AV Geeks 16mm Lunch 7-25-2023

foreign everybody I'm skip Alzheimer welcome to the AV Geeks lunchtime streaming show where we watch old 16 millimeter films and uh comment about them I'm back uh we were back from our travels uh we were in Greenbelt oh my hair is stop looking and thinking about my hair it doesn't matter it will never be right um what we were in Greenbelt we did a home movie digitizing weekend uh at the old Greenbelt Cinema it was great it was um all the film slots were filled most of the video slots were filled it was a great time and uh I got some photos here's me uh with a mobile uh telesini uh scanning and what was great is besides us being supported with coffee and such uh Bill sudbrink who watches our show came by from Silver Springs and he brought us Donuts Donuts because coffee coffee is great but Sunday Donuts man so great and so it was a much needed sugar boost uh it was great to meet him in person uh Bill thank you he's been a long time viewer it's always great to meet you guys in person so slowly as we get our get more and more out in the world doing shows and doing events like this uh I'll be able to meet more of you and that's that's pretty exciting uh here is a film that was made post-world War II about uh potentially working in the fire or Police Services enjoy your life work all right all over the country wherever people live and wherever they go Prime the other is fire together they destroy many lives and cost billions of dollars for preventing and fighting fire and crime we have special departments in every community there are thousands of persons in fire and police work and recruits are constantly being added to the ranks but only those with certain qualifications are accepted for instance to become a fireman in most Municipal departments a candidate must first take a civil service Examination for physical and mental Fitness those who pass are placed on an eligible list in the order of their marks from this list the fire commissioner selects men for special training under the Drill Master who supervises the school for probationary firemen there is very little book work in this school the emphasis is on learning by doing first the candidates must become familiar with the things used in fighting fire they study the various types of hose couplings and the street hydrants installed in their City they learn the purpose and proper use of many tools and how to meet special problems such as handling electrical wiring safely first aid 2 is a very important part of a fireman's training but it is in the strenuous practice drill that the probationary fireman finds out if he is really suited for the work in these sessions the men are put through the same actions that they may experience in a real fire getting hoses into a building calls for top speed yet safety precautions must be observed nowadays the use of pump here ladders at a fire is an unusual occurrence but the firemen must prepare by practice to meet any emergency teamwork is the firefighters byword it is essential in nearly everything they do teamwork is especially noticeable in handling the life net which is moved quickly to catch a dummy representing a person leaping from a burning building skillful use of the map has saved many lives training in the fireman school is augmented by real experience in fire companies and whether a probationer is accepted as a permanent fireman depends on his company record as well as his fire School record but being appointed doesn't mean that training is completed while waiting for calls the men have practice drills including a so-called brain drill in which they test each other on the location of streets and hydrants [Music] [Applause] [Music] there is action thrill and adventure in fire service but most of it is just plain physical hardship under dangerous conditions it calls for young men with good health mental alertness and a willingness to risk personal injury even death in protecting the lives and property of others although a fireman's Duties are essentially the same no matter where he is employed the nature of a police officer's work depends on what force he belongs to and his specific assignments there are numerous types of law enforcement agencies including Village County state and city police there are also various federal agencies but comparatively few persons are employed in federal police work City forces employ the largest number of men and it is here that all typical major police activities are found protective patrolling is one of the major activities officers are assigned districts or beats which they Patrol on foot or by motor a patrolman's job is to observe everything the people the buildings and the vehicles he is on the lookout for possible violations and for conditions which may endanger the safety of people or property traffic regulation is another major police activity calling for the efforts of many officers but this work includes much more than directing traffic some officers are assigned to accident prevention or traffic engineering work investigation of traffic conditions to find out where signal lights and other control devices are needed is one phase of this job other policemen specialize in accident investigation entailing countless duties and Gathering evidence and disposing of cases criminal investigation another major activity requires the employment of many detectives or plain clothes men with special skills and knowledge for solving various types of crime some detectives concentrate on investigating burglaries collecting evidence and information to Aid in finding and Prosecuting the guilty persons but burglary is just one of many different types of crime the detective Bureau of every large police force has other Specialists trained to handle such crimes