small semi-rigid coax with air dielectric

[ge]

Possibly this question should go under hobby...
Does small semi-rigid or rigid coax with approximate air dielectric exist? I'm thinking of a diameter to the nature of 0.047 inch for making baluns and impedance transformers. The lower z would make it easier to go up in frequency.

I see larger cable using a spline to support the center conductor but do not see it in a small diameter.

tnx,
GE

 

[vfone]

The thinnest Spline dielectric coax cable that I've seen is about 6.3mm (0.25 inch) external diameter.

 

[ge]

Yes that is also the smallest I've found. It must be too difficult or expensive to manufacture.

 

[SLK001]

An air dielectric coax has limited bending ability.