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 The Colossus of Radio -- Crosley Radio Corporation’s 1936 “WLW Model Super-Power Radio Receiver”
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 Return to top of page · Post #: 1 · Written at 4:51:21 PM on 3 August 2020.
GTC's avatar
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6406

QUOTE: In 1935, the Zenith Radio Corporation produced a stunning radio receiver called the Stratosphere model 1000Z. The set used 25 tubes and three loudspeakers — more than any other radio to date. An amazing (for the time) 50 watts drove its three speakers — one 6 inch dynamic high-frequency and two 12 inch dynamic low-frequency speakers.

Standing 50-1/2 inches tall, the Stratosphere sold for $750.00 — more than many automobiles; in comparison, a new Ford cost $652.00. At that price, it’s no wonder that only about 350 sets were produced during the four years that the Stratosphere was offered.

This achievement impressed Powel Crosley, Jr. — the President of the Crosley Radio Corporation — who praised it as a fine example of quality in radio construction, but it used “only” 25 tubes and three speakers! Crosley — who also owned the 500,000 watt powerhouse radio station, WLW — was inspired to surpass Zenith by bringing the world the largest and most powerful radio receiver yet known.

A close friend of Commander Eugene MacDonald — President of Zenith — Crosley may have taken the Stratosphere as a light-hearted challenge. That aside, Crosley later said, “It is fitting that the owner of the world’s most powerful radio station make the world’s greatest radio receiver.”

Crosley’s engineering and marketing staff urged him to forget the idea. They felt that it was an impractical exercise from an engineering standpoint and that the market for such a radio — if one existed — would be miniscule. Crosley, however, was not easily discouraged and, as one employee put it at the time, “It is characteristic of Mr. Crosley that he is a good salesman — enough so to win his point in an amiable manner.” Of course, the fact that Crosley owned the company had some bearing on the matter.

Surpassing the Zenith Stratosphere turned into a bigger project than anyone had expected.

Read all about it here:

 Return to top of page · Post #: 2 · Written at 5:45:31 PM on 3 August 2020.
Brad's avatar
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 6851

All you'd then need is your own 500kVA MG set to power it up. Wink

A valve a day keeps the transistor away...

 Return to top of page · Post #: 3 · Written at 6:54:38 PM on 3 August 2020.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 1049

Oh, that is GREAT.
That would make a terrific project!

I'll start the planning now.


 Return to top of page · Post #: 4 · Written at 7:57:30 PM on 3 August 2020.
Robbbert's avatar
 Location: Hill Top, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 1737

Every conceivable feature that you'd want in a radio.... maybe, but there was no record player.

The thing must have drawn a lot of power, with its 2 rectifiers.

 Return to top of page · Post #: 5 · Written at 9:33:14 PM on 3 August 2020.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4749

Two rectifiers was not unusual I have serviced Midwests with 16 & 18 valves & there were two #80's with their plates paralleled.

Consider 18-36: two 5Z4's with a 6F6 driving four 6F6's in parallel. Autodyne with separate Colpitts exciter. Electrodynamic woofer & tweeter.

18-37: 2 by #80 : Two 6L7 as phase splitters feeding four 6N6 power amplifiers http://frank.yueksel.org/sheets/127/6/6N6G.pdf also auto dyne with Colpitts exciter.

Welding transformer for the 18 room heaters

 Return to top of page · Post #: 6 · Written at 10:15:43 PM on 3 August 2020.
NewVista's avatar
 Location: MilwWI, US
 Member since 10 May 2013
 Member #: 1340
 Postcount: 858

The speakers are from Jensen, the first choice back then for pro-quality in radios, organs, movie bass..

Radio is 5-ft high, so are the ladies, 'forced perspective' Smile

 Return to top of page · Post #: 7 · Written at 9:28:34 AM on 4 August 2020.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 1049

Re #4 Rob,

Ah, ok, I'll add a record player!


 Return to top of page · Post #: 8 · Written at 12:12:07 PM on 4 August 2020.
Irext's avatar
 Location: Werribee South, VIC
 Member since 30 September 2016
 Member #: 1981
 Postcount: 420

I wonder if any examples still exist.

 Return to top of page · Post #: 9 · Written at 6:49:32 PM on 4 August 2020.
NewVista's avatar
 Location: MilwWI, US
 Member since 10 May 2013
 Member #: 1340
 Postcount: 858

Its 18" woofer is identifiable as a Jensen by the characteristic cast alloy basket moulding.
With same cone and 2" voice-coil used for Jensen/WE-ERPI TA-4181 film-sound woofer.
I tested the resonance of these once, came in at 28 to 30Hz, this resonant rise compensating for some open baffle cancellation.
The Bass from this radio would have been deep, effortless, 'magnifique'

 Return to top of page · Post #: 10 · Written at 10:37:51 PM on 4 August 2020.
Tallar Carl's avatar
 Location: Latham, ACT
 Member since 21 February 2015
 Member #: 1705
 Postcount: 1817

Irex yes they do still exist


 Return to top of page · Post #: 11 · Written at 11:39:53 AM on 5 August 2020.
Irext's avatar
 Location: Werribee South, VIC
 Member since 30 September 2016
 Member #: 1981
 Postcount: 420

Amazing pair of radio's.
Would have been a marathon restoration.
Video was a bit cheesy and hard to watch but the subject matter was awesome.
All that chrome and still original with very little pitting.
Just goes to show what can be made when the budget is unlimited.
The Bugatti Veyron of radio's.

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