BITX making will start this 1st week of the 2015.
Actually I wanted to finish my DSB transceiver and a linear project. But due to persistent request from a friend I have to make the bitx-20/bitx-40. I have all the materials, components, tools, and friends with expertize. But there is shortage of quality time due to MQTH and work.
I am also supposed to find the fault with my own bitx--20 and a friends bitx-40. There has been a classical mistake. All the components are soldered with big lead. All the coils are wobbly. There are dry solders. Did not write its making. there is no documenting the process and components changes etc. Thanks ,it has landed on my lab. Nothing to worry my friend i will find the fault. Some time I also do same type of mistake, every body has some ENTROPY. Well, I am 100%committed to solve and send it back.
Well as promised I am starting with printing the bitx schematics and other hams write-ups...
First will be the bill of materials... as per BITX-40......HFI2014.
BLOCK DIAGRAM
Now bill of materials...
03jan2015
prepared the list of resistors
One thing I noticed , total R-73 total C-72, nice combinations. wow !
Now other components
Transistors :-2N3904 / BC549c
IC:- LM386
DIODES:- 1N4148
balun cores,
Actually I wanted to finish my DSB transceiver and a linear project. But due to persistent request from a friend I have to make the bitx-20/bitx-40. I have all the materials, components, tools, and friends with expertize. But there is shortage of quality time due to MQTH and work.
I am also supposed to find the fault with my own bitx--20 and a friends bitx-40. There has been a classical mistake. All the components are soldered with big lead. All the coils are wobbly. There are dry solders. Did not write its making. there is no documenting the process and components changes etc. Thanks ,it has landed on my lab. Nothing to worry my friend i will find the fault. Some time I also do same type of mistake, every body has some ENTROPY. Well, I am 100%committed to solve and send it back.
Well as promised I am starting with printing the bitx schematics and other hams write-ups...
First will be the bill of materials... as per BITX-40......HFI2014.
BLOCK DIAGRAM
 |
| BITX |
Now bill of materials...
03jan2015
prepared the list of resistors
Bitx bill of materials. Bitx-20 or
bitx-40
Component number
|
Value
|
Module
|
Transistor
|
| R1 | 2k2 | RF Rx input amp | q1 |
| R2 | 1k | ||
| R3 | 10 | ||
| R4 | 220 | ||
| R5 | 220 | ||
| R6 | 100 | ||
| R7 | 2k2 | Rf TX output amp | q2 |
| R8 | 220 | ||
| R9 | 100 | ||
| R10 | 220 | ||
| R11 | 10 | ||
| R12 | 1k | Rx, If amp-1 | q3 |
| R13 | 2k2 | ||
| R14 | 1k | ||
| R15 | 10 | ||
| R16 | 220 | ||
| R17 | 220 | ||
| R18 | 100 | ||
| R19 | 2k2 | Tx, if amp-2 | q4 |
| R20 | 220 | ||
| R21 | 100 | ||
| R22 | 220 | ||
| R23 | 10 | ||
| R24 | 1k | ||
| R25 | 100 | Rx, if amp-2 | q5 |
| R26 | 220 | ||
| R27 | 2k2 | ||
| R28 | 1k | ||
| R29 | 1k | ||
| R30 | 470 | ||
| R31 | 2k2 | Tx, if amp-1 | q6 |
| R32 | 1k | ||
| R33 | 4r7 | ||
| R34 | 470 | ||
| R35 | 100 | ||
| R36 | 220 | ||
| R37 | 2k2 | Rf tx output amp | q7 |
| R38 | 1k | ||
| R39 | 10 | ||
| R40 | 100 | ||
| R41 | 100 | ||
| R42 | 2k2 | Vfo amp | q8 |
| R43 | 1k | ||
| R44 | 10 | ||
| R45 | 220 | ||
| R46 | 100 | ||
| R47 | 100k | Xtal vxo | Q9,10 |
| R48 | 1k | ||
| R49 | 1k | ||
| R50 | 1k | ||
| R51 | 100 | ||
| R52 | 220 | Mod/demod | pad |
| R53 | 22r | ||
| R54 | 220 | ||
| R55 | 4k7 | vfo | Q11 |
| R56 | 220k | ||
| R57 | 10k | ||
| R58 | 10k | ||
| R59 | 100 | ||
| R60 | 4k7 | Q12 | |
| R61 | 2K2 | ||
| R62 | 1K | ||
| R63 | 10 | Audio amp | LM386 |
| R64 | 100 | ||
| R65 | 220 | ||
| R66 | 4K7 | Af pre amp | Q14 |
| R67 | 120k | ||
| R68 | 2k2 | Tx af amp | q14 |
| R69 | Not needed | ||
| R70 | 10k | ||
| R71 | 220 | ||
| R72 | 2k2 | ||
| R73 | 4k7 | ||
| preset |
and capacitors. ...
