all
Bands
1.5 kW
Output
Frequency0 - 500 MHz
TX power1500 W (Power handling 1.5 kW (1500 W) from 0-30 MHz and 1 kW from 100-500 MHz. The power_w lists the 1.5 kW HF figure.)
Modesn/a
Connectors
antenna portsFour SO-239 antenna ports plus a common SO-239 to the station (DELTA-4B/N version uses N connectors).
groundA separate external ground wire to the station ground is required for the Arc-Plug surge protection to work.
power reqNone - a passive manual switch (the surge protection needs a good external ground).
Four-position antenna coax switch with HF-through-UHF (0-500 MHz) performance Power handling 1.5 kW (0-30 MHz), 1 kW (100-500 MHz) Low-loss micro-strip cavity design: ~0.1 dB loss and 60 dB isolation at 30 MHz Positive-detent switching with a precision-machined shaft/quadrant Master antenna ground function - unselected antennas are grounded Field-replaceable ceramic gas-tube Arc-Plug surge-protection cartridge (Model D-4) on the active port SO-239 ports (N-connector DELTA-4B/N version available)
Strengths

A high-quality four-way antenna switch that doubles as surge protection: the micro-strip cavity keeps loss low and isolation high right through UHF, the positive detent gives a confident click, and unused antennas are grounded automatically. The field-replaceable gas-tube Arc-Plug cartridge protects the active line against static and nearby strikes - a genuine safety bonus.

Weaknesses

The surge protection only works if you actually run a proper external ground wire to it (easy to overlook), the Arc-Plug cartridge is a wear item that should be replaced after a big hit, and like any single switch it routes one antenna at a time. It is not a lightning 'cure' - it complements, but does not replace, a proper station grounding/disconnect plan.

Verdict

The Alpha Delta DELTA-4B is a premium four-position coax switch with low loss, good UHF performance, auto-grounding and built-in gas-tube surge protection. An excellent everyday antenna switch that adds a layer of static/surge defense - provided you ground it properly.

The Alpha Delta DELTA-4B is a four-position antenna coax switch that does double duty as a surge protector. It lets you select among four antennas (or feedlines) from one common station port, and it performs cleanly all the way from HF through UHF (0-500 MHz): a low-loss micro-strip cavity keeps insertion loss to about 0.1 dB and isolation to 60 dB at 30 MHz, and a precision-machined shaft with positive detents gives a reassuring click at each position. Power handling is 1.5 kW up to 30 MHz (1 kW into the VHF/UHF range), so it suits an amplified station.

Two features set it apart. First, a master antenna ground function automatically grounds the antennas you are not using, which helps bleed off static. Second, the active port is continuously protected by a field-replaceable ceramic gas-tube 'Arc-Plug' cartridge (the Model D-4 pill), which clamps the kind of voltage spikes that static buildup and nearby lightning produce. The cartridge can be swapped from the front panel if it ever takes a hit.

The important caveats: that surge protection only works if you actually run a solid external ground wire from the switch to your station ground - it will not function otherwise - and the Arc-Plug is a wear item to replace after a major surge. It is also one-antenna-at-a-time, and it complements rather than replaces a proper grounding and disconnect plan. As a high-quality switch with real added protection, it is excellent. Compare it with the remote Ameritron RCS-8V and the Daiwa CS-201A.