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American FM Koffer radio in the 1950's?

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Forum » Manufacturer's / brands history » Set makers in other countries than German speaking (not in R » American FM Koffer radio in the 1950's?
           
Joe Sousa
Joe Sousa
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20.Mar.09 23:18

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There were several European brands making portable tube radios "koffer-radio" with FM included.

Did any American companies make portable tube radios with FM?

All the American tube portable battery radios from the 1950's seemed to have AM or SW, from the simple 4 tube AM sets to the Zenith Transoceanic types.

Regards,

-Joe

Konrad Birkner † 12.08.2014
Konrad Birkner † 12.08.2014
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21.Mar.09 16:13

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I know only of the FM Jr. made by Hastings in 1958.

Zenith came with its first FM portable in 1961, the Trans-Symphony Royal 2000, which was advertised as "America's first all-transistor Portable FM/AM Radio". No tube FM either...

Well, I think, that portables/pocket radios were for young people, not interested in classical music, operas etc. . They would rather listen to swing, bebop. But I can figure a housewife, fond of operas, watching such kind of music in the kitchen.
 
In Europe it was different. Particular in Germany, where the Kopenhagen plan had divested our country of BC band channels, we had to evade to FM for standard programs. i.e. the customer was the same for portables as well as for home sets (provided they could afford the rather expensive portables).  The market war completely different.
 
 

This article was edited 23.Mar.09 10:45 by Konrad Birkner † 12.08.2014 .

Joe Sousa
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21.Mar.09 21:01

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This is amazing.

There was FM in the USA in the 1930's, and plenty of inexpensive American AC/DC table radios with FM in the 1950's, from brands like the Granco, GE and Zenith.

I saw the Hastings radio in person once, at a radio swap meet, but I did not take photos. However, a few examples came up in a google search, including a schematic:

http://www.somerset.net/arm/radio_pictures/hastings_fm_jr.jpg

http://www.somerset.net/arm/radio_pictures/hastings_fm_jr.pdf

http://www.somerset.net/arm/fm_only_lowtech.html

These examples came from "FM only" radio site owned by Andrew Mitz.

Regards,

-Joe

Hans M. Knoll
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21.Mar.09 21:26

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Hello Mr. Sousa.

 
I began as beginners in the year 1949 in the VHF-LAB of a big company as technicians. At last I the head of the TUNER-group was there.
To me is in the 60 years until today, not encountered yet any portable radio that was built in the USA with tubes.
 
regards
 
Hans M. Knoll

This article was edited 22.Mar.09 03:46 by Hans M. Knoll .

Emilio Ciardiello
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21.Mar.09 22:24

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Dear Joe,

I believe that US manufacturers considered FM as a system for high quality broadcasts. They had thoroughly investigated in the ‘930s on the propagation of VHF and UHF waves, as well on the s/n ratio obtainable using FM emissions with different characteristics. FM was suitable for hi-fi transmission within few miles from the transmitter, typically urban areas. For this reason, US manufacturers focused their production on hi-fi receiving components and equipment. In the late forties and in the fifties were introduced many and many good FM receivers, tuners and speaker enclosures. Any good receiver had its adjustable Yagi dipole, over a high mast. Far from the towns, somewhere in the mountains or on the shore, a FM portable radio would have been ineffective at all, while any AM radio could have been used to tune a lot of stations.

According to several pre-WWII studies, AM performed better than FM as soon as the distance from the transmitter increased over 20 to 50 miles, depending upon the power of the transmitters and on the propagation. This assuming a receiving antenna placed at about 30 feet.

The skilled US manufacturers were not interested in promoting portable FM radios. Also because, the same were attracted by more profitable business, as military, and were moving oversea their low end civil productions, in Germany or in Japan. No wonder then, that portable FM radios, even if mainly sold in America, were developed in these countries. I remember that the Schaub-Lorenz (ITT) was the favorite portable radio of US Navy crews here in Naples.

