Member of: ARRL, AMSAT, and QRP-ARCI # 13072

Hello, and thanks for stopping by! Ham radio has been very good to me over the years--providing me with an enjoyable hobby, as well as a springboard into a very fulfilling professional life! I wish you well, and hope that you find it as fun and challenging as I do!  Please permit me to tell you a bit about who I am...and what I am:

First, a bit of my ham history:

I grew up in West Covina, California, a suburb of Los Angeles. With the help and encouragement of my elmer, Bob Howard (WA6DLI), I got my novice license (WN6SVQ) at age 10. Upgraded to Technician class a year later. I accidentally let my license lapse while I was out of the country, working as a missionary in Brazil from 1972 to late 1974. When I got back, I studied up for a week, then went down to the Long Beach, CA, FCC field office (no Volunteer Examiner program back then), passed my 13wpm code test, as well as the General and Advanced written tests, all in the same day. I received my new call--WB6VYN--in early 1975.

At the end of 2007 I decided to change my call from WB6VYN to K7DAA, since it fairly closely matches my initials, is much easier and more distinctive to shout at a DX station (I think it's worth an extra 3 dB!), and because I've lived on and off in Utah--where I expect to retire after I've had my fill of fun and excitement here in Silicon Valley, CA.

My present QTH, Morgan Hill, is a town with a population of about 40,000, and shares its northern border with San Jose, in Santa Clara County. We are about 75 miles south of San Francisco.  

I've been an Advanced class ham almost as long as that license class has existed, and finally decided to upgrade to Extra, mostly to get the additional 25 kHz CW sub-bands on 80. 40, 20, and 15 meters--most of the good DX is down in the bottom end of the band.  I passed the Extra (Element 4) test with a score of 100%.  I also hold an FCC General Radiotelephone license (was 1st Class until the FCC combined the 1st and 2nd together a few years back).  I "aced" that license test also--in 1978.  That's so long ago that I think I used a slide rule for the test!

I've worked for Apple Inc. since 2002 as senior group manager of the Communications Standards & Architecture team. It's a bit like working in Santa's toy shop!  We create and develop directions for Apple's wired and wireless communications technologies that get incorporated into our portable and desktop computers, as well as other fun and interesting things!

I have RF engineering in my blood, and my ham hobby has greatly enriched and provided direction for my professional life.

I have 9 issued patents so far, with several more still rattling around somewhere in the bowels of the USPTO.  Here are several technologies or products of which I am the inventor:

• The 300 MHz SAW oscillator circuit that allows all of us to lock and unlock our cars with small keyfobs, or simply by pressing a button on the key heads.
  
• The infamous "I've fallen and I can't get up!" pendants that seniors and the disabled might wear around their necks to signal for help, as well as similar remote control hand-held products (lots and lots of various types of these).  Many of these are on 303.875 MHz.  Some are also on 418 MHz.
  
• The wireless security/duress systems used in, among other places, the Paul Revere home (a US historical landmark) in Boston, MA.
  
• The majority of the 295 to 433.92 MHz wireless smoke alarms, PIR motion detectors, and glass-break detectors used by many of us in our homes or businesses.
  
• The Panasonic Gigarange series of 2.4 GHz cordless phones--the first successful use (in 1997) of the ISM 2.4 GHz band by consumer-grade cordless phone products--a huge money-maker for Matsushita Corporation.  I, along with 3 other guys (one of which is also a ham!) designed a novel, low-cost spread-spectrum method, as well as the radio subsystems that gave this product its amazing range and performance.
  
• The pop-out X-Jack 2.4 GHz antenna system used by US Robotics and 3Com for their wireless LAN and Bluetooth products.
  
• Six other assorted antenna and RF patents, mostly for WLAN and Bluetooth products in use all over the world today.
  
• A number of goodies at Apple that I can't mention just yet!
  

I'm a member of IEEE, and a voting member of the IEEE 802.11 working group. I'm also on the board of directors of the Wi-Fi Alliance.  We're the ones responsible for giving you all of this fun Wi-Fi Internet stuff!  We're presently working on finalizing the 802.11n standard.

I was involved in developing the original Bluetooth specification, and led one of the 9 original Bluetooth promoter groups while senior director of wireless engineering at 3Com Corp (back when it was a force to be reckoned with in the Ethernet and networking markets).

