SSB6.1 with Si5351 RX Working

After a few trials, it looks like I figured out how to get the SSB6.1 to hear stuff.  I had several issues:

• The board and parts layout diagram had an area for R15-R18 and a part labeled WI (WJ?) but the schematic did not have any reference to these parts.  (Edit:  I discovered that this part is actually M1 -- the letters are transposed on the board so it looks like WI/J.)
• I was missing the 2 100 Ohm resistors (R42 and R63).
• C22 is incorrectly labeled as a 2.2uF where a 10uF should be used.

Other than these pretty minor issues, the assembly was straight-forward.  I substituted a couple of non-surface mount resistors for R42 & R63 (they look kinda funny but it will do for now).  The M1 part seems to be for a preamp that actually was included with the parts but I bypassed it since I did not find it on the schematic.  Close examination of a picture of the board from the internet shows a 10pF capacitor installed across 2 pins of M1 instead (the resistors were not populated).

The Si5351 cobbled to the SSB6.1

I decided to only wind the coils for 10m, 15m, and 20m to confirm that I could get something working (and frankly I wanted to get something ready for testing as fast as possible).  I'll wind the 40m coils next.  I am not sure if I'll bother with the 75/80m coils as I'm not sure I will use this radio for that band.  I'd really like to figure out how to get this working on 17m as that is a great band.

The SSB6.1 has an intermediate frequency (IF) of 8 MHz.  During my first tests with the Si5351, I used a DDS mixing frequency of 22 MHz thinking that would give me 14 MHz after the mixer.  Well, it did but I was not able to demodulate signals properly.  The signals all sounded like they were using the wrong side band.  I then tried a DDS frequency of 6 MHz and I started hearing properly demodulated signals!  I then tried a DDS frequency of 13 MHz and was able to hear 15m signals.

After fooling around with the optical encoder code, I am easily able to tune up and down the band.  I display both the DDS frequency and the actual frequency on the microView. I do not have an easy way to switch bands yet; I have to recompile the code and switch jumper connectors.

I read another site about using the Si5351 with a '602 mixer and how the 5351 can overload the '602. I implemented a 10dB attenuator using a few resistors based on information from radio-electronics.com.

Another cool thing about the Si5351 is that I was able to product a sweep frequency to test the receiver incredibly easily.  I simply enabled one of the other clock outputs and it worked great.

SSB6.1 RTX

I like portable radios.  I assembled a Wilderness Radio Sierra and an Elecraft K2 and have taken them camping.  They're great for Field Day, too.  But I've been thinking about a backpacking SSB radio that covers several bands that would be fun for day hikes.  Maybe even using it bicycle mobile!

Sometimes you find interesting things on EBay.  I stumbled onto a 6 band transceiver kit (SSB6.1) from a seller in China.  I found it intriguing so I dropped the sixty bucks to have a building adventure.

(Before anyone gets upset about my not buying something from the US:  I also have kits for the R2 and T2 from Kanga US that I am slowly working on.)

This shows the complete contents of the box:  a bunch of surface mount parts, a few NE602s, a few opto-isolators, coil forms, and some connectors.  No instructions, no parts list, no schematic.  Fortunately, the schematic and parts layout are available on the InterWeb.

Soldering surface mount parts can be a challenge but a fine tip iron made that straight-forward.  I was really concerned about winding the coils.  I've wound plenty of toroidal coils but never these.  It turns out (yeah, I said it) that they were pretty easy to wind - I just had to pay attention to what I was doing.

It only has an exciter output level of about 20 mW so I'll need to investigate some amplifier options.

Si5351

Adafruit has a board for the Si5351A.  For 8 bucks you get a itty bity board with 3 clock outputs with a range of 8 KHz to 150 MHz.  I picked up a few to play with homebrew HF radios.  (EtherKit has a version, too.)

I am using the EtherKit library for Arduino.  It is very straight-forward and I was generating clock signals in no time.

This shows the Arduino MicroView handling a rotary encoder and the I²C to the Si5351.

Icom AH-4 Remote Tuner

My current antenna is the B.A.L. -- a large, horizontal loop that's about 150 meters of wire about 15-20 meters up in the trees around the yard.  I think it's a great all band antenna.

I buried a couple of coax runs from the shack wall to a spot about 15m away behind a large bush.  The ladder line from the loop falls down to this spot so I do not have wires directly hanging off the house (which makes the YL happy).  I was using a DX Engineering MAXI-CORE Balun and was happy with the results.  (As an aside:  I love hamfests!  I picked up this used balun for a song.)  I used this setup for a few years and have been pretty happy with the results. 

