Second Hand Elecraft K3 HF Transceiver With ATU, Second Hand Elecraft K3 HF Transceiver, Elecraft’s state-of-the-art K3 transceiver offers a unique combination of ultra-high performance and affordability. Both 100-watt and 10-watt (upgradeable) models are available, the K3 is comparable in both features and performance to transceivers that are more expensive. In a first for the industry, the K3’s identical main receiver and sub receiver each feature a high-dynamic-range, down-conversion analog architecture. This allows Elecraft to provide roofing filters with bandwidths as narrow as 200 Hz, while up-conversion designs have roofing filters typically 3,000 to 15,000 Hz in width. Unlike some competing down-conversion designs, the K3 also provides 6-meter coverage, as well as continuous tuning from 0.5 to 30 MHz. Each receiver has its own bus-switching mixer, narrow ham-band front-end filters, 32-bit I.F. DSP, low-noise synthesizer, and up to five crystal roofing filters.