as homicide forgery arson automobile theft shoplifting and so on a vital Aid in criminal investigation is the crime detection laboratory where latest scientific methods for solving crimes are employed the experts in the lab cooperate with detectives in uniform police in many ways here a chemist is applying acid to a firearm to reveal the serial number which was defaced by the criminal firearm identification experts use comparison microscopes to check bullets recovered from bodies or at scenes of crimes with test bullets fired from confiscated firearms microscopic or chem analysis of seemingly unimportant things such as dust stains and fibers often provides decision to crimes fingerprints on fire on the records division are compared by fingerprint experts with those found at crime scenes and here too is another major activity utilizing and keeping track of thousands of Records on fingerprints complaints reports arrests warrants and other essential materials civilians as well as officers are engaged in this work in some police departments the records are kept close to the central Communication equipment thus necessary information is near at hand when complaints and reports come in or when messages are sent by teletype phone or radio to stations and patrols or to other law enforcement agencies the operation and maintenance of communication equipment is one of many phases of Police Service requiring special training the guiding children into good citizenship is a primary aim of modern police work crime prevention which deals mainly with juvenile problems calls for the assignment of police women as well as policemen it requires a thorough understanding of the laws affecting children and ways to cooperate with parents schools and social agencies the physical and educational requirements for entering police work depend on the type of force its location and administration civil service entrance examinations are required by most city and state forces Village and County policemen are usually appointed or elected the FBI has the highest entrance requirements of all in order to qualify as a special agent an applicant must be a graduate of a law school an expert accountant or have had a constructive type of law enforcement experience nevertheless the FBI has a long waiting list of eligible men ready to take the Intensive course of training for which this force is noted in other police forces there is a great need for persons with training Superior to that gained in most in-service police schools several universities now are horses in police science and administration or those who wish to make Police Service a career and certainly police work offers a splendid opportunity for a worthwhile career only through the employment of persons with real aptitude and training can the criminals toll in life and property be reduced crime must be fought just as fire is fought by those who are suited to and trained for the job if you are interested in fire or Police Service investigate the one you wish to enter find out what the requirements are and make plans to meet them devoting yourself to the public welfare by entering fire or Police Service would be an admirable Choice as your life work [Music] so they don't have a your life's work for uh an AV geek so I had to figure that out on my own um so one of the things that was clear in talking with people uh they wanted more films about oscillators they wanted to know more about oscillators that and Wankel engines and unfortunately I have not found another Wankel Engine film I'm actively looking for more Wankel engine films but I do have this film about oscillators so enjoy the oscillator is of the Hartley type which as you know has a tapped inductor in the Hartley oscillator and again on the culpits the tank circuit is directly coupled to the tube it's important for you to know they tuned plate tuned grid oscillator but neither this circuit nor the Reversed feedback type of circuit is used in receivers in these circuits the voltage fed back from the output and applied to the grid of the tube must be approximately 180 degrees out of phase with the voltage existing across the load impedance in the plate Circuit of the amplifier the oscillator signal is combined with the incoming signal in the mixer or first detector stage a signal voltage is produced which is equal in frequency to the difference between the incoming radio frequency and the local oscillations fusing isn't it well what he's been trying to explain to you are the devices used to produce oscillations and they're not so tough really take that clock for instance the pendulum is oscillating it's dull well remember the swing at the picnic that was more fun and the swing was an oscillator pendulums and swings aren't the only things that oscillate electric current can oscillate too let's borrow a section of the professor's diagram and make ourselves a circuit we'll start the alternator turning this causes the current to flow back and forth in the circuit these are electric oscillations the faster the alternator turns the faster the current oscillates but the rotor like the swing and the Pendulum is a mechanical device and can go only so fast electric oscillations like those used in radio are much faster than this if you want to spend your Liberty listening to something like this [Music] you have to have about a million current oscillations a second or if you want to watch some television you must have around 50 million oscillations per second and no mechanical oscillator can respond that fast now the trick is to get the electric current to move without using a mechanical oscillator so let's get rid of the alternator and put a Charged capacitor in here now the only moving part of the oscillator will be the electric current