My cable internet connection had been having sporadic outages, so the cable company sent someone to test the signal. He came by and tested the signals coming out of the splitter (one port going to the cable modem, one port going to the digital cable converter) and determined that the signal going to the modem was “losing 9,” so his solution was to swap the connections between the modem and the converter. After a slightly confusing conversation I gathered that he did this because the converter was less finicky about the signal.
So my question is, what exactly does “losing 9” mean? And why would the signal be fine coming out of one port and not the other, aside from a malfunctioning splitter? I asked him if there was a problem with the splitter, but he said no, and just repeated the “losing 9” out of one port bit. So I’m a little perplexed.
He may have meant that the signal was 9 dB weaker on the port that was going to the modem. A perfect splitter would introduce a 3 dB loss on both ports. 9 dB is an excessive amount of loss. It should be 4-5 dB.
IANAE, but i believe he means Losing 9 decibels. The problem with what he did, was he saved the company money by NOT installing an amplifier. He should have. Our Cable company had to do the same thing. He installed an amplifier to boost the signals.
I had similar problems with my cable modem. One of the things that was done (and redone, several times), was playing with the device that split the cable service between my cable modem and the TV service.
The tech switched between a splitter, which had equal loss on both legs, and a tap, which had one leg with quite a bit of loss and the other with a little. Over time, various techs went back and forth, along with adjusting to the amplifier in the hallway and, once, calling someone to rebalance the whole system for the block.
As it was explained to me, there was usually little problem with signal getting downstream from the cable company to my cable modem. However, there was sometimes a problem with return signal from my cable modem swimming upstream to register with the cable company.