Photos

The missing photo of the Metamec is still mostly missing here. The clock appears at the extreme LH masked by another clock. I also have some more pocket watch photos to absorb your mind.

Octagonal Pocket Watch. Pretty but.....

This is a very popular model. Once set it remains in operation until it stops.  This similar model is much more difficult to get started.  

 Worn, of poor quality, I persisted with it until I had a 27hr result. Mainspring wound right out. For a pin pallet the accuracy quite good.
  

Revival

Hello! Since visiting here in October a week or two ago something has happened! My ability to Post has been re-activated. Not only here but on my altar ego BLOG as well. 
I have so much to report. My exile has been enduring...... an injuring! I have learned things about text and clocks. Even some watches have responded. There are so many photos to upload - surly I will be penalised. I'll start modestly:-

   Who is that dear little chap? What does he know?  He knows that time flies and texts, fonts, and typefaces are apt to revert to type. {Did you see what I did there?}.
I refuse to be beaten!  We will not squander our time in these islands so selflessly won for us. The goodness we aimed to project will be seen to be done.
This octagonal brass pocket watch may seem very pretty but in fact it has been a complete pain.

    

It had belonged to dear David my So-I-L who died of esophageal cancer in July this year. His widow asked that I look at it. No glass and hands. Very mucky and dried out. I dismantled and cleaned it but alas it has a number of faults difficult to remedy. These ranged fro a distorted lever to a tangled hairspring on through worn pivots, out of adjustment pallets and gummed up mainspring. I have had much difficulty getting it to run at all let alone in every orientation.
Let it be said that this is not a quality item! Attractive does not substitute for quality. A pin-pallet lever escapement, no jewels. Eventually, having got over many of the snags, I was left with an oval T2 wheel. In something of a quandary I eventually eased down the teeth  with some very fine abrasive paper and it does at least run. It seems unable to make more that 27 hours from a full wind by which time the mainspring is almost completely unwound. It will start to run from the first half wind. 
Here's another recent challenge:-

This clock is a Metamec 8 day with a french mechanical movement. I think it is a budget model. Very thin plates showed much pivot wear as it witnessed here by the installation of new pivot bushes. The great wheel of the mainspring drum has two chipped teeth which I managed to replace. Here we can see the movement in place.

Another shot shows the frontal appearance which some people have expressed a liking for. It is finally running for a full week and keeping time to within 2 minutes as the mainspring unwinds.

May I just say how wonderful it is to be back. I am looking forward to new exchanges on the BLOG I first started way back in 2009.

Rgds to all. 

The Lift Trick

Next time I add to the BLOG I will tell you about a trick you can play with lifts. I haven't yet had the opportunity to try it myself yet. So I will try to ratify it before I publish it. Meantime it's a waiting game... and a G-Force!
OK even though I have not had an opportunity to test it I will publish and be damned. 

If you want to send the lift directly to your floor without it stopping for other requests. Hold down the DOOR CLOSED button, while you push button for your choice of floor. Hold both in until lift starts. {Police & Firefighters trick}. You can also cancel calls by pushing the button twice.

SOMETHING ENTIRELY NEW

To me that is. Will I ever stop learning? This little gem appeared in the paper today. I have just tried it out and it works! Drop a battery (AA is what I used) on to a hard surface, (my PC desk), from a couple of inches. A fresh Alkaline type will land with a thud and scarcely bounce. However, a run down battery will jump up and down several times. On test there's a voltage difference too. Only 1.36V for a low battery and over 1.6V for a fresh one. {Both measured off load}. This is a splendid trick for someone without a meter.
The reason? There's a soft gel inside a fresh battery that absorbs the bounce. This gel turns solid with use and the kinetic energy is not then absorbed. Thus the little jumps on a hard surface.

Tesla Battery Technology

Tesla is an American company who specialise in electric cars and so called "power train" production. Last Thursday they announced a special battery that will harness and store the gains made from solar energy panels. It is designed to be used within domestic households as well as on a more indutrial scale. It is very likely based on lithium-ion (Li-Ion) technology and therefore might not really merit the fanfare it was given on 30Apr2015. Nevertheless it does focus our minds on the problems of storing electricity in huge quantities needed for a car or undeed , a household. That these batteries can be dangerous should not alarm us too much - as nearly everything we do with regard to electricity carries some danger.
Yet here we be, in the year 2015, and still a long way  from clean energy. These batteries have to be manufatured of course. The's still much to be said for pumping water uphill thus to reclaim the energy spent in a gravity hydro-power system!  More as and when it comes to (wait for it) light!

