Mixer will be driven very hard to saturate it. To operate the mixer in the required saturated mode, the RF signal level should be at least:

• +1 dBm for Standard Level (+7 dBm LO) mixers
• +7 dBm for Standard Level (+13 dBm LO) mixers
• +10 dBm for High Level (+17 dBm LO) mixers

so if we use the right (optimum) cable we would have ~8dBm, which should be perfect for a level 13 mixer.

Let's see if we can confirm the calculations...