://archive.is/www.mds975.co.uk * Mike Smith's vast eclectic radio technology and history resource, now archived. Navigation now difficult, as linking between pages has not been preserved.
http://www.oldatheart.co.uk "Grandad" tells "Junior" about vintage technology - reel-to-reel tape recorders, radiograms, telephones with dials that you dial . . . Beautifully written.
http://www.dailymotion.com/video/x3wrzo_fabrication-d-une-lampe-triode_tech   A charming French video showing the step-by-step manufacture of a triode valve in a "cottage-industry" way that makes you feel you could do it too!
http://www.pasttimesradio.co.uk/ Richard Booth's repair service for vintage radios and amplifiers, "Junk Shop" for new and salvaged spares, and a growing resource of tuning dial images.
http://www.vintageradioworld.co.uk/index.htm * Site belonging to Tony Thompson, author of Vintage Radios. An ample resource for anyone interested in any aspect of vintage radio.
http://www.tvstudiohistory.co.uk Martin Kempton’s excellent site with a wealth of information on current and past TV studios.
http://www.whirligig-tv.co.uk * Terry Guntrip's cornucopia of vintage tv entertainment, programmes and milestones, with many movies and audio clips. Hours of fun!
http://www.turnipnet.com/whirligig/radio/index.htm Visit Terry's companion site for vintage radio entertainment memories, facts and clips.
https://www.youtube.com/watch?v=g99kFlgtlrM Interview with Vera McKechnie recalling her early career including her time on the Studio ‘E’ programme.
https://www.youtube.com/user/britishpathe/featured British Pathe's youtube archive of films on numerous topics - but search "wireless" for radio topics, or "cycle radio" for two cycle radios!
http://www.americanradiohistory.com/index.htm A great resource for British radio enthusiasts as well as for Americans. Scans of issues of several British radio publications including Amateur Wireless, Modern Wireless, Popular Wireless, Practical Wireless, Radio Constructor and Wireless World. This page https://www.americanradiohistory.com/Archive-Bookshelf/Bookshelf_Hobbyist.htm leads to scans of books by several well-known British authors, including some of Davey's books, listed under "Gilbert Davy" (sic), and also to a scan of the BBC's own copy of the Focus transistor set leaflet (incomplete - the entire leaflet is available on this site with the permission of the BBC and other rights-holders). Much of the material on the American Radio History site must still be in copyright (the BBC leaflet certainly is). If the site owner (David) has obtained reproduction permission for those of his claimed five million pages still in copyright, this represents a considerable achievement.
http://www.jumpjet.info/Pioneering-Wireless/index.htm Early British, Australian and American radio publications. Some overlap with the American Radio History site (above).
See also CONSTRUCTION RESOURCES page for links to component suppliers and other sources of useful information.
Sites relating to the
Boy's Own Paper:
Informative pages on Boy's Own Paper and Boy's Own Annual.
http://www.philsp.com/index.html Phil Stevensen-Payne's "Galactic Central" site with extensive indexes of children's books, comics and magazines.
http://www.philsp.com/homeville/BJSP/0start.htm#TOC Steve Holland's site, British Juvenile Story Papers and Pocket Libraries index, operates as a satellite of "Galactic Central", and lists the contents of many editions of Boy's Own Paper.
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