Did These Folks Make The Phase Linear Transformers?

mlucitt

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From their Website:
"Schumacher Electric, proudly headquartered in Fort Worth, Texas, is an American powerhouse in the world of power innovation since 1947. Known for industry-leading patents and technologies, Schumacher has built its reputation through an unwavering commitment to quality and producing products that represent a remarkable value.

With an owned, vertically-integrated global supply chain, including facilities in Belgium, India, Mexico, and Vietnam, Schumacher designs and produces a full complement of power-conversion products including battery chargers, testers, maintainers, jump starters, portable power, lithium, and electric vehicle charging as well as custom transformers for the electronics industry. Every product reflects American ingenuity and a commitment to excellence backed by U.S.-based customer service and lifetime technical support."

 
Well, I don't think Phase Linear wound their own transformers. Am I wrong here?
They did not wind their own transformers Mark. Likely some shop local to Edmonds or Lynnwood. Nobody likes to ship really heavy transformers.

There used to be a lot of US 50-60Hz transformer shops, much fewer now due to switchmode PSUs as well as regulatory restrictions (nasty business).
 
Early Phase Linear 700's (sometimes referred to as a 700 series 1) transformers were made by Bob Carvers brother Chuck. According to Bob Carver, these transformers can be identified by the color of the shellac on the windings. Unfortunately, I can't recall what the colors were. Some of the transformers also were made by Bob Carvers partner Steve Johnston brother Greg.

A.P. Van Meter told me a story about how he was tasked (shortly after he was hired as an engineer at Phase Linear in approximately 1973 or 1974?) to see if he could find any ways to reduce the cost of the building of the amplifiers. A.P. asked Bob Carver if there were any sacred cows. Bob replied no and then A.P. responded by saying that his brother Chuck was charging too much money for his transformers. A.P. passed away last month.

The 700 and 700B transformers Phase Linear used thereafter were made by Woodward-Schumacher and Custom Coil. Woodward-Schumacher (founded in 1947) was renamed Schumacher Electric after the death of Mr. Woodward. NOTE: Schumacher Electric is the same (Don Schumacher) family that is into auto and motorcycle racing.

SIDE NOTE: Don Schumacher grew up living above his grandparents' tavern in Chicago. This tavern served as the setting for his parents' bookmaking operations and also the initial establishment of "Woodward Schumacher Electric" by Don Schumacher's father Albert and a former supervisor. “Albert was a transformer winder up in Michigan, but he was a gambler, and after the war….. “.

"As for how Don Schumacher got into drag racing, well, here's the zero-to-60 version: He had lent a former supervisor $2,000 so they could start a business that made transformers for radios and televisions after World War II, and when his business partner died (while attending his father's funeral), Woodward-Schumacher Electric became Schumacher Electric in 1971."

"Albert Schumacher turned over the bookmaking business to Don's mom. Eventually, Lefty and Big Frank had to find another apartment over a tavern at which to make their bets, because the transformer business had taken off."

There were (2) versions of the 700 (series 1) transformers made. The 120V version was part number 050-0335-0. The 240V version was part number 050-0336-0. The 700’s had a “hum shield” mounted on the power supply capacitors with fiber washers. I am not sure how effective this “hum shield” was, as I have not performed any measurements of the amplifier with and without it.

The 700B had a 117V/146CT version (part number 125-0034). There is an inner end bell (aluminum casting) part number 010-0407-0 made by a (local?) foundry whose name escapes me at the moment. The initials of the foundry were BTM. This aluminum piece also provided some magnetic shielding.

Phase Linear also used a 220V or 240V(?) transformer in 700 (series 1) and 700B amplifiers sold overseas. I was not able to locate the part number version.

Near the end of the production of the 700B’s (and into the 700 series 2), Phase Linear used a dual secondary transformer exclusively which can be wired for either 117V/240V operation. The part number was 125-0034.

Phase Linear primarily used non-polarized power cords on their products. The exception were those countries that required a 3-prong power cord. I mention this because depending upon which way the amplifier is plugged into a wall outlet this will affect the AC leakage. You may see a significant difference on the measurement when reversing the power cord. This may have an effect when using (2) transformers in the same chassis if not wired correctly(?). Reversing the line cord can also make a difference in the S/N ratio of up to 5dB on some 700 series amplifiers.

NOTE: An old version of an ANSI C101 standard (…for leakage current for appliances) used a 1.5Kohm shunted by a .15mF capacitor. Over the years, the ANSI standard added additional requirements. It is now a UL standard.
 
