As part of a project to make a VFO based on an Adafruit style "SI5351 module", I wanted to explore the chip's VCO lock range. The only test kit needed is a domestic medium wave radio receiver
The accompanying GCB code was used to see if the VCOs published range (600MHz-900MHz) could be reliably extended. In the couple of SI5351A modules that I had purchased, it could readily be extended to 250MHz-1GHz, offering the possibility to generate a rather wider range of o/p frequencies than claimed by SI.
Great Cow Basic code for controlling a VFO based on ADAfruit SI5351A VFO module.
VFO provides contiguous (square wave) output from 60kHz to 225MHz.
Frequency is set using an optical rotary shaft encoder.
Schematic for the SI5351A VFO is the same as that used for the VCO Range analyser (above)
VFO complementary outputs are on CLK0 and CLK1 ports of SI5351
VERSION OF VFO WITH QUADRATURE OUTPUTS (2.4MHz - 125MHz)
Great Cow Basic code for controlling a VFO based on ADAfruit SI5351A VFO module.
VFO provides continuously tuneable (square wave) quadrature outputs from 2.4MHz to 125MHz.
(It actually generates an output all the way up to 225MHz, but quadrature output accuracy has not been verified at higher frequencies)
Frequency is set using an optical rotary shaft encoder.
Schematic for the SI5351A VFO is the same as that used for the VCO Range analyser (above).
VFO quadrature outputs are on CLK0 and CLK1 ports of SI5351.
Dave,
Very interesting!
I had bought and built a si5351 prog osc from QRPkits but I never finished the receiver. This was because i was modifying it to receive TV channel 2 carrier on 55.259 mhz. I am an amateur radio astronomer and using tv carriers, you can count meteors. That was my intention but it got back burnered a couple too many times and then the dongle sdr's came along.
But I dug it out a couple weeks ago scheming another project with it . Then you posted code for it. Maybe that is a sign i should use the code to complete my idea. Thank you!
73
Mike W9YS
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As part of a project to make a VFO based on an Adafruit style "SI5351 module", I wanted to explore the chip's VCO lock range. The only test kit needed is a domestic medium wave radio receiver
The accompanying GCB code was used to see if the VCOs published range (600MHz-900MHz) could be reliably extended. In the couple of SI5351A modules that I had purchased, it could readily be extended to 250MHz-1GHz, offering the possibility to generate a rather wider range of o/p frequencies than claimed by SI.
And here is the schematic.
(Updated to Ver2 as some microcontroller pins were mis-labelled on Ver1)
Last edit: deltadave 2021-02-09
Great Cow Basic code for controlling a VFO based on ADAfruit SI5351A VFO module.
VFO provides contiguous (square wave) output from 60kHz to 225MHz.
Frequency is set using an optical rotary shaft encoder.
Schematic for the SI5351A VFO is the same as that used for the VCO Range analyser (above)
VFO complementary outputs are on CLK0 and CLK1 ports of SI5351
Last edit: deltadave 2021-02-06
VERSION OF VFO WITH QUADRATURE OUTPUTS (2.4MHz - 125MHz)
Great Cow Basic code for controlling a VFO based on ADAfruit SI5351A VFO module.
VFO provides continuously tuneable (square wave) quadrature outputs from 2.4MHz to 125MHz.
(It actually generates an output all the way up to 225MHz, but quadrature output accuracy has not been verified at higher frequencies)
Frequency is set using an optical rotary shaft encoder.
Schematic for the SI5351A VFO is the same as that used for the VCO Range analyser (above).
VFO quadrature outputs are on CLK0 and CLK1 ports of SI5351.
Dave,
Very interesting!
I had bought and built a si5351 prog osc from QRPkits but I never finished the receiver. This was because i was modifying it to receive TV channel 2 carrier on 55.259 mhz. I am an amateur radio astronomer and using tv carriers, you can count meteors. That was my intention but it got back burnered a couple too many times and then the dongle sdr's came along.
But I dug it out a couple weeks ago scheming another project with it . Then you posted code for it. Maybe that is a sign i should use the code to complete my idea. Thank you!
73
Mike W9YS