[TenTec] Tentec roofing filters and Inrad filters for the Orion.

[Bill Tippett]

Hi Jason,

N1SU wrote:
 >My INRAD 250Hz #751 CW filter performs as well as my stock
TT 1.8KHz filter, but the TT 1.8 should have far lower loss than the
INRAD.

         ??? Something got lost in the translation here.  When you said
"performs", surely you didn't mean your 1.8 kHz filter has the same
6 dB bandwidth as the 250 Hz filter!  I assume you meant insertion loss
only, since insertion loss always goes up as you narrow the bandwidth.

         I agree it pays to check your filters.  When applying a test
signal and switching filters, if you see a large drop anywhere,
it may mean you have a bad filter.  I had a 250 Hz TT219 which
had 18 dB insertion loss.  TT's spec is 14 dB and the replacement
they sent me had 12 dB.

         I agree with Sinisa that there is negligible difference in the
Inrad and Ten-Tec 1.8 kHz filters.  But there are greater differences
in the 500 and 250 filters (i.e. different bandwidths and shape factors).

                                                 73,  Bill  W4ZV