The Browning Mark 4A receiver has one crystal for each band it covers. The factory installed one at 22.82 MHz for channels 1-27 and 23.14 for channels 28-59. There was a crystal available to cover 32 channels below channel 1, 22.5 MHz.
They were available for years from Barkett Electronics, but I'm gonna try out a more high-tech alternative.
Stumbled across QRP Labs. https://qrp-labs.com/
In particular they sell a pc board with a SI5351 frequency synthesizer chip, the same "DDS" frequency source used in the Troy Radio gadgets. This one has no controls, other than three binary input pins. It's shrunk down to fit inside a HC6/U crystal can. My plan is to use three wires from the radio's front-panel band switch as inputs to this board.
They call it the ProgRock. https://qrp-labs.com/progrock2.html
I added the right-angle pins to make prototyping easier.
The mock-up here hasn't even been soldered together. The idea is to just replace the factory board and its crystals.
The ProgRock is eighteen bucks plus shipping. About what you'd pay for just one crystal.
Maybe.
My ultimate ambition is to make a pc board to use in either this receiver or the Mark 3. That will require a rectifier and filter to use the 6.3 Volt AC heater power to run it. The Mark 4A has a source of 11 Volts DC. A simpler place to start from.
Film at 11.
73
They were available for years from Barkett Electronics, but I'm gonna try out a more high-tech alternative.
Stumbled across QRP Labs. https://qrp-labs.com/
In particular they sell a pc board with a SI5351 frequency synthesizer chip, the same "DDS" frequency source used in the Troy Radio gadgets. This one has no controls, other than three binary input pins. It's shrunk down to fit inside a HC6/U crystal can. My plan is to use three wires from the radio's front-panel band switch as inputs to this board.
They call it the ProgRock. https://qrp-labs.com/progrock2.html
I added the right-angle pins to make prototyping easier.
The mock-up here hasn't even been soldered together. The idea is to just replace the factory board and its crystals.
The ProgRock is eighteen bucks plus shipping. About what you'd pay for just one crystal.
Maybe.
My ultimate ambition is to make a pc board to use in either this receiver or the Mark 3. That will require a rectifier and filter to use the 6.3 Volt AC heater power to run it. The Mark 4A has a source of 11 Volts DC. A simpler place to start from.
Film at 11.
73
