1 1 Radiogram Issue 119 September 2011 ISSN 084-6209 Issue 119 RADIO-GRAM The Vintage Wireless and Gramophone Club of Western Australia September 2011 News from the Vintage Wireless and Gramophone Club, Perth. WA. This issue comprises the March to August Meetings! Our April Meeting featured Norbert Tourneys presentation on some early and unusual TV receivers. . At the March Meeting, Barry Kinsella gave a pres- entation on Tuned Radio Frequency Receivers, prevalent in the early 1900‘s. Colin Hayes gave an interesting talk at the May Meeting on his work at Atkins WA and his connection with CS Baty. At the July Meeting Peter Cutler talked about his search for old recordings on various media in particular in relation to the AFL.
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1 Radiogram Issue 119 September 2011
ISSN 084-6209
Issue 119
RADIO-GRAM
The Vintage Wireless and Gramophone Club of Western Australia
September 2011
News from the Vintage Wireless and Gramophone Club, Perth. WA.
This issue comprises the March to August Meetings!
Our April Meeting featured Norbert Tourneys
presentation on some early and unusual TV
receivers.
. At the March Meeting, Barry Kinsella gave a pres-
Norbert Tourney- Has a new phone number…0448881187.
Meeting closed 8.45pm. Guest speaker was Peter Cutler talking about the development of the WAFL football audio vis-
ual archive that is in process of being collected.
Some of the early AFL material collected by
Peter Cutler
Peter Cutler presents his work
Some of the audience present at the July meeting
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Richard Rennie and Rodney House present ―Royalty on Records‖
Minutes of Vintage Wireless and Gramophone Collectors Club meeting held at clubrooms Tuesday August 20th
2011. 16 members present, 2 visitors.
8.00pm. Meeting commenced.
The meeting was opened by Vice President Steven Austin. Welcome was extended to visitor George Noble. Apologies
were given for President Rob Nunn and Barry Kinsella. The minutes of the July meeting were moved as correct by Rich-
ard Rennie and seconded by James Wemm. Passed unanimously.
Secretary’s Report.
There was an incoming email from the Radio Heritage Society. An outgoing brief newsletter is to be sent shortly by email
or post.
Treasurer’s Report.
There was no treasurer‟s report tabled due to the absence of our treasurer.
General Business.
Steven Austin- Notification has come from the City of Melville advising of a meeting for the „Process of Determining the
Significance of the Wireless Hill Collection‟. This is to be held on Wednesday 31st August and an RSVP on 1300 635845
needs to be received by Tuesday 30th August. Merv Thompson put forward a motion that the executive find a club member
to follow this up. This was seconded by Steve Austin and passed unanimously.
Tony Smith- Has an 8track recorder player. He is looking for cartridges in good condition so he can work on this machine.
James Wemm- Wished to extend thanks to Richard Rennie for the school holiday programme magic lantern projector pro-
ject. The next project scheduled is build a crankophone.
George Noble- Asked for a contact for reel to reel tape repairs. Was given the number for Tim Gillett
Items of Interest
Laurie Bugeja- Showed a boxed Western Electric photoelectric cell last tested in 1939. Also a novelty Sprite can radio and
Mercedes Coupe novelty radio.
Merv Thompson- Was at the Antique and Collectable fair at Claremont on the weekend where there was a number of
miniature novelty radio replicas on sale.
Tom Newsome- Displayed an early external horn gramophone. A modified early Gramophone and Typewriter Monarch
model.
Steven Austin- Showed a restored external horn gramophone c.1910 of unknown provenance. Possibly a Western Austra-
lian manufacture. Powered by a 2 spring Brunswick motor.
Meeting closed 8.35pm. Guest speakers were Richard Rennie and Rodney House speaking about Royalty on record.
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GUITAR AMPLIFIERS
While I am reliving my second puppyhood by repairing guitar amplifiers, I was
asked to write a little about Fender amplifiers. I considered this and thought about
throwing the other major manufacturers into the story.
Initially, strummed stringed musical instruments were purely acoustic in their opera-
tion. That is, the strings were stretched over a bridge that sat on the top panel of a wooden box. Much refinement of the
strings and the shape, size, construction and materials used in construction of the box brought us the melodic instruments
that we know and enjoy today.
Acoustic instruments are not loud on their own. This limits their use in performances. One can place a microphone in front
of the instrument and feed the sound signal through an amplifier to make it sound louder. Later the microphone was built
into the instrument and a cable carried the signal to the amplifier.
Later, in the fifties, the electric guitar came into its own as an instrument. It had a solid timber body with channels and
holes cut into it to house electronic parts. The sound is picked up by a pickup installed under the strings next to the bridge.
The signal is given some basic tone and volume treatment by potentiometers and circuits mounted on the body near the
musician's strumming hand. The sound signal was amplified by an amplifier and fed to heavy duty speakers. As the years
passed, the amplifiers increased in power and sound quality.
Along came the next step, accessories that altered the sound of the instru-
ment. A "tremolo" lever near the strumming hand that quickly stretched and
relaxed the strings to give a trill or tremor to the note played. Then an echo
effect generated by sending the sound signal through a set of springs in a
reverberation unit. These were a great advance, however, they had a prob-
lem. This is that if the amplifier is bumped during use, the springs start vi-
brating and put an unwanted twanging noise into the sound.
