Silvertone 1580, 1582, 1584, 1585, 1586, 1587, 1588, 1589etc

See the company details about Sears, Roebuck & Co. in this link, which you will find on each model. There you will find a multi page PDF with the index to the Service Information. See also the link on the models which are contained in the Service Information 1928 thru 1936, which is also linked on the models concerned.

In this article I have noted the common information for the model family with the same chassis and basic schematic.
The family includes at least the following Sears models with brand Silvertone:
1580, 1582, 1584, 1585, 1586, 1587, 1588, 1589 and 7100.

This chassis offers quite some remarkable details of interest for an involved collector.

To put every detail into the remarks on the model page would be too much text and would be complicated to change because of the many models concerned. Here it can easily be updated at one place - for all linked with this article.

 

The manufacturer

This model was manufactured for Sears by Colonial Radio Corp., Buffalo, NY (Sears Manufacturer Source Number Code 101). In fact it is the schematic for the Colonial model 62. But within the same models there were quite some changes made. They are explained in the original plans we show, thanks to John Kusching who carefully scanned and prepared them and will upload as time permits. Even some tubes could be different (see plan "B").

You find the Rider's schematics in volume 3, pages Colonial 10 to 14. We show them in more detail on the Sears models concerned. Some of the model pages also unveil the chassis and other details. The best comparison can be made on Sears model Silvertone 1585.

The Colonial Radio Corporation (in Delaware) was founded in 1924, in 1929 a successor registered in New York and started to manufacture and sell radios to Sears. They also delivered to other "private brand" companies. Sears gave them the Manufacturer Source Number Code 101. In 1931, Colonial bought the King plant from Sears (established in 1924 by Sears) and manufactured mainly for Sears. In 1934/35 it discontinued to sell under the name Colonial.

 

Special features on this model family

1.  "Micro-Vision Triple Scale Dial"
This is a moving scale AND a moving pointer!

See the full picture (for members) on the model 1585 by Norbert Konersmann

The scale and the needle move in opposite directions! The numbers refer to the frequency, not meters.
The high number of all three bands is on the right of the scale. The values: 55 - 155, 170 - 500 and 520 - 1660 have to be multiplied by a factor 10 to determine the actual frequency - and are not the true beginning and end of reception.

This special scale was continued on some later models but is quite unique. I would be glad to get information on which other models this can be found outside of Colonial and Sears.

 

2.  Long wave reception ?
This would be very unusual for domestic US models. "For long and short wave reception" was the slogan.
The models could be ordered for the same price for a line power with 25 cycles, which was then quite usual for other models. Both mains transformers do not have taps for other voltages and were built for 110 to 120 volts. But there is also a "Universal transformer" for 40 to 60 cycles possible, with taps: 115, 130, 155 and 230 volts. Therefore we have to assume that radios with this chassis were also exported. Indeed, the Colonial 62 schematic turns up as a drawing from Thali in Switzerland.

The long wave reception is in fact just a marketing trick. The true reception is:
Broadcast Band: 550 - 1600 (or 540 - 1580) kHz (kc),
Short Wave 1 Band: 1600 to 5100 (or 1650 - 5150) kHz (kc or 1.65 to 5.15 mc).
Short Wave 2 Band: 5000 to 16000 (or 5200 - 16600) kHz (kc or 5.20 mc to 16.6 mc).

 

3.  3-gang tuning condenser
There is a band pass filter in front of the mixer tube. This function was then called "translator".
But there is no RF stage - and reduced IF circuits depending on schematic version. The IF coils without parallel condensers are referred to within the Sears documentation as "self-tuned" IF output transformers.

 

4.  The loudspeaker has a hum bucking coil.
This means a second coil is used in conjunction with the field coil for the loudspeaker. This special coil, which is wired in series with the secondary of the audio output transformer, was wired 180 degrees out of phase with the field coil in order to cancel the power supply noise. Since the rectifier tube in these models use full wave rectification, the power supply noise is twice the power line frequency. For example, 120 Hz noise will be present when using a 60 Hz power source. Thus, the field coil and the hum bucking coil need to be used together and using a speaker without the hum bucking coil would result in excessive hum. Using the hum bucking coil was common practice at that time.

5. Five knobs
The knobs are: top left is "Volume", below left is "3 tap Band Switch", center "Station Selector", top right is "Tone" and below right is the "ON-OFF Switch".

Example for model All Wave Silvertone Superheterodyne 1585

Often one finds wrong knobs when radios are pictured.
Therefore and to prove data and dates of sales, we provide model pages with pictures of fliers, folders, catalogs or advertisements. Not only the picture of a set but also the entire page, which should be readable (for members) in the big size format of max. 933 x 1400 pixels.

 

The different versions for the wiring and tubes

In principle there is a version "A" and a version "B" - the same for colonial 62 as for the mentioned Silvertone models. But one has to be careful to also see the alterations within a version.

We show the "original" schematic (page 245) and the "revised" schematics "A" (page 249)  and "B" (page 247). Page 246 shows the additional circuit changes. Changes in schematic "B" have been made in Models 1588 and 1589 receivers. The 57 "translator" tube has been replaced by a type 58 with its cathode connected to the volume control for improved volume action. Coils G and H have been changed. The "self-tuned" If output transformer has been replaced with one having a condenser tuned secondary. The Oscillator grid circuit 150 ohm resistor has been replaced by a 100 ohm resistor. Two other values have been changed to 75 M and 3 M.

There are many more details - up to page 252.

 

Newer models with equally placed knobs

At least the next generation used the same basic support structure, scale and knob arrangements but is in fact quite different. They use 8, 11 or 12 tubes. You see for instance 11 tubes for model Silvertone 1721 or 12 tubes for Silvertone 1722. The escutcheon also featured the "New Automatic "Flash" Tuning Light", which flashes only when a station is perfectly tuned. See an article about the history of different tuning aids.

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As stated above, there is a family of sets with the same chassis and schematic. For models 1588 and 1589 we reported changes in schematic "B". When we look at the Silvertone 1588, we see that it has only 3 knobs, but 1589 has five. Missing on 1588 are the 3-tap band switch (at left) and the ON-OFF-switch at right.

It seems simple: the volume gets also (as lager usual) the ON-OFF-switch - and the missing of the band switch shows us that the model has broadcast band only.

John Kusching saw also that the dial looks like it has a single band, not 3 bands.  You can see the lines going straight up the whole height of the dial, but on the 3-band dial the marks are different. It can just be noticed on the big sized picture from the Sears catalog #166, page 502.

So far so good. But I found pictures called Silvertone 1588 from Joe Napoli at Radio Attic, which show exactly the same cabinet with the same escutcheon and scale with our pointer with three circles but the straight single vertical lines. But if you look at the chassis, you see 7 instead of 5 tubes in a row plus the two tubes in the second row. Otherwise the dimension and form of the chassis seems to be the same.

Hopefully we will find out (one day) which model this really is - or if Sears was mistaken by the order number or so. Joe napoli seems not to be a member, otherwise I would have asked for pictures. A change of chassis is unlikely because the type is dictated by it (and the form of cabinet). Specially Silvertone 1650 is a very similar cabinet with a 9 tube chassis and broadcast only, whereas Silvertone 1631 has also a very similar 6-leg Low-Boy cabinet with stretcher base but the 5 knobs.

We miss information from the separate radio catalogs from Sears. Maybe they showed also other models than the big catalogs.

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