Soft66Lite is slightly changed. Because some components are becomming expensive. Yen is higher rate. I am re-designning Soft66Lite for keeping cheap price.2010/9/5
Price of Soft66Lite is not changed.


Default kit including
all components for building. see details parts list.
50.022MHz,50.15MHz,50.19MHz,50.22Mhz crystals
7.03MHz,7.07MHz(may be changed)

sample wav file of 50.19MHz




40m  C1,C3 -> 1000pF   C2 -> 100pF , L1,L3 -> 0.47uH , L2 -> 5.6uH
6m  C1,C2,C3 -> 47pF  , L1,L2,L3 -> 0.22uH

About R4
Soft66Lite has RF amp upc1658. upc1658 is high gain amp. It is over spec for HF band under 15m band. If you hear only 40m and 80m, it is reccomended R4 is 6.7k ohm.  I reccomend R4 is 10k or 20k trimmer for adjusting sensibity. If you receive over 20m band, it is reccomended 330 ohm.

 New version PCB. Please look silk of trim resister.

PIN asign of ICS512M

Connecting to PC

3.5mm Jack to LINE IN of Sound Card.
DC power is 9V to 15V.
ANT impedance is 50 ohm.

Configuration of multiplier

SV3 2-3 -> x1, 1-2 -> SV1 and SV2

SV1 M 2-3 M 1-2 2-3 1-2 M 2-3 1-2
SV2 M M 1-2 M 2-3 2-3 2-3 1-2 1-2
x x2 x2.5 x3 x3.333 x4 x5 x5.333 x6 x8
M is no connecting.
 Example  Q1-> 50.19MHz SV1->M,SV2->M,multi->x2,ICS512M OUT->100.38MHz,74LVC74->50.19MHz
Example  Q1-> 7.05MHz SV1->1-2,SV2->M,multi->x6,ICS512M OUT->42.3MHz,74LVC74->21.15MHz
Example  Q1-> 7.05MHz SV1->M,SV2->M,multi->x2,ICS512M OUT->14.1MHz,74LVC74->7.05MHz
Example  Q1-> 7.05MHz SV3->2-3,ICS512M OUT->7.05MHz,74LVC74->3.525MHz

If you select 3.525MHz, center frequency is 3.525MHz.
You can receive 3.501MHz to 3.549MHz with 48kHz sampling sound card.
If you use 96kHz sampling sound card, you can receive 3.477MHz to 3.573MHz.

Crystal frequency is selected by SV1,SV2,SV3.

2type johnson counter

Soft66Lite has 2 type of johnson counter.
One type is needed 2 times of target frequency with 74AC86.
Usually yu should make this 2 times type.

another type is needed 4 times of target frequency without 74AC86.
Please do not solder 74AC86.
SJ1 jumper is soldered both side. If you have crystal which is 4 times of target frequency.
Please use this type.
Example   42.8MHz crystal -> SV3 -> 2-3 ->74LVC74 -> 10.7MHz

How to receive with Soft66Lite

There ars few type of Software Defined Radio. Soft66Lite works with demodulator software on PC. You need Windows PC and Sound Card. Demodulator soft is Rocky, Winrad, SDRadio.  Installing software to your PC, connect LINE IN to 3.5mm Jack of Soft66Lite. Soft66Lite needs about 7V to 15V DC. 12V is reccomended. Do not forget antenna. Raunch Rocky or SDRadio and set up sound card setting. click start button.

Soft66Lite parts list

C1,C2,C3,C4,C5,C6,C12,C15,C16 0.1uF

Plastic bag

R1,R5,R6 47

C7,C9,C13 1uF

R7,R8 5.1k

C8,C11 330pF

R9,R10 2.2k

C18,C19 20pF

R4 330 to 1k *

C10 47uF

3PIN x 3, jumper x3

Plastic bag


0.01uF or 1000pF

L1,L14,L28 22uH or 47uH

D1 1N4004


IC1 74LVC74

IC2 OPA2356

U$2 upc1658


IC3 74AC86

U$3 SN74CBT3306

U$6 ICS512M


Plastic bag


Plastic bag

14pin IC socket

Plastic bag

BPF components for 40m and 6m. 14pin socket is optional.

Simple instruction for builders

1st step solder ICs first.
2nd step solder resisters
3rd step solder capacitors

SJ1 and SJ2 is no soldering.

You need solder jumper of back side of PCB. Please solder 5V line side ON.

2011.5.16 New PCB is arriving. Please look bellow image.
UPC1688 is placed at side of C15.
There is no solder jumper on solder side of PCB.