Showpiece: valves and innards on show.

Is that horizontal stick thing the pre amp? I like it, mind you the blue glowing valves look like they have gone a to air a bit!

[David G4EBT]

No - the horizontal thing is the speakers - one of the amps is a pre-amp.

The description label on the Victoria & Albert Museum display case is appended below.

As you'll note, it was produced in 1985 in the States in small numbers, and hand finished - the appearance being considered as important as its performance.

I wouldn't like to guess the price tag!

There is quite a range of distinctive radios on display at the V&A including the controversial Pye M78F, which made good use of Perspex, as Nick has in mind.

[Jim McLay]

Originally Posted by SurreyNick

Yeah, these are the sort of thing and also the valves on this beautiful looking homebrew set posted by merlinmaxwell. I have no idea what these valves are though.

Not necessarily to the point, but Merlinmaxwell's set looks absolutely beautiful.

[ionburn]

I have sometimes thought about this but apart from the odd valve sticking into the air from a case have done little.

Thinking toward my art work though - If it is not easy to get a brightly lit valve then reduce the background light level, either directly or by subtle design and colouring such that the valves become the focus of attention. Component placement can also have a large effect. Underlit valves and other such tricks, to me, imply a modern touch which defeats the object although I must admit the effects can be very good, as have been shown here.

[broadgage]

Could anything be designed around cheap and plentiful valves intended for TV use ? The ones that used a series 0.3 amp heater chain.

These have a reputation for durability and should withstand some MODEST overrunning of the heaters thereby giving a bright and almost authentic heater glow.

How many TVs withstood years of nightly use on 240 volt mains whilst set on the 220 volt mains tapping ?
How many others withstood years of use with an open circuit mains dropper that had been shunted with a lower than correct resistance, thereby significantly overrunning the heaters?

IIRC TV valves tended to fail if the circuit design pushed them close to the limit of HT volts or anode dissipation, and very seldom failed with an open circuit heater.

TV valves are not only cheap, but have the moral benefit of not depleting stocks of older radio types that should perhaps be saved for the intended use.

[Ed_Dinning]

Hi Broadgage, it should be very easy to do as there are many equivalents of "P" series valves in the "E" series. Plenty of Rf pentodes will also work at AF but not high output powers (EF80) as well as plenty of triode pentodes and double diodes.
Not too many triode hexode etc mixers but they can be replaced with separate mixers and oscillators.
TRF's would be the simplest sets to build; have a look at old copies of PW etc. There are also some Mullard/ Philips app notes that show radio circuits using TV valves.

A good candidate would be Prof Tuckers Synchrodyne circuits.

Ed

[FrankB]

David,
They are marketing some USB modules on ETSY here that have blue LED's illuminating the bottom of a valve, which is attached to the USB stick.
Looks sort of neat, but not my cup of tea. (Also spendy!)

[Radio Wrangler]

So the rules of the original game from the beginning of the thread is that all valves should look the same, and should light up brightly and the finished thing should work as a radio.

Though not balloon shaped, there are some coke-bottle shaped valves which are designed to light up. VR150/30 for example. The challenge then becomes one of designing a radio to use only VR150s or VR105s. They DO have a negative resistance region, so something ought to be possible. AND the illumination will probably vary along with the signal

Nixies have negative resistance, too, so you can make ten neon oscillators with one device, though they tend to interact. Guess which idiot as a kid tried to build an electronic organ with ten nixies as a hundred oscillators....

David