From here, as musicians wanted them, many more accessories were manu-
factured by the instrument manufacturers and other accessory manufactur-
ers. These accessories changed the sound of the guitar to special effects and
mimicking other instruments.
During the 1940's Leo Fender improved the performance of hollow bodied
guitars by using a solid bodied instrument and amplifying the sound of the strings.
During 1951 the first of the electric guitars that he made was the Telecaster, a Spanish style instrument. He also built a
bass guitar that year that meant a bass player did not have to carry around a huge stringed double bass instrument. He
could play the bass on a guitar. This guitar was called the Precision Bass guitar. He then invented the vibrato or tremolo
bridge where the musician has a small lever in his strumming hand that can be moved to and from the instrument very
quickly to stretch and relax the strings thus causing a trill on the note played.
In those days the "big band" format of music was very popular, however, now that strummed string instruments were of
more a manageable size, volume and tone the smaller quartet type bands started and became very popular, especially in
the rock and roll format.
Leo Fender succumbed to ill health during 1965 and the company was sold to CBS, a music company. It would appear
that Leo had no real workshop or factory as CBS had to build one.
Fender amplifier system
Fred Franklin (Darwin, NT)
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During 1981 William Schultz was appointed president and the company changed its name to Fender Musical Instrument
Company in Corona, California. The services offered continued to expand and the company grew. Schultz retired in 2005
and Mr. Mendello became the CEO.
Fender Musical Instruments Company encourages everyone to learn and play music. They have music schools and kids
clubs.
In the mean time, in Chicago, Gibson started developing amplifiers and electronic instruments between 1935 and 1942.
World war two came along and swallowed up all the electronic parts and talent.
After the war, Gibson employed Barnes and Reinecke to do some electronic design
work for him. The designs were of low power but better toned amplifiers. Later, Gibson
started doing his own electronic design and the circuits were many and varied and with
many modifications to existing circuits (like Kriesler radios).
These two manufacturers have their
die-hard fans similar to Ford and Hol-
den in the car industry.
During the 1960s the manufacturing of
electric guitars and amplifiers took off
in a big way with many manufacturers
large and small. Some came and went
quickly and some who stayed on to the
present day.
Hartley Peavey was influenced by
Fender's attitude to build the best equipment to suit the requirements of the musi-
cians.
Peavey Electronics Corporation was founded in 1965 building amplifiers, speakers, keyboards and other sound accesso-
ries.
Peavey grew up in Meridian, Mississippi where he worked in his father's Peavey Melody Music Store. He aspired to being
a rock 'n' roll musician but he admitted to being pretty lousy at it. He tinkered with amplifiers until he was building one
amplifier each week and selling it during that week. Then he would build an other one and sell it. This business grew into
a company employing 2,200 people and a turn over of $210 million.
Meanwhile in England, Jim Marshall started a company called Marshall Amplification during 1962. There appears not to
be a lot written about the history of this company. He mainly used 6L6 or 5881 output valves.
During 1964 he changed to KT66 output valves and a GZ34 rectifier for 100 watt amplifiers. In 1966 he changed to the
very popular EL34 (6CA7) output valve. These valves are widely used by nearly all amplifier manufacturers.
Marshall then went loud in 1967 with a 200 watt amplifier using KT88 output valves.
He introduced the first of his transistorised 100 watt amplifiers during 1974.
According to musicians, there is a difference in sound quality between valve and transistor amplifiers. Generally, guitar
amplifiers are driven very hard. This means that the valve's harmonic response and compression qualities come to the fore
and interact favourably with the speakers. Marshall's engineers noted this factor and managed to get the transistors to
sound like valves. This was called valve state. It would appear to be a 12AX7 pre-amplifier and mixer stage with a transis-
tor power output stage. I presume 2N3055. These were a good all round power transistor.
Fender amplifier top view
Fender amplifier under view
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Other manufacturers tried to emulate the valve sound by using a transistorised pre-amplifier stage and a valve driven
(EL34) output stage. I am, personally, not a lover of hybrid circuits. In my experience, transistors work well and valves
work well, but a hybrid amplifier is touchy. I have found them to be noisy while not in use and turned on or incorrectly
matched impedances in the input, even while using the manufacturer's own instruments and cables.
The applications and performance of amplifiers is limitless, as the musicians think of new applications and sounds and
present these demands to the manufacturer's engineers who design and build these amplifiers and accessories.
The amplifier is a good rugged, basic audio amplifier with a good tone and volume. Its frequency response was observed on the oscilloscope and the signal provided by a signal generator. The pleasing result was a clean undistorted trace from 8 Hz. to 22 kHz. The sound pick up that is mounted on the body of the instrument has many different ways of converting the vibration of the strummed string to a small electrical signal of around 100mV.. One way is to have a small magnet installed under each steel string with a coil of many thousands of turns of fine enamel insu-lated wire wrapped around it. As the string vibrates it modulates the magnet's field and a small electric signal is induced into the coil. This signal is sent to the amplifier. As the device is an inductor, it can pick up unwanted other signals that are present in the area and special consideration is given to this during manufacture.