[Milsurplus] Softening hard coax

[James C Whartenby]

I guess nothing is special about the coax.  The instrument is a GR Vacuum
Tube Bridge, which think it is from the late 1930s.  The coax, all eight
of them, are used as a "patch panel" to connect to a tube socket adapter.
 They are about two feet long.  The coax connects to what looks like
shielded banana plugs.  The whole thing runs at audio frequencies so I
doubt that there is anything critical beyond low capacitance.  I guess I
will have to bite the bullet and try to make something similar out of
rubber jacketed line cord.
Thanks for all of the suggestions,
Jim

On Sat, 4 Jun 2005 01:44:20 GMT "gl4d21a at juno.com" <gl4d21a at juno.com>
writes:
> Jim:
> 
> Indirect answer.  What is special about the coax?  If it is old 
> enough to have lost its flexibility, there is a better than even 
> chance the plasticizer (which made the jacket flexible) migrated 
> into the dielectric and changed the loss and dielectric constant 
> therein.  If all you want to do is one time straighten them out, 
> moderate heat is the answer, but changed loss/impedance may still 
> linger.  If at all possible, replace with modern coax.  You didn't 
> specify which GR unit it is, but I do not recall seeing anything 
> unusual in any of the GR stuff I have used over the past 50 years.  
> And, replacement GR874 connectors for RG223 (and similar size) coax 
> are still available, if that is the problem.  So are them new, 
> expensive, I never remember the number, jobs for microwave.
> 
> HTH,
> George
> W5VPQ