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In these situations, it also helps that I have a copy of the 86 page Phase Linear Master Parts Catalog dated 4-8-1981.
The X-formers are listed on pages 84-86. I obtained the list from the estate of Dan K. after he passed away. Dean was going to throw it in the garbage.

I only wish I had a more recent copy listing those products made when Jensen owned the company.

Here is a scan of page 1.

NOTE: I have never shared any copies of the catalog with anyone before.
Don't ask.
 

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Early Phase Linear 700's (sometimes referred to as a 700 series 1) transformers were made by Bob Carvers brother Chuck. According to Bob Carver, these transformers can be identified by the color of the shellac on the windings. Unfortunately, I can't recall what the colors were. Some of the transformers may also have been made by Bob Carvers partner Steve Johnston brother Greg. I will have to ask Dean N. or Steve Johnston. Both Chuck and Greg have since passed away.

A.P. Van Meter told me a story about how he was tasked (shortly after he was hired as an engineer at Phase Linear in approximately 1973 or 1974?) to see if he could find any ways to reduce the cost of the building of the amplifiers. A.P. asked Bob Carver if there were any sacred cows. Bob replied no and then A.P. responded by saying that his brother Chuck was charging too much money for his transformers. A.P. passed away last month.

The 700 and 700B transformers Phase Linear used thereafter were made by Woodward-Schumacher and Custom Coil. Woodward-Schumacher (founded in 1947) was renamed Schumacher Electric after the death of Mr. Woodward. NOTE: Schumacher Electric is the same (Don Schumacher) family that is into auto and motorcycle racing.

SIDE NOTE: Don Schumacher grew up living above his grandparents' tavern in Chicago. This tavern served as the setting for his parents' bookmaking operations and also the initial establishment of "Woodward Schumacher Electric" by Don Schumacher's father Albert and a former supervisor. “Albert was a transformer winder up in Michigan, but he was a gambler, and after the war….. “.

"As for how Don Schumacher got into drag racing, well, here's the zero-to-60 version: He had lent a former supervisor $2,000 so they could start a business that made transformers for radios and televisions after World War II, and when his business partner died (while attending his father's funeral), Woodward-Schumacher Electric became Schumacher Electric in 1971."

"Albert Schumacher turned over the bookmaking business to Don's mom. Eventually, Lefty and Big Frank had to find another apartment over a tavern at which to make their bets, because the transformer business had taken off."

There were (2) versions of the 700 (series 1) transformers made. The 120V version was part number 050-0335-0. The 240V version was part number 050-0336-0. The 700’s had a “hum shield” mounted on the power supply capacitors with fiber washers. I am not sure how effective this “hum shield” was, as I have not performed any measurements of the amplifier with and without it.

The 700B had a 117V/146CT version (part number 125-0034). There is an inner end bell (aluminum casting) part number 010-0407-0 made by a (local?) foundry whose name escapes me at the moment. The initials of the foundry were BTM. This aluminum piece also provided some magnetic shielding.

Phase Linear also used a 220V or 240V(?) transformer in 700 (series 1) and 700B amplifiers sold overseas. I was not able to locate the part number version.

Near the end of the production of the 700B’s (and into the 700 series 2), Phase Linear used a dual secondary transformer exclusively which can be wired for either 117V/240V operation. The part number was 125-0034.

Phase Linear primarily used non-polarized power cords on their products. The exception were those countries that required a 3-prong power cord. I mention this because depending upon which way the amplifier is plugged into a wall outlet this will affect the AC leakage. You may see a significant difference on the measurement when reversing the power cord. This may have an effect when using (2) transformers in the same chassis if not wired correctly(?). Reversing the line cord can also make a difference in the S/N ratio of up to 5dB on some 700 series amplifiers.

NOTE: An old version of an ANSI C101 standard (…for leakage current for appliances) used a 1.5Kohm shunted by a .15mF capacitor. Over the years, the ANSI standard added additional requirements. It is now a UL standard.
Hello Ed,
Thank You for your input, always appreciated.
 
I thought I had remembered a post about Greg Johnston winding transformers.

Sure enough, here is a post by Robin Gudgel (former Phase Linear employee).:

"In my early days of audio, 1971, at Phase Linear, Steve Johnston was Bob Carver's partner. Ken Cox ran the stores, and Greg Johnston wound transformers............."
 
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