[TenTec] Inrad Roofing filter board in Omni VI

[Chuck Guenther]

A couple of weeks ago, Ken Brown, N6KB, asked:

 "Can you discern any difference in the noise blanker function with/without the Inrad roofing filter? For instance when band conditions are such that your ability to copy a signal is not limited by close in strong signals, and is limited by QRN and you are using the noise blanker, what works best? Inrad roofing filter in or out?"

I had an experience yesterday, I'd like to share.  During a time when I had strong line noise, some of the locals were working 5T0CW on 30 meters, and I couldn't copy at all.  The Omni VI noise blanker helped, but not enough.  Then I turned my NAR switch off ( which disengages both my narrow IF filter-- INRAD 753-- and the 600 Hz roofing filter.  Now I could copy the 5T station!  The noise blanker was more effective in smoothing out the harsh hiss of the line noise in this case.  When the line noise is not present, I always have better copy with the NAR switch on.  

I've been considering dedicating the Omni VI to CW only by wiring the roofing filter so  it is in line all the time (using the NAR switch in its normal mode).  That would provide me with options in terms of CW selectivity (since I have the VI, not the VI+).  Now I'm wondering if this would compromise my noise blanker.  

73,
Chuck  NI0C