I am confused by the scheme used to automatically cut in the Orion roofing filters. Why does the filter not cut in until the DSP bandwidth is substantially less than the filter? For example, the 2.4
K4IA: filters. I believe Ten-Tec uses an algorithm to switch their roofing filters at ~75% of nominal bandwidth. Remember that the purpose of the roofing filter is to block unwanted products at the f
Manual is way to cumbersome. It would be easier if there was one button you could push to cycle through customized filter settings (like the AGC) but alas, no such button exists on the Orion. MENU =>
Well I'm really no expert and I think Ten Tec's basis for the decision to deploy roofing filters when DSP b/w is at 75% of roofing b/w would be better explained by them. Having said that, I offer the
I noticed the same thing as I started getting to know my new Orion. I think that part of the confusion is that the roofing filters are not the signal bandwidth filters that we are used to seeing adve
I disagree. Roofing filers serve the same purpose, are located in the same place and are even the same physical part they have been for the past 30 years. Roofing is simply a new term invented to des
Steve: All I can say is that you are wrong. Please review the Orion diagrams and schematics. They not the same as what we were used to 30 years ago. Period! 73, Bernard, WA4OEJ to has both audio I th
Bernard: I am refering to the basic block diagram of the receiver section. Yes, the Orion does have DSP as I mentioned however, the RF chain ahead of the DSP unit is the same basic superhetrodyne rec
Steve: I was just looking at the schematic diagram of my FT-1000 to see if I could determine the filter bandwidth going into the receiver front end. I didn't see it called out on the set of diagrams
Please believe me. The roofing filter is not in the front end. The front end is as broad as an entire ham band! The roofing filter is in the IF stage where it has always been. I can take the 9mhz fil
I think Bernard's comments about the point the roofing filters are kicked in is a very good one. I was just doing some listening on SSB with the 2400 hertz DSP filter and switching back and forth wit
Bernard, at your invitation I quickly looked over your discussion and have to agree with Steve that Orion's design is not new. However I disagree with Steve in that the term "roofing filter" is also
So Steve what would should we call the 12 kHz wide 2-pole filter on the 9 MHz board of my Omni V?? I believe your Omni VI has a similar filter. Do you think "roofing filter" would cover it? 73, Rick
All the Omni series receivers had a 9 mhz first IF just like the Orion. That's why you can use the Omni filters as roofing filters in the Orion. The difference is the Only filtering is still very sha
Well...........the one thing that everyone appears to be overlooking here is PBT. If the 2400 Hz roofing filter were to switch in at 2400 Hz DSP then the PBT control would not function. Instead of ad
Bill I think this is the first time I have seen something you have written that I disagree with! Single coversion superhets are inompatible with the roofing filter concept. The filters in the K2 are
Not true. It is easy to verify that PBT functions correctly with both filters at 2400 Hz, or any other value. No, Orion normally uses only the central part of roofing filter's BW in order to prevent
Sinisa You are correct, I am mistaken. Which, I guess, brings us back to the original question about whether switching roofing filters at DSP b/w = 75% roofing b/w is optimum or unecessarily conserva
I'd say it is quite good. Only the flat [central] part of roofing filter's passband passes through the DSP filter and DSP filter's passband flatness is mostly preserved. Also, group delay variation o
Thanks for the explanation. That seems to pretty much answer everyone's questions concerning roofing filter cut in. Bob, 5B4AGN 75% _______________________________________________ TenTec mailing list