Archive for the ‘GHz’ Tag

Not Your Grandpa’s Ham Radio at the Bay Area Maker Faire 2014   Leave a comment

This is our third consecutive appearance at the Bay Area MF, and continues my theme of showing how some ham radio operators continue the tradition of “teaching, mentoring, making, modifying, repairing and improving” radio and radio-related technology. Read my post about ham radio and the Maker movement.

Today’s ham radio operators have an incredible amount of exotic surplus material that can be converted into everyday use on the ham radio bands. Grandpa certainly never heard of surface-mount technology, talking on homemade 47 GHz transmitter-receiver systems or pocket-sized, satellite navigation systems (GPS). But he sure did mentor, make, modify, repair and improve the equipment in his bedroom radio station…..

Not Your Grandpa’s Ham Radio – Maker Faire 2014 Team

Wayne Yoshida KH6WZ

Dennis Kidder W6DQ

Brian Yee W6BY

Marty Woll N6VI

More information on the Maker Faire Bay area.

Here is a gallery of our booth posters for the 2014 Bay Area Maker Faire. More photos, videos and stories will follow. . . . .

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Maker Faire Bay Area is May 17 and 18!   Leave a comment

Maker Faire 2012-2 010

 

 

The big show is coming soon. Last year, over 120,000 people attended this science-art-food-engineering-fun-educational event.

This year, my team (Dennis Kidder W6DQ, Brian Yee W6BY and Marty Woll N6VI) will bring their newest ham radio projects to show. We will continue with my original theme called “Not Your Grandpa’s Ham Radio.”

A group of University of California, Davis (UCD) engineering students will join us to demonstrate their experiments and projects. These new engineers are getting a great head-start by doing hands-on, practical experiments and projects that go beyond their lecture and textbook learning.

Read my LinkedIn post to understand my personal passion about amateur radio, Makers, the Maker Faire and education.

 

 

CQ Magazine Article, “The Science of Ham Radio” Published in the September Issue   Leave a comment

This is a screen capture showing the KH6WZ APRS beacon data from the Discovery Science Center - Meet the Makers event.

This is a screen capture showing the KH6WZ APRS beacon data from the Discovery Science Center – Meet the Makers event.

My article, “The Science of Ham Radio” is published in September CQ magazine: http://www.cq-amateur-radio.com/cq_current_issue.html

Microwave Radio Tune Up Party in Costa Mesa   Leave a comment

028-wayne yoshida-microwave radio

This past weekend, some of the active San Bernardino Microwave Society (SBMS) gathered at Fairview Park in the early morning to perform a field test of their microwave systems. Since I did not do anything with my rigs this past year, I decided to skip this field test, and take some pictures of any new more interesting rigs for this contest season.

Here are some pictures of the various station equipment SBMS club members built and tested that day . . .

A post-Tune Up Party party and BBQ was held at Dennis W6DQ’s house. It was nice to relax and visit with the other SBMS members and enjoy some great BBQ chicken….. In the picture below, Walt, WALT explains one of his radio wave demonstrations to a captive audience… Watching and learning, from left to right are Bill Preston, KZ3G; Dan Slater, AG6HF and wife Sandy Slater; Walt, and Jason Sogolow, W6IEE.

KH6WZ tune up and KH6WZ-5 050

If you are curious about the test setup, here is an article written by Kerry Banke, N6IZW, with some small edits by me:

Checking Microwave Radio Performance with a Simple ERP/MDS Test Unit

By Kerry Banke, N6IZW (Edited by Wayne Yoshida, KH6WZ)

Before heading for the hills with 10 GHz equipment around contest time, members of the San Diego Microwave Group (SDMG) and the San Bernardino Microwave Society (SBMS) check the Effective Radiated Power (ERP, transmit) and Minimum Discernible Signal (MDS, receive) with the simple setup described in this article. We hold the test sessions at the June and July meetings in preparation for the ARRL 10 GHz and Up Contest in August and September. The advantage to having two sessions is that it provides a second opportunity to verify improvements or allow participation if the first session is missed. The test unit works with both wide band and narrow-band radios.

The Pole-Mounted Test Setup

The setup consists of a pole mounted X-Band converter unit connected by coax to a signal source (for MDS) and an amplifier/power meter located near the radios to be tested some 200-300 feet away. The MDS test must be performed first to align the radio antennas with that of the converter. A signal generator is connected to the IF coax and a suitable frequency (145 MHz) and power level (-40 dBm set to transmit an easily detectable carrier around 10368 MHz at the output of the converter.

MDS for Receive

Each participant adjusts their equipment and the system antenna for maximum signal as the power level of the signal generator is reduced to the point where it is no longer detectable by the radios. The level at which the signal can just be detected is considered the MDS.

ERP for Transmit

The ERP measurement is performed by connecting the IF coax to the amplifier and power meter. Each radio transmits one at a time and the power meter reading recorded. The variable attenuator is adjusted to keep the reading in a suitable power range for the power meter and amplifier. For the amplifier used, the maximum output power was about +10 dBm and the power meter range is about –20 to + 10 dBm so the attenuator was adjusted to keep the reading in the –20 to 0 dBm range.

The choice of the IF frequency for the converter depends on what is available for a 10 GHz local oscillator but needs to be low enough to keep the losses reasonable through hundreds of feet of coax. The amplifier gain and maximum output need to be based on the power meter characteristics. The signal generator needs to match the IF frequency chosen, have suitable stability for CW work (NB only), and have variable output (may be an external attenuator).

