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Description: The low HF bands are preferred for operation, primarily using CW, with some PSK31 and SSB. The transceivers utilized include an Elecraft K3 paired with an SDR-IQ for panadapter functionality, and a Flex 6700. Amplifiers in use are the SPE-1K-FA, Alpha 77Dx, 87A, and 70V. The station's AC power is supplied through dedicated, isolated-ground circuits, further isolated by a pair of 1 KVA balanced isolation transformers. The Alpha 70V employs steam from a one-pint distilled water reservoir as its sole cooling mechanism, with a column of purified water separating the 4KV high-voltage supply from the chassis. A resource list is maintained for current Alpha 70V owners, and those with an amp are encouraged to contact for a copy of the list by providing the amplifier's serial number. The reference oscillator for the Flex and Elecraft transceivers is sourced from a Trimble Thunderbolt GPS-locked frequency standard, while a Frequency Electronics FE-5650A rubidium standard is utilized to lock the frequency of an HP 5385A counter and various test equipment. Bench test equipment includes Agilent N1996A and Tektronix 2710 spectrum analyzers, both equipped with internal tracking generators, Sencore LC102 L/C analyzer, GenRad/IET 5000 LCR Meter, HP 8640B RF signal generator, Rigol DG1062Z arbitrary waveform generator, N2PK vector network analyzer, Fluke 8842A, and Keithley 2100 digital multimeters (DMMs). Oscilloscopes in use are the Agilent MSO-X-3024A (digital) and Tektronix 2465B (analog). On the station desktop, a Tektronix TM series test set integrates a dual-trace scope, function generator, and two ultra-low-distortion audio oscillators with a distortion analyzer. An attorney in the telecommunications industry and business immigration, the individual has earned an MBA, BSEE, and BSCS degrees in Illinois and Florida, with part of their legal studies completed at Trinity College, University of Cambridge in the U.K. Recent projects focus on designing various station switching utilities, all controlled by an Arduino Nano or PIC microcontroller. One Sequential QSK (S-QSK) Board can manage multiple switching applications through different microcontroller programs. Currently, three programs have been developed for the S-QSK Board. The Nano and Uno boards, compared in the top photo, are functionally equivalent and programmed in C++. A significant advantage of the Arduino boards is that they come pre-loaded with a bootloader, allowing for easy code uploads via a mini USB cable without requiring an external hardware programmer, which is often necessary for PIC and EEPROM chips. The larger Uno is used for quick code testing, while the compact Nano microcontroller board is implemented in the S-QSK Board. Power for the microcontroller and peripheral circuits is supplied via the USB port during testing and through an external +7 to +12V source during normal operation. After developing code for various station switching operations, it became clear that a single board could serve multiple switching and timing projects, with the Nano handling complex operations. Sample code, line-by-line documentation, and structured flowcharts are provided to assist novice programmers with code customization, utilizing structured logic for easy modifications.

The described electronic setup represents a sophisticated amateur radio station, integrating various high-performance components for optimal HF band operation. The use of advanced transceivers like the Elecraft K3 and Flex 6700, combined with powerful amplifiers, allows for effective communication across low HF bands. The cooling mechanism for the Alpha 70V amplifier highlights an innovative approach to thermal management, utilizing distilled water to maintain safe operating temperatures while isolating high-voltage components.

The integration of a GPS-locked frequency standard ensures precise frequency control, essential for maintaining signal integrity during transmissions. The extensive array of bench test equipment, including spectrum analyzers and oscilloscopes, facilitates thorough analysis and troubleshooting of radio signals and equipment performance. The dual-trace scope and function generator within the Tektronix TM series test set further enhance testing capabilities, allowing for simultaneous observation of multiple signals.

The focus on microcontroller-based switching utilities demonstrates a modern approach to station automation, with the Arduino platform providing flexibility and ease of programming. The Sequential QSK Board's ability to handle various switching applications through different software configurations exemplifies the versatility of microcontrollers in radio operations. The inclusion of structured documentation and flowcharts supports users in customizing their code, promoting a deeper understanding of the underlying logic and functionality.

Overall, this electronic schematic reflects a well-thought-out design that combines traditional radio operation with contemporary technology, ensuring effective communication and operational efficiency in the amateur radio domain.I still prefer the low HF bands and mostly operate CW, with some PSK31 and SSB. Transceivers include an Elecraft K3 + SDR-IQ as a panadapter, and Flex 6700. Amplifiers are SPE-1K-FA, Alpha 77Dx, 87A, and 70V. AC Power for the station runs from dedicated, isolated-ground circuits and further isolated through a pair of 1 KVA balanced iso-transformers. The Alpha 70V uses steam from a one-pint distilled water reservoir as the sole mechanism for cooling. A column of purified water separates the 4KV HV supply from the chassis. I maintain a resource list for current Alpha 70V owners. If you have one of these amps, contact me with your amp`s serial number and I`ll supply you with a copy of the resource list.

The reference oscillator for the Flex and Elecraft transceivers comes from a Trimble Thunderbolt GPS-locked frequency standard. A Frequency Electronics FE-5650A rubidium standard is used tolock the frequency of a HP 5385A counter and several pieces of test equipment.

Bench test equipment includes Agilent N1996A and Tektronix 2710 spectrum analyzers, both with internal tracking generators, Sencore LC102 L/C analyzer, GenRad/IET 5000 LCR Meter, HP 8640B RF signal generator, Rigol DG1062Z arbitrary waveform generator, N2PK vector network analyzer, Fluke 8842A and Keithley 2100 DMMs. Scopes include: Agilent MSO-X-3024A (digital), and Tektronix 2465B (analog). On the station desktop, a Tektronix TM series test set incorporates a dual-trace scope, function generator, and two ultra-low-distortion audio oscillators with distortion analyzer.

I am an attorney working in the telecommunications industry and business immigration. In addition to a law degree, I have earned MBA, BSEE and BSCS academic degrees in Illinois and Florida, and spent a portion of my legal studies in the U. K. at Trinity College, University of Cambridge. My latest projects are focused on the design of several station switching utilities, all controlled by an Arduino Nano or PIC microcontroller.

Through a choice of microcontroller programs, one Sequential QSK (S-QSK) Board can manage many different types of switching applications. Presently, three programs have been written for the S-QSK Board and are described below. In the top photo above, the Nano and Uno boards are compared. They are functionally equivalent and both are programmed in the C+ language. A powerful attribute of the Arduino boards is that they come pre-burned with a bootloader, allowing the user to upload new code to it without the use of an external hardware programmer that is commonly needed for PIC and EEPROM chips.

Just grab a mini USB cable and you`re ready to program. The user can also bypass the bootloader and program the microcontroller through the ICSP (In-Circuit Serial Programming) header. I use the larger Uno for quick code testing; the tiny Nano microcontroller board is used in the S-QSK Board.

The microcontroller and peripheral circuits are powered by the USB port during testing, and an external +7 to +12V supply during normal operation. After writing code to perform several different station switching operations, it became apparent to me that one board could be used for many switching and timing projects, using the Nano to perform all of the complex switching and timing operations.

Sample code, line-by-line documentation, and structured flowcharts are provided to assist the novice programmer with code customization. Structured logic is used for easy code modification. Here`s a complete parts list for the M