Saturday, January 4, 2014

CBLA Technical Manual, beginning draft

ColorBurst Liberation Army
Field Operative Technical Manual




Chapter I:
Obtaining Materials for
Improvised Equipment
for the Suburban Operative.

Step 1: 
Once material source has been secured, gather the necessary tools. Standard Phillips screwdriver may be substituted for the drill motor for the non-homeowner. 

Warning: DO NOT plug in AC cord, or "Victory Against Ignorance" will occur!

Step 2:
Remove rear housing, saving screws, as they will be replaced.

Step 3:
Connect High Voltage discharging tool to chassis ground.
Step 4:
Discharge Anode.
Step 5:
Discharge power supply filter capacitor.
Step 6:
The internals are now safe for handling.
Cut ground wires and zip ties, and any other necessary non-connectorized interconnects.
Remove electron gun driver board, main board, and degaussing coil.
Remove speaker.
Remove deflection yoke it is not the bonded type.
Bonded yoke shown, do not attempt to remove unless CRT has already been shattered into 1000 pieces, and you enjoy handling jagged glass.
The following pieces should now be Liberated, shown from 12:00 clockwise: Degaussing coil, outboard transistor and heatsink,  Main Board/electron gun driver board, (this unit had integrated VCR.) and speaker at center.
Step 7:
Remove main board from components from plastic board carrier. Re-install board carrier back into main plastic housing. This will stabilize unit when reassembled, and give "Electronic Waste Management Specialists" a false sense of security that nothing is amiss with the unit, and therefore avoid arousing suspicion and unnecessary questioning.
Step 8:
Replace rear housing, using all available screws. Save for power cord and rear connectors, the unit will appear at first glance undisturbed.

DISPOSE OF UNIT AS RESPONSIBLY, OR AS IRRESPONSIBLY, AS SPECIFIC OPSEC DICTATES.

Ideally, unit should be turned over to local municipality recycling apparatus. However, if you happen to have a QRP-L list troll/whiner in your neighbourhood,  these units make for an excellent petunia-bed flattener, property-value enhancer, or HOA-Stasi magnet/decoy.

DO NOT USE FOR TARGET PRACTICE.
Find a washer/dryer combo instead. 

Step 9, optional, but recommended:
Soap, rinse well, shake excess water, dry in sun. Do not wash speaker.


Step 10:
Identify primary objective:
Liberation complete:









To be continued...


***Thanks to K6FWT for the logo!
  


Tuesday, December 31, 2013

Tilting at windmills, mobilize now!

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
There is a vast army mobilising, and its aim is to re-take territory abandoned by the National Television System Committee.

Why is an army needed for something already abandoned? For the squatters, the carpet-baggers,  and they are the the most bovine, stubborn, and obnoxiously LOUD sort.

We intend to retake 3579.545455 KiloCycles from the blaring, and bleeping, and warbling robots, with their Windows XP hive-minds, their "push F1 through F5" QSO's, and their "rigblaster nomics," whatever diabolical appliance those might be.

This territory is the Colorburst Frequency, and we are the Colorburst Liberation Army. We are the true believers of "CW Forever," and the few who remain that endeavour to construct instruments of transmission and reception from the donated organs of the political football known as "electronic waste."

We will re-take,  restore,  and DEFEND CW to this slice of spectrum. We will create a sanctuary for those tinkerers who "Liberate" 3579.545455 quartz crystals from defunct machines on our neighbour’s curbside on trash day.

We will vanquish the robot horde, and we will attain ultimate Victory!

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


;) <--- please note! The above is meant as HUMOR, hyperbole, and sarcasm! (With tinges of truth here and there, but...)

DISCLAIMER - I have operated PSK-31 and RTTY , I have nothing against them, I even own a "SignaLink USB" and a pair of Mechanical teletypes! However, for BPSK modes that are designed to be decoded down in the noise, I believe operators in the 80m digital area run WAY too much power, blowing everyone else's AGC wide open.



Ok, all kidding and fun aside, a few of us crazies on the Internet (a vast army of 4, at last count) have decided that we'll try like heck to make CW QSO's (hopefully with each other) with QRP tube rigs right smack in the middle of the 80M digital-mode watering hole.

I find this to be a formidable and... possibly worthwhile... challenge due to:

1.) I stink at CW. I need the practice.

