As an enginner, who has followed the electrical connector industry for more than 30 years, I must disagree with the posters, who scoff at the 3 Ghz recommendation.
Good enough or meeting minimal specifications or the lowest bid meeting minimal specifications is fine, but I, myself, in particular, want better than minimum.
A connector designed for 3 Ghz is different from the old standard F81 socket. In the old socket, two brass springs contact the center conductor at two small points of contact. Both Stirling and Thomas and Betts make the best 3 Ghz connectors. The socket is a machined phospher bronze tolerance entry cone and tube, into which center conductor of the coax fits. There is a 360 degree contact over a length of tubing.
In the early days of cable TV, there was no real voltage, just a very low strength signal transmitted over the connection. And, the signal was not pure DC. DC voltage transmitted over time in the presence of moisture and polution from humidity in the air causes electrolytic corrosion over time. The connection actually becomes an electrplating setup.
So, in dbs applications, "overkill" in the connection is good insurance for long term reliability.
I do a lot of service calls. Connections or badly degraded ones make up the majority of problems.