June 12 Meeting

Our next WVARA meeting will be held in-person on Wednesday, June 12, in Meeting Room 3 at the Silicon Valley Chapter of the American Red Cross, 2731 N. First Street at Plumeria Drive (southwest corner) in San Jose.  Social time begins around 6:45pm, with the meeting commencing at 7pm.  If you haven’t been to the Red Cross in a while, “talk-in” is usually available on the Association’s repeaters. Best choice would be 2m/220.  

This month’s meeting will be a double-header.  

  1. Ed Fong, WB6IQN, will tell us about the latest original idea in ham radio — the ultra compact, all-mode portable HF transceiver:  the uSDX+ .  
  2. After Ed’s presentation, we’ll finalize our WVARA’s plans for Field Day on Mora Hill, which in case you haven’t heard is June 21-23. If you haven’t done so already, feel free to fill out our on-line participant survey so that we can include you in our Field Day plans.  
    Here’s the URL:  https://www.surveymonkey.com/r/NB28TGZ


Here are some details about Ed’s presentation:  

The uSDX+ is a software-defined transceiver based on the Silabs synthesizer chip and the Atmel ATMEGA 328P  FPGA.  The entire radio including the 4000mAh Lion battery is only 1 lb 2 oz.  The radio can operate all weekend with a single charge.

  • General coverage receiver – 3.5MHz- 30 MHz
  • Transmits on 80-10 meters including all WARC bands
  • Built-in CW decoder, keyer, all DSP filter from 4KHz to 50 Hz, DSP noise reduction
  • Output –  5 watts for CW –  for SSB  slightly under 10 watts.

This rig uses a Class S is a switching amplifier, so although efficient, it cannot be directly used as a SSB output stage which historically requires a less efficient linear amplifier.  So how do they achieve linear SSB amplification from a switching amplifier and achieve 80%+  efficiency?  The key is in the 800 kHz sigma delta modulator.  Ed’s presentation will focus on this clever approach to generating SSB.

Ed Fong was first licensed in 1968 as WN6IQN.  He later upgraded to Extra Class (when 20 WPM was required ) with his present call of WB6IQN.  He obtained the BSEE and MSEE degrees from the Univ. of California at Berkeley and his Ph.D. from the Univ. of San Francisco.  A Life Senior Member of the IEEE, he has 12 patents and over 40  published papers and books in the area of communications and integrated circuit design.  Presently, he is employed by the University of California,  Santa Cruz (previously with Berkeley from 1997-2010) as an instructor teaching graduate classes in Antenna Design,  RF design and high speed interface.  In his 35 year career, he has done work for Stanford University, National Semiconductor, Advanced Micro Devices, numerous startup companies in the Silicon Valley.


BTW, several of us meet nearby for dinner prior to the meeting at 5:30pm at Disn-N-Dash (2551 N. 1st St. San Jose):  https://dishdash.com . Feel free to join us.

Three things to remember:

• Since the west side entrance to the Red Cross Building is always locked, we recommend entering the Red Cross Building through the main entrance situated on the north side of the building.

• The Red Cross locks the main entrance at 7pmsharp, so please come early in order to get access to the building.  

• Since Meeting Room 3 is about 100 feet from any entrance, any late comers who knock on an outside door won’t be heard from our meeting room. So please try to arrive early!  If you need help getting in the door, you can call my cellphone:  408-636-6172.

Jim, K6EI

WVARA Vice President