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FS: Cobalt Amorphous Toroid Cores + High Mohm Metal Film Resistors 100M-1.1Gohm

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Well-known member
Jan 17, 2013
Saint-Petersburg, Russia
Have some extra stuff from my builds for sale:

Cobalt Amorphous Toroid Cores - great for small signal Transformers and Inductors \ Chokes,
MSF-20A-T 22.5mm 120μ:

*ruler is in cm :)

Price is 5$\ea

For 5+ qty - feel free to send your offers

Registered trackable airmail shipping worldwide ~7$
Shipping is free if over 50$ total :D
Paypal is accepted

Manufactureres info:
Cobalt Amorphous Core Toroid MSF-20A-T in hard plastic protective container of glass-polyamide and mechanically fixed with silicone sealant.

MSF series toroidal magnetic cores are made of thin (25 microns) Co-based amorphous ribbon with flat hysteresis loop have high permeability and very low losses.

The container has rounded edges and is designed for direct winding of a thick wire. The container provides reliable mechanical protection and preservation of amorphous material's properties. All materials comply with UL94V-1 / 0.


Dimensions: 22.5mm-10.4-10.1

High tech modern production, perfect for Audio signal transformers as well as critical applications of Common Mode Chokes

Induction amplitude, Bm (25°C) 0.59 T
Induction amplitude, Bm (90°C) 0.50 T
Curie temperature, Tc 220°C
Operating temperature range -60°C ... 100°C
Magnetostriction less than 0.1´10^-6
Typical permeability (10 kHz) - 120 000
Typical permeability (100 kHz) - 35 000

High permeability
Decrease in choke size
Decrease in the amount of winding turns
Low active resistivity
Low core loss
Low wire loss
High impedance in a wide frequency range
Comply with IEC 950, EN 60950, BS 601
Low profile

Full Manufacturers info:


+ Some high voltage (5kv-10kv) High value metal film resistors (100Mohm \ 220M \ 330M \ 560M \ 680Mohm),
I use these for tube mic builds with great results    :)

Have two types:

1. R1–32-1  (330Mohm and 680Mohm) Thin-metal film high value resistors (10kV max voltage)

Modern production, excellent quality - High–value, high voltage thin–film resistors


All climate version - stable at wide range of atmospheric pressure and humidity - Operating temperature range from – 60ºC to 125ºC
Designed for use in electrical circuits of DC and AC current.

Maximum operating voltage: 10kV DC

5% \ 1W

Great for measurement equipment and for many DIY projects like tube condenser microphone builds etc.

Full Manufacturers info:

2. C3-14-1 and C3-14-0,5 100Mohm \ 220Mohm \ 560Mohm - vintage made in USSR (NOS 1988 - OTK 5 - top military grade)

Not to much detailed info is available on these, from what I read and can state for sure is that they are:

"Non-wirewound lacquered composition ceramic base resistors in metal encapsulation."

Not stating "carbon" in the data list I found, so I assume they are either metal film or carbon film, not sure if they could actually be carbon composition at this size \ value \ voltage esp. considering metal casing:


Excellent quality

Designed for use in electrical circuits of DC and AC current.

Maximum operating voltage: 5kV DC for 0,5W \ 10kV for 1W

10% 1W \ 0,5W

Price is 5$\ea

For 5+ qty - feel free to send your offers