Scanner Coax Cables & Connectors

The cable connecting your antenna to your scanner matters. Good coax delivers signals with minimal loss; bad coax wastes your antenna's potential. Here's how to choose the right cables and connectors.

Coax Cable Types

RG58

50Ω 5mm diameter

Best for: Most scanner applications. Good balance of flexibility and low loss. Standard for mobile and portable use.

Max length: 50-100ft before significant loss at UHF

RG174

50Ω 2.5mm diameter

Best for: Short runs, mobile antennas. Very flexible but higher loss.

Max length: 10-15ft recommended

RG8 / LMR-400

50Ω 10mm diameter

Best for: Long runs to outdoor base antennas. Lowest loss but thick and stiff.

Max length: 100ft+ with acceptable loss

Recommended Cables

BNC Jumper Cable 2-Pack

$10–$14

Short 12" jumpers for connecting scanner to SWR meter or antenna tuner. High quality with gold-plated connectors.

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BNC to PL-259 Adapter Cable 10ft

$18–$25

BNC to PL-259 (UHF) adapter cable. Useful for connecting scanner to base station antennas that use SO-239 connectors.

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BNC Cable 1ft 2-Pack

$9–$13

Short 1ft cables for clean connections. Ideal for two-way radio, ham radio, and scanner applications.

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Common Connector Types

BNC

Bayonet-style quick-connect. Most common on older handheld and desktop scanners. Reliable, easy to use.

SMA

Smaller threaded connector. Used on SDS100, SDS200, and many modern handhelds. More compact than BNC.

PL-259 / SO-239

UHF connectors common on base station antennas and amateur radio. Male plug is PL-259, female jack is SO-239.

N-Type

Weatherproof threaded connector. Used on outdoor antennas and professional equipment. Better performance than PL-259.

Adapters

BNC to SMA Adapter

$7–$10

Connect BNC antennas to SMA scanners (like the SDS100). Keep a few on hand—they're inexpensive and useful.

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Adapter Tips

  • Every adapter adds a small amount of signal loss
  • Minimize adapters—one or two is fine, avoid chains of multiple adapters
  • Buy quality adapters with gold or nickel plating
  • Check male vs female orientation before ordering

Frequently Asked Questions

RG58 vs RG8 vs RG174 - which should I use?

RG58 is the standard for scanner use—good balance of flexibility and low loss. RG174 is thinner but has more loss (use only for short runs under 10ft). RG8 has lower loss but is thick and stiff. For most scanner applications, RG58 is ideal.

Does my scanner use BNC or SMA?

Most older Uniden scanners (BCD436HP, BC125AT) use BNC. The SDS100/SDS200 use SMA. Check your scanner's antenna connector before buying cables.

Can I use TV coax (RG6) for my scanner?

Not recommended. RG6 is 75 ohm cable designed for TV/satellite. Scanners and antennas use 50 ohm systems. The impedance mismatch causes signal loss and poor performance.

How do I know if my coax is bad?

Signs of bad coax: intermittent signal loss, visible damage to outer jacket, water inside the cable, corroded connectors, or kinked sections. When in doubt, replace—coax is inexpensive.

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