Page 1
CS Series SSB Transceiver Single Band SSB Transceiver Kit Manual Rev. Preliminary Release – CRKITS.COM April 8, 2017 – Preliminary Release Original written by Adam Rong, BD6CR/4 Modified by Larry Lovell, N7RGW Email: http://www.crkits.com Thanks to the following people for their editing and help.
THANK YOU! Thank you for purchasing your CS-SERIES Single Band SSB Transceiver Kit. The kit was designed by BA6BF, and is now supplied by CRKITS.COM and its worldwide distributors. The CS-SERIES kit is an ideal candidate for field operation, back pack and emergency use.
To download your local language documents, you can search the CHINA_QRP group file section on Yahoo or go to the document archive section of http://www.crkits.com/. There you will find a list of all documents (Thanks EA2SN for Spanish translations and JL1KRA for Japanese translations).
Page 4
PA is easily damaged. NOTE: With this initial revision of the Assembly Manual, it is recommended that you first begin with the assembly of the Digital Detailed manual with photos located at Sandwich: See: http://www.crkits.com/...
Page 5
Step 0: Sandwich Digital VFO Let's start with the Sandwich Digital VFO. It is an Arduino and Silicon-Labs si5351a based open-source design by CRKITS.COM to offer stable and wider range frequency coverage. A dual-color LED offers frequency reading capability. It has three outputs: One for VFO, another for BFO and the last one for crystal calibration.
Page 6
8467.2kHz Other than the above setting difference, for CS-series kit building, please refer to the kit building manual at http://crkits.com/sandwichkitassemblymanual.pdf We will assemble the Sandwich Kit first, but not install it with the main PC Board at this time. DO NOT attach Sandwich Kit to faceplate at this time.
Step 1: Power Supply Circuit Let's start with the power supply circuit. Should you want to study the whole schematic prior to the building to have better understanding, you may find a copy of the circuit at the end of this manual. Please study the partial schematic before soldering.
Page 8
Solder 1x 7808 as shown for test purposes now. If your kit comes with LM2940-8.0, it is an upgrade for lower dropout voltage. Plug in a 12~13.8 V power supply to the DC IN connector (center positive) and measure the voltage on pin 3 of 7808 near to the 104 capacitor to see if it is within +/-5 % of 8 V;...
Step 2: Audio Amplifier The core component of the audio amplifier is a TDA2822M. It is a dual channel amplifier but we only use one channel here. Please study the schematic before soldering. Place 1x 8 pin IC socket, paying close attention to the notch, and solder, then insert a TDA2822M with correct orientation as shown on the photo Solder 1x 1000 μF capacitors;...
Page 10
Plug in a 12~13.8 V power supply and connect an external speaker of 8 Ω or higher impedance to the speaker connector. Touch pin 5 of the nearby NE602A using tweezers to inject some noise, and note if the audio amplifier works. If not, please check your soldering, and check the pin 2 of the TDA2822M for the presence of 8V.
Page 11
Step 3: Detector/ Double Sided Band Modulator The core component is a double-balanced mixer and oscillator NE602A. It acts as the detector in the RX path and also as a DSB modulator in TX. Please study the schematic before soldering. DETECTOR Sandwich BFO +8VR...
Page 13
Step 4: RX IF Amplifier The core component is an MC1350. There is no AGC circuit designed, and the IF gain is controlled by a potentiometer (IF GAIN) and also used as volume control. A crystal filter is added after the output network of the MC1350. Please study the schematic before soldering.
Page 14
Pick the potentiometer marked B10K and solder it as IF GAIN control, making sure that the shaft is vertical to the PCB side Solder the remaining inductors, resistors and capacitors. When finished, it will look like the photo below. Plug in a 12~13.8 V power supply and connect an external speaker to the speaker connector.
Page 15
Step 5: IF Crystal Filter This part includes 6 each 8.4762 MHz IF crystals, 7x capacitors and 2x relays. Please study the schematic before soldering. Xa is a marking for IF crystals. Always check PCB marking for the difference between 20m and 40m versions. Pick 6 each 8.4762 MHz IF crystals and solder.
Page 16
Step 6: Mixer and VXO Local Oscillator The core component is another double-balanced mixer and oscillator NE602A. It acts as the RX/TX mixer. The Digital Sandwich will replace the VXO crystals and the BFO oscillator. DO NOT install: VXO crystal(s). Do not install parts with marking ended with #.
Page 17
Connecting the Sandwich to the PC Board Solder on the main board as shown to get regulated 8V power. Mount assembled sandwich to the front panel as shown Solder the two 104 capacitors as shown. Connect the ground pin as shown...
Page 18
Plug in a 12~13.8 V power supply and connect an external speaker to the speaker connector. Touch pin 1 of the NE602A using tweezers or even with an antenna cable tip to note if strong band noise comes out of the speaker. Turn the TUNE control to check if VFO frequency changes thus the noise tone changes.
