Please visit my page.Assembled New Soft66AD is arriving. This kit is aready discontinued.


Assembly description


80M is option

New Soft66DB2 is arriving

The recording which received can be heard.

The software radio released until now began from the test prototype, and had two or more versions. If it includes to what is not exhibited, the trial production board is one cup of carton box.

This Soft66DB carries the band path filter which used the troid core, and thinks that the appearance as a receiver would be ready now.

In an old version, it is the most highly sensitive, and is finished. Even if it hears TS680V which are at hand and being compared, it is audible equal.

For the time being, it is a release with a 7MHz belt. Other bands are due to be developed little by little after this.

Please mail me feel free, about Soft66DB.

You can use DDS-33 with Soft66DB.

New version is start from April.

The assembly of Soft66DB ,EASY SOLDERING!

Soft66DB adds the band path filter which used the Troid core for Soft66D. 74HC(s)74 of devider are changed into 74AC74, and TC4066 of a mixer is changed into 74HC(s)4066. The frequency band which can respond was not only extended, but sensitivity is improved by change of a mixer chip. If an office dispatch number can be poured in well, it is the specification which can use even a 28MHz belt.

Center frequency is 7.056MHz(NEW).

Since the assembly is using the DIP parts and the usual part, there is no difficult to solder them by hand. In the portion which rolls a coil, since the bifiler coil is carried out, if cautions remove a required point for a while, a soldering beginner should be able to also assemble easily. Although UEW melts and it should be able to solder with the heat of solder iron, since 0.32attached UEW line does not melt in iron with small capacity, it is necessary to polish it by sandpaper beforehand.  

A shematics and part arrangement

It is a shematic. It will become large if it clicks.

It is a part arrangement plan. It will become large if it clicks. Since a jumper wire is under 74AC74 and an operational amplifier, please wire first(red line is jumper).

It is the home made PCB contained in a kit.

Please wire jumper first.

Example construction.kits is not include ANT pin and V+ pin.

New PCB and Parts

click enlarge

How to roll a band path filter

Please coil a UEW line around a core first. If it winds in order of L2, L3, and L1, a PEW line should be able to be used up well. Respectively required length and a respectively required number of turns are as follows (the following data is an object for 7M belts.). About 3.5M, 14M, and 21M, a number of turns and the capacity of a capacitor are due to be raised one by one.

L2  14T(T30-6,yellow)、12T(T30-2,red)
L3  33T(T30-6,yellow)、30T(T30-2,red)
L1  bifiler14T (T30-6,yellow)、12T(T30-2,red)
C10,C15= 220pF + 680pF

3.5M & 7Mband
L2  20T(T30-6,yellow)、19T(T30-2,red)
L3  33T(T30-6,yellow)、30T(T30-2,red)
L1  bifiler 20T(T30-6,yellow)、19T(T30-2,red)
C10,C15= 100pF + 680pF

The state which rolled L2


Since L1 is bifiler, it turns up and twists a PEW line. If it turns to a finger round and round through one of the two, it can twist easily.

Please coil the twisted line 14 times and confirm an electrical connection, respectively.

It will be easy to solder if the end of the PEW line of the core which it finished rolling is polished by sandpaper.
Please set C11 150pF and C15,C16 1000pF to make BPF zone large.
Please set C11 120pF and C15,C16 800pF to make BPF zone narrow.


Description of including parts

It is description of the part attached to a kit. It may change without a preliminary announcement into other parts.

The 0.1uF tantalum capacitor of C14, C4, C5, C3, and C2. The one where a leg is longer is +. It is small written as 104.

C11,100pF ceramic capacitor. 150pF may be contained.

C15, C16 or 1000pF ceramic capacitor. 680pF may be contained.

The tantalum capacitor of C1. The one where a leg is longer is +.

The tantalum capacitor of C12 and C13. Please turn + with a longer leg to an operational amplifier side.

Operational amplifier. NJM2068DD of JRC.

The laminating ceramic capacitor of C8 and C9.

74AC74 (it is careful in the direction which applying cuts.) It is a very confusing chip.



5.1k of R5 and R6. There is also a case of 4.7k.

2.2k of R7 and R8. There is also a case of 3.3k.


The tantalum capacitor of 47uF(s). The one where a leg is longer is +.

The diode for rectification of 400V1A

OSC(change to daughter board with 28.224MHz crystal resonator)

Earphone jack. Please cut two inside legs with nippers. Please make the remaining legs straight on radio pliers.

The ceramic capacitor of supplementary 0.1uF. Since the frequency characteristic is good, it may put in instead of tantalum.

It connects with a personal computer and recieve.

Please check whether it is correct to connection of better [ in the end of an assembly ] た et al. and parts. An antenna is connected with ANT. Although it connects with the sound card of a personal computer, since the microphone input is a monophonic recording, please connect almost all sound cards with the line in of a stereo input.

Download of SDR radio

It is click in the middle of this homepage. Since it is with here, it clicks and downloads. It will be installed if the downloaded file is performed. If SDRadio is started, please connect a power supply with an experiment circuit. A push on the lower left RX button starts reception.


Download Rocky

It seems that Rocky is suitable when receiving amateur radio. Compared with SDRadio, receiving sound can be heard quite firmly. But it is very easy to hear the Morse code.

When the signal reversed in the contrastive position can be heard, please adjust the balance of line in. Moreover, the whole noise level also falls by adjusting the level of line in.


最終更新日: 06.3.23