The Snowflake (schematic here) is built around a 7400 TTL NAND integrated circuit. Two gates comprise the VXO and the other two gates are connected in parallel to form the PA. A 3.58MHz ceramic resonator is used in the VXO circuit. All of the components in the above photo had been removed from various other equipment. The 20-60pF variable capacitor (labeled "VC1" in the schematic and seen in the above photo) allows the transmitter to tune from 3500 to 3560KHz.
If you build this circuit into an enclosure, be sure to mount the variable capacitor on insulators and use an insulated shaft between the front-panel knob and the rotor; as both side of the variable capacitor are "hot" with RF. Of course, a quartz crystal may be substituted for the ceramic resonator for fixed-frequency operation.
Here's the contact log of the Snowflake working into an end-fed, 80m, half-wave antenna. In each case, an output power of 17.5mW was used from from start to finish.
Date Station His/Mine QTH Km/Miles Miles per watt Comments
11/28/07 W1FZY 599/449 Athol, MA 169/105 6,000 Solid QSO 10min.
K1NM 589/559 Pittsfield, MA 184/114 6,514 Solid QSO
KA1JNB 589/559 Westport, MA 305/190 10,857 Lost me
11/29/07 KA1JNB 589/569 Westport, MA 305/190 10,857 Solid QSO 20min.
WB2PEF 449/549 Cherry Valley, NY 213/132 7,543 Lost him
WA3MIX 599/559 Williamsport, PA 466/289 16,514 Solid QSO 15min.
AA4XX 559/219 Raleigh, NC 1051/653 37,314 Sked - hrd my call
11/30/07 K8JPM/M 579/??? Akron, OH 776/482 27,542 Returned my call
WA3SLN 599/449 Montoursville, PA 448/278 15,885 Solid QSO 15min.
12/05/07 W2QF 599/599 Belfast, ME 302/187 10,727 Solid, 15min.
W1PKX 599/449 Groton, MA 191/119 6,794 "S7 on peaks"
12/13/07 WA1JWJ 599/589 Bethel, ME 170/106 6,057 Solid, 10min.
WA1SKQ 599/449 Cranston, RI 280/174 9,943 Some repeats rqd
W3DP 589/339 Camp Hill, PA 547/340 19,457 "FB on 17mW"
WA2FCF 589/549 Stanhope, NJ 381/237 13,543 "Ruff cpy"
12/20/07 VE1QY 449/339 Kentville, NS 656/407 23,257 VE1QY pwr 1W
12/27/07 NM3B 589/449 St. Mary's, PA 547/340 19,428 S7 pks, 30min.
KA1FFO 459/339 Severn, MD 635/395 22,571
12/30/07 W3MC 579/439 Severn, MD 635/395 22,571 KX1, 4w, QRM
12/31/07 N2UC 589/559 Ithaca, NY 221/138 7,874 15min.
K1LGQ 589/569 Brookline, NH 172/107 6,114 20min.
W1PID 599/589 Sanbornton, NH 109/68 3,868
VE2CLC 599/? Montcerf, QC 375/233 13,314