C-band IF filter...
C-band IF filter...
(OP)
I'm looking for a source to obtain a 70MHz IF bandpass filter for 3.7 to 4.2GHz. Anyone know of one?
Thanks...Dave
Thanks...Dave
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RE: C-band IF filter...
To request an 70 MHz IF filter would mean you are looking for a IF filter (with a unstated bandwidth) for a application where the center frequency is 70 MHz.
70 MHz is a common center frequency for a second IF and is commonly used for commercial and military receivers. A 70 MHz IF might have a bandpass as wide as 50 MHz.
Now, the difference between 3.7 and 4.2 GHz is 500 MHz and sounds more like the input frequency range of a receiver, or of a downconverter, or the tunable bandwidth of a tuner ahead of the first mixer for a superhet receiver.
Can you provide a little more information on your application?
RE: C-band IF filter...
BTW - typical satellite TV receivers can cover all bands (C, Ku, Ka, whatever...) provided they're connected to suitable LNBFs.
The specs for the filter would be fairly tight for this sort of application (depending on the receiver design). On the other hand, the filters probably sell for pennies in the quantities that are used these days. The entire receiver wholesales for typically US$30 (+/- $20).
RE: C-band IF filter...
Thanks for both your replies.
-Dave
RE: C-band IF filter...
1) Use a feed with low sidelobes (concentric circles)
2) Relocate the dish so that it isn't in view of the interference (but still sees the satellite)
3) Add petals to the edge of the dish so that it improves sidelobes (reduction of edge diffraction).
I'd also make sure that you use high quality 'quad shield' coaxial cable and good terminations. Signals might be leaking in along that path (maybe).
If the interference is at C-band, then filtering it at 70 MHz (effectively the 2nd IF) is probably too late. The strong radar would have already clipped before then and couldn't be filtered out. If it wasn't clipping, then you probably wouldn't be seeing it now...
I've never had a C-band B.U.D. myself (not yet), but there is tons of info on the www on this topic.
RE: C-band IF filter...
Regards,
Dave