itself here the size of the plus and minus signs will represent the amount of charge on the capacitor this circuit is the heart of every oscillator and is called a tank circuit back and forth just like the swing to start the girl swinging you had to pull the swing back and to start the current oscillating you had to charge the capacitor when the girls started to swing she didn't stop at the bottom she kept on going and in the tank circuit the same thing happens when the capacitor discharges electrons flow through the circuit and build up the opposite kind of charge on the plates of the capacitor just as the girl's momentum on the downswing carries her up the other side as the capacitor discharges a magnetic field is built up around the coil some of the stored energy from the capacitor is transferred to the magnetic field after the capacitor is discharged the energy stored in the magnetic field acts to keep the current flowing this puts a reverse charge on the capacitor now the capacitor will again discharge and this will happen over and over again in the same way the girl keeps on swinging but she won't keep swinging forever neither will the oscillations in the tank circuit they will die out because energy is lost mainly in the form of heat due to resistance you can keep the swing going by giving it a little push each time but how are we going to do the same thing with the tank circuit if we could add a little energy from outside the circuit would keep on oscillating we may try operating the switch but it is difficult to time the switch accurately and impossible to operate it fast enough for high frequency oscillations so there is the problem provide a device which will supply the needed energy rapidly enough and at the proper time to keep the circuit oscillating let's see how we can use a vacuum tube for the purpose we shall start with a simplified amplifier circuit a small input voltage applied to the grid will be Amplified into a much larger output in the plate circuit if we connect the tank circuit between the grid and cathode of the amplifier the oscillations when set up in the tank circuit will cause changes in the potential across the grid and cathode of the tube these signals will produce an amplified output in the plate circuit some of this energy can be used to supply The energy needed to keep up the oscillations in the tank circuit since the changes in the flow of current in the plate circuit are controlled by oscillations in the tank circuit the timing is perfect but our oscillator is not a very stable one to make clear what is wrong with it let's go back to the swing you don't have to push a swing all of the time at the top of each swing is enough in our oscillator circuit energy is supplied to the tank circuit during a large part of each cycle this provides more energy than is required it is equivalent to giving too much push at each swing to prevent this we use a Gridley which controls the amount of energy supplied to the tank circuit to show how this works let's look closely at this part of the circuit during part of the tube's operation electrons flow from Capital to plate and from cathode to grid electrons collect on the plate of the capacitor that is connected to the grid the grid becomes negative and stops the flow of electrons in the plate circuit with the plate current cut off the charge on the capacitor leaks off through the resistor when the capacitor loses its charge the grid is no longer negative so electrons again flow and the action is repeated now we have a kind of switch by controlling the frequency with which we open and close this switch we can supply the exact amount of energy needed by the tank circuit the oscillator is truly a remarkable device by using an oscillator the superhetrodyne receiver provides definite advantages over other types of receivers more uniform amplification greater sensitivity and finer selectivity wait a minute Professor is the super heterodyne receiver the only place you use oscillators circuits of this kind are employed extensively and many other applications the portable low power transmitter used by the Armed Forces yes he's right for instance without the electronic oscillator we wouldn't have these Quest mortar fire dog one Salvage boat stand by redfish this is Pat Natalie latitude 41 Vector 61 41 61 this is zero zero Victor save all of our oscillators operated at the same frequency we would get something like this [Music] which would be somewhat of a mess with the swing we can change the time hey [Music] with the swing we can change the timing by changing the length of the Swing rope the shorter the Rope the shorter the time of each swing now we can do the same thing to our oscillator in one of two ways we can change the size of the capacitor smaller capacitor means a smaller charge and a smaller charge can be discharged in less time we can also control the frequency of oscillation by changing the size of the coil for variety let's try making the coil larger since the coil is larger more energy can be stored in its magnetic field so it takes longer to give up this energy this means slower oscillation so it's easy to remember increasing the size of either the coil or the capacitor cuts down the frequency are you through with this yet yes I guess that's about it let's get out of here I'm tired of being an oscillator this is a great example of Folks at the Army signal Corps who were working on these films uh trying to come up with some way to take the driest uh lectures like they were hinting at at the beginning and like making it at least a little bit more interesting and like well let's let's put a pretty girl in it and like let's talk about Liberty like you know these are things that uh folks uh in the military are looking forward to and so