The NorCal 20 was a single band 20 meter CW transceiver that was kitted and sold by NorCal, the Northern California QRP Club in 1999. It was designed by Dave Fifield, AD6A to be a high performance transceiver. It has an excellent receiver that is capable of operating in the presence of strong out-of-band broadcast and nearby amateur band signals.
The NC20 has a 5 watt transmitter with a built-in electronic keyer utilizing the Embedded Research TICK keyer chip. The TICK chip included in the NorCal kit did not offer memory keying, however a drop-in upgrade superchip was available from Embedded Research that offered beacon mode and two 50 character memories.
The receiver is a single conversion superhet with a 9 MHz IF and a 5 MHz VFO. A pre amp stage, high level double balanced mixer and a four pole crystal filer give the receiver it's excellent performance. The NorCal kit included a single turn potentiometer to control the VFO varactor tuning circuit. Frequency coverage of the stock unit using the single turn pot is any 30 KHz of the 20 meter CW band. Receive Incremental Tuning (RIT) is also included in the design.
Many builders installed a 10 turn tuning potentiometer which greatly improved ease of tuning. With a ten turn pot, the frequency range is easily increased to 70 KHz or more. The NC20 in the photograph was modified to use a 10 turn pot and the frequency range was tweaked to cover 14001 to 14068 KHz. I used a 5 K pot, which is a different value of tuning pot than NorCal specified. Technical information on changing the pot value is posted here: Ten Turn Pot Modification Info
The case supplied with the NorCal kit was pre-drilled, however it was unpainted aluminum. Although many builders painted and customized their cases, I left mine bare aluminum as I used this rig primarily for portable field operating trips where it got banged around a bit.
My NorCal 20 was an excellent performing rig at WØCH. In May / June of 2000 I carried the rig in the photograph overseas to Australia and New Zealand and used it to work back to Missouri.
NorCal produced 1000 NC20 kits, of which only 500 were offered for sale at $100 each. The profits from the sale of the first 500 were used to produce the next 500 kits which were donated to hams overseas at no cost. Rev. George Dobbs, G3RJV from the GQRP Club coordinated the worldwide distribution of the donated transceivers. Many of these fine rigs are in service today in less developed countries through the efforts of NorCal and GQRP clubs.
A commercial version of the NorCal 20 transceiver, as well as a 40 meter version were sold by Dave Fifield, AD6A who produced kits under the Red Hot Radio name (now discontinued).Ten Turn Pot Modification
Updated June 15, 2016