Thursday, September 23, 2010

Equivalents of Russian Transistors

1. Bipolar transistors

Russian part

Short description

Western analog

KT3102A general use n-p-n silicon transistor BCY43, BC107A, BC170, BC207A, 2N4123, MPS3709


npn silicon transistors with high h21e (>600)

2N5210, for example
KT312A-B general use n-p-n silicon transistor Almost the same as KT315, excluding case type.
KT608A HF middle-power silicon n-p-n transistor BSX21, 2SC796
KT606A-B middle-power silicon n-p-n transistor for use on HF and VHF applications Couldn't find, sorry
KT326 Common general-use p-n-p silicon device. I guess, any appropriate western transistor will be able to replace it. I wonder, why i can't find it in my databases...
KT602B rather old n-p-n silicon transistor, specially designed for working in final stages of wideband amplifiers. BSY71
GT308 Very old general-use p-n-p germanium transistor. Can't find, sorry.
GT311 Old, but still good germanium n-p-n device for working with frequencies up to 800 MHz. Can't find, sorry.
KT315 general use n-p-n silicon transistor, an old design BC146,
GT402 low-frequency germanium p-n-p transistor, old design Do not know*
GT404 complementary pair for GT402 Do not know*
MP25A-B Very old p-n-p transistor for 'draft' purposes ACY19, ACY23, 2N190-191
KT503A general use n-p-n silicon transistor (for rather low frequencies) 2SD762, for example
P214A Very old p-n-p high-power transistor for low frequencies AD142, for example
KT368A-B Very good high-frequency n-p-n transistor with low noise factor BFS17 , 2SC252
KT812A high-power transistor for low frequencies (n-p-n) KU601, KU602
KT815 Middle-power n-p-n silicon transistor for use in low-frequency circuits BD165
KT814 Complementary pair (p-n-p) for KT815 BD170
KT818G High-power p-n-p transistor, widely used in power supplies and output stages of AF amplifiers. AD142
KT819G The same as KT 818G, but with n-p-n structure BDY20, BDY23
KT940A high-voltage transistor for final stages of video-amplifiers in TV BF338

* - I suppose, any general use germanium transistor will work instead.

2. Field-effect transistors

Russian part

Short description

Western analog

KP303A n-channel JFET with rather low amplification haven't found*
KP307B n-channel JFET, general use 2N3819
KP302A the same as above haven't found*
KP303E the same as above MPF102
KP350A two-gate n-channel MOSFET transistor 2SK39
* Though I haven't found a direct equivalent for this device in my databases, it seems to me,that they are replaceable to 2N3819 and other general-use JFETs (may be, with a slight correction of DC conditions)

3. Analog and digital integrated circuits

Russian part

Short description

Western analog
K544UD1 General-use operational amplifier with high input impedance CA740
K155LA3 four TTL 2&-not elements SN7400
K155LA12 the same as LA3, but with more powerful outputs SN7437
K155IE2 Asynchronous TTL counter.. Has two counters inside - one counts up to 2, the second - up to 5. They may be used separately or connected in series forming a decade. SN7490
K155TM2 Two dynamical TTL triggers of 'D'-type. Also has external 'set' and 'reset' inputs. SN7474
K155TM7 Four TTL triggers of 'D'-type. Ideal for using as a 4-bit storage device SN7475
K155ID6 A simple 4 -> 10 decoder SN7442
K514ID2 4 -> 7 decoder with blanking input for a 7-segment indicator (LED, for example) MSD101
K500LP116 Three differential ECL receivers/amplifiers MC10116
K500TM131 Two ECL D-triggers MC10131

Valentin Gvozdev, Moscow


Wednesday, September 22, 2010

MW_TRF Good Radio_1T_1IC_2Diodes

Here's a very simple AM Radio circuit I've designed couple of years ago. Don't know whether anybody listen to AM stations anymore. But I still use it(maybe I wanted to listen to my own built radio lol..). The radio section is wired using a single transistor(BF494) and it was so amazing that an audible sound is recovered at the output which is faint though. It doesn't use any external antenna and the sensitivity/selectivity of the receiver is pretty good. However I used an amplifier(TA 7368P Toshiba, Low voltage) which drives an 8ohm/1W 4" speaker inside a box rocks the entire room with a high fidelity audio that is unbelievable and outperforms Superheterodyne ones in this regard . It is a reflex receiver.

The audio recovered at inductor L is rather strong comparing to ZN414 and free from oscillations.(I've never succeeded in building ZN414 which always give me annoying motorboating and chirping crappy I say!)

Using a flat ferrite bar antenna allows local reception for a pocket radio and a big rod antenna captures stations beyond 200miles! So it doesn't require an external wire antenna, adding it only helps in electrical noise catch.

Only critical part in the circuit is inductor L, its optimum value gives excellent results. Make rf parts close to the transistor. I made it on a 1.5" ultra small pcb. 2 x AA battery lasts very long.

Another important thing is that the radio is absolutely silent in between the stations - means no noise at all if no any electrical interferance which is a plus point over Superheterodyne receivers. It was so amazing to tune it during power failure period. So I'll call it a true radio.


Suggestion: Replace the upper diode by a Germanium one for more sensitivity.

Monday, September 20, 2010

Theory_Reflexive Circuit and pre-Amplifier

Theory_How to modify the coupling


Valve Sensitive Amplifier_1V_1T

Theory_Using NPN Transistor in Class A Amplifiers

MW_2V_2T_Valve Transistor Hybrid Receiver

MW_Reflex_4T_Spontaflex Radio by Sir Douglas

MW_1V_One Valve Reflexive Radio

MW_2V_Two Pentude Valvees Radio