BNC connector

BNC connectors come in several forms. All need either soldering or crimping for the center wire to centre pin connnection; it depends on the pin type.  The outer sheath is either a crimp sleeve or spanner tightened compression ring.

See images: BNC connector images from Google

F type connectors are normally used for BUCs.
F type connectors also come in several forms.
The cheapest just consists of a threaded outer tube.  You use the centre wire of the cable as the pin and the sheath/braid is simply screwed onto the end of the cable.
As with BNC, some F types use crimping for the outer sleeve and sometimes for the inner pin, if used.  The best F connectors use axial crimping.

In all cases it is vital to use the correct size connector to match with the cable type.    

It is recommended to smear the centre pin with elecronic grade silicone contact grease to exclude oxygen and moisture from the exact points of metal to metal contact and to wrap the whole joint in self amagamating rubber tape to exclude water.

When joining an F connector to equipment use firm finger force only.  Use of a spanner can permanently damage the internal parts of the BUC or Modem.

When using an F conenctor with the wire as the centre pin it helps to smooth the tip of the wire to ease insertion.  The diameter of the centre wire is not spectified and varies.  If a socket has previously been used with a plug having a larger diameter centre wire and then a new connector is applied with a thinner wire, then the new wire may not make good contact.

See images here: F connector images from Google

Best regards, Eric.  

If the tubular sleeve or centre pin needs squeezing inwards from all around the outside, you need the proper matching crimp tool.  The outer sleeve needs a large hexagonal crimp. The inner pin a small hexagonal crimp. If the inner pin is made of soft metal and has a tiny vent hole in the side it is intended to be soldered.  Don't crimp solder type pins as the metal is too soft and relaxes and makes a bad connection after a while.

If the connector needs squeezing lengthways (axial crimp) again it is good to have the right tool. These tools are rare and expensive.  Some of the images show coloured rings. These plastic rings compress in the axial crimp and are intended to seal against the cable outer sheath.  It is important that the cable sheath has the correct outer diameter. I must admit that on occasion I have successfully closed such an axial crimp connector by using a large nut (pin into the hole) to support the pin end, a pair of pliers gently held around the cable and then hammered the pliers down to push the rear end towards the pin end!  Closing the axial crimp is a one way process so make sure the centre pin is perfect and of the correct length before closing.

Best regards, Eric.