KC9ASI's 6m CW rig project

Why?

Why 6m? Why CW? Why Not?

6m is the lowest band that all new amateur operators here in the U.S. (i.e. me) can operate on. Sure, you could go and master the 5 wpm code test and get a General, or Extra class license, but that takes... well, work and study. Just about anybody can get a Technician license... a fairly simple 35 question test is all it takes. The downside? No HF. To get HF, you have to be Morse proficient. To be Morse proficient, you have to make CW QSO's (or at least, so we think...).

Enter the 6m band. It's low enough so that you can almost work the entire world with it, without bouncing off of satellites. There's all types of propagation. And, it's legal for everyone above Novice class, in any mode.

It's also high enough that you won't be polluting the world's spectrum in places far far far away unless you get lucky. So, this means that you and your frienasd across town can practice code back and forth with each other without accidentally causing interference on a more "valuable" frequency.

You do not need to have passed the Element 1 (Morse Code) portion of the US Amateur to operate CW on 50 Mhz or above. A valid Technician or higher license is all that is required.

So, my goal is to build one of these and see if I can talk to anybody, developing my skills as a CW operator.

CW is what makes Ham Radio fun. It's one of the things that sets us apart from FRS/GMRS/CB users and makes us operators. Phone is for wimps (sorry, OM KC9ASJ.).

Design Goals

• Cheap. Less than $75 retail, excluding tools, enclosure & knobs.
• Easy to build. No hand-wound inductors. Most parts should be available from Radio Shack. Yes, I'm biased because I work for Radio Shack. But because 94% of the American population lives or works within 5 minutes of a Radio Shack, that means that just about everyone can build this radio, which is a good thing. Hopefully, I'll even make a PC board layout for this, and provide step by step instructions from turning a printout of this into a circuit board with the help of your local copy shop, a household iron, and a small drill.
• QRP. Fewer chances of injuring yourself due to RF burns, high power supply lines getting shorted through you, etc. Longer battery life for Field Day and other remote operations. Fewer complaints from the neighbors because Billy's running his ham radio during Seinfeld/Friends/Star Trek.
• Frequency display. There must be some type of frequency readout. Scratches, transfers, silk screening, or anything else around the tuning knob just won't cut it. Currently, I'm thinking of attaching a panel meter to the VCO, because most frequency counters would exceed the cost restriction.
• Alignable without spending 2 arms and a leg. That means that we shouldn't need to rush out and buy a 100 Mhz oscilloscope. A $100 multimeter with a 2 Mhz frequency counter, MAYBE, since you should have one around anyway. Currently I'm thinking about using a 4020 14 stage binary ripple counter to knock the VCO frequency down to a reasonable range for cheap equipment to handle (and they're available at your friendly local RadioShack, and they're less than $3....). When I build mine, I will probably use my computer's sound card with the xoscope program for Linux (my OS of choice) to align the radio... and that means that I'll need any signals I'm looking at to be under 22 Khz (50 Mhz / 2^14 = about 3 Khz... this is mostly for calibrating the frequency readout. Probably go with 2^12 for xoscope, or 64 (2^6) for the 2Mhz counter so resolution is maximized.).
• Tuning range : undecided. 50.0 Mhz to ... 50.1? 50.250? 50.5? 54? All good choices. Given the above requirements on cheap and available, it'll probably be 50.250 Mhz. That's well past the end of the CW only band, should cover the "international" frequencies, and will be more than 1 degree per khz when tuning. It will also work nicely onto a 500 mA panel meter, which will likely be the frequency display (once relabeled).
• RIT. Zero-Beat switch which disables it. Good operating practice requires zero-beating, right? My belief is (going into this) that the way to ZB is to find an interesting station, hit the ZB button, tune the main dial until they disappear, and then when you let go of the ZB button the station is at the audio frequency that you've set on the RIT knob, according to your personal tastes. Sure, this may make it hard to work split, but... will you actually need to operate split?

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  Progress so far.

  Well, I've got a brilliant idea to cheat on the VCO, in the interests of EASY. Radio Shack part #276-2913 is a 74HCT4060A, PLL w/ VCO. We can ignore the PLL part and just use the VCO - takes 3 external components for the oscillator (2 resistors and a capacitor), and then maybe another 5 for the control voltage (resistor, zener diode, 2 trimpots, 1 pot... arrange as a voltage divider off of the the zener, use the trimpots to set the high and low bounds of frequency adjustment).

  If you plan on building this radio set, buy this part now. The last few times I've gone looking around for one at a Radio Shack, it's been really really cheap, and in the parts section I think that means it's getting discontinued. If your Radio Shack doesn't have it... can they find you one?

  If you don't plan on building this radio set, you should buy this part anyway, if you intend to hack together your own radio and might want a VCO.

  How you can help.

  If you've ever done this before and care to offer advice (preferred!), want to heckle me for undertaking such a foolish mission, or whatever, Send me your comments and ideas. I'm happy to know that someone out there is interested in this besides me.