2.) I don't operate much on HF any more, I need to do more to justify all the wire in the sky over my yard!

3.) 80 Meters in my neighbourhood is a QRN Charlie Foxtrot. If I can operate here, I can anywhere. I should also look into chasing down some of the neighbourhood RFI, its BAD.

4.) IMHO, CW ops need to assert themselves in this part of the band. CW is "legit" everywhere, and technically its a digital mode. So There!

5.) There's something ridiculously fun about a pretend guerilla insurrection. ;) (If I wasn't on an NSA watchlist, I am now!!!)

6.) I like building useful stuff, and then tinkering with it. There is a clinical condition when one ceases to learn stuff. They call it "death." ;)

Number 6 being the main motivator, and not having a "proper" QRP CW tube rig for 80, I slapped together a NOGA Twin Tube 80. (links and references at the end.)






Its got a pair of paralleled 6AU6's. Haven't done a proper power measurement yet, but I'm guessing 2 watts out!



Clearly the power supply is a separate animal. I built an isolated, (back to back xformers) full wave power supply that gives 162V no load. Pulled an "Arnie" and used rectifier diodes and electrolytic from dead CFL bulb ballast! TX is taking 25 mA, so woohoo, 4 watts input! Built PS into one of the Trader Joe's peppermint bark holiday tins, 10lbs of %^& in a 5 lb bag. Thin sheet metal, so the thing buzzes like a ticked off hornets nest when powered up. ;) Unfortunately buzzing not modulated by keying, that would be too cool.

I've got a pile of dynamotors here, I need to make a portable supply next.

I have had it on the air the past two evenings, called lots of CQ, but no QSO's yet. Tonight is Straight Key Night, so maybe something will come of that.





With so much CQ'ing I decided to automate!



I paired an Arduino with a relay shield, added a push button and a clip lead, and can call CQ with a push of a button. Surely I'm outside of the ratings of the relay, but not in a bad way. Designed to not be any sort of hindrance to manual keying. Code at the end.


Links and stuff:

NOGA Twin Tube 80:
http://www.qsl.net/kl7h/GlowBug.htm
http://skattagun.blogspot.com/p/ham-radio-master-links.html?m=0
http://www.nogaqrp.org/projects/nogacomp1.html
http://www.nogaqrp.org


Direct link to schematic:
http://www.qsl.net/kl7h/NOGA80.gif


http://en.wikipedia.org/wiki/Colorburst
http://en.wikipedia.org/wiki/NTSC

;)
http://www.sunflower.com/~brainbol/frank/

http://www.af4k.com/glowbugs.htm


Relay Shield for Arduino:
http://shop.evilmadscientist.com/productsmenu/tinykitlist/544


Arduino Code: (copy and paste into text editor, small font used for brevity)

// cqer.ino
// Automatic CQ Caller
// Drives a relay, which keys cw rig
//
// Hacked and Muntzed from original work by Mark VandeWettering K6HX blog @ http://brainwagon.org
//
// Pin 13 is the ubiquitous LED
// Pin 4 is digital out that drives a relay
// Pin 11 has 10k to gnd pulldown, also button across pin 11 and VCC
// 12/30/2013
// w6iee.blogspot.com
//

struct t_mtab { char c, pat; } ;

struct t_mtab morsetab[] = {
      {'.', 106},
    {',', 115},
    {'?', 76},
    {'/', 41},
    {'A', 6},
    {'B', 17},
    {'C', 21},
    {'D', 9},
    {'E', 2},
    {'F', 20},
    {'G', 11},
    {'H', 16},
    {'I', 4},
    {'J', 30},
    {'K', 13},
    {'L', 18},
    {'M', 7},
    {'N', 5},
    {'O', 15},
    {'P', 22},
    {'Q', 27},
    {'R', 10},
    {'S', 8},
    {'T', 3},
    {'U', 12},
    {'V', 24},
    {'W', 14},
    {'X', 25},
    {'Y', 29},
    {'Z', 19},
    {'1', 62},
    {'2', 60},
    {'3', 56},
    {'4', 48},
    {'5', 32},
    {'6', 33},
    {'7', 35},
    {'8', 39},
    {'9', 47},
    {'0', 63}
} ;

#define N_MORSE  (sizeof(morsetab)/sizeof(morsetab[0]))

