Edwin Spector wrote:

I have just done some measurements, and it hardly makes a gnat's cock of
difference!

Aim
Compare signal losses due to various types of join in coax cable.

Apparatus
Coax cable (unknown type, about 2-ft length, 50 Ohm, terminated in SMA
connectors)
Network analyser (HP 8753E)

Method
1. Measure insertion loss and return loss (or VSWR) of unbroken cable. Use these
results as reference.
2. Cut cable near the middle.
3. Re-connect the ends as crudely as possible (inner soldered, braid just
twisted) and re-measure IL and RL at 650MHz and 750MHz.
4. Re-connect ends as well as possible and re-measure.

Results
Original return loss: 27dB (Very good)
Original insertion loss 0dB (relative, not absolute)
Crude join: IL = 0.3dB at 650MHz, 0.31dB at 750MHz.
Better join: IL = 0.1dB over 650 to 750MHz.

Note: Yes, this is high-quality 50-Ohm coax, not 75-Ohm TV stuff, but the
principal's the same.

Conclusion: Yes, there's a measurable difference, but it's damn small. As
someone else said, you'd have a very marginal reception to notice any
difference.

Regards

Edwin
Bath.


What was teh VSWR?