BATTERIES cont.....
Progress in this area has been so fast that several new and sometimes conflicting considerations need to be outlined. These are mainly how to store, (charged or discharged),  what dangers from over charging/discharging, and perhaps ambient temperatures. 
As well as the progress in secondary (rechargeable types) there has been some progress in the primary types too. I am now strictly of the opinion that Lithium cells (AA or AAA) are best for cameras and remote controllers. We aren't just talking economy here. Reliability & dependability are a far greater issue for these items. This brings up longevity issues and for my money I'd opt for that in the form of Lithium cells. These can be purchased at reduced prices on-line. Try E-bay. 

MORE on MICROPHONES

This entry supplements a previous post on microphones. This time we are going to look at the implications of so called quality or goodness. To do that we need to recap on a few "givens." Although aural acuity varies between individuals just as our vision does, it is a matter of fact that the fairer sex can generally hear much higher frequencies than the men. The usual range for a youngish person is said to be 30 to 20,000Hz at the outside, with the males being some 10 to 20% less at the high end. It is a also true that we can all follow a slowly rising sound frequency up much further than when it is just presented. As we get older our hearing tails off particularly in the higher frequency range.

Unfortunately there are some side issues. "Attack" or onset may require the presence of frequencies that lie beyond our perceived range. Another issue concerns "distortion." Most people would agree that this occurs when the process imparts new elements to the original sound. Unfortunately, it is nonetheless true that some such distortions are thought of as pleasing! Therein lies a very busy little bundle. Surely by that definition even amplification is a "distortion." Yes and so it might be argued. The words used to describe processed sounds are nearly all borrowed from existing language. In the main the English language as interpreted by the Americans!

This gives rise to such wonders as "colouration" (coloration if you must).
"Loudness" - "Level" - "Fader" - "Presence" - "Phasing" - "Chorusing" -
"Trim" - "Treble" - "Middle" - "Bass" - "Echo" - "Flanging" - "Reverb"- "Noise"- "Reflections" - etc. etc.
And here's a couple of French ones - "Ambience" - "Envelope"
Then there are the processes:- "Equalisation" - "Parametric EQ" - "Notch Filter" "Graphic EQ" - "Harmonizer-ing" - "Limiting" - "Compression" - Signal to Noise & "SINAD" - "Over-spill" - "Mono" - "Stereo/Binaural" - "Noise-cancelling" - {there'll be more!}.
We haven't got into the musical terms yet either if only because not all sound recording is of music.

Traditional thinking would have it as a pre-requisite that a microphone should be able to deal with all the frequencies in the range of our hearing without any undue distortion. However, this does not take into account the peculiarities of the human ear. There is a non-linearity in our hearing that changes with perceived volume or intensity. Then there is this very peculiar selective and directional ability that we have to somehow select the things we most want to hear. The best example is that of conversation across a noisy room. Some people can listen to, and concentrate upon, just a single instrument from a whole orchestra. Once you make a recording some of these clever options are denied to us.

This innate ability that we humans have to be selective with what we hear is very interesting. The more so since I have noticed that with advancing years my ability do do this is severely curtailed. Given that we might call the unwanted sounds "Noise" then we seem able to deploy some very sophisticated noise cancelling techniques. We do it without much thought. Those who have sought to understand that mechanism more thoroughly are soon forced to recognise just how very clever the faculty actually is. For example, our ears are directional collectors, but they are displaced to each side of our head and that allows us to tilt and otherwise align our heads for maximum pick-up of the desired sound. It emerges that we can actually get some unwanted sounds to cancel each other and the reason for this is to do with time delays in the arrival of the sound at each ear. In some circumstance that delay causes the two sound "waves" to oppose each other and the energy is dissipated in mutual cancellation. Our brain can do the rest! By the precise swivel of the head we can change the group of frequencies that we "tune in to" from a high group to a low group. Some of the mechanisms are not well understood. {See older posts "EAR 'ERE"at foot of page}.

The point is that once such sounds are recorded and played out to us through a single sound source such as a speaker, we can no longer do that. The microphone will react equally to ALL the sounds unless........

NOISE CANCELLING & CARDIOID MICROPHONES 
 To try and get around such problems, engineers have developed all manner of devices. Microphones with directional pick-up. Microphones that do that by noise cancelling - just as we do. Shielded microphones. Limited sensitivity microphones. Then follows the sound processing devices. At first developed to improve the selection, then to remove unwanted noise, and finally to change or enhance. The latter class are collectively known as "EFFECTS."
The larger size of condenser microphone reaches back to the earliest days of sound recording and in particular, broadcasting. Certainly back to the 1950's if not earlier. They were said to give an excellent sought after result. There is no doubt that they were a triumph in their time, but as technical knowledge has moved on, so has human taste & amp; opinion.