#define SPEED  (13)  // Beacon speed in words per minute
#define DOTLEN  (1200/SPEED)
#define DASHLEN  (3*(1200/SPEED))
#define VOLUME 64

int LEDpin = 13 ;
int Rlypin = 4; // relay pin
int buttonPin = 11; // our push button, which gets the ball rolling
int buttonState = 0;

void dash()
{
  digitalWrite(LEDpin, HIGH) ;
  digitalWrite(Rlypin, HIGH) ;
  delay(DASHLEN);
  digitalWrite(LEDpin, LOW) ;
  digitalWrite(Rlypin, LOW) ; //
  delay(DOTLEN) ;
}

void dit()
{
  digitalWrite(LEDpin, HIGH) ;
  digitalWrite(Rlypin, HIGH) ; //
  delay(DOTLEN);
  digitalWrite(LEDpin, LOW) ;
  digitalWrite(Rlypin, LOW) ; //
  delay(DOTLEN);
}

void
send(char c)
{
  int i ;
  if (c == ' ') {
    Serial.print(c) ;
    delay(7*DOTLEN) ;
    return ;
  }
  for (i=0; i<N_MORSE; i++) {
    if (morsetab[i].c == c) {
      unsigned char p = morsetab[i].pat ;
      Serial.print(morsetab[i].c) ;

      while (p != 1) {
          if (p & 1)
            dash() ;
          else
            dit() ;
          p = p / 2 ;
      }
      delay(2*DOTLEN) ;
      return ;
    }
  }

}

void
sendmsg(char *str)
{
  while (*str)
    send(*str++) ;
}

void setup() {
 
  pinMode(LEDpin, OUTPUT) ;
  pinMode(Rlypin, OUTPUT) ;
  pinMode(buttonPin, INPUT);
}

void loop() {
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);
 
  int i;
 
  // check if the pushbutton is pressed.
  // if it is, the buttonState is HIGH:
  if (buttonState == HIGH) {    
    // then do it:  
    sendmsg(" CQ CBLA CQ CQ CQ DE W6IEE W6IEE W6IEE K ") ;
  }
  else {
    // otherwise sit patiently and wait:
    delay(10);
  }
 

  };

 


Sunday, May 12, 2013

ARC-5's and dynamotors

The Milradio bug has come out of remission! Half my old boatanchor collection (easily by weight, probably by volume too) is military stuff, mainly from WWII. At the moment, very little of it works, none of it transmits! Projects are being re-prioritized to change that. Initially, I had thought I'd get my TCS set going, but the proper cable connectors will be a challenge. Instead, I got out my BC-454 ARC-5 receiver and did a quick alignment on it. On a hunch, I wondered if it would play nicely running off of a stock dynamotor, ( http://en.wikipedia.org/wiki/Motor-generator ) at the reduced voltage of 12 to 13.8V. (These are most always 24V sets, often "ham-hacked" to run off of 12V by rewiring the filaments.) It was already running well at reduced B+, 160V vs 250V, so the 126V that the freshly re-greased dynomotor worked out well, I can barely tell it isn't as loud playing through a speaker. Its just fine, if not TOO loud with standard 8 ohm contemporary headphones, as there's no AVC.

Next, I'm going to gather up all the other dynamotors, grease their bearings, and see if I can't put together a "rotating" transmitter power supply.

   Thats the BC-454 ARC-5 receiver, running in the dynamotor with the end bells removed, I heard that this was necessary to do to cook out any moisture that might be inside the unit. I sorta doubt that, but its good to give the thing a listen to see how its running. The TCS receiver is in the background.

So, I've got a couple of TCS pairs, a GRC-9 that needs a power supply, a Wireless set 19 that needs a power cable, scads of ARC-5 TX's and RX's, a BC-610 that likely needs a restoration, a BC-342... Heck, there's more, I just can't think of it at the moment. ;)

Monday, March 18, 2013

Improvised Amateur Television Downconverter

The only W6ATN ATV repeater I have a semi-clear shot to is Oat Mountain. It has an output on 919.25 Mhz. I have an old analog TV that goes up to cable channel 125, which is right around 800.25 Mhz . How convenient!

So, with a 900 Mhz yagi on the roof fed with heliax, I plugged in an SMA mixer (that I'm supposed to be building a 1296 transverter with) and dialed up my K5BCQ DDS signal generator up to 119.0 Mhz, and connected it to the TV.