Since the loop is a non-resonant antenna, the SWR can be high.  I've been using the tuners built into my transceivers (Elecraft K2 & K3) but have been concerned about loss in the coax.  Since I only run 100 watts or less, I want every bit of power to get to the antenna and not be used to heat the coax. Placing a tuner at the end of the coax run is supposed to reduce the coax loss.  I had always planned on adding a remote tuner when the budget allowed.  When I buried the coax, I also threw in a couple of runs of CAT-5 cable that I had laying around for use for some sort of remote control.

The remote connection at the end of the coax run

I recently acquired an Icom AH-4 remote antenna tuner.  I am using one of the CAT-5 runs as the control cable for the AH-4; I simply used each twisted pair together for the power and control signals.  I no longer use the balun.

All connected and ready to go!

Since I am using this tuner with a non-Icom radio, I needed a way to tell the tuner to initiate the tune cycle.  I whipped up the circuit described as the universal controller and it seems to do the job. (Edit Jan 2019: The link to the universal controller diagram http://www.k2.dion.ne.jp/%7Esradio/AH-4En.htm no longer works!  There is a discussion on eham with a diagram that I think is similar.)  I do plan on building a better controller that will initiate the tune cycle and then key the radio automatically.

The 'controller' in the shack

I've been very happy with the tuner so far.  It finds a decent match (less then 1.5:1) on all bands and I believe it has made a difference.  I don't have empirical evidence to support that, though!  At least I no longer worry about loss in the coax...

Fun with SLO2016 LED displays

I love going to hamfests; you never know what you will find.  At one 'fest a few years ago, I picked up several SLO2016 LED matrix displays. I had no idea what they were when I bought them -- they just looked kind of cool and I thought they might work for small, minimal displays (as opposed to a larger LCD display). After a quick web search, I found this data sheet.

They are modules of 4 little 5x7 LED matrix characters.  They have 7 data lines for 127 characters, 2 address lines to determine which character is updated, and a enable/write line.  They can be chained together by sharing the data and address lines and controlling the individual enable/write pin on each display.

I posted a video to youtube showing 3 displays chained together for a 12 character scrolling display controlled by an Arduino Pro Mini.  You can find several other videos with examples. 

I got a request for the code for the scrolling text.  I make no claim as to how wonderful my code is; if it is useful, have at it!