I have also designed and built a number of ham and commercial VHF and UHF repeaters, remote bases, and Internet control systems. I developed and sold a small number of very sophisticated 65C02-based talking repeater controllers for ham groups in the 80's and early 90's.  This was before repeater ID's and other functions were commonly announced using voice--something that's pretty much taken for granted now.

I've also written tech articles for 73 and Ham Radio magazines, as well as some smaller-circulation ham newsletters.

I'm currently set up for most of the ham satellites, as well as CW, SSB, FM, PSK-31, RTTY, and just about any digital mode on 1.8 through 450 MHz. For HF, I use Ham Radio Deluxe and DM-780 for the digital modes, along with a RIGBlaster USB Plug-n-Play interface.  For satellite operation, I'm usually using one of my MacBook Pro laptops and MacDoppler.  It can easily connect to both my FT-847 and my Az-El rotator, which uses the LVB Tracker's USB interface.

I try to keep abreast of new developments, and have also enjoyed experimenting with station remote control over the Internet, VoIP, EchoLink, etc.

When I get really frustrated with my poor location and even poorer antenna systems, I operate via a remote HF base in New Mexico. It's fun to experiment with differences in propagation between Northern California and New Mexico, a distance of about 1000 miles southeast of here. Using the Internet, I'm able to operate this system, as well as my own home station, from anywhere on the planet.

CURRENT SHACK RADIOS:

• Yaesu FT-950 - My most recent purchase.  The roofing filters and IF DSP make this a very hot transceiver!
• Yaesu FT-847 - 160m thru 70 cm transceiver.  Great for full-duplex satellite work.  Wouldn't part with it.  In some ways superior to the Kenwood TS-2000, in my humble opinion.
  
• Kenwood TS-440S/AT - bought new in 1988, and just recently had to do the "all dots" PLL surgery on it.  It's again working like a champ!  All TS-440's eventually have to undergo this surgery.  Thanks for that, Kenwood!  Still a great radio, and no problems outside of this one thing.
• Kenwood TM-V7 - It's an early unit, but no display problems (knock wood).
• Yaesu FT-7800 - I really enjoy this radio.  It will eventually be installed into my wife's SUV.  For now, it's hooked to a homebrew 6 element 2 meter beam in the attic pointed north.  The gain of this beam allows me to be almost full quieting into the Palo Alto N6NFI repeater on 145.23 MHz.
• Alinco DR-235 - For 1.25 cm FM.  Connects to a 4-element homebrew 223 MHz yagi in the attic that I mounted to the rafters with nylon string.  I built the yagi with 10 gauge bare copper wire elements on a 26 inch wooden broomstick for a boom.  Total cost was about $8.00.  Also points north towards the majority of the Silicon Valley repeaters.
• A pair of Yaesu VX-5R HT's - I always keep one in my computer bag in case of emergency, and they also make a neat FM full-duplex pair, used along with a handheld Arrow satellite antenna, for those sudden "sat portable" urges.

ANTENNA TUNERS/AMPS/MISC:

• LDG Z-11 Pro auto tuner--works like a champ, even with just a watt or two of drive!  Added the internal batteries for portability.
  
• Elecraft T-1 QRP auto tuner--works great also, but much smaller than the LDG tuner.
• MFJ-948 Versatuner II--some times you just can't beat a good manual tuner!
• Heil GM-5 dual-element desktop mike
• Bencher BY-1 Key
• Palm mini paddles for portable keying
• Heathkit SB-220 - I like the fact that it proclaims that it's a "2 KW Amp" on its nameplate!  It was very well-constructed and lightly used before I bought it on eBay.  Since then, I've completely rebuilt it with all of the Harbach mods, including the much beefier Peter Dahl 1.3 Amp continuous-duty high-voltage transformer for added OOMPH!  Too bad I can't use it routinely here in this house, but I do use it on "special" occasions (hopefully not when the neighbors are home)!
• Ameritron ALS-500M 500 watt PEP mobile amp, used with a 70 Amp Astron linear 13.8 volt supply.  Like the SB-220, it sees only infrequent use.  The vast majority of the time, I'm on 100 watts or less.  Often far less.
• I also have built the K5OOR QRP amplifier kits: the 40 watt HF Packer and the 100 watt Packer Pro amps.

ANTENNAS:

• Pacific Antennas PAC-12 mini vertical - great little portable antenna!
  
