I was an undergraduate at the time. My friend and classmate Tony (KC6QHP) had been trying to convince me to get my ham license for months.

I finally decided to go for it over winter break. I picked up a copy of Now You’re Talking! from a local bookstore (remember those?) and crammed for a week. I took the test the following weekend and passed with a perfect score, 35/35. (The morse code requirement for the Technician license was eliminated in 1991.)

That Christmas I got a Kenwood TH-79A/D, a very modern-looking radio at the time. (I still think it looks great, but it has aged poorly, the controls are scratchy and the battery becomes disconnected easily.) I nervously waited for my new call sign to show up in the FCC database. (This was before the ULS existed, but there was a website where you could see the call signs that were issued each day.)

Imagine my horror when on December 31st my name came up listed next to the call

KF6PBP

What’s wrong with that, you say? Sound it out. K F 6 P B P. Imagine trying to make a contact on the air with that call. PBB? BPP? PPP? I have even had operators struggle with the phonetic version (Papa Papa Bravo? No, Papa Bravo Papa. Easy, right? Wrong.) I remember some old-timers trying to console me when I first got my license by coming up with clever mnemonics such as “Peanut Butter Pretzels”, which I still chuckle at.

Admittedly, my frustration level has always been kept in check by the fact that I have never been very active on the air, and most of the contacts I have made have been with friends who had memorized my callsign anyway.

This year, after having the callsign KF6PBP for over 13 years, I finally decided to do something about it. I applied for a vanity call sign.

But which call to apply for? I’m an Amateur Extra now (I tested for General and AE in 2009 and 2010, respectively), so I could have tried to get one of the much-fought over 1×2 or 2×1 callsigns (like K6RF, W6TC, etc). I didn’t see any that were worth fighting (and waiting) for. So, I decided to take a different approach and searched for an easy-to-get 1×3 callsign that reflected my personality or interests. I found a few that I liked and narrowed them down to 2 candidates (one favorite and a backup in case someone else applied for the same call and I didn’t get it).

As luck would have it, I got my first choice. Last night, I was granted the new call sign

It feels a little bit weird to be saying goodbye to the call sign I’ve held for so long, but I’m looking forward to operating with my new call with fewer corrections. (The phonetic version has a nice ring to it – Whiskey 6 Oscar Hotel Mike.)

I’m getting back into amateur radio these days, so expect to see more posts on the subject. Maybe I’ll even get to chat with some readers of the blog on the air?

(Are you a ham?  Leave a comment!)

Soldering is Easy morse code translation, by David July.

(Click for the full-size version.)

Thanks, David!  Mitch and I both really like this one.  Mitch, who used to be able to do 20 wpm, could read it much faster than I could!

The Bay Area Educational Amateur Radio Society (BAERS) is hosting a Ham Cram on Saturday, January 9th from 8AM-5PM at St. Mary’s Cathedral in San Francisco.  The cost is $30 including the VEC fee.

A “Ham Cram” is a one day workshop where you can get your ham radio license (usually the Technician level) without studying in advance.  I’m not sure I completely agree with their methods of blind memorization over actually understanding the rules, but apparently this method works and most people pass on their first attempt.  If you’re short on time and want to get your license in a hurry, this is one option.

Thanks to Robert for the heads-up on the January session.

AERO is another SF-based group that regularly posts flyers advertising their own ham cram sessions.  Their most recent poster is outdated, but the site mentions there will likely be an upcoming session in February 2010.  I just took the General license exam at their November session and was really impressed by how many people were there and how professionally run the event was.

Update: Their next session is on February 7th, 2010 at 8:45AM.  Details here.

Studying the old fashioned way:

If you don’t like the “cram” method, you can always pick up a study guide (Technician, General, Extra Class) and spend a few weeks studying for the test like I did for both my Technician and General license exams.  There are even a couple online practice tests to help you study.  When you feel comfortable with the material, you can take the exam at the sessions above for a $14 VEC fee without doing the cram.  I know AERO allows this, but it would probably be a good idea to check and make sure BAERS permits this as well.  In either case, I recommend that you RSVP to ensure you get a seat and get notification about changes to the venue, etc.  Contact info for each group is on their respective websites.

Good luck and 73 from KF6PBP!

I received my Technician class license in college shortly after my classmate Tony introduced me to the world of amateur radio.  I started out playing with TNC‘s and packet radio.   Later, with Tony’s help, I built various microwave radios so I could participate in the very active San Diego Microwave Group.  Some of my projects included a 10GHz transverter and a simple 24GHz wideband radio that used a surplus gunnplexer as an RF source, the same kind as found in police radar guns and many automatic door openers.  (Please excuse my ancient webpages, they were cool ten years ago, ok?)

