Russian Capacitor Types - UK Vintage Radio Repair and Restoration Discussion Forum

Neil Purling · 1st Feb 2010, 12:11 pm

Does anyone know for sure what the designations on Russian surplus capacitors mean?
I think the Rhombus mark means special quality, maybe military grade.
Can anyone say with accuracy how to decipher what the dielectric material is, if there is any marked reference?
Looking at my stock I see marks like: K42Y-2, K40Y-9 or MbM.

HG MICKE · 1st Feb 2010, 1:25 pm

I have this list of Rusian types which should be of use to you.

K15-4 Ceramic HV "doorknobs"
K15-5 Ceramic HV Disc

K31 Silver Mica "kidney bean" style cap

K40P-2B Paper in Oil, aluminium foil, 5% tol.
K40U-9V Paper In Oil , aluminium foil, Silver body, 10% tol. (also called K40Y-9)

K41-1A PIO, High Voltage "Pulse" caps

K42U-2 metalized paper PIO, green painted body (K75 are better)

K50 Aluminum Electrolytic

K70 Polystyrol

K71-7V Polystyrol "High Tolerance" 1% or 2% tol.

K72P-6 Teflon Dielectric 5% tol. (see example below)

K73-14 PETP High Voltage
K73-15 PETP / Dry Mylar
K73-16 PETP / Dry mylar
K73-17 PETP
K73P-4 "tub " style AC capacitors (may be paper or mylar, still TBD).

K74 PETP HV caps

K75-10 PIO, Green body (these are the prime quality PIO)
K75-15 PIO, High Voltage "tub"
K75-17 PIO High Voltage "tub"
K75-24 PIO Green body tubular (see example below)
K75-28 PIO High Voltage "tub"

K76 Laquer film

K77 PolyCarbonate film

K78 PolyPropylen film

BMT-2 Paper In Oil

FGT High Voltage Teflon Dielectric, Ceramic body (almost beer can size)

KBG, OKBG PIO (no, this isn't the KGB, they're a different entity altogether)

KBI HV "doorknob" RF / Transmitting cap

KSO Silver-Mica "precision" caps

SGM3-A, SGM3-B Silver-Mica "precision" caps (in oil?)

MBG, OMBG-2, MGBO-1, -2, MBGP-2, -3 Metallized Paper-Aluminum "tub" AC caps

MBGCh Metallized Paper pulse capacitors.

Colin

1st Feb 2010, 12:11 pm	#1
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Russian Capacitor Types Does anyone know for sure what the designations on Russian surplus capacitors mean? I think the Rhombus mark means special quality, maybe military grade. Can anyone say with accuracy how to decipher what the dielectric material is, if there is any marked reference? Looking at my stock I see marks like: K42Y-2, K40Y-9 or MbM.

1st Feb 2010, 1:25 pm	#2
HG MICKE Pentode Join Date: Jul 2007 Location: London, UK. Posts: 165	Re: Russian Capacitor Types I have this list of Rusian types which should be of use to you. K15-4 Ceramic HV "doorknobs" K15-5 Ceramic HV Disc K31 Silver Mica "kidney bean" style cap K40P-2B Paper in Oil, aluminium foil, 5% tol. K40U-9V Paper In Oil , aluminium foil, Silver body, 10% tol. (also called K40Y-9) K41-1A PIO, High Voltage "Pulse" caps K42U-2 metalized paper PIO, green painted body (K75 are better) K50 Aluminum Electrolytic K70 Polystyrol K71-7V Polystyrol "High Tolerance" 1% or 2% tol. K72P-6 Teflon Dielectric 5% tol. (see example below) K73-14 PETP High Voltage K73-15 PETP / Dry Mylar K73-16 PETP / Dry mylar K73-17 PETP K73P-4 "tub " style AC capacitors (may be paper or mylar, still TBD). K74 PETP HV caps K75-10 PIO, Green body (these are the prime quality PIO) K75-15 PIO, High Voltage "tub" K75-17 PIO High Voltage "tub" K75-24 PIO Green body tubular (see example below) K75-28 PIO High Voltage "tub" K76 Laquer film K77 PolyCarbonate film K78 PolyPropylen film BMT-2 Paper In Oil FGT High Voltage Teflon Dielectric, Ceramic body (almost beer can size) KBG, OKBG PIO (no, this isn't the KGB, they're a different entity altogether) KBI HV "doorknob" RF / Transmitting cap KSO Silver-Mica "precision" caps SGM3-A, SGM3-B Silver-Mica "precision" caps (in oil?) MBG, OMBG-2, MGBO-1, -2, MBGP-2, -3 Metallized Paper-Aluminum "tub" AC caps MBGCh Metallized Paper pulse capacitors. Colin