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Transistor radio series – The 7 MHz scratch synthesizer

Posted on Wednesday, November 29th, 2017 in DIY, RF by DP

pDSC_1351-1-600

Vasily Ivanenko has written up documentation on his 7 MHz synthesizer project:

Above — All 4 boards were built in re-purposed Hammond boxes. A PIC-based counter sits on top of the offset mixer. I build modular gear and this allows modification and fosters experimentation. When I build a final transistor radio receiver, I plan to place the offset mixer, PLL circuitry and VXO on the same board inside the radio with some shielding. My VCOs always go in a RF tight container. A 0.0033 µF feed through capacitor connects the VCO varactors to the outside world.

See the full post on his blog, QRP HomeBuilder.

This entry was posted on Wednesday, November 29th, 2017 at 3:08 pm and is filed under DIY, RF. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

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Recent Comments

  • Pekka Akselin: This is ridiculous!? :-) We are back at 256(!) byte EPROMs that needed multiple, a handful, of voltages to run! :-(
  • KH: Let's try a back-of-envelope calc balancing energies. From MCP1700 datasheet, there are graphs for a 200mA load step. Estimate the energy shortfall as 12uJ. Say...
  • Daniel: It's been a week and my comment is still awaiting moderation. Apparently the CIA doesn't want their involvement known?
  • KH: Agree, so okay, I guess he must have learned from somewhere. 100nF and 1000uF is so far apart, that was jarring; it's more magic incantation...
  • Max: I have a suspicion the hefty electrolytic cap might be some sort of cargo cult carry-over from other RF-based projects - for instance, I've seen...