Note
QST, Oct 1977, p. 103. (544 available first)
QST, Jan 1978, p. 101.
QST, Apr 1979, p. 113.
QST, Apr 1980, p. 176.
540 – analog display, $699.00.
544 – digital display, $869.00.
The 544 was the Triton IV model 540 with a digital dial. The front panel of the transceiver pictured here is marked "Triton IV Digital," a designation that would disappear and be replaced with the model number in subsequent production. The digital readout is the only significant difference between the 540 and 544. The CW selectivity of both models was improved with the addition of an optional, plug-in active filter.
References
Review. QST, Jul 1979, p. 45.
Review (supplemental) . QST, Aug 1979, p. 48.
Add a crystal filter. QST, Aug 1981, p. 16.