Posts Tagged ‘vintage’

Hallicrafters Shortwave Radio; Winning WWII With Technology (1944)

Great film about a great radio manufacturer and radio set.

In 1944, this short subject film was produced by the Jam Handy Organization and sponsored by the Hallicrafters Company. It shows the construction of the SCR-299 and dramatizes its use during World War II. This is a B&W documentary presenting a look at the manufacturing and use of the (now defunct) Hallicrafters Company’s SCR-299 “mobile communications unit.” This 1944 film, produced with help from the US Army Signal Corps, and by the Hallicrafters Company, explains how, using radio gear such as this Hallicrafters shortwave radio transmitter and receiver technology, the US Forces and Allies were better equipped to win World War II.

The SCR-299 “mobile communications unit” was developed to provide long-range communications during World War II. The US Military sought improvements of range, flexibility and durability over its existing SCR-197 and SCR-597 transmitters. In 1942, Hallicrafters Standard HT-4 was selected as the SCR-299’s transmitter, known subsequently by its military designation as the BC-610. The SCR-299 was first used on November 8, 1942, during Operation TORCH involving companies of the 829th Signal Service Battalion establishing a radio net that could exchange messages between beach-landed forces and bases in Gibraltar. Despite initial problems unloading the sets from convoy ships, the SCR-299s served until the installation of permanent Army Command and Administrative Network stations. According to US Army military historians, “General Dwight Eisenhower credited the SCR-299 in his successful reorganization of the American forces and final defeat of the Nazis at Kasserine Pass.”

The SCR-299 was a “self-contained” receiving and transmitting mobile high-frequency (HF; or, shortwave) station capable of operating from 2 MHz to 8 MHz. Using conversion kits, it could operate from 1 MHz to 18 MHz. The transmitter output reached 350 watts.

The entire unit came in a K-51 truck except for Power Unit PE-95 which was in a K-52 trailer. Power could either be supplied by the Power Unit and a 12-volt storage battery or 115-volt 60-cycle AC commercial power and two spare 6-volt storage batteries. The power requirement was 2000 watts, plus 1500 watts for heater and lights.

The system could be remotely controlled up to a distance of one mile (1.6 km) using two EE-8 field telephones and W-110-B Wire kit. Remote equipment was provided for remotely keying or voice modulating the transmitter, remotely listening to the receiver, and for communicating with the operator of the station.

Read more details here: http://en.wikipedia.org/wiki/SCR-299

Public domain film from the Library of Congress Prelinger Archive.

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73 de NW7US

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MGM 1939 film: Radio Hams / More than a Hobby

“Radio Hams” do more than play with their machines. They are also invaluable in relaying vital information during times of tragedy and disaster.

Here is a mildly entertaining look at radio hams, those amateurs sending and receiving coded messages during the late thirties when films first dealt with the subject of “radio hams.” In this case, the ham operators manage to be helpful during situations of stress, using their abilities with code to help someone in distress and to seek aid for pilots flying a missing plane.

The humorous ending has the family gathered around the radio listening to someone speaking Chinese while the narrator tells us how impressed the family was to be hearing someone across the world on their radio set.

This little vintage film, a rather more serious film than many of Pete Smith’s other presentations, takes a look at how ham radios can become priceless aids during emergencies. The two stories shown, one dealing with sickness, the other with a missing plane, are bookended by a humorous look at a typical three-generation family’s fascination with their ham radio.

Of course, amateur radio, or “ham radio”, is alive and doing very well, in our modern times. Using satellites, moon-bounce communications, repeater networks, as well as shortwave, mediumwave, and longwave telecommunications technology, amateur radio continues to provide emergency services in times of need, from hurricanes, tornadoes, earthquakes, and even during such times as the infamous 9/11 atrocity. But, amateur radio also breeds invention and experimentation, always at the cutting edge of science. It is a hobby worth investigating, having room for a wide-range of interests. Preppers, science lovers, experimenters, and those with a passion to meet people from all over the world by way of radio waves, all together make up the radio hobby of amateur radio.

Clayton Moore, later famous as the Lone Ranger, appears uncredited as a ship radio operator.

