Transmitter, 10W

The Transmitter is built into the chassis of an HP 436A Power Meter with custom front and rear panels. A single screw on each of the top and bottom covers allows the respective cover to slide off the chassis providing quick and easy access.

Transmitter Top Deck

On the right hand side of the chassis adjacent to the front panel are the following boards, from top to bottom.

  • SSB Generator Board – Audio Input, Carrier Osc. (BFO) Amplifier, Balanced Modulator (TUF-1), and SSB Filter.
  • 1st and 2nd Mixer Board – identical to board used in the Receiver
  • Three BFP boards, 160M – 10M
  • Driver Amplifier – 0.25W

All frequency generation and control is done in the Receiver. LO, VFO and BFO (Carrier Osc.) signals are fed to the Transmitter via SMA cable assemblies. Split frequency/band operation is possible using VFO A & B on the Receiver with VFO B designated for TX.

Transmitter Bottom Deck

The bottom deck contains the Arduino Mega with a breakout board; Power Distribution Board providing unregulated 13.8V, regulated 12V and 5V; I2C Relay Control Board.

Transmitter LPF and PA

The PA is the PennyWhistle from TAPR. The LPF board is the
LPF-100 R3B Kit 100W Low Pass Filter from HF Projects.

2 Replies to “Transmitter, 10W”

  1. Your construction is amongst the best I’ve seen for amateur homebrew work. I assume your work involves electronics product manufacture. I’m intrigued that you remain engaged with ‘traditional ‘ analog amateur transmitter and receiver architectures of the 70s and 80s such as superhet. (Like me!). Is that nostalgia?

    How do you do those amazing front panels?

    73 Rod. Paul VK3HN.

    1. Hi Paul,

      Thanks for the feedback!

      I grew up with likes of Solid State Design for the Radio Amateur, so yes definitely nostalgia and enjoyment I get from building on the designs from that period with technology available today. I get as much enjoyment sitting down with a schematic, laying out a PCB, or debugging hardware/software, as I do operating. I spent number of years designing and building before I had a station to put on the air!

      The front and rear panels come from Front Panel Express here in the US, with their CAD software it is straight forward to design nice looking panels. I don’t use them for all projects, but I like the look for my main station equipment!

      Interestingly, the first aspect of the receiver that I put down on paper was the front panel layout, including the information to be displayed on the LCDs. I knew I wanted to build a multi-band up-converting superhet, but having the front panel layout from the beginning helped drive many other design decisions and kept me focused on the finished product.

      Regards, Rod

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