0.5dB makes a noticeable difference to the sync and thus throughput. It's around 8% of the typically available SNRM! On further investigation however, the fluctuation can actually be more like 1.5dB. Having fluctuations in the power supply the gateway is fed, is clearly not good for line stability. It generates errors and packet loss according to the monitoring on my line. It's also not particularly conducive to long life of the gateway.
I'm also struggling to understand how connecting a power cable directly to a circuit board risks electrical safety. The only reason for the configuration as is, is for convenience.
That aside, it seems the socket in the gateway either has a dry joint or is in some other way not permanently connected to the circuit board. As an experiment, I pressed the plug up in the socket and downstream SNR dropped to around 5.4dB. When I pressed it down, it went up to 6.8dB. It seems to be holding there now.
Regardless, instigated an RMA from Amazon and they're sending me out a new one. I'll just back up the config file from the current one, making the switch over less painful.
I have to say, Amazon have gone back up in my estimations as the return process, once I got to 'talk' to someone, was very painless.
Service: HOME::1 FTTC (TTB) 80/20 (2TB)
Modem/ router: Billion BiPAC 8800AXL R2
Current sync: 59411/ 10211
G.INP: Enabled (DS & US)
Edited by youngsyp (Wed 14-Nov-18 23:04:03)