I would like to update some things especially the roofing filters first so the question I would like to ask is Has anybody upgraded from the 2.7 five pole filter to the 2.8 eight pole filter?
You will not notice any difference going from the 2.8 KHz to 2.7 KHz filters. The ultimate bandwidth is determined by the DSP in the second (15 KHz) IF and the roofing filter skirts don't make much difference once they're down 30 - 40 dB. If you're into serious SSB contesting you may want to add either the 2.1 KHz or 1.8 KHz roofing filter for that additional protection from strong adjacent channel signals but in most cases the adjacent channel garbage is often transmitter IMD (splatter) that is actually "on channel" and can't be rejected by any filtering. > also could I use the fm filter for use in the am position. Yes, he FM filter (13 KHz) can be used for both AM transmit and receive. Note: even with the 13 KHz filter, the widest receive bandwidth will be 4.2 KHz - not 6+ KHz - as the receiver audio chain includes a sharp 4.25 KHz low pass "brick wall" audio filter to limit artifacts from the digital to analog converter. 73, ... Joe, W4TV On 1/30/2017 8:21 PM, mtruss wrote:
I have purchased a used K3, serial number 3000 or so, it has been sent back to Elecraft for updates etc and returned to me working great so far. I would like to update some things especially the roofing filters first so the question I would like to ask is Has anybody upgraded from the 2.7 five pole filter to the 2.8 eight pole filter? I understand the 8 pole is a wider filter with 3 more filtering crystals , does it make any difference in received audio? also could I use the fm filter for use in the am position. Any other suggestions would be appreciated. Thanks Mike W8FLT -- View this message in context: http://elecraft.365791.n2.nabble.com/Filters-tp7626294.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
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