Small Wonder Labs

The White Mountain Series
SSB Transceivers

View of Board kit

The 'White Mountain' is a single-board SSB transceiver design, with a top-quality double-sided printed circuit board measuring 4.4" x 5.25" (11 x 13.4 cm). In keeping with my previous offerings, this design is available as a board and parts-only kit. The Enclosure kit is no longer available as pictured. I can instead supply a handsome Lansing enclosure of the same size and style. The color scheme is medium grey with black-anodized and blank (undrilled/unlabeled) end panels..

Unlike some of the minimum parts-count designs, the White Mountain was designed conservatively for high performance. The receiver lineup features a low-gain J309 RF preamp, diode-ring mixer, and mixer post-amp. The remainder of the receiver chain is conventional and features an LM380 audio amplifier for plenty of audio punch. An AGC function is included. The transmitter chain also uses diode-ring mixers for good inherent carrier suppression and RF stability.

Frequency readout is provided by a Morse frequency counter function. This is mechanized as a series of three frequency digits (hundreds, tens, units kHz) sent at 13 WPM when the user depresses a pushbutton switch.

Specifications:

• Intermediate Frequency (IF): 9.83 Mhz (75Mor 40M), 8.00 Mhz(20M)
• Transmit/Receive Crystal filters: 2.3 Khz BW
• Receiver MDS: -128 dBm (0.1 uV)
• Two-tone Dyn. Range 90 dB
• Image Rejection: 70 dB
• Frequency Coverage: 180 Khz nominal (20M,75M)
• Cold Start Drift (Typical) 300 Hz
• Transmitter Power Out 3-4W PEP
• Carrier Suppression -40 dB - no adjustment required
• Transmitter Harmonics/Spurs -45 dBc
• Transmitter IMD3 (2-tone) -36 dB PEP / (@3W PEP)
• Power requirements: 12-14 VDC @ 120 mA (receive), 1A peak (TX)

This design is presently available for 75, 40 and 20 meters. The 75M version has been checked out down to 3600 Khz for users in locations other than North America

The board-only kit includes board, all on-board parts and manual. Interconnect to the controls is via .100" header strips and wiring harnesses (provided) toease troubleshooting and installation. The manual includes a "build-and- checkout in stages" assembly approach to break the experience into evening-sized chunks.Assembly time on this kit is about 12 hours.


(You provide an HT speaker/ mike). The WM design is compatible with the Yaesu MHW-12AB, Icom M-54, MFJ-284 and Radio Shack HT speaker/mikes. / This is the type with a pair of 2-conductor prongs (2.5 and 3.5 mm)

last updated 1/2/2003