Step 7: RX Front End This part of circuit includes an antenna connector, a relay, two 1N4148 diodes as a level limiter for protection purposes and two DIY7-xx IFT's (DIY-3.8 for 80m, DIY7-7 for the 40m or DIY-14 for 20m) as RX band-pass filters (BPF).
Page 20
Now let's do a brief alignment and enjoy receiving on-air signals. Plug in a 12~13.8V power supply and connect an external speaker to the speaker connector. Touch ANT pin using an antenna cable tip to note strong band noises or signals coming out of the speaker.
Page 21
Step 8: TX Amplifiers and Low-Pass Filters (LPF) This part of the circuit includes a BPF composed of two DIY7- IFT's (DIY-3.8 for 80m, DIY7-7 for the 40m or DIY-14 for 20m), three amplifier stages using a C3357, a D882 and an IRF510 respectively, and a two stage LPF. Please study the schematic before soldering.
Page 22
Solder the remaining parts, with the exception of all toroid coils, and the D882 and IRF510 transistors, which will be installed later in final assembly stages. When finished, it will look like the photo below.
Page 23
Unsolder the 7808 voltage regulator, and clean the solder from the pads and pins We will use two kinds of toroid coils as shown. LPF coils (2x) are on the top. They require (11 turns for 20m or 15 turns for the 40m version, 22 turns for 80/75m) windings on the toroids T37-2 (red) using about 25 cm of enamel wire.
You will need to drill 7x M3 holes on any one of the two chassis pieces, since they are identical, but only on one, please :-). Download the drilling template from http://crkits.com/template.pdf. Print it on a piece of A4 size paper with 100% scale (the default scale is not necessarily 100%). Cut off the outline and fit it into the chassis bottom.
Page 25
Install the 4x rubber feet with 4 pairs of M3x10 screws and M3 nuts. The nuts should be placed in the holes of the rubber feet, otherwise the screws will be too long to interfere with the PCB. You can press the rubber feet by your fingers so you can drive screws easily to the nuts and tighten them.
Page 26
Bend the pins of the 7808, IRF510, and D882 semiconductors as shown. Please note that IRF510 is a electrostatic sensitive part, so handle it with care. Place insulator pads on the places where the body of the D882 and IRF510 transistors will lie.
Page 27
After you are done, the front panel will look much like this one. Make sure the B10K potentiometer has a nut on first. Plug in the microphone cable into the SIP5 socket on board, install the front panel using two black chassis screws, then put a washer and another nut on the potentiometer.
Page 28
Preset the IF GAIN control to mid-way and you are ready to start alignment. After alignment, remember to install the top chassis using another 4x black chassis screws.
Page 29
Alignment RX Alignment In previous steps we have done most of the RX alignment. Now we are going to use an audio spectrum analyzer software (on a PC running Windows) to fine tune the BFO frequency, so the RX voice can be very clear, and more importantly, the carrier and the opposite sideband are well suppressed.
Page 30
Follow the setup on the screen capture below, and click start, you will see a similar audio spectrum. If not, you may need to turn clockwise or counter clockwise the IF GAIN control. In BFO calibration mode of the Sandwich digital VFO, tune encoder to move the pass-band to the left or to the right.
Page 31
Then, tune the Sandwich digital VFO to check the frequency coverage and accuracy. You can use a calibrated radio to receive the same signal and know where you are on the band, or you can use a signal generator to inject a specific frequency so you can get the range that you want quickly.
Page 32
Setting bias voltage for the final amplifier IRF510: Make sure that the SET BIAS trimmer is preset to fully counter clockwise first. Connect an ampere meter in series with the power cable (set to measure 1A or more) Press PTT but do not talk to the microphone, the current will likely be 0.50 A.
Theory of Operation We have explained the theory of operation in each functional block. Here it may be beneficial to go through the signal flow so it will help to understand the whole schematic diagram on the last page. The CS-SERIES is a simple design with two NE602A chips which are used both for RX and TX.
Troubleshooting If you follow the manual step by step, the success rate of the kit should be very high. Should you have any trouble, the #1 rule of thumb you should remember is that you probably have soldering problems, either cold soldering, solder bridges or misplaced components.
Page 36
Voltages in RX @ 13.8 V, “var” means variable, * is for detector IC near BFO, and ** is for mixer IC near NE602A* MC1350 NE602A** TDA2822 C3357 D882/BD1 IRF510 8050 13.4 D 13.4 C Voltages in TX with PTT on but no modulation @ 13.8 V, “var” means variable, * is for detector IC near BFO, and ** is for mixer IC near VFO NE602A* MC1350 NE602A** TDA2822 C3357...
Need help?
Do you have a question about the CS Series and is the answer not in the manual?
Questions and answers