GPSrChive Discussion Forum

I have done an image search on different connectors on the internet and bought an SMB female adapter to test on an old passive iridium antenna.
The SMB connector fit perfectly and my Montana 750i showed the symbol for external antenna at the top of the display.
The signal strength of the GPS satellites went up.

Is SMB the right connector or was I lucky that it is close enough?

A quick internet search revealed:

Google AI wrote:
The Garmin Montana 750i connects to external antennas via a specialized adapter cable, not a standard port, which attaches to the device and then to an external passive antenna with an SMA connector. This adapter is required for using an external GPS/Iridium antenna with your device.

and

Google AI wrote:
SMA (Sub-Miniature version A)

• Coupling Mechanism: Screw-on, providing a secure and stable connection.
• Frequency Range: High frequency, capable of operating up to 18 GHz and beyond, making them suitable for high-performance tasks.
• Durability: Robust and reliable, ideal for rugged and industrial environments.
• Applications: Used in demanding fields like military, aerospace, wireless communication base stations, and RF test equipment.

SMB (Sub-Miniature version B)

• Coupling Mechanism: Snap-on, allowing for quick and easy plugging and unplugging.
• Frequency Range: Lower frequency, typically operating effectively up to about 4 GHz.
• Durability: Less robust than SMA connectors, not ideal for high-vibration or harsh environments.
• Applications: Best for small RF devices and systems where quick connections are prioritized, such as mobile devices and some communication systems.

Key Differences Summarized

• Connection: SMA is threaded; SMB is snap-on.
• Frequency: SMA handles much higher frequencies; SMB has a lower frequency limit.
• Durability: SMA is more robust for harsh conditions; SMB is less durable but convenient for frequent mating.
• Size: SMB connectors are generally smaller than SMA connectors.