Here I am with my 10GHz transverter in the summer of 2000 during the ARRL 10GHz and Up Contest.

Sun, sand, and microwaves in Santa Barbara.

I also used to be somewhat active on 2m/440 and still have the Kenwood TH-79A radio my Dad bought me after I got my license.  I still use it today, but not for voice communications.  It has a new life now as part of my APRS Tracker project.

After seeing how many hams there were at NOTACON earlier this year, I finally decided it was time to upgrade my license to General class.  This will give me more operating privileges on the HF bands, the traditional low frequency / long distance communication bands that are most commonly associated with amateur radio.  My goal is to set up an HF station at home and maybe start playing with a Software Defined Radio system such as GNU Radio with custom homebrew hardware.

Before my trip to HAR I picked up a copy of the ARRL General Class License Manual and printed out a list of VE sessions in the Bay Area over the next couple of months.  Now that I’m back, it’s time to start studying!

So here’s the background….I’m building a ham radio that operates at 47 GHz.  At such a high frequency there are very few components that can be soldered on to circuit boards, let alone components that even come packaged!  The easiest way to build a high performance radio at these frequencies is to use MMICs (Monolithic Microwave Integrated Circuits).   These are really just fancy, yet fairly simple circuits made from exotic materials, most commonly Gallium Arsenide (GaAs) instead of the usual Silicon used for normal chips.  Before MMICs were in widespread use, individual transistors had to be used, requiring delicate and hard to make external matching elements.  MMICs are like nice little 50 ohm building blocks.  Low Noise Amplifiers (LNAs), mixers, Power Amplifiers (PAs), phase shifters, etc. etc. are all available in this form.  Trouble is that you have to connect these pieces up to make a functional radio (or at least the microwave portion of it).

My WestBond wedge bonder

Wire bonding is the usual method for connection and is really just a method of welding a wire (or ribbon) from one chip to the next.  It turns out that you actually need space in between the chips, for thermal reasons, RF reasons, and for placing the requisite bypass capacitors.  So what goes in between the chips?  Well, coax cable is pretty much out, and most common circuit board materials start getting pretty lossy at 10+ GHz, and even the good stuff (PTFE-based usually) starts getting kinda lousy at 40+ GHz.   At very high frequencies, materials like ceramics and quartz become worthwhile.  In my radio I chose to use pre-made alumina ceramic substrates (tiny circuit boards).   These come with a gold layer on the back, and a gold line on top etched to perform as a 50 ohm transmission line (just like coax and just what the MMICs want to see).  I bought these with a number of other hams last year in a group buy.  They are fairly expensive being that they are 5 and 10 mils thick!

My first test bonds on an alumina ceramic substrate (ugly)

To make the best use of the sections that I bought I decided I needed to cut them to length.  Well how do I do that?  The thickest pieces are 10 mils thick (a piece of printer paper is 4 mils thick) and they are brittle!  Beyond cutting, how do I hold the piece while cutting and when it’s done?  The resulting pieces may be just 100 mils long, and 50 mils wide.   Obviously a pair of vice-grips simply won’t do.

So my first thought was a Dremel tool and tape.  This method could work, but it does not lend itself well to making measured cuts.  At 47 GHz, a few hundredths of an inch is a lot! Also, the available diamond blades for dremel tools are fairly wide and I wanted to waste as little of the  small substrates as possible.  At this point I made  a lucky find on eBay.

In the semiconductor industry, one of the last steps of making a chip is called “wafer dicing.”  After a wafer full of chips is made, they need to be cut out into individual parts.  To do this, wafer dicing machines were developed.  These are CNC saws that use a high speed (as high as 60,000 rpm) air bearing spindles with diamond abrasive blades.   They can cut lines across large dinner plate sized wafers that are as narrow as only a few tens of microns.   Luckily there is enough wafer dicing going on in the world that there is a source of surplus blades on eBay.  Not all blades are well suited for all materials, so do some research if you are interested.  Disco (a Japanese company) is one of the largest dicing blade manufacturers.

Large (4.6 inch diameter) wafer dicing blade in it's packaging.

While reading the last paragraph you may have spotted a few words indicating unobtanium.  Those words are “high speed air bearing spindle.”   Well I chose to use a hard drive motor instead, because they have excellent bearings and are readily availble  for free.  While they don’t move as fast, I don’t care.  I have a few short cuts to make, not millions of chips.

So that is an introduction to what I’m doing.  For the most part the saw has been built using surplus parts and remnant pieces of metal from my favorite local metal supply house M&K Metals in lovely Gardena, CA.   As of this entry, the saw is nearly complete, all that is left is the splash guards.  I’ll be posting the build of this project in several parts, so stay tuned.

And a link to my Flickr photo set for this project: Dicing saw

-Tony