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Hygrade Lamp Company

Hygrade Lamp Company, Salem, Massachusetts, USA



First seen: 20-Jun-1929
Last seen: 30-Jun-1930

Brand(s): Hygrade, Neptron

Becomes Hygrade-Sylvania


Big history to write here...

Hygrade Lamp Co. hugely sucessful tungsten lamp company.

Hygrade Lamp Co. buys Vossburgh Miniature Lamp Co., 1927

Hygrade Lamp Co. forms wholly owned subsidiary 'the Neptron Corporation' to develop radio tubes; bef 11-Oct-1928

Hygrade Lamp Co. enters the radio tube business, June 1929.

Hygrade becomes 'Hygrade-Sylvania' July 1930. 

Hygrade-Sylvania changes it's name to Sylvania Products in 1942. 


Hygrade variants:

 
H
Y
G
R
A
D
E
X-201A
1
Tube
{v1} Globe, "Hygrade" "X-201A" short engraved bakelite base, tipless, gray/red envelope label.


Hygrade X-201A variant
Hygrade variant
 
 
 
 

{v1} "Hygrade" "X-201A" with gray/red envelope label.[1]



The following Hygrade-Sylvania history was published September 14, 1943 in Warren, Pennsylvania, USA

Hygrade-Sylvania History A
Hygrade-Sylvania History B
Hygrade-Sylvania History C
Hygrade-Sylvania History D
Hygrade-Sylvania History E
Hygrade-Sylvania History F
Hygrade-Sylvania History G

Neptron variants:

 
N
E
P
T
R
O
N
X-201A
1
Tube
{v1} Globe, "Neptron" "X-201A" short engraved bakelite base, tipless.


Neptron X-201-A
Neptron variant
 
 
 
 

{v1} "Hygrade" "X-201A" with engraved base. [11]


Bibliography references:
  1. eBay auction listings, 2018
  2. The Baltimore Sun, 20-Jun-1929, pg. 13. From Newspapers.com. *
  3. The Baltimore Sun, 27-Jun-1929, pg. 14. From Newspapers.com. *
  4. The Evening Sun, Baltimore, MD, 18-Jul-1929, pg. 21. From Newspapers.com. *
  5. The Pittsburgh Press, 11-Sep-1929, pg. 18. From Newspapers.com. *
  6. The Hartford Courant, Hartford, CT, 26-Sep-1929, pg. 22. From Newspapers.com. *
  7. The Baltimore Sun, 03-Oct-1929, pg. 13. From Newspapers.com. *
  8. The Star Press, Muncie, IN, 06-Dec-1929, pg. 20. From Newspapers.com. *
  9. The Evening Sun, Baltimore, MD, 30-Jan-1930, pg. 28. From Newspapers.com. *
  10. The Warren Times-Mirror, Warren, Pennsylvania, 14-Sep-1943, pg. 1-2. From Newspapers.com. *
  11. eBay auction listings, 2018

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