[TowerTalk] DIY Air Wound Coils

[Brian Beezley]

> Can you cite some examples of plastics that have high loss at HF and low 
> loss at UHF or vice versa?  I've never encountered that phenomenon.

Rick, see CUSTOMIZE.TXT in gnd.zip (download from the COIL page) for 
several examples. One is PVC, whose dissipation factor is 2.9 times 
higher at 1 MHz than at 3 GHz.

> The web site (plasticfantasticlibrary) doesn't appear to give an 
> information about dielectric constant and dissipation factor.  Did I somehow miss where 
> this info was listed?

Pick the plastic and then scroll down to Electrical Properties. They do 
not give values for multiple frequencies. I listed them because their 
coverage of plastics is so comprehensive. See README.TXT for several 
less comprehensive references that do give electrical properties at more 
than one frequency. This information is not easy to find in one place. I 
spent years accumulating it for COIL. The default values the program 
uses (listed in CUSTOMIZE.TXT) are the most reliable values I have found.

Brian