Didn't quite work. I could tell there was something there that said W6ATN if I stared long and hard at the snowy screen. ;)

Made the following improvements.

1.) Moved the antenna higher. ;)

2.)  I connected a cavity bandpass filter. Used my 8924c (and a mini-circuits directional coupler as an improvised return loss bridge) to put the "dip" right at 919.25. Dunno how much gain/loss/rejection it came out to, I'm still learning in that dept. ;) Either way, inserting this helped, noticeably.

3.) fished out a DEMI MMIC kit (10 bucks!!) from the bin, this one had a MAR-6. Soldered together and installed SMA connectors, and inserted between the Bandpass filter and the mixer.

Pretty good:

Untitled Untitled Untitled
Here you can see the components: The water heater-lookin' thing is the BPF, MAR-6 preamp is floating in front of it with the green cable connected, and the mixer is floating off to the right with the three SMA's in a row. DDS VFO is on the bottom with the knob and the LCD that you can't read in this picture. Thats it!

Untitled
Antenna: You can see I have my DVB-T dongle connected, used that to aim and peak.

Untitled

Friday, January 18, 2013

Wireless sensor network, now with MORE messy wires!

I've been doing a little bit with Linksys WRT54G's that I've gotten for  <$6 from neighborhood thrift stores.

I've been re-flashing them with OPenWRT. Here I have one with an analog temperature sensor, which is on top of an Arduino (Diavolino kit!) which is sending text to one of the WRT's serial ports. I've since added one additional wire, and the Arduino is running happily (and reporting temperature quite accurately) from the WRT's 3.3v supply.

This whole thing could be made much, much smaller, though I'm presently more interested in the ambient room temperature out there, vs. the internal temp of the WRT.

So, I can ssh into the WRT from inside the house, cat /dev/tts/1, and read the temp out in the shack.  In addition, functioning as as a wireless network bridge is fairly useful as well!

Perhaps someday I'll connect a real teletype to that tty. ;)

Monday, December 10, 2012

"New" 10 Ghz transverter in progress

No more borrowing gear for 10 Ghz contests! I'm well on my way to having my own working X-band station.

Thursday evening at the SBMS meeting, I got my hands on a completed Qualcomm lambchop conversion, a waveguide switch, a nice "whitebox" dish, and a few other goodies. Friday evening I hooked some of it up and shot the video below.

Its a few KC's off, and you can hear some drift in there. It was cold that evening (probably below 60F!!!) and I was using an uncalibrated 10Mhz txco. A rubidium disciplined oscillator would be much better, a lot more accurate. Combined with a few other goodies I already have, including a rubidium unit, I hope to have a rugged, portable transverter built up soon.


Progress on the Beach 40 txcvr

Spent a couple of hours Sunday on the Beach 40. ( The new commonly accepted name for VK3YE's 40M DSB transmitter/ receiver.)

I got the Receive audio section installed, and a few immediate problems debugged. I had absolutely no audio out, except for when I touched my finger or signal tracer to the input of the audio chain.

Further probing revealed:

1) The transistor in the VFO buffer amplifier was bad. Replaced it.

2) A 500 ohm bournes trim pot is not a satisfactory substitution for the required 200 Ohm part. I tacked in to 100 ohm resistors for now, need to get out to All Electronics soon.

3.) "Trying to be cool" and using surface mount diodes in the mixer ring failed. ;)  There was poor gain, and things "looked funny" on the scope. Tore a few jumpers out, but left the SMD diodes as a lesson to myself, and then installed a new diode ring with proper through-hole diodes. MUCH better.

Once it was working in hard-wired receive mode:

4.) For my tastes (listening with a speaker, not headphones) this thing needs an additional audio amplifier stage. Using the good old Radio Shack amplified speaker cranked all the way up, I found that my perceived MDS was down below -110 dBm on my HP sig gen. Yeah, that won't occur in real life, but its a usability enhancement worth adding. I'm not excited about using the ubiquitous LM386, instead I'm going to try a TDA7052, (perhaps like SPRAT 142) which I have on hand but have never played with.

5.) I started building it "Drilled Island Manhattan" style, then for my attempted SMD mixer stage, I went crazy with the dremel. Made some mistakes. At that point, I found it much easier to switch to "Super Glued Island Manhattan."  That's how I think I'll finish it.

More updates when I have them!