Study sheet: BNC Crimp Connector Assembly

📋 Course Outline

1. Connector Compatibility and Construction
2. Components and Crimp Tooling
3. Cable Preparation Dimensions
4. Assembly Sequence and Inspection

📖 1. Connector Compatibility and Construction

★ Must-know

• The Telegärtner straight crimp/crimp G1 BNC male connector is designed for RG-58C/U cable with an outer diameter of 4.95 mm and a characteristic impedance of 50 Ω.

• The connector consists of three pieces:

  • BNC male body
  • crimp centre pin
  • crimp ferrule

📌 Crimp/crimp termination crimps both the centre pin and the braid ferrule, with no soldering.

Further detail

• The connector is specified under die reference 100025879 and instruction T00100A0200 (A0205).

💡 Memory Hook

Crimp/crimp means both the centre pin and braid ferrule are crimped, whereas soldering is not used.

📖 2. Components and Crimp Tooling

★ Must-know

• The compatibility group includes:

  • RG-58C/U
  • YR23092
  • LMR-195
  • RG-58

• Crimping requires an XM-type die with reference 100025879 and two HEX cavities measuring 1.72 mm and 5.41 mm.

• Inspection requires a magnifier and a multimeter to verify that continuity between the conductor and braid is open.

Further detail

• Cable preparation requires a coax stripper, preferably a three-blade adjustable model.

📖 3. Cable Preparation Dimensions

★ Must-know

📌 The specified strip lengths must be followed without approximation because they govern the 50 Ω impedance match and return loss.

• The total strip length from the jacket end to the conductor tip is 18 mm.

• The dielectric length measured from the conductor tip is 10 mm.

• The centre conductor must be exposed over a length of 5 mm.

Further detail

📌 The 7 mm stripping value applies only to double-foil cables because it removes the outer foil, so it does not apply to RG-58C/U with a single braid.

💡 Memory Hook

18 mm total strip → 10 mm dielectric → 5 mm conductor exposure.

📖 4. Assembly Sequence and Inspection

★ Must-know

• Assembly proceeds by sliding on the ferrule, stripping the jacket, folding back the braid, stripping the dielectric, crimping the centre pin, inserting the assembly into the body, and crimping the ferrule.

• Before commissioning, verify:

  • conductor-to-conductor continuity is OK
  • conductor-to-shield isolation is OK
  • the cable length is controlled and labelled

📌 The centre conductor must be flush with the centre-pin tip after crimping, and no braid strand may protrude after ferrule crimping.

📌 No braid strand may touch the conductor because a short circuit completely corrupts the Acoustic Emission signal.

Further detail

📌 The braid crimp must be uniform because intermittent ground contact generates noise and false hits in Acoustic Emission measurements.

💡 Memory Hook

Ferrule first → strip → fold braid → expose conductor → crimp pin → insert body → crimp ferrule → inspect.