The BBC 1-Valver - 2
 

Hi all,
This is my first post, so please forgive if I commit any gaffes . . .

Inspired partly by the previous thread on this topic (Jan 2005 - May 2008, now closed),

https://www.vintage-radio.net/forum/...ead.php?t=1595

I decided to see if I could locate one of those long-lost leaflets. I first made enquiries at the obvious places - British Library, BBC Written Archive. Then in early 2010 I put up a web site that described my "conjectural" rebuild of the set using the parts from the set my father built for me and which I had saved for over 50 years.

It took 14 months for the right person to visit the site and contact me with scans of the elusive leaflet.

With his permission and that of the BBC, the leaflet is now available for download at www.thestudioeonevalveradio.org.uk

My "conjectural" rebuild was some way out, and I will rebuild it (again) soon.

Also on the site can be found:

- a sketch of Gilbert Davey, who presented the BBC series, and published many other radio designs in the "Boy's Own Paper" and in his own books. Sadly he died recently at the grand old age of 97;

- an overview of the several versions of the Beginner's One valver - the BBC set is perhaps the best-known;

- a source list of Davey designs (being expanded as info becomes available);

- details of other Davey-designed sets built in recent years.

I would be glad to hear from anyone who has anything to contribute about the BBC 1-valver (including those who contributed to the earlier thread) or about any other Davey design, either via this forum or via my web site.

Re: The BBC 1-Valver - 2
 

Well done. A interesting historical document saved.

I remember the original series, but would have been 7 years old when it was broadcast.

Re: The BBC 1-Valver - 2
 

Great site
Ironically that's Digital Radio Propaganda. Unlike TV, no-one anywhere has any Analogue switch off/Digital Radio plan. Not even in UK.

I haven't got the required valve, but I must try it with the really cheap Russian 1j18b (about 60p in quantity). It may work on 18V!

Re: The BBC 1-Valver - 2
 

I'm glad you've finally found the BBC leaflet.

I've visited your site a few times in the past and found it fascinating. Good work!

Sorry to hear of the passing of Gilbert Davey - a ripe old age though!

Re: The BBC 1-Valver - 2
 

Thanks to Graham for adding the link to the previous thread - a black art that I'll no doubt master eventually!

Re the "planned" analogue radio switch-off, when I first put up the site, the switch-off issue was getting a good deal of publicity.

As visitors to my site will gather, the biggest problem for anyone building the BBC set from scratch is the Teletron D/R coil. So if anyone has a secret stash of them . . .

Re: The BBC 1-Valver - 2
 

maybe some easy to wind functional equivalent is possible?

I'll try the coil and ferrite bar out of a €5 radio and see what modification is needed. Maybe two of them on one bar. If so, that can be wound, though no idea where to buy Litz wire. Solid enamel wire isn't as good, though I have wound RF PA transformers by twisting 10 strands of enamel wire and then winding with that.

Re: AM/FM Radio switch off: Yes the publicity was misleading. Maybe that was someone's ploy to get people excited so that it would be harder to "really" set a date. The back-peddling has been extensive, even during last Government.

Re: The BBC 1-Valver - 2
 

http://www.wires.co.uk/acatalog/litzwire.html

But its not cheap.

John

Re: The BBC 1-Valver - 2
 

500grams is a lifetime supply though :) £43 + vat

700Grams 30 Strands of 0.04mm Silk Covered Stranded Copper Litz Wire £69 + vat

You'd need a lot of friends wanting to wind coils. Certainly maybe 100 LW coils possible!

Re: The BBC 1-Valver - 2
 

Is Litz wire really necessary for the coil in this circuit ?
I'd have thought that the regeneration would compensate for the lower Q if the coil was wound with ordinary enamelled copper wire.
I like "neon indicator's" idea of modifying/adding a coil on a small ferrite rod aerial - good luck with your experiments !

By the way Les, I am very impressed with your web-site, it has a suitably vintage look to it. (I hope that was the intention :))

Regards,
Andy

Re: The BBC 1-Valver - 2
 

I've never seen details of the Teletron coil on the internet, but I don't think my example uses Litz wire. For myself, I think the choice for a substitute - to remain in the spirit of the original design - lies between a) the Repanco DRR2 and b) a homebrew toilet-roll technology coil such as I describe on my site (see first post on this thread).

a) The Repanco coil (whch might be as scarce as the Teletron, but was in manufacture later) has no aerial winding as the Teletron does, but has a tapped medium wave winding, a long-wave winding, and a reaction winding. Davey specified this coil for later versions of the design when the Teletron went out of production.

b) The homebrew coil using ordinary enamelled wire on a 2" former is based on a Davey design, and gave me similar results to the Teletron coil. Its size make it necessary to offset the valve from its dead-centre position as shown in the BBC design.

By the way, I'm keeping my eye on another thread -
https://www.vintage-radio.net/forum/...light=BBC+coil
where the same topic is in danger of being discussed in duplicate. Moderators - help!

Re: The BBC 1-Valver - 2
 

I think I repaired one of these for a friend back in the early 1980's. Somenody had stuck in a DL96 instead of a DK96. Once the correct valve was fitted I powered the heaters up via my psu and cannot remember how I obtained the HT supply. I fed the output to the gram input of my HMV1124 and was amazed at the results. It was amazingly sensitive and selective on the shortwave bands. I was reluctant to hand it back and would love to own one.

Re: The BBC 1-Valver - 2
 

Thanks Andy for your kind comment. It was certainly the intention to give the site a 1950s feel.

Les.

Re: The BBC 1-Valver - 2
 

The site has just had a major update. During the long pause since my last update in October, the site has been re-cast to allow for a wider treatment to Gilbert Davey's work. Much new material has been added - and there's more to come - but most of the material familiar to past visitors is still there.

To reflect this change of emphasis, the site is now hosted at a new web address: http://www.daveysradios.org.uk The old address ( http://www.thestudioeonevalveradio.org.uk ) still works but, if you use it, please make sure to refresh the homepage.

New material includes:-

The Focus Transistor Set - New page
With the kind permission of the BBC, the leaflet that accompanied Gilbert Davey's second BBC-tv series (March-April 1959) is available for dowload for personal use. Images were kindly supplied by the BBC's Written Archive Centre.

A message from Gilbert Davey's daughter
I was delighted to hear from Claire Davey (see NEWS AND LINKS page), who sent me photos and memories of her father, and put me on the track of an interesting newspaper article. This has allowed me to expand the GILBERT DAVEY page.

Expanded Source Pages
The previous "Davey Source List" page has now been expanded into four separate pages plus an introductory page (see DAVEY SOURCE PAGES). Three of these are substantially complete, with brief practical details of all projects published. A fourth page is present in outline form with some expanded detail, but already contains details of all projects in all three editions of "Fun with Short Waves / Short Wave Radio". So if you're searching for a Davey project you once built, it's already well worth scouring these new pages!

A "pukka" Studio E set
A correspondent has built a Studio 'E' one-valver according to the BBC leaflet. Pictures on the YOUR DAVEY SETS page.

I hope you enjoy the updated site.

Les.