Regards, Emilio
 

Bernhard Nagel
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22.Mar.09 01:12

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Nevertheless, some German FM tube portables were developed beginning with the mid 1950's for export to the north American market. Two portables more known as German domestic variants are: Grundig FM-Concert-Boy 57 USA and the UKW-Boy USA. These had usually the extented FM range up to 108 MHz, and lacks often the long wave range. BC dials has CD markings. I don't know wether other manufacturers also built their FM tube portables for export to the USA.

I suppose the FM tube portable was pretty much a German speciality, since the very fast growing FM transmitter quantity leads to a demand for such radios. Started has it with Telefunken Bajazzo U in early 1953, but one year before the first FM-capable car radios appeared at the market. But this is another interesting story.

Regards, Bernhard

Joe Sousa
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22.Mar.09 05:38

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Thank you all for helping to clarify this mystery.

As I write this message, I am sitting in my living room listening to the evening Blues Music program on the local public station WGBH in Boston MA. The radio is the Grundig Concert Boy 57 USA just mentioned by Bernhard.

I am very satisfied with it's sensitivity and fidelity. On a casual appraisal, it is comparable to AC powered FM tube radios of that era. The station I am listening to is 35 miles (56km) away and there is no noticeable hiss.

The good performance of this FM portable has sparked my curiosity about the front end additive triode mixers in a different thread

.The radio needed some restoration. I replaced the NiCd battery with a sub-C NiMH cell with tabs that I soldered at the rear of the chassis. Beyond that, there was some chassis corrosion causing ground loop hum. The corrosion was between the two major chassis section that are screwed together.

The radio still had some hum, so I added 330 Ohms to separate the two 50uF filter capacitors in the AC high voltage supply. Very strange to see these two caps wired together via a switch. Can't be good for the switch to short charged caps together.

Now the hum is gone.

The NiCd cell drove the filaments originally and is needed in AC mode to regulate the filament voltage. So it is necessary, even if battery operation is not needed. A shunt regulator diode could replace the 1.25V NiCd with some heavy electrolytic filtering.

I also made a 90V power pack from twelve 7.5V NiMH batteries. I connected the batteries to a modern PCB edge connector. Then I use a PCB plug to wire them in series for use with the radio, and a different PCB plug to wire them in parallel for long term storage, recharging and battery charge equalization. When I went on vacation last summer to our beach house, we took the radio and recharged the batteries in series with the original built-in charger.

Addressing several points raised so far:

1-Dear Emilio, I wonder how much effect the change from the original 50MHz pre war Armstrong band to the post war 100MHz band, had in the low FM radio production during the 50s. I have heard from several sources that RCA was very happy with it's AM radio business, and actively thwarted the growth of FM broadcast.

2-Dear Hans, you are a major force in this forum, in particular in matters dealing with FM. Few others know and understand as much as you, and, perhaps, no one else has your experience with early FM in Germany. If you can get past your natural modesty, I think it would be of great interest to the forum audience to hear an account of your career in FM radio design. I think your account would inevitably tell much more than your particular experience, and shed a lot of light in the creative and engineering  processes of FM radio design in Germany. Please feel free to write in your native German, so you would feel most comfortable. Google translate does an acceptable job of translation. We would all be (further) indebted to you.

3-Dear Bernhard, you and Emilio may have the reason why very few FM portables were sold in the USA. The few exceptions were German imports. The main reason may be US population density, compared to the number of FM stations on the air. Even today, the AM dial is full of stations in the US. The AM program content is mostly talk, or news oriented. Some AM stations have enough power for country-wide coverage at night.

Then again, the portable mystery remains, because there were plenty of FM table radios in the US in the 1950's. See Andrew Mitz's FM-only page mentioned above.

I contacted Andrew Mitz, and he commented that "Americans had no use for FM without hi-fi sound before 1960". Andrew also added that there were imitations of the Hastings FM radio that could be found in the back pages of radio magazines.

Regards,

-Joe

This article was edited 22.Mar.09 07:15 by Joe Sousa .

  
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