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Homebrew 6m SSB & CW QRP transceiver | Radioaficion Ham Radio

Homebrew 6m SSB & CW QRP transceiver


homebrew 6m SSB/CW transceiver 6m SSB/CW transceiver is built around two AD831 mixers with cross-switched VFO and BFO. The VFO is actually a VCXO followed by frequency doubler and covers the 50,000MHz … 50,245MHz portion of the 6m band. Since the noise figure of an AD831 itself is not acceptable at frond-end on 6m, there is also a BF981 RX preamplifier. I've got more than 10W of output power using a Mitsubishi power block. Although not built into the prototype example yet, there is enough space in the 145mm x 150mm x 55mm housing to add a suitable frequency counter.

The concept of the 6m SSB & CW transceiver is similar to the 80m SSB & CW transceiver, described on this web site with some minor changes in AGC and audio PA. An additional RF preamplifier, which is not needed on 80m, has been added to get enough receiving sensitivity. The VFO is built as VCXO with frequency doubler, now.

Although the basic SSB module is very similar to that of 80m SSB transceiver, I've designed completely new PCB to maximise the usage of SMT components. The transceiver "base" board includes all IF and AF circuits, both mixers, preselection and bandpass filters, as well as 100mW TX driver. This is in fact a complete transceiver. Only the VFO and BFO have to be added to get a 100mW (QRPP J) HF SSB/CW transceiver. Both oscillators including a diode-switching matrix are placed on a separate board.

RX preamplifier is built around a BF981 MOSFET placed on a separate PCB. The preamplifier has some 20dB gain.

For the TX PA I have chosen a rather easy solution - 10W Mitsubishi PA hybrid module. I've built the TX PA in an "ugly" way on a "hand-made" double-sided PCB. The bottom layer serves as ground. All components are placed on the top side of the board.

6m SSB/CW transceiver project in pdf

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