somehow we'll combine that um I don't know get their interest in some way pretty great though um and I learned something learned something all the time when I watch these films and that's that's kind of The Accidental part of this is like oh I didn't realize that uh all right here's a living in the United States second edition enjoy [Music] the New England states the Middle Atlantic states the Southern States the Midwestern states the plane States the southwestern States the Rocky Mountain States the Pacific States the United States [Music] thank you [Music] the New England states birthplace of a Nation we're the early voyages across the Atlantic the pilgrims Plymouth Rock Plymouth Plantation Beginnings in the New World time worn mountains lakes and wooded Hills the sea industrial Beginnings in America growth development modern New England but the past is still important in the New England states the Middle Atlantic states Urban complex we're people millions of people people crowded together living playing working we're industry heavy in light Steel Shipbuilding coal mining [Music] we're movement mass movement goods and people uh [Applause] we're government we're Commerce and trade but mainly we're people millions of people in the big crowded cities in the Middle Atlantic states the Southern States historic lands new ideas tradition where tradition and architecture in history an agricultural past and an agricultural present mechanization specialization food processing cotton and textiles forests and furniture wood Pulp and Paper resources that grow and resources that are mined and from them chemical processing the Mississippi world trade route River of History we're growing in touch with the past living in the present looking to the Future Atomic power bass we're still making history in the southern states the Midwestern states the nation's heartland Chicago marketing Transportation industry Big Industry [Music] Goods up rich farmlands crops cattle dairy products [Music] farming an industry transportation and marketing Commodities bought and sold come a one it all works together here in the Midwest the plane States meat and grain where there's enough rain corn where there isn't wheat livestock fed by the grain we grow technology and one man doing the work it once took many to do mechanization on a big scale [Applause] movement to Market to the cities for processing green and meat [Music] um we feed the nation with meat and grain from the plain states the southwestern States growth in the desert first we grew on cattle and then on oil and we grew a lot [Music] we had cotton high grade cotton to help it grow in dry country irrigation irrigation for fruit too spectacular land for touring for retiring for living we're growing under blue skies in the warmth of the Southwest the Rocky Mountain States changing frontierlands the mountains what a treasure we have what a rich resource historic barriers to travel barriers no more strange and beautiful lands grazing lands [Music] [Music] oh man [Music] forests on the mountains and minerals inside them mining and smelting oil and refineries streams rushing down the mountainsides to give us power for homes or Industries irrigation for crops in these dry but Rich soils of the Rocky Mountain States the Pacific States variety and change we work using the varied and plentiful resources the Northern Forest lumberman on the sea and rivers seamen and fishermen fruits from the responsive land and mild climate we irrigate water from dams and dams for power the Pacific coast with its weather vacation lands [Music] we're people and cars and places to go where big cities all around the Pacific North from Washington into Alaska from the mountains of Alaska across the Pacific to the mountains of Hawaii and its Sandy Shores [Applause] we're Travelers and we attract travelers from All Over America to our Pacific States the Pacific States [Music] the Rocky Mountain States [Music] the southwestern States the plain states the Midwestern states the Southern States the Middle Atlantic states the New England states the United States [Music] foreign [Music] oops hit the wrong thing um yeah so that's actually this film is actually kind of an intro to a whole series of those Coronet films that basically at the beginning they talk about you know the the Northeast and the mountain states so I have a bunch of those that we can bust out with so yeah all right so the next film I got uh I'm surprised I haven't shown this and I apologize if I have I just I couldn't find it in the database but or in the spreadsheet that I have been putting together that lists all uh nearly well four thousand two hundred and twenty five thirty uh films that we've shown over the last several years couple years uh so I apologize again if this has been shown but it's a pretty great one it's called on impact enjoy [Applause] [Music] thank you what you just heard were two accidents the first was the car crashing into an object the second was the car's occupants being thrown against parts of the car's interior or being thrown through open doors under the highway it's this second accident this accident inside an accident that causes human injuries when a car hits a tree and stops suddenly the passengers continue moving forward forward that is until they strike something inside the car like the steering wheel foreign designers policemen researchers are vitally concerned with their problem of Crash injuries actually automobiles have never been safer based on Miles traveled accidents have declined 57 percent in the last 20 years yet accidents continue to happen because human error can't be completely eliminated the problem is this 38 000 persons are killed each year and one and a quarter million injured the question is what can