Hi Frank: I didn't receive yet my optional filters, but I wondering what is the software you are using in conjunction with the K3. I'm using the Mixw2 Best regards Oms PY5EG
-----Mensagem original----- De: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Em nome de Frank Lammel Enviada em: Friday, May 16, 2008 3:40 AM Para: [EMAIL PROTECTED] Cc: [email protected] Assunto: Re: [Elecraft] RTTY Filter for K3 Hi Axel, full ack with Joe. I use the 400 Hz 8 Pole with a DSP of about 300-350 in dual tone. Perfect! 73! Frank, DD7ZT Joe Subich, W4TV schrieb: > After making extensive tests and plotting the selectivity curves > of the 200 Hz filter in my K3, I'm convinced that it is too > narrow for reliable weak signal RTTY operation, particularly in > conjunction with the dual-tone filter. > > The measured -6dB bandwidth of the 200 Hz crystal filter was > 209 Hz and the composite bandwidth of the 200 Hz crystal filter, > 200 Hz DSP and dual tone fitter was less than 170 Hz. A standard > 170 Hz shift 45.45 baud RTTY signal needs at least 235 Hz > (170 + 3*22.7) and the dual tone filter represents a 220 Hz (two > 50 Hz filters with center frequencies separated by 170 Hz). > > After extended discussion with a well know RTTY op and K3 beta > tester, I believe the combination of a 300 Hz 5-pole crystal filter, > 300 Hz DSP and the dual tone filter will have a composite -6 dB > bandwidth of about 250 Hz - about optimum for narrow RTTY. The > currently available, "250," "400" or 500 Hz filters in combination > with a 300 Hz DPS bandwidth and dual tone filter are very close to > optimum. > > 73, > > ... