I've recently acquired a Dell Optiplex 5070 in the micro form factor cabinet. It has BT5 and dual-band (AC) WiFi.

As the title suggests, besides just plain understanding how things work, I'm wondering whether replacing the (? 2.5 dBi) external duckie antenna would improve WiFi reception.

The machine uses an Intel AC9560 M.2 RF card bearing 2 antenna connectors whose colors are reversed compared with the non-Dell version. From the Intel specs and the Dell service manual, I conclude the following:

• The Antenna 1 (AUX) connector is used for BT and WiFi, and there is some kind of (black) internal antenna lead plugged into it which disappears somewhere into the front of the chassis.

• The Antenna 2 (MAIN) connector is used for WiFi only, and the (white) wire plugged into it, leads to a standard RP-SMA socket on the back panel.

• Packed in the box is the tiny generic duckie antenna mentioned above. It is without markings whatsoever (except for 2 rings molded near the top of the plastic jacket), and the tiny label on the factory baggie does not having anything useful on it.

Questions:

1. Is the internal WiFi antenna dual band, or just 2.4 GHz as it doubles as the bluetooth antenna?

2. Is the external Wifi duckie antenna dual band?

3. How does one identify whether a random duckie antenna is tuned for single or dual band without breaking it open?

4. Assuming I were to replace the external duckie antenna with a known directional dual-band antenna, would the diversity reception capability of the Intel card utilize that and result in better WiFi range?

5. My understanding is that the two antennas plugged into the same card should be more or less electrically equivalent. Is there any actual harm associated with attaching a higher gain external antenna?

6. Am I just beating a dead horse here?

Thanks for any learned insight