Retired



Image of prototype board/assembly
shown connected to the FCC-1
The FCC-2 Mark II is an addon to the FCC-1

This is the second generation of the popular FCC-2 introduced in 2006. Recent advances by Analog Devices, the manufacturer of the DDS chip, have enabled increased performance and the latest chip supports a clock frequency that’s 50% higher than the original. This permits the new FCC-2 to produce frequencies up to 31 MHz with the same performance as its predecessor. The firmware has also been enhanced to provide x2 and x4 frequency output, making the FCC-2 Mark II suitable for use with software defined radios which employ frequency division to develop a quadrature LO. Of course, all of the familiar features of the FCC-1 and FCC-2 have been retained.

For those new to the FCC-2, it is an add-on DDS VFO board that extends the basic capabilities of the FCC-1 counter kit. All of the FCC-1 features have been retained, so you won’t lose them by upgrading. A lot of work has been put into this kit to minimize power consumption and permit battery operation for extended periods. Surface mount technology (SMT) has been used extensively to minimize the size and weight of the kit. The FCC-2 is peerless in its low power consumption and flexibility.

The kit features a DC – 31 MHz DDS (Direct Digital Synthesis) chip, a shaft encoder and provides RTTY support. A new PIC microcontroller is supplied with the kit, which adds the VFO to the basic counter features. The VFO firmware supports 13 bands from 160m through 2m, plus a non-specific, Direct band. There are numerous user-programmable parameters which are stored in EEPROM for one-time setup convenience. You can easily switch between VFO and frequency counter modes and the DDS output will retain its frequency. You’ll see later on how we use this feature to calibrate the counter. The userprogrammable IF offsets and scale factors permit the VFO to operate in a wide range of HF and VHF applications.

Dual VFOs and Split operation are supported in the firmware, and the FCC-2 will operate RTTY straight off your workbench. Just connect a COM port cable and launch the software. I’ve used MMTTY and it works great. You can incorporate the FCC-1/2 combination into a homebrew rig or package them into a separate enclosure for use as a portable test instrument. Typical current consumption for the pair is approximately 70mA. Operation is as simple as connecting a power supply.

If you ordered the FCC-2 Mark II kit with the DDS chip, it will be included in one of the component bags. If you chose the lower cost option and haven’t yet ordered the AD9834CRUZ sample from Analog Devices, point your browser to http://www.analog.com . Search for AD9834 and scroll down the page to order a sample. Make sure you order the “CRUZ” part, which supports the 75 MHz clock frequency used in the FCC-2 Mark II. New users will need to register first, but it’s quick and straightforward. Your new DDS chip will be in the mail shortly and best of all, it’s totally free!

The kit contains all of the essential parts. All you need to supply are your favorite I/O connectors. Over 90% of the components are SMT. To successfully assemble the FCC-2, you need to have previous kit building experience, preferably with SMT components. It’s not recommended that beginners attempt this project because of its intricate nature. If you find yourself in over your head after purchasing the kit, no problem. You can have the SMT components installed by Kit Builders. Send Mike, WA6OUW, an email at wa6ouw@aol.com for further information.

FCC-2 Mark II Features

• Complete FCC-1 Frequency Counter support
• Shaft encoder for frequency entry, Memory and Menu mode operations
• 3 pushbutton and shaft encoder user interface
• Dual VFOs
• Split operation
• VFO copy: A-> B, B->A
• VFO can be band limited or full range
• Fast T-R switching
• FSK (RTTY) support
• 10 programmable frequency memories, store and recall to/from either VFO
• Last band frequency used is stored in EEPROM – after 30 second dwell
• Programmable transmit IF offset
• Programmable receive IF offset
• Programmable transmit frequency scaling per band
• Programmable receive frequency scaling per band
• Programmable transmit frequency calculation per band:
  • Direct
  • VFO+IF
  • VFO-IF
  • IF-VFO
• Programmable receive frequency calculation per band:
  • Direct
  • VFO+IF
  • VFO-IF
  • IF-VFO
• Programmable transmit RTTY Mark frequency offset – 2125 Hz nominal
• Programmable transmit RTTY Space shift frequency – 170 Hz nominal
• Programmable receive RTTY Mark frequency offset
• Programmable shaft encoder pushbutton function
• DDS Calibrate mode
• Extensive Menu mode
• Computer-controlled contest keying

FCC-2 Mark II Specifications

Dimensions	1.5” x 3.0” x 1.25” (HWD)
Weight	1.2 oz
Power Requirements	Approximately 70 mA including the FCC-1
Inputs	FCC-1 connection RS-232 compatible FSK input: TXD, RTS, Ground
Usable Frequency Range	DC to 31 MHz
Outputs	1. Lo-Z:    50 Ohm, 15KHz – 31 MHz output (-4 dB typ)    3.0mw (4.7dBm) to >20mw (13 dBm) @ 1MHz 2. Hi-Z:    600 Ohm, DC-31 MHz output,    580 mVpp typ. 3.Key Out:    Active low, open collector, computer    controlled via RTS
DDS Lowpass Filter	7th order Elliptic
T-R turnaround delay	1mS max.
Frequency Memories	10, user programmable
Band Memories	13, frequency is automatically stored after 30 second dwell
Receive IF Offset	0 to >268 MHz, one setting for all bands
Transmit IF Offset	0 to >268 MHz, one setting for all bands
Receive Prescale Factor	Divide by 2 to 254, Multiply by 2 or 4, per band
Transmit Prescale Factor	Divide by 2 to 254, Multiply by 2 or 4, per band
FSK Mark Frequency Offset	0 to >268MHz, one setting for all bands
FSK Space Frequency Offset	0 to >268MHz, one setting for all bands
Supported Bands	160m, 80m, 60m, 40m, 30m, 20m, 17m, 15m, 12m, 10m, 6m, 2m, Direct
Controls	Shaft Encoder with built-in pushbutton
Encoder Pushbutton	Programmable: Decade Increment, VFO A/B select

Designer Comments

The original FCC-2 has been a terrific success since its introduction a few years ago. It's gratifying to see so many uses for it. Technology has evolved and I'm pleased to introduce the upgraded version. The new Mark II kit produces frequencies up to 31 MHz, permitting full HF coverage. The firmware has also been upgraded to include multiplying scale factors, so you can use the FCC-2 Mark II with SDR rigs and quadrature mixers. The manual has been updated to reflect the revisions, with new photos and step-by-step instructions.