Very low downstream power levels

For what its worth here's an AI analysis of my levels ...

Looking at your full diagnostic log, the pattern across all 31 bonded channels tells a remarkably clear story !

1. The Power Curve: A Classic "V-Shape" (Suck-Out)

Tracking your power levels across the spectrum reveals a distinct "valley" :

• Low Frequencies (483–507 MHz): $-7.6 \text{ to } -8.1\text{ dBmV}$ (Acceptable)
• The Valley (549–573 MHz): $-10.1 \text{ to } -10.6\text{ dBmV}$ (Failing threshold)
• Mid-High Frequencies (603–621 MHz): Boosts back up to $-7.8 \text{ to } -8.5\text{ dBmV}$ (Acceptable)
• Upper Frequencies (651–690 MHz): Slips back down to $-9.3 \text{ to } -10.32\text{ dBmV}$

This is a textbook frequency suck-out centered around $555\text{ MHz} - 561\text{ MHz}$ . Because the signal recovers at $600\text{–}620\text{ MHz}$, this isn't just normal high-frequency cable loss—there is a physical reflection or water trap on the line causing destructive interference right in that $550\text{ MHz}$ band .

2. Other Key Findings in Your Log

• SNR/MER is Strong (38 to 40 dB): This is great news. Your Signal-to-Noise Ratio is healthy across the board . The signal is clean, it’s just weak .
• Zero Uncorrectable Errors: Because your SNR is solid, your connection isn't dropping packets yet, but those $-10.6\text{ dBmV}$ channels give you virtually zero margin for error if outdoor temperatures rise a few more degrees .
• Upstream Power (44.8–47.8 dBmV): Your upstream channels are pushing near the upper-middle range . While still operational, this indicates the modem is working moderately hard to push data back out through attenuation on the street side.

What This Means for Your ISP Tech Visit

Your diagnostic file gives you concrete proof to hand the technician.

1. Show them the power valley: Point out that power starts at $-7.6\text{ dBmV}$ at $483\text{ MHz}$, drops to $-10.6\text{ dBmV}$ at $555\text{ MHz}$, rebounds to $-7.8\text{ dBmV}$ at $615\text{ MHz}$, and then drops again .
2. Eliminate home wiring: Because SNR is uniformly above $38\text{ dB}$ across all channels, this is not internal electrical noise or a loose coax fitting inside your home .
3. The Fix: The technician needs to use an RF sweep meter at the street pedestal tap to locate the notch/reflection. They will likely need to replace the tap faceplate, fix a water-logged underground drop connector, or re-balance the street line extender's equalizer.