NewYorkDave
Well-known member
Last year, we replaced a number of audio line amps that had been in service in our master control room for about thirty years. These were made by Dynair; and although the company has vanished almost without a trace, it was once a leading manufacturer of terminal equipment for the television broadcast industry. The line amps seemed "interesting" and had good transformers in them, so I decided to save them from the dumpster.
In search of a schematic, I contacted the present owners of the Dynair name, to no avail. Eventually, I happened upon the name and email address of Dynair's founder, Garry Gramman, who'd sold the company some years earlier. I emailed him:
I received a reply the next day:
I was hoping to save myself the trouble, but I took Garry's advice and traced out the circuit. Over a year later, I finally got around to drafting a legible schematic, and here it is:
10kB PDF
By the way, Mr. Gramman shuffled off this mortal coil only three days after responding to my email, so I present this as a tribute to him.
Pictures to come.
In search of a schematic, I contacted the present owners of the Dynair name, to no avail. Eventually, I happened upon the name and email address of Dynair's founder, Garry Gramman, who'd sold the company some years earlier. I emailed him:
Mr. Gramman,
I happened across the page about you on the "Order of The Iron Test Pattern" website while doing a websearch on Dynair. I've been looking for a schematic for an old Dynair product... Meret couldn't help me, but perhaps you could point me in the right direction. The schematics I need are for the AD-3081A audio line amplifier and the PS-3015 power supply. Thanks in advance for any advice you can offer.
Oh, by the way, I'm happy to report that our System 21 routing switcher is still in service after more than 22 years. It's only now slated for replacement.
David ______
I received a reply the next day:
Dear Mr. ______,
The AD-3081A and the PS-3015A were developed in 1963 at the same time as the 5100 switching equipment was designed.
When I sold the Company in 1995 I did not bring any instruction manuals or schematics with me.
Since the products were, I believe, designed entirely with discrete components and single-sided circuit boards, the circuits should be traceable without too much difficulty.
I'm sorry that I can't give you any real information.
You made my day with the news that your System 21 is still in service after 22 years!
Garry Gramman
I was hoping to save myself the trouble, but I took Garry's advice and traced out the circuit. Over a year later, I finally got around to drafting a legible schematic, and here it is:
10kB PDF
By the way, Mr. Gramman shuffled off this mortal coil only three days after responding to my email, so I present this as a tribute to him.
Pictures to come.