On Thu, Feb 9, 2017 at 6:31 PM, John Backo via Groups.Io <iam74@...> wrote:
Ken:
They are T-37-6 toroids.? Toroids are classified by their diameter and their color.
Hence, T50-2 toroids would be 1/2 inch across and color red, usually used in a frequency range below 30m.
The usual colors for RF are? red (type 2). yellow (type 6) and white (type 7).
Beware of toroids that are yellow with a white side. They are common in switching power supplies. These are #26 material and are meant for low frequency switching.
Note that this nomenclature applies to powdered metal toroids. Ferrite toroids are different. Generally they are all black or grey. The same
size nomenclature applies but they a totally different mix. Usual ones in Rf are FT-37-43 and FT-37-61. The "FT" stands for "Ferrite Toroid".
FT's are usually used in broadband transformers and mixers.
