A really nice matched pair of UTC Input & Interstage transformers … Milspec version of the H-21 (Hermetic sealed series). Both units were tested with audio signals and observed on a scope to be well matched with good response, as these are known for. Introduced in the early 1950's to provide the USA military with rugged, sealed, and hi-fi performance similar to the A, HA series. The H series was amongst UTC’s best rated ruggedized compact transformers..excellent today for audiophiles and recording professionals.
These appear to have the exact same performance and specifications of UTC's listed H-21 model, 15,000 primary to 80,000 secondary -- both of these were measured with an audio signal (see included test sheets) -- they both test GOOD and well matched. They re guaranteed safe arrival and NO DOA.
UTC's H-Series military, audio grade ...always costly -- premium quality and widely used during the heydey of early tube audio recording an playback -- reliable, and well documented interstage and input applications. Compact in in size, and perfect for various interstage and input tube audio -- the split secondary adds to the versatility -- allowing these to be used for phase splitting in parafeed circuits. Early black UTC's are now very sought after as -- they're great to use or collect for to many tube audio projects to name.
If you are looking to get into vintage transformers, early UTC is always a good place to start -- these are the real McCoy and known good performers. And earlier is best -- the early 1950's era produced the finest quality and most beautiful looking and sounding of this series.
These nice transformers include the papers shown, along with UTC info for the H-21.
Tested by audio signal, and scope matched on both units (see papers in photo exhibit), swept 10hz to 20k-- a very nice wonderful functioning, matched performance pair, in every way I could see . Paint is fair, and has many minor nicks, chips ans cosmetic flaws from storage, normal for age. Welded, sealed terminals are nice, tight, no cracks. They present nicely-- these are the old ones, from the first production back in the early 1950s and nice looked after units are getting scarce -- this may be the only set online to buy -- and they are nice, tested and well matched -- Buy Now to avoid a bidders war, they will sell quickly.
Reliable performance is assured with these, they are guaranteed no DOA and will be packed in a double box to assure safe arrival.
Overseas buyers welcome, all vintage audio customers give us 100% feedback, you’re happiness is assured. Combine items for lowest price shipping (If purchasing multiple items, please email first and I will send custom invoice through ebay).