Directed by Felix E. Feist

Writing Credits Buddy Adler (screenplay) (as E. Maurice Adler)

Cast (in alphabetical order)

Barbara Bedford – Mrs. Crane (uncredited)
Eleanor Counts – Miss Mulligan, Jimmy’s Sister (uncredited)
Jack Daley – Pa Mulligan (uncredited)
Robert Homans – Lighthouse Keeper (uncredited)
Clayton Moore – Ship Radio Operator (uncredited)
Alonzo Price – Clyde DeVinna (uncredited)
Jason Robards Sr. – Pilot in Distress (uncredited)
Pete Smith – Narrator (voice) (uncredited)
Harry Strang – Man in Montage (uncredited)
Phillip Terry – Co-Pilot (uncredited)
Dorothy Vaughan – Ma Mulligan (uncredited)

Produced by Pete Smith – producer (uncredited)
Music by David Snell (uncredited)
Cinematography by Robert Pittack
Film Editing by Philip W. Anderson (as Philip Anderson)
Music Department Jack Virgil – orchestrator (uncredited)
Other crew Douglas Smith – technical advisor

According to https://archive.org/details/wwIIarchive this film is in the Public Domain.
Creative Commons copyright.

1920 film: How the Telephone Talks (A Silent Film)

This is for you vintage science film buffs: here is a circa 1920 film: How the Telephone Talks (A Silent Film).

This is an educational film from 1920 that explained the “modern” telephone. The concepts are still relevant to today’s modern versions, including the cell phone, which is both radio and telephone.

From Wiki:

A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are not in the same vicinity of each other to be heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals suitable for transmission via cables or other transmission media over long distances, and replays such signals simultaneously in audible form to its user. The word telephone has been adapted into the vocabulary of many languages. It is derived from the Greek: τῆλε, tēle, far and φωνή, phōnē, voice, together meaning distant voice.

First patented in 1876 by Alexander Graham Bell and further developed by many others, the telephone was the first device in history that enabled people to talk directly with each other across large distances. Telephones became rapidly indispensable to businesses, government, and households, and are today some of the most widely used small appliances.

The essential elements of a telephone are a microphone (transmitter) to speak into and an earphone (receiver) which reproduces the voice of the distant person. In addition, most telephones contain a ringer which produces a sound to announce an incoming telephone call, and a dial used to enter a telephone number when initiating a call to another telephone. Until approximately the 1970s most telephones used a rotary dial, which was superseded by the modern Touch-Tone push-button dial, first introduced by AT&T in 1963. The receiver and transmitter are usually built into a handset which is held up to the ear and mouth during conversation. The dial may be located either on the handset, or on a base unit to which the handset is connected by a cord containing wires. The transmitter converts the sound waves to electrical signals which are sent through the telephone network to the receiving phone. The receiving telephone converts the signals into audible sound in the receiver, or sometimes a loudspeaker. Telephones are a duplex communications medium, meaning they allow the people on both ends to talk simultaneously.

A landline telephone is connected by a pair of wires to the telephone network, while a mobile phone, such as a cellular phone, is portable and communicates with the telephone network by radio transmissions. A cordless telephone has a portable handset which communicates by radio transmission with the handset base station which is connected by wire to the telephone network.

The telephone network, consisting of a worldwide net of telephone lines, fiber optic cables, microwave transmission, cellular networks, communications satellites, and undersea telephone cables connected by switching centers, allows any telephone in the world to communicate with any other. Each telephone line has an identifying number called its telephone number. To initiate a telephone call the user enters the other telephone’s number into a numeric keypad on the phone.

Although originally designed for simple voice communications, most modern telephones have many additional capabilities. They may be able to record spoken messages, send and receive text messages, take and display photographs or video, play music, and surf the Internet. A current trend is phones that integrate all mobile communication and computing needs; these are called smartphones.

( http://g.nw7us.us/1996vSl )

 

From Backblocks To High Seas

I came across this great piece of history via the Google+ page of Cristian YO8TNB and had to share it here for others to enjoy. I have a soft spot for New Zealand, being so close to my country of birth, and I particularly noticed the carefully cultured accent of the announcer. On a more serious note, this video is an invaluable record of the wired and wireless technology used in 1939 and the procedures for transmitting a message from land to sea.

