Note
It is important to understand that the SA-2550 is not a tuner. It is a matcher designed specifically for use with single or multi-band half-wave dipoles, inverted-Vs, and quarter-wave vertical antennas. It is not for use with beams, random wires, or balanced feed line antennas.
The SA-2550 allows you to effectively double the bandwidth of your dipole so you can work the phone or CW end of the band from a single antenna while maintaining a low SWR. The unit will operate with antennas from 1.8 to 30 MHz and is rated for full legal power.
To use the SA-2550 to its fullest requires you to lengthen your existing half-wave dipole, inverted-V, or quarter-wave vertical by 5 to 15 percent, depending on the frequency.
The control unit contains a simple switching circuit, and the remote unit contains a motor-driven high voltage variable capacitor.
The remote unit takes the place of the center insulator in your dipole or inverted-V, or can feed the base of your quarter-wave vertical. Proper operation requires the use of an external dual wattmeter or SWR bridge. An RF choke coil is recommended to the antenna feed point.
Note: A two-wire control cable (#22 or larger) is required only if RF power from the transmitter is capacitively coupled to your antenna. If so, connect the free end of the antenna feed line to the “out" connector on your SWR meter. Refer to Figure 1.
Note: Matching should be accomplished first at low power.
Having the manual would be useful.
References:
Review. Ham Radio, Jan 1987, p. 110.
Review. QST. Aug 1988, p. 43.
Frequency range: 1.8 to 30 MHz
Input impedance: 50Ω
Input power capability (with 3:1 maximum SWR):
SSB: 1300 watts PEP
CW: 1500 watts
Bandwidth increase (between 2:1 points): 100% or more, typical
Operating temperature range: –40 to +140 F
Photos, general information and specifications from "Heathkit: A Guide to the Amateur Radio Products," by Chuck Penson, WA7ZZE. Used with permission.
