[TowerTalk] Re: narrowband filters

[Lau, Zack, W1VT]

  Someone asked whether the filters I designed will handle 
200 watts.  No they won't--the losses are too high. 

   However, if someone wants to tackle some new territory in
filter design--may I suggest coupling two small transmitting 
loop antennas?  A transmitting loop can be used as a very high
Q resonator that will handle lots of power.  Ideally, these
would be rigidly enclosed in shielded enclosures.  Walking near
an unshielded loop will detune it--not to mention the RF safety
issues.

	Good mechanical construction is essential with high Q filters.
A little bit of coil wobble can cause serious problems in a narrow
filter--this is why I mounted the coil on a PVC form.  You should 
also take into account thermal stability issues.

73--Zack Lau W1VT