Category Archives: Projects

Passing Pixie!

Posted on February 21, 2017 by robert

After experimenting with T37-6 yellow core inductors, it was time to change to the T37-2 red core.  These have a lower operating frequency, up to 10 MHz, and it is possible that they might have a higher attenuation on 14 MHz … Continue reading →

Posted in Gear, Pixie, Projects, QRP | 1 Comment

Pixie PLUS 5-Pole LPF

Posted on February 20, 2017 by robert

My Pixie produces about 500 mW of output power when driven by a 13.8 volt supply.  The total input power to the board is about 1.5 watts.  As I’ve mentioned the Pixie only suppresses the 2nd harmonic by about 10 … Continue reading →

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A 40 Meter LPF for the Pixie

Posted on February 20, 2017 by robert

As I mentioned the 40-meter Pixie QRP rig has pretty horrible harmonics, well above the maximum allowable FCC limit (-43 dBc).  One Pixie was about -9 dBc, and the other was about -20 dBc. The output filter in the Pixie … Continue reading →

Posted in Gear, Pixie, Projects, QRP | 2 Comments

Pixie Varibility

Posted on February 16, 2017 by robert

Given the dismal harmonic supression of my first Pixie kit, I was excited to test another. While still not passing, it is isn’t absolutely dismal. The readings were taken with a 40 dB external attenuator.  So the fundamental is actually … Continue reading →

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Kenwood TH-F6A Passes Spur Test

Posted on December 12, 2016 by robert

Running a spectral purity check on my Kenwood TH-F6A tri-band radio, I found that it passes FCC requirements as you would hope it would. The test setup used for the UV5R was only slightly modified to change the bandwidth so that the … Continue reading →

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Kenwood TH-D72A Passes FCC Spur Limit

Posted on December 12, 2016 by robert

Running a spectral purity check on my Kenwood TH-D72A APRS radio, I found that it passes FCC requirements as you would hope it would. The test setup used for the UV5R was only slightly modified to change the bandwidth so that the noise … Continue reading →

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BaoFeng UV82 Fails FCC Spur Limits

Posted on December 12, 2016 by robert

BaoFeng sells more radio models than you can shake a stick at.  Another handheld dual band unit that fails FCC spectral purity is the UV82.  This is somewhat larger than the UV5R, sells for a premium, but has an odd … Continue reading →

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Icom ID-51A+ Spectral Purity

Posted on December 12, 2016 by robert

Running a spectral purity check on my Icom ID-51A+ DSTAR radio, I found that it passes FCC requirements as you would hope it would. The test setup used for the UV5R was only slightly modified to change the bandwidth so that the … Continue reading →

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BaoFeng UV5R Spectral Purity Testing

Posted on December 9, 2016 by robert

I have seen some reports of BaoFeng radios not passing FCC Spurious Emission Standards.  I have a old UV5R that is affixed to my Fox Hunting RDF antenna.  I re-enabled the transmitter (normally programmed off to avoid accidentally blowing out … Continue reading →

Posted in Operating, Projects | 3 Comments

Getting the RPi 3 to work with Bluetooth

Posted on March 23, 2016 by robert

After solving the display rotation issue, I was anxious to get rid of the USB based keyboard and mouse, and move onto Bluetooth based devices.  I had followed a RPi blog instruction to update various parts of the OS, and … Continue reading →

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