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A RADIO RELATED JOKE WARNING ANTENNA CONTENT!!

My webmaster sent me a radio related joke today - it's so bad that it is really funnny.  So,,,,..........

For your enjoyment........

 Two antennas met on a roof, fell in love and got married. The Ceremony wasn't much, but the reception was excellent.

WOULD YOU HAVE A TEPPAZ OR A DANSETTE

Teppaz was an electronic brand founded in Lyon, France by Marcel Teppaz in 1931. In the late 1950s and into the 1960's the brand dominated the European mainland with it's portable record players, indeed, this company produced the 'Gallic Dansette'!!

However, the company differed from the staid Margolin brand by employing adventurous advertising as shown below: -

They also cultivated the patronage of their products by iconic figures such as Marlene Dietrich: -

So, based on the above, which would you prefer to choose to ruin your 45s!!!

 

MULLARD MAGIC ADVISES

Mullard Magic are very excited at the prospect of the new 1950's village to be built at Beamish Museum, especially as we have been asked to act as technical advisor for the supply and restoration of suitable items.     Radios currently seem to be absent from the Beamish exhibits, excepting the rather cute round Ekco radio at Home Farm - which we didn't supply.

THE MULLARD MAGIC SHOP IS FULL

I really must get the Mullard Magic stock room sorted out - it's so full, there is barely enough room for me and a valve tester as you can see: -

Seriously though, this photo was taken yesterday by my good friend Stuart who is currently in Tokyo, he is having a whale of a time dodging earth tremors, experiencing heated and vibrating (ooo-eeeer!) toilet seats as well as enjoying exploring electronics emporiums.    

This picture reminds me that we have a whole raft of collectable goodies to put up on  the Mullard Magic website once I get over an attack of stultifying man inertia, honestly, some days I feel like Neil the Sofaworks sofa sloth!

RADIOFIRE BY A RADIOPHILE

Well, the Tories are in, Ed Milipede will not now freeze energy prices but we have a solution here at Mullard Magic.... forget about wind power, how about woodie power, they burn well, throw off lots of heat and look really pretty so you don't have to waste electricity whilst keeping warm by watching Britain's Not Got Talent.     Now stand in line to buy this pile of Bush AC34s!

WHAT A BEAUTIFUL PAIR - COLLINS S-LINE & RCA 77A MICROPHONE

Here's an image to cheer up this Good Friday which is wet and windy here at Mullard Magic HQ.   I like the microphone which takes it's styling cues from either the Aiwa VM18 or the RCA 77A and similarly, the transmitter from the Collins-S line but the Ormond 1930s tuning dial looks a bit strange as does the tuning knob from a Crystal Calibrator No 10.

I think that's it, nothing else in the photo that is interesting and bears passing comment on is there????????

MORE ON VALVE VIBRATION!

Well, today, I had an e-mail from an 'expert' on valve vibration.  He attempted to 'correct' my last blog entry  but rather than telling him to buzz off, I thought I would clarify matters a little further in my own 'non expert' way

My last blog entry dealt with an example of swept frequency sinusoidal microphonic testing where the gross effects of vibration on valve performance was being assessed at typical conditions potentially found in an accelerating aerial shell.

There existed a number of direct excitiation methods of measuring the affect of vibration on valves and for completeness, I will describe just one which is a typical system for examining specific effects on electrode structure - and hence electronic performance - this one was used by Mullard Research Laboratories for both initial design, competitor analysis and complaints analysis.  Here below, we see a wonderful photo of this paragon of instrumentation:-

Perhaps a block diagram used in conjunction with the following text will help to describe how this contraption worked:-

As the frequency of the vibrator is varied, the microphonic output voltage of the valve will vary.  If the vibrator excitation frequency is lower than the resonant frequency of the system, the deflection will be in phase, conversely, if the vibrator excitation frequency  is higher than the resonant frequency, the deflection and force are 180° out of phase. The transition between these two states takes place in a narrow frequency band near the resonant frequency, at which a 90° phase shift between the deflection and the vibrator excitation force will exist. These changes of phase are visible on the oscilloscope as an oscillogram displaying Lissajous figures.

At the resonant frequency of a component, both the amplitude of the vibration of that component and the microphonic output voltage will be a maximum, accordingly, by varying the frequency of the vibrator until the microphonic voltage shows a maximum, and by observing the oscillogram in conjunction with viewing the valve through the microscope, it is possible to determine which component(s) within the valve envelope  are responsible for any microphonic effect.   As the vibrator and stroboscopic signal generators ar set to operate with a frequency differential of 10 Hz, any vibration of a component can be visualised as a slowly 'moving and blurring' artefact.

VIBRATIONS FOR VALVES - BUZZZZZZZZZ!

 

Oooh, what is this nice man doing........ well, you might think he's making some sort of mine though you would be wrong.  In actuality, here is a Philips technician, vibration testing a batch of experimental thyratrons and triodes for use in a European variant of the Mk 53 aerial mine's proximity fuse.

The working of these devices was rather elegant.  The shell contained a miniaturised transmitter using the shell body as an antenna to emit a continuous wave of approximately 200 MHz. As the shell approached a reflective target, an interference pattern was created.  As the distance to target decreased, a radiated power and corresponding oscillator supply current change would occur.    The Doppler frequency shift could be tuned between the ranges of 200 - 750 Hz to trigger a detonation once a chosen amplitude was reached. 

 

PHILIPS HERLEEN B9A VALVE BUTTON BASE MAKING MACHINE

This is a very nice photo of the Philips Herleen B9A base making machine circa 1955 - see earlier blog entries about the three part base wires and glass eutectics.

 

 

 

A MULLARD DUMMY!

Well, look at this,  I have known quite a few dummies, some of them even like valves..... and radios!!!!!!!   But the only Mullard dummy I had ever seen before was my reflection looking back at me from the mirror - haha - that was a Mr. Mullard Magic joke.

I wonder, was this just an empty space box filler?   Maybe  a delve through the Mullard archive I have here may tell me or even one of you customer type people may know the secret.