The first condenser microphones had to make use of valve(s) to amplify the tiny signal coming from the transducer. Thus the need for a power supply which became standardised at 48V. The triode valves usually chosen do have a downside in that they produce some "noise" which is heard as a hiss by those with acute hearing sensitivity. The studios sought out ways to reduce or mask this tendency with such clever devices as noise-gates, and filters. This whole process is usually referred to as "EQ" or Equalisation. An interesting by-product of the valve is said to be the added "warmth" that is added to the sound. It is here that we depart from pure science as the precise reason for that remains elusive and open to conjecture. For my own part I would put it down to an inbuilt "compression", of which more later.

Certain anomalies now present themselves. While a certain microphone, amplifier, indeed studio, might make your particular guitar, violin, or voice sound the way you wanted it to, another might not! Therein lies a discussion that might yet go on forever. It leads us to such phrases of convenience as "beauty is in the eye of the beholder" and "it's right if you think it's right."

For the would be sound engineer the availability of so many choices can be a veritable nightmare. Philosophically it might lead to another phrase that I have grown to like. "The good enough sound." This leads us to the study of perceived improvements. One very important aspect of this is known as "SIGNAL to NOISE." That is that which we wanted to accentuate or make prominant, and the opposite of that. In measuring what we have achieved in this respect our old unit of sound intensity the decibel (db) makes a re-entry. Because it is difficult to entirely separate the wanted signal from the noise, we often talk in terms of SINAD. This is SIgNal AnD noise to Noise only ratio - expressed in db. Whoops - have we lost you? Think slowly here. We can rarely, if ever, have perfection. We will have to settle for there being some noise, some unwanted sounds. It then becomes a question of masking the unwanted with extra volume or using other rather snazzy devices such as a noise gate. Is it worth a moments thought? I think so.
ADDENDUM - It can be argued that the various studio processes used to condition the condenser microphone (or any other device inc other types of microphone) will change, and may even reduce, their overall performance.

THE NOISE GATE
This started life in the studios when it was realised that even a low level hiss (from processing circuits, wiring etc.), can be very annoying in the dead area of a an acoustic (anechoic) chamber. The idea is that the signal is clamped or shut off to an absolute quiet until it has risen to a small but predetermined level called the threshold. Signals over this are allowed through, with the noise, which tends to mask its presence.

DIGITISATION
We spoke in another earlier post about the digitisation process. Technological advances have moved us in this direction because these techniques get us over several other difficult hurdles. For example the digital process can make faithful copies of sound tracks & sequences without any degeneration. We can do complex edits and "condition" the sound in ways that were once impossible. {e.g. change tempo but not pitch and vice-versa}. We can also accomplish with software, many of the analogue processes that only very expensive hardware can achieve.

However, there is a slight downside to it in that the best quality of sound needs many samples and levels which leads to large files. While technology has made huge strides in digital storage, we are still challenged to reduce the file-size and to accept the resulting shortfall in sound quality. Many are they who will argue that the process is so magical that they can't tell any difference!

To a purist however, this quality of sound is a non-starter. The tricks used to save space come at a price in terms of real sound quality. This is further compounded by the inferior capabilities of small speakers and some ear-pieces.

One needs to look at the weakest link in the chain to decide just what the other links should be like. Look at ALL the outlets that the source sound will traverse and apply a similar rule. Sometimes, of course, one just has to do as one is told by "the piper who calls the tune" or the depth of our pockets!

COMPRESSION
Let's look at Limiting first. Right from the earliest times it soon became clear that audio equipment was not tolerant to overload. Just look at the grooves of an old plastic record. If the stylus or cutter that is making the master recording swings too far laterally, it will slice into an adjacent groove or channel. Yet we need to consider what happens during very quiet passages when the signal is barely able to modulate the cutter. What we hear then is the hiss of the groove mixed with the quiet signal that we really wanted. If we solve the first problem by saying "there is a LIMIT beyond which we will not let this cutter move" - we get over the first snag. However, the ideal solution would be if we could turn the volume of quiet passages UP and turn DOWN the louder sequences.
Thus is born the idea behind COMPRESSION. That this is now done electronically is of little importance. If these ideas are carried to extremes, the dynamic range is foreshortened and gives rise to an obviously processed sound that is "Punchier." Some folk like that EFFECT. We need to use compression even inside our own ears and we certainly need to guard against overloads when using tape or even during digitisation. In some respects it's not very different from the shock absorber on a car wheel.

NOISE CANCELLING MICROPHONES
Please refer to my previous BLOG on microphones for a description of how a noise cancelling microphone works. We need to remember that audible sound reaches us through slight pressure variations in the air. We are sensitive to a very large range indeed yet we must guard against overloads because our ears are very fragile.

LOW V HIGH IMPEDANCE
The advantage of a low internal ac resistance (called impedance or "Z") is that incidental noise coming through the sheilding (cable etc) is shunted away. The disadvantage is a much lower signal level in need of more amplification. Go to the button at the end of the page to see another of my previous BLOG pieces  

'ERE' EAR for more.