• Superantennas MP-1 - neat portable vertical, and very well-made
• A couple of homebrew 1/4-wave aluminum verticals.  I mount them (temporarily on some weekends) on a 1.25 inch 10-foot copper pipe I drove down into the grass in the back yard.  About 10 inches of it protrudes from the ground, making it both a good mounting point, as well as the beginnings of a ground attachment point for the radials I spread out onto the grass.
• High Sierra Sidekick - screwdriver antenna with extended stinger mounted at ground level.  I've experimented with it, but don't routinely use it.  It doesn't seem to be very efficient compared to my others (strictly in a non-mobile setting).  As time goes by, I'll try some different experiments with it and its big brother, the HS-1800/Pro.  Those of us that live in CC&R-land will try anything to get a decent signal out!
  
• 75 foot horizontal loop and balun, about 5 to 15 ft high (a real cloud-warmer).  Works on 40 meters and up.  It's stealthy enough that this is my only "permanent" antenna that I dare to leave in place.
  
• And sometimes, when I get really desperate, I even end-load my aluminum rain gutter on 40, 80 and 160, too!  Works surprisingly well, but fairly noisy on receive, and it favors the south and west--not great when you live on the West Coast.  Hey, at least Hawaii's no problem!
• I've also been experimenting with very small HF loops made with copper pipe.  So far, I've been very pleased with the results.  I may mount a 1-meter diameter model in the attic for 30 through 10 meters when I finish perfecting the remote tuning motor drive for its tuning capacitor.  It's very efficient, and really gets out well.  I had 5-watt 17 meter SSB contacts with both the east coast and Hawaii within 30 minutes on the first day I finished building it--mounted about 6 inches above ground!  Both ops were running 400-500 watts, and both gave me 5-7 to 5-9 signal reports.
• For satellite work, I'm using a homebrew 11 element 436 MHz yagi, and another homebrew 6 element 2 meter yagi.  Great antennas, but I'm working on redesigning them for circular polarization.  Not always pleased with the polarization fades I'm getting at times on FO-29 and AO-52.
• I've designed a LHCP 2.4 GHz helical feed (for AO-51) that will soon be mated to an old Dish Network 18" reflector.

MOBILE:

• Yaesu FT-857 - a real gem of a compact DC-to-light transceiver!
  
• Yaesu ATAS-120 - a compact screwdriver antenna that covers 40 thru 6 meters.
  
• Larsen 2M/440 VHF/UHF antenna
• Diamond K-400 trunk lip mounts for both antennas

QRP:

• Elecraft K2 - a very enjoyable QRP rig to build and operate.
  
• Elecraft KX1--neat little handheld QRP rig that puts out about 1.5 to 4 watts on 80, 40, 30 and 20 meters.
• Yaesu FT-817ND - Neat little portable HF/VHF/UHF all-band rig. Great for QRP and satellite QSO's.  I might buy another for full-duplex portable operation on the SSB satellites.  I think I'll need to grow another arm to do this effectively, though--one to hold the Arrow antenna at the sat, one to tune the receiver, and another to tune the transmitter for doppler compensation.  Oh, wait--I guess I'll need a fourth arm to hold and key the mike!  I'll have to think a bit more about this first...

It also seems that I have a growing number of little QRP homebrew transceivers popping up in the shack and on the workbench. This is definitely a fun part of the ham radio experience. Nothing like building your own gear and being thrilled to see it working!  These are some of the kits I've been enjoying lately:

• Rock-Mite 500 mW fixed-frequency direct conversion transceivers for 20, 30, and 40 meters from Small Wonder Labs
• The Small Wonder SW-40 - it's a tunable 40 meter 2.5 Watt CW transceiver: Link to SW+ page
• The PFR-3 portable, self-contained transceiver from Doug at: QRPKits.com
• BitX20A 20 meter CW/SSB rig, also from Doug at: QRPKits BitX20A page
• I'm working on building the MMR-40 right now: QRPKits MMR-40 page

So...

My biggest challenge these days, ham radio-wise, is to find a decent enough HF antenna system to satisfy my need for DX, given the confines of my typical postage-stamp Bay Area lot and a handful of neighborhood CC&R's.

Any of you living on large lots with lots of open space for your antennas should definitely understand my envy and admiration!

72 and 73,

Dave

www.k7daa.com