[NLRS] Helical Filters and high power?

[Dr. Gerald N. Johnson]

On Fri, 2007-04-20 at 02:44 +0000, Scott wrote:
> 
> Can these little TOKO helical filters (like used in some DEMI kits) be 
> used as filters between the PA (say 10-15 Watts) and antenna or does one 
> liberate the smoke at those levels?
> 

3Db insertion loss, not much volume or metal there. Motorola radios that
had helical filters in the transmitters did that at half watt or lower
levels and Motorola helicals were much larger than Tokos.

Then too there would be high voltage at the ungrounded end of the coil
since the resonating C is very small, its a Tesla coil! Quarter wave
open stub coiled up resonant. Might arc before it over heated from loss
dissipation, but either way I think 10 watts would lead to smoke.


-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer