gamma match insulating materials

[byder]

trying to get a idea on the options i can use for insulating between the rod and tube on a gamma match . i know it has to be non-conductive to RF . the only way i can check that is doing the microwave trick . not the best way , but from what i understand is a good enough indicator for home-brewing .

ATM im thinking heat shrink tubing would be a easier way to keep the layering consistent on the rod compared to wrapping it in teflon plumbers tape . plus the friction from it shrinking should hold it in place compared to having to tape or glue the teflon tape to keep it on . im gonna use 3/8 inch diameter solid aluminum rod and 1/2 inch inside diameter aluminum tube . 200 watts is the most i PEP (if i hit a small lottery i would bump up to an AL-80B...LOL) . i also want to use heat shrink over the shoulder where the rod exits out the top of the tube to keep moisture from running in , as well as on a few other sections .

is the heat shrink tubing a decent material for this use ? or will it cause issues ?
what would you suggest instead ?

coaxial foam ! ,rg8 is good handle 2000 watts

 

[C2]

You could probably use the whole RG8 cable, solder the inner/outer together...

 

[HiDef]

Teflon dielectric aluminum hardline worked for me.
The outer aluminum from some 10mm 50 ohm stuff fit right inside the rest of the gamma being built.

 

[BOOTY MONSTER]

LINK

Link won't come up right. Virgin teflon tube for $4.40/ft., 1/2"OD x 3/8"ID.

thank you 359 . the teflon with the inside and outside diameter ill need is $4.40 plus $5 shipping .
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Material
Fluoropolymers
Fluoropolymer Material
Virgin Electrical Grade Teflon® PTFE
Backing
Plain Back
Finish
Smooth
Shape
Tubes
Tube Type
Round
Wall Thickness
1/16"
Length
Cut-to-Length
Available Lengths
Sold in 1' increments
Maximum Continuous Length
6'
Inside Diameter
3/8"
Inside Diameter Tolerance
Undersized for finishing to stated size.
Outside Diameter
1/2"
Outside Diameter Tolerance
Oversized for finishing to stated size.
Opaque
White
Operating Temperature Range
-350° to +500° F
Softening Point
Not Rated
Performance Characteristic
Electrical Insulator, Weather Resistant, Very Low Friction
Tensile Strength
Poor
Impact Strength
Good
Tolerance
Standard
Hardness
Rockwell R58
Specifications Met
3A Sanitary Standards (3A) Compliant, Aerospace Material Specifications (AMS), Food and Drug Administration (FDA) Compliant, Underwriters Laboratories (UL)
AMS Specification
AMS 3656
UL Rating
UL 94V0
Note
Color varies from translucent white to opaque white.

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im a poor duck so im gonna try the cheap and local teflon plumbers tape first . but im definitely gonna get the teflon tube if i decide to put it up to stay

whewww !!! that garolite stuff aint cheap at all
thanks again