[TenTec] INRAD filter for OMNI VI/Plus series

[Dave Bowker]

I can personally confirm that W2VJM (Inrad) is working full-time on the OMNI
VI+ mod., and I assure it will be worth waiting for.

For an indication of the IP3 DR performance improvement that [can] be
achieved in an OMNI VI+ (Opt 3), I have tabulated the measured data of an
8-pole roofing filter mod. (of my design) and that of the OEM 2-pole
monolithic crystal filter with a 15 kHz BW.

Measurements were performed at 3.5 MHz using the ARRL Test Procedures
Manual, Rev. G (Sect. 5.8) and nearly identical test equipment.

Offset       OEM        K1FK Mod.

-20             97.4         100.0
-15             92.0         100.0
-10             87.1         99.7
-5               82.0         99.6
-4               79.8         98.3
-3               78.5         97.0
0
+3             79.0         98.0
+4             81.0         99.3
+5             83.2         99.7
+10           88.0         100.0
15             93.2         100.0
20             98.0         100.3


73, Dave, K1FK
Fort Kent, ME