and is being done about it here is Dr Russell Harris who was called out last night to treat the injury case you witnessed this morning he and his wife are on their way to the annual Convention of the American Medical Association Dr Harris is particularly interested in the part of the convention that concerns crash injuries he knows that researchers working with doctors and policemen have studied thousands of actual accidents and compiled revealing statistics about what happens to people inside a car that crashes but he wants to see and understand it in more detail from the scientific exhibits he will see and the medical papers he will hear to find out specifically about the extent of the problem he and John O Moore director of Crash injury research at Cornell University Medical College go on to the actual convention floor to see Lieutenant Frederick McGuire Dr Harris asks how critical crash injuries are to the Armed Forces well about one-third of all our Hospital admissions are due to motor vehicle accidents and about 85 percent of all our off-duty Hospital admissions are due to the same cause and these men when they do get on the sickler spend an average of 42 days there in the Korean War for example we took up on the sick list twice as many Marine Corps and Naval Personnel due to motor vehicle accidents than were placed there because of enemy action from reports like this Dr Harris obtained a clearer understanding of the problem involved its immensity its total effect then he asked about the all-important Cornell statistics on Crash injuries and how the statistics are collected Mr Moore explained that to collect the facts doctors and police in States all over the nation carefully studied thousands of individual accidents and make detailed reports to train Cornell researchers then Mr Moore took Dr Harris to Sergeant Elmer Paul of the Indiana State Police one of the groups that makes crash injury facts available Sergeant Paul explained how the reports were filled out at the local level this is the vehicle Report The Trooper completes about Crash damage collapses structure he also lists the causes of the injuries then we have the medical report which The Physician completes the actual injury itself as the talk continued Dr Harris satisfied himself that the crash injury statistics were as valid as they were vital then at the Cornell booth on the convention floor he asked well Mr Moore how would you sum up the Practical results of your work in facts and figures well Dr Harris I would attempt to do it this way when the passengers are thrown out of the vehicle 54 percent of them suffer a moderate through fatal grade injury but when the passengers remain inside the protected body of the car the percentage of people suffering moderate through fatal grade injuries drops to 24 percent less than half in other words you're twice as safe if you stay inside the car during an accident then Dr Harris asked if staying inside the car was enough how do people who remain inside get hurt well Dr Harris we've found that 40 percent of all drivers who are hurt are hurt by being thrown against the steering wheel suffering primary inches of the chest about 38 percent of the passengers in the right front seat are injured by contact against the instrument panel Mr Moore explained that using these recent findings automobile safety Engineers work to develop devices to protect the passenger in the event of an accident specifically the engineers work to reduce injuries from the parts of the cars singled out by the Cornell statistics the steering wheel the instrument panel or by ejection from the car here for example is a new steering wheel being tested in the laboratory and crash padding for the instrument panel after years of laboratory tests the devices were tested in actual and violent crashes at the test track Engineers here are putting electronically wired dummies into cars that will be crashed together this will be a typical intersectional crash this car will be hit on the front quarter by the car coming down the track [Music] oh boy in slow motion now notice how the safety belt protects the right front seat Dummy from the windshield while the unbelted dummy in the driver's seat crashes into the sun visor and windshield area and here is the same crash as you would see it from the rear seat 20 feet to go each dummy and each car is literally covered with devices to let the engineer know what forces are Unleashed in the crash here is a crash into a barrier Dr Harris now knew how the crash injury statistics told automobile Engineers which parts of the car caused the most injuries and he could see how the engineers used the statistics to develop the new safety devices for a closer look at them he returned to Sergeant Paul's exhibit and asked for a description of the devices available here we have the new door locked which is an improved version over last year's we have a crash pad on the instrument panel which will absorb Force we have the safety balls to [ __ ] the forced projection of occupants we have here the padded sun visor which will protect the head and the forward impact [Music] and with the recessed hub much better than a previous type steering wheel so Dr Harris saw that something really significant already had been done to reduce the problem but as a doctor he wanted to know what he could do in his day-to-day work to help to get the answer he sought out Dr Fletcher Woodward chairman of the American Medical association's official committee on medical aspects of automobile injuries and deaths Dr Harris asked about the role of a busy physician a position should be interested both in the prevention of these accidents as well as in the definitive care of the engine and in consideration of prevention he should consider these