The converter consists of a Frequency West Brick as a 10,223 MHz local oscillator for a mixer used as an upconverter for MDS and down converter for ERP. The converter has a 13 dB horn antenna connected to the mixer RF port. Power is supplied by a 12V battery on the ground with a DC/DC converter supplying the required voltage for the local oscillator. The coax used is 300 feet of RG-59 which was readily available. No attempt to correct matching losses for the 75 ohm coax has been made. The loss of the coax and mixer as well as the amplifier gain was measured at the operating frequencies. It is not really necessary if only relative measurements are to be performed but it does allow a good comparison between measured and calculated values.

The results of the test are entered into a spreadsheet, which then calculates the ERP based on dish size in inches and estimated PA output of the radio under test. The distance in feet from the radios to the converter is input to the sheet, which then calculates the path loss in dB. For ERP, the sheet provides calculated ERP, measured ERP and the difference between them. For MDS at this time, only the signal generator level is recorded and is used for relative measurements.

Block diagrams for the 10 GHz and 24 GHz units are described in the PDFs below:

10 GHz ERP-MDS Block Diagram

24 GHz ERP – MDS Block Diagram

Intro to the MDS/ERP Event Results

(From an entry on the SBMS website on August 10, 2012)

These spreadsheets show the results of workshops/picnics where amateur microwave stations were compared on a unique test range for both transmitting and receiving performance. The test setup was developed by Kerry Banke, N6IZW and has been used by the San Diego Microwave Group (SDMG) and the San Bernardino Microwave Society (SBMS) over the past few years. The test setup consists of a remote TX/RX transmitter/sensor unit installed on a pole about 15 ft. high at a distance of approximately 220 ft. from the stations being tested.

The remote transmitter produces a stable signal on the operating frequency, such as 10368 MHz. Operators tune this in with their rigs and peak their antennas. The signal is then reduced in level until barely discernible (MDS). That level is logged. The operator then transmits with maximum CW power and the RX sensor power level is logged. The spreadsheet is used with the logged data and with data on each rigs claimed antenna size and transmit power to allow comparison of measured versus expected performance.

The results have been useful, not from an absolute basis, but by allowing operators to compare their rig’s results against other amateur’s rigs having similar TX, RX, and antenna characteristics. Any major performance differences between systems can help focus on problems that can be solved before upcoming contest events.

In past events, operators have discovered problems with relays, cables, connectors and even non-functioning power supplies.

Interpreting Results

Receive (MDS) performance is shown in the column marked “MDS Gen dBm.” You want the largest negative value compared to other stations having the same size or performance antenna on that frequency band.

In the last column marked “Meas-Calc,” transmit ERP performance is shown. A zero means that the ERP came out exactly as expected given the claimed transmitter power and antenna gain. A positive number indicates an ERP that is better than expected by that many dB. A negative number indicates system performance measures worse than expected.

Here are some results over the past years – 2013 results added!

TuneUp2013

SDMG ERP-MDS-2013 Results

TuneUp-2012

TuneUp-2011

TuneUp-2010

TuneUp-2009

Tune-Up-2008

TuneUp-2007

TuneUp-2006

TuneUp-2005

TuneUp-2004

TuneUp-2003

TuneUp-2002

TuneUp-2001

TuneUp-2000

Report on Maker Faire 2013   Leave a comment

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Maker Walt discussing something fascinating with Jeri Ellsworth, aka “Circuit Girl.” Photo by Tony KC6QHP

Here is a report on the 2013 Maker Faire by Tony Long (KC6QHP):

Another great Maker Faire is in the books, amateur microwave radio was well represented!

Thanks to the coordination efforts of Wayne KH6WZ, Brian W6BY, the 50 MHz and Up Group, the SBMS, and UC Davis, the “Not Your Grandpa’s Ham Radio 2” booth at the Maker Faire was a great success.

This year we shared a booth with UC Davis whose impressive student projects ranged from a radar demonstration, to video processing, audio sequencing, and mechatronics.  Along with that, we had a  10/24 GHz SDR setup courtesy of Dennis W6DQ (on a big screen courtesy of Brian), some of Brian’s homebrew gear, Walt’s EM field demos and transceivers, and some of my stuff including a 10 GHz radio and beacon.

LA Times says that about 165,000 people were expected to attend this year, so at a minimum 10,000 people passed by our booth.  Our raspy voices are an indicator that a great deal of talking was done!  I personally interacted with a number of people who are really interested in amateur microwave radio and if even a fraction of them get involved or raise general awareness, I think it is a success.

Walt’s demos, owing in part to their elegant simplicity and visual nature attracted a lot of attention and interest.  On Sunday night he took them to a post-fair get-together with the who’s who of the hardware hacking scene (Jeri Ellsworth, Ben Heckendorn, Diana Eng, Alan Yates and many many others). All were impressed!

Something I see very encouraging in the “maker” scene is a real interest in RF.  This crowd includes a good deal of embedded systems engineers, talented software people, etc.  There’s a real opportunity to make connections with this crowd and get more activity on the microwave bands.
As Software Defined Radios decrease in cost and become more open source, I predict massive interest in RF and likely in the microwave bands because of their large bandwidths.  While they may not be interested in SSB mountaintop to mountaintop contesting (there will be those who are certainly), an increase in use of our bands will only help to further the cause of maintaining our spectrum to help further the state of the art.

I posted a gallery of pictures on Flickr:  http://goo.gl/cAy3p

Tony KC6QHP”

Thanks for the report, Tony!