Difference between revisions of "4A"

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== As Advertised ==
 
== As Advertised ==
 
The 4A was first introduced in the April-August issue of <i>Collins Signal</i> magazine.
 
The 4A was first introduced in the April-August issue of <i>Collins Signal</i> magazine.
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[[File:4A m.jpg|center|Its first appearance.]]
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[[File:4A m.jpg|right|Its first appearance.]]
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The production units were a bit different than the Museum's artifact.
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COPY - The 4A transmitter marks the entry of the COLLINS line in the extremely low-priced field. The 4A uses a 47 crystal oscillator and parallel 46's in the power amplifier permitting an output of 18 to 20 watts on 1.7, 3.5 or 7 me. The power amplifier is operated on the crystal frequency in each case. Despite its low cost, the 4A embodies the mechanical and electrical refinements found in the larger COLLINS transmitters. A separate power supply is used for the oscillator to reduce frequency "chirp." Standard COLLINS plug-in coils are employed. A single Weston meter is provided with a switching arrangement to read plate and grid currents. The 4A is ideal for an amateur who wants to start out with a minimum investment and yet have a transmitter which will deliver a high quality C. W. signal. The 4A can also serve as a stand-by transmitter in a high-powered station to be used when full power is not required.
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The Power Amplifier Neutralization control was moved from the interior to the front panel. The crystal was moved from inside to a socket on the front. Notice this particular unit did not have a manufacturers plate - that we can see.
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Really surprising results can be obtained and amateurs who are accustomed to think in terms of kilowatts can get a great deal of service and amusement from one of these little transmitters.

Revision as of 20:55, 30 March 2020

This Amateur Radio Transmitter was introduced in the October 1933 issue of QST. It is a crystal-controlled CW-only transmitter capable of 20 watts RF output. The crystal and associated band-changing coils were plugged from the top of the unit.

This unit is now in the UTC museum.
Internal View

The 4A was a kit, all parts included, however, you were responsible to purchase the tubes separately.

Construction

Like many home-assembled projects - this unit had no cover, top, sides or back.

As Advertised

The 4A was first introduced in the April-August issue of Collins Signal magazine.

Its first appearance.

COPY - The 4A transmitter marks the entry of the COLLINS line in the extremely low-priced field. The 4A uses a 47 crystal oscillator and parallel 46's in the power amplifier permitting an output of 18 to 20 watts on 1.7, 3.5 or 7 me. The power amplifier is operated on the crystal frequency in each case. Despite its low cost, the 4A embodies the mechanical and electrical refinements found in the larger COLLINS transmitters. A separate power supply is used for the oscillator to reduce frequency "chirp." Standard COLLINS plug-in coils are employed. A single Weston meter is provided with a switching arrangement to read plate and grid currents. The 4A is ideal for an amateur who wants to start out with a minimum investment and yet have a transmitter which will deliver a high quality C. W. signal. The 4A can also serve as a stand-by transmitter in a high-powered station to be used when full power is not required. Really surprising results can be obtained and amateurs who are accustomed to think in terms of kilowatts can get a great deal of service and amusement from one of these little transmitters.