[50mhz] Replacing coax

[John Geiger]

I went out this morning and did a visual inspection on my coax runs, and they all look in very good condition. No cracking on the jacket at all, and the jacket still looks as good as when new.  One run of RG-11 I have is 12 years old, but still looks great.  I don't recognize any signal degradation on the coax runs either, nor changes in SWR.  Now I don't have any complex test equipment to test the coax runs with, just a SWR/power meter built into my antenna tuner.

Given that the jacket on the coax looks ok, and I haven't noticed any change in antenna performance, is it safe to assume that the coax is still good, or is there an age limit for coax after which it starts to deteriorate from the inside?  Is there a rule of thumb on how often coax should be replaced?

73s John AA5JG