Capacitor
|
Component number
|
Value
|
Module
|
Transistor
|
|
C1 |
*text |
BPF |
|
|
C2 |
22pf trimmer |
|
|
|
C3 |
*text |
|
|
|
C4 |
100n |
|
|
|
C5 |
22pf trimmer |
|
|
|
C6 |
100p |
|
|
|
C7 |
10p |
|
|
|
C8 |
22pf trimmer |
|
|
|
C9 |
100p |
|
|
|
C10 |
68p |
|
|
|
C11 |
0.1 |
Rx, RF input amp |
q1 |
|
C12 |
0.1 |
|
q2 |
|
C13 |
0.1 |
|
q1 |
|
C14 |
0.1 |
|
q1 |
|
C15 |
100n*/0.1 |
|
q1 |
|
C16 |
0.1 |
TX, RF output amp |
q2 |
|
C17 |
0.1 |
|
|
|
C18 |
0.1 |
|
|
|
C19 |
0.1 |
|
q3 |
|
C20 |
0.1 |
|
q4 |
|
C21 |
0.1 |
Rx,If amp-1 |
q3 |
|
C22 |
0.1 |
|
q3 |
|
C23 |
0.1 |
|
q3 |
|
C24 |
0.1 |
TX, If amp-2 |
q4 |
|
C25 |
0.1 |
|
q4 |
|
C26 |
0.1 |
|
q4 |
|
C27 |
100p |
Xtal filter |
|
|
C28,28a |
100p,100p |
Xtal filter |
|
|
C29 |
100n/0.1 |
Rx, IF amp-2 |
q5 |
|
C30 |
100n/0.1 |
|
q5 |
|
C31 |
0.1 |
TX, IF amp-1 |
q6 |
|
C32 |
0.1* not needed |
|
|
|
C33 |
0.1 |
|
q5 |
|
C34 |
0.1 |
|
q6 |
|
C35 |
0.1 |
|
q6 |
|
C36 |
0.1 |
|
q6 |
|
C37 |
0.1 |
|
q6 |
|
C38 |
0.1 |
Tx, RF PA
|
q7 |
|
C39 |
0.1 |
|
q7 |
|
C40 |
0.1 |
|
q7 |
|
C41 |
0.1 |
|
q7 |
|
C42 |
0.1 |
VFO driver amp |
|
|
C43 |
0.1 |
|
|
|
C44 |
0.1 |
|
|
|
C45 |
22pf trimmer |
Xtal OSC |
q9 |
|
C46 |
47p |
|
q9 |
|
C47 |
220p |
|
q9 |
|
C48 |
220p |
|
q9 |
|
C49 |
0.1 |
|
q9 |
|
C50 |
0.1 |
|
q10 |
|
C51 |
50micro henry |
|
|
|
C52 |
22pf trimmer |
Mod/demod |
d12 |
|
C53 |
10p |
Mod/demod |
d11 |
|
C54 |
0.1 |
VFO |
q11 |
|
C55 |
0.1 |
|
q11 |
|
C56 |
10p |
|
q11 |
|
C57 |
22pf trimmer |
|
q11 |
|
C58 |
47p |
|
q11 |
|
C59 |
220p |
|
q11 |
|
C60 |
220p |
|
q11 |
|
C61 |
220 micro H,25v |
|
q11 |
|
C62 |
1 micro H, 25v |
|
|
|
C63 |
0.1 |
Af amp LM386 |
|
|
C64 |
220 micro H,25v |
|
|
|
C65 |
0.1 |
|
|
|
C66 |
1 micro H,25v |
Af pre amp |
q13 |
|
C67 |
50 micro,25v |
Tx, AF amp |
q14 |
|
C68,68a |
1 micro H,25v, 100p |
|
q14 |
|
C69 |
1 micro H,25v |
|
q14 |
|
C70 |
50 micro H, 25v |
|
q14 |
|
C71 |
50 micro H, 25v |
|
q14 |
|
C72 |
0.001 / 1000pf |
|
q14 |
One thing I noticed , total R-73 total C-72, nice combinations. wow !
Now other components
Transistors :-2N3904 / BC549c
IC:- LM386
DIODES:- 1N4148
balun cores,