The Code

const int LED = 13; const int CLEAR_PIN = 7; const int ADDR0_PIN = 8; const int ADDR1_PIN = 9; const int LEFT_WRITE_PIN = 10; const int MIDDLE_WRITE_PIN = 11; const int RIGHT_WRITE_PIN = 12; const int SCROLL_PAUSE = 175; const String SPACES = " "; const String SCROLL_STRING = "This is a test of the interesting SLO-2016 LED matrix display. It's pretty awesome, dude!"; char ALL_CHARS[128]; const byte NUM_DISPLAY_CHARS = 12; void setup() { // DDRD = 0xFF; pinMode (0, OUTPUT); pinMode (1, OUTPUT); pinMode (2, OUTPUT); pinMode (3, OUTPUT); pinMode (4, OUTPUT); pinMode (5, OUTPUT); pinMode (6, OUTPUT); pinMode (LED, OUTPUT); pinMode (LEFT_WRITE_PIN, OUTPUT); pinMode (MIDDLE_WRITE_PIN, OUTPUT); pinMode (RIGHT_WRITE_PIN, OUTPUT); pinMode (ADDR0_PIN, OUTPUT); pinMode (ADDR1_PIN, OUTPUT); pinMode (CLEAR_PIN, OUTPUT); digitalWrite (LEFT_WRITE_PIN, HIGH); digitalWrite (MIDDLE_WRITE_PIN, HIGH); digitalWrite (RIGHT_WRITE_PIN, HIGH); digitalWrite (CLEAR_PIN, HIGH); for (byte i = 1; i < 127; i++) { ALL_CHARS[i] = i; } ALL_CHARS[0] = ' '; // can not set the zero byte (null char) in a string ALL_CHARS[127] = '\0'; // properly terminate string } void loop () { digitalWrite (LED, HIGH); displayClear (); delay (SCROLL_PAUSE); digitalWrite (LED, LOW); // displayString (" Hi!"); scrollString (SCROLL_STRING); scrollString (ALL_CHARS); delay (1000); } void displayClear () { digitalWrite (CLEAR_PIN, LOW); delay(10); digitalWrite (CLEAR_PIN, HIGH); } void scrollString (String str) { // Go through the given string 4 characters at a time. String visible = String (SPACES); byte strLen = str.length (); byte strIndex = 0; byte lastCharPos = NUM_DISPLAY_CHARS - 1; while (strIndex < strLen) { // move chars in visible string to the left // add the char at strIndex at right. char ch = str.charAt (strIndex); for (byte i = 0; i < lastCharPos; i++) { visible.setCharAt (i, visible.charAt(i+1)); } visible.setCharAt (lastCharPos, ch); displayString (visible); strIndex++; delay (SCROLL_PAUSE); } // add trailing spaces. for (byte count=0; count < NUM_DISPLAY_CHARS; count++) { for (byte i = 0; i < lastCharPos; i++) { visible.setCharAt (i, visible.charAt(i+1)); } visible.setCharAt (lastCharPos, ' '); displayString (visible); delay (SCROLL_PAUSE); } } void displayString (String str) { // Send characters to display byte len = str.length (); byte index = 0; while ((index < len) && (index < NUM_DISPLAY_CHARS)) { char ch = str[index]; displayChar (ch, index); index++; } } /* * Display a character in one position. * * ch - the character to display * addr - the character display address (0-3 left, 4-7 right display) */ void displayChar (char ch, byte addr) { digitalWrite (LED, HIGH); int write_pin = 0; // set the address pins switch (addr) { case 00: digitalWrite (ADDR0_PIN, HIGH); digitalWrite (ADDR1_PIN, HIGH); write_pin = LEFT_WRITE_PIN; break; case 1: digitalWrite (ADDR0_PIN, HIGH); digitalWrite (ADDR1_PIN, LOW); write_pin = LEFT_WRITE_PIN; break; case 2: digitalWrite (ADDR0_PIN, LOW); digitalWrite (ADDR1_PIN, HIGH); write_pin = LEFT_WRITE_PIN; break; case 3: digitalWrite (ADDR0_PIN, LOW); digitalWrite (ADDR1_PIN, LOW); write_pin = LEFT_WRITE_PIN; break; case 4: digitalWrite (ADDR0_PIN, HIGH); digitalWrite (ADDR1_PIN, HIGH); write_pin = MIDDLE_WRITE_PIN; break; case 5: digitalWrite (ADDR0_PIN, HIGH); digitalWrite (ADDR1_PIN, LOW); write_pin = MIDDLE_WRITE_PIN; break; case 6: digitalWrite (ADDR0_PIN, LOW); digitalWrite (ADDR1_PIN, HIGH); write_pin = MIDDLE_WRITE_PIN; break; case 7: digitalWrite (ADDR0_PIN, LOW); digitalWrite (ADDR1_PIN, LOW); write_pin = MIDDLE_WRITE_PIN; break; case 8: digitalWrite (ADDR0_PIN, HIGH); digitalWrite (ADDR1_PIN, HIGH); write_pin = RIGHT_WRITE_PIN; break; case 9: digitalWrite (ADDR0_PIN, HIGH); digitalWrite (ADDR1_PIN, LOW); write_pin = RIGHT_WRITE_PIN; break; case 10: digitalWrite (ADDR0_PIN, LOW); digitalWrite (ADDR1_PIN, HIGH); write_pin = RIGHT_WRITE_PIN; break; case 11: digitalWrite (ADDR0_PIN, LOW); digitalWrite (ADDR1_PIN, LOW); write_pin = RIGHT_WRITE_PIN; break; default: break; } digitalWrite (write_pin, LOW); PORTD = ch; digitalWrite (write_pin, HIGH); digitalWrite (LED, LOW); }

EEVBlog video on Arduino

This YouTube video captures my feelings about the Arduino boards.  It's from Dave Jones of EEVblog and he makes his, ah, unique comments about the whole project and I found that I agree with most of what he says.

Certainly, there's a ton of Arduino stuff out there on the web, but this video really expressed the essence of why I am using these boards now.

Fun with Arduino and modules

I bought an Arduino Uno R3, a ProtoShield, and a Ping sensor from my local Radio Shack store.  It took me about 10 minutes to get my first blinking LED example to run on it after ripping open the box!  That's mostly due to the LED being on the board itself, but I thought it was neat to be able to pull up example code in the IDE, compile it, and upload it to the board pretty quickly.

Arduino UNO with a few fun modules

Playing with the Parallax PING ultrasonic sensor is fun and there is example code for it as well.  I had code running that sent distance in inches and centimeters to the serial console in no time.

The blinking LED and serial interfacing only thrilled me for so long, so I ordered a couple of fun modules from SparkFun.  One is the Emic 2 text to speech board that takes ASCII text from a serial port and speaks the text.  Used with the PING sensor gave me a talking toy that announced a greeting and distance when somebody walked by.

Another module I ordered is the Dead On RTC real time clock board which is a Dallas Semiconductor DS3234 chip with a SPI interface and battery backup.  Now I have a personal greeter that announces the time at the top and bottom of the hour. Cool!