conditions of the nervous system for instance does the patient have epilepsy is this patient senile they should also consider the question of his cardiovascular system these things are all important at times in the causation of automobile crashes it should also be very careful as to the types of drugs that she may prescribe especially the drugs still commonly used today the tranquilizing drugs and they have a histaminic drugs these drugs at Times May interfere with drama and skills should also consider the question of the special sensors versus vision for real provision central vision and the other special census particularly hearing and the question are vertigo another thing that he should pay for stick your attention to is if a patient asks in doctor am I hip to drive a car well Dr this is the type of information I've been hoping to find at these exhibits and here at the convention at the special medical Symposium on automobile crash injuries Dr Harris heard 11 papers that dramatized The Firm resolve of American doctors to play an increasing role in the progress being made and he heard the automobile industry commended for its major contribution to that progress finally he heard Dr Woodward propose the formation of a national Foundation like the polio Foundation to coordinate the work of all groups interested in reducing highway accidents so that still more knowledge can be gained and more progress made then Dr Harris went to the Ford scientific exhibit where he saw solid examples of the progress being made by the industry to reduce Highway injuries and death and he heard a report on a speech given by Henry Ford II at the national Safety Forum in Dearborn Michigan when the five safety devices were first introduced furthermore we wish to announce that all of the pioneer safety features and the specifications and design of those features developed by Ford Motor Company are to be made available to any automobile company that wants them well to me this is pretty solid evidence that these people mean exactly what they say yes and those devices are based on design criteria that was gathered by police Physicians and researchers cooperating in local communities just like yours Dr Harris now tell me Mr Moore do you have any statistics from the field on the effect of these devices I mean do they actually reduce injuries in case of accidents yes for the first time since these protected devices were introduced last fall we can State clinically that the severe crushing injury to the chest of the driver has been reduced by one half by the safety steering wheel the new safety door locks have significantly reduced the frequency of door openings during impact in fact in non-overturned accidents some designs have reduced this occurrence by 60 percent we have the same trend from seat belts the energy absorbing instrument panel and Visa padding are having a marked effect in reducing the frequency of the lacerative type injury of the face and head in our opinion if we could suddenly equip all 50 million of the vehicles on our highways with these properly engineered devices the safety steering wheel the safety door lock the seat belt and the instrument panel and advisor padding we could expect to reduce by one-third the crash injuries we see this would mean that one half million persons annually would Escape injury and the great proportion of all of our deaths will be reduced to recoverable injury well that's very encouraging but what about the future where do we go from here the future the future will be written tomorrow next month next year and on and on it will be written by the many hands of progress inspired by dedicated and inquisitive Minds by the researcher the position the policeman the automobile engineer and most importantly by you the driver the one with the most to gain in presenting this film The American Medical Association acknowledges the cooperation of Ford Motor Company and its contribution to passenger safety the future what will the future bring the future well we are having lived in the future we know what it brings uh it brings us seat belts that go across us it brings us um airbags all over the car brings us uh different types of bumpers all that stuff is is kind of interesting to see um what has come up and certainly I have seen some devastating crashes on YouTube or Instagram or wherever where people or cars are flipping over and people are getting out um and are not hurt uh which is phenomenal so there is advances in that regard uh so thanks for tuning in today uh it's happy happy to be back seeing everybody live um it was a really rewarding weekend to be able to work with people to digitize their home movies and video it's also amazing stuff um and people got to see stuff that they hadn't seen or uh hadn't seen in 30 years so that's part of our mission that's like what we like to do is we certainly like to Showcase what we have in our collection but we also like to help people see stuff that's been locked away in a format that they don't have access to so yeah um if you like what you saw hit the Thumbs Up Button as always or the like button or the Subscribe button uh you can also hit the super thanks button and donate a little bit of Moolah to us so we can pay for new screwdrivers this is a very old screwdriver but we need new new ones um and that's what uh going to KO Dash fi.com AV Geeks or patreon.com Geeks it goes to buy coffee and supplies that we need around the house um yeah so we'll be back again tomorrow Wednesday and I'm all not working yesterday or spending all day driving yesterday kind of threw off my calendar so we'll be back tomorrow um and we'll talk to you about some cool stuff and we'll show you some cool stuff and um yes it's happy to see you all and we will see you soon bye