On 5/1/2014 6:38 PM, Bob McGraw - K4TAX wrote:
If one intends to operate with 5 to 10 active stations in an area the
size of a football field on an event such as Field Day, then they are
absolutely necessary.
Roofing filters serve the function of protecting the IF from very strong
IN-BAND signals, like between CW and SSB signals on the same band. On
most rigs, out of band signals, like between stations on 80, 40, and 20,
are dealt with by bandpass filters. We can also use dedicated outboard
bandpass filters and stubs.
Otherwise, if you live in an area 5 to 10 miles from town and the
nearest ham does not operate on the same band the same time as you,
then they aren't necessary but, certainly nice to have available.
With most rigs of this quality, the only time you need more than one
roofing filter is during contests, or with another ham nearby. And, as
noted, a roofing filter won't do anything to filter the trash that other
stations put on your frequency.
Just remember, the selectivity is developed by the DSP system.
Yes.
73, Jim K9YC
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|