Philco Tropic Model 3012

Last weekend I attended the Houston Vintage Radio Association holiday dinner & picked up a Philco Tropic Model 3012 during the fundraiser auction. I had let a few other radios go without placing a bid and was beginning to think I might go home empty handed when I saw the Philco “on the block”. A few seconds later I was the proud owner of this vintage receiver.

Philco Tropic 3012

Information on this model seems a little scarce, however the style of case was introduced by Philco in 1951 and used in their line of AM/FM receivers for many years after that. This particular example is a transformer-less AC/DC set with a potentially live chassis and the unusual (to me) lineup of 14Q7, 7B7, 14B6, 35A5 & 35Y4 vacuum tubes.

What prompted me to bid on this particular radio was the inclusion of two shortwave bands in addition to the typical AM broadcast band. The dials are marked off in meters which also appealed to the ham radio side of my interests.

After attaching a short length of wire as an antenna I was able to pick up signals across the two SW1 & SW2 bands so I’ll be interested to see what it can receive with a long wire antenna at night.

After a gentle cleaning with dilute mild detergent to remove dirt I rubbed in some beeswax polish to restore the original gloss. Sadly the plastic dial is cracked in the middle but I can look past that given its a little more unusual than the typical All American Five receiver.

Being over fifty years old I wonder what this radio has been used to listen to and what stories it could tell. Perhaps it gave some youngster his or her first taste of ham radio, listening to shortwave stations and AM QSOs until they received the final demand to, “Switch that radio off and GO TO BED!”

The Johnson 275W Matchbox Antenna Tuner

I had purchased a Johnson Matchbox from an estate a while back & decided that while I was home with the flu I would open it up and check on its condition.

The Johnson Matchbox is found most commonly in two versions, the smaller “275W” unit and the larger Kilowatt Matchbox. Why did I use quotation marks around 275W? Well, these units were manufactured back in the good old days when men were men and transmitting voice meant using AM, not single side band. The conservative rating of 275W of AM translates into roughly 800W of peak SSB  (Not really but close enough so you get the idea)

Unlike many who own a Matchbox I was hoping to keep it 100% original and that it would contain all its original components, including the antenna change-over relay and wiring for the high-impedance receiver antenna connections. I plan to use this Johnson Matchbox with a Heathkit AT-1 transmitter and Hallicrafters SX-25 receiver so the inclusion of an antenna change over relay and 300 Ohm receiver connections will make life MUCH easier. Something I didn’t realize until I had the unit apart (There are a LOT of screws holding this thing together) is that there is also a receiver control contact on the relay to break HT and mute the receiver during transmit which will work with my SX-25.

An initial inspection showed that the only modification was a small piece of plastic wedged into the relay contacts that held the relay in the transmit position. It was easily removed and the relay coil and contacts tested for continuity. The contacts seem a bit dirty which, from the little I have read online, seems to be a common problem.

Once the relay contacts and band-switch are cleaned I will button the unit back up and connect it to the loop antenna I have recently run around the eaves of the house. The loop has been a huge improvement to the long-wire and magnetic antennas I have run in the past, at least as far as reception goes … but that is a topic for another post.

The further adventures of the Heathkit AT-1

Work has been conspiring to eliminate my spare time but I was able to spend a few hours over the Easter holiday to clean up the shack and make space to put the Heathkit AT-1 on the desk again. I have been able to spend a little time going over parts that need to be replaced and making a list.

The Heathkit AT-1 chassis with case and VFO-1 behind.

There doesn’t seem to be any show stoppers although the wafer of the meter switch has broken in two and will need to be repaired. If I’m not able to repair it then thankfully it is fairly simple and replacement rotary switch can be substituted.

This isn’t going to be a museum quality restoration but the changes that were made to this transmitter in the past were sensible and if left in place are representative of period modifications. The original meter for example was not the highest quality and a Western or Simpson replacement would be an improvement. The original slide switches have been replaced with period snap-toggle switches which are also an improvement over the original.

The Heathkit VFO-1 however has been modified for grid-block keying which is a significant departure from the original and I plan to revert it back to cathode keying. Although a technical improvement it is not in keeping with the original design and needs to be undone. Everyone will have their own opinion but I think if I wanted modern circuits I’d get a more modern rig, so the VFO-1 will be returned to stock.

Hopefully I can carve out a bit of time here and there to work on this and slowly return it to working condition.


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