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Welcome!

This is a site for those interested in building their own HF amateur radio station equipment.

The site documents my current station consisting of the 2020 HF Transceiver and MRF101 amplifier. Detailed information is also included for the Express Receiver, and some limited information for the Express Transmitter and 6146B amplifier. I don’t own a commercial rig and operate exclusively digital modes, mainly FT8. I find FT8 to be a fascinating mode in terms of exploring propagation, antenna performance, and receiver performance. As of November 2021, I have 149 / 143 countries worked / confirmed with a 43-Ft vertical.

The Express Receiver was designed and built between 2014 and 2016, and the Express Transmitter between 2017 and 2018. As such, some of the parts I used may no longer be available, however, for most there will be substitutes.

November 15, 2021 Update. The 2020 HF Transceiver was used on the air for the first time on October 30, 2021, and has since been used on all bands. From start to finish, the build took approximately 15 months. During the course of the New Hampshire winter, I will add build information for the complete transceiver.

The 2020 Transceiver started out in 2020 as a concept with the following objectives in mind:

  • Build a highly integrated transceiver
  • Learn KiCad to take advantage of low cost PCB manufacturers in Asia
  • Maintain the building block approach of the Express Receiver / Transmitter
  • Utilize H-Mode Mixers and a Quadrature Sampling Detector (QSD / Tayloe Detector)

The only objective not met was the use of H-Mode Mixers. I decided to use Analog Devices AD831 monolithic mixers in the 1st and 2nd mixers stages as I was very pleased with the performance of the Express Receiver and it was the fastest route to getting the transceiver on the the air. The modular nature of the transceiver will allow later upgrade to H-Mode Mixers by simply changing out the 1st Mixer, 2nd Mixer, Roofing Filter, & Post Mixer Amp Board.

Thanks for visiting.

Rod, AD5GH

Windham, New Hampshire

November 2021

5 thoughts on “HOME

  1. Jean Pierre Mallet March 10, 2021 / 11:56 am

    Fine Business 73 F5MI

    Like

  2. Paul Taylor May 3, 2022 / 6:25 pm

    Hi Rod, checked back, great to see you have built a full multiband HF transceiver, just in time for the cycle peak. Looking forward to reading about it. I am also fully homebrew and active, running AM 150w transmitters on 160 to 40 and QRP SSB and CW mostly. I own an Icom HF box but it is packed away! 73 Paul VK3HN.

    Like

    • Rod Gatehouse May 8, 2022 / 4:58 pm

      Hi Paul, thanks for checking in. I enjoy following your homebrew activities and SOTA activations. The transceiver works very well, I’m closing in on 5B DXCC with FT8. Also building a second version of the transceiver with some changes to the audio stages (adding Sotabeams DSP audio filter module) and GPS disciplining the Si5351s. All the best, Rod

      Like

      • Paul Taylor May 11, 2022 / 7:42 am

        Hi Rod, I’m looking at your second revision, keen to see your design choices. It’s great to reap the rewards of all that thought and effort with some operating success. I’m watching that DSP audio filter, seems like an ideal way of getting digital quality filtering, particularly for CW or digital modes.
        Do you mean replacing the usual 25mhz crystal with a GPS derived timebase? Is this simply for high stability si5351 VFO/BFO/CO? I guess that’s important for digital.
        Will watch your blog with interest.
        73 Paul VK3HN.

        Like

      • Rod Gatehouse May 11, 2022 / 6:09 pm

        Hi Paul, the DSP audio filter is small footprint and ~30mA current draw, so could be a nice addition for a portable xcvr. I am using an Arduino Nano equivalent as a frequency counter on a dedicated Si5351 channel with the GPS 1pps providing the accurate gate. The Si5351 channel is set for 2.5-MHz and the frequency measured over a 40 second period. With this accurate frequency measurement, you can determine a more exact value for the 25-MHz xtal. This more exact xtal value is then used in the Si5351 MultiSynth functions to program the other Si5351channels. If you look at the 1st & 2nd Mixer board photo, you will see a place for Adafruit Mini Metro and Ultimate GPS board. I will put the 1pps on the backplane bus so I can do the same thing with the Si5351 on the audio board providing BFO and Carrier Osc. Not my idea, I first saw this in an article by W3PM in July/August 2015 QEX. I have always wanted to GPS discipline an oscillator, and this will certainly help with digital modes such as WSPR where you are aiming at a 200-Hz segment. Today I calibrate each band with an offset to get within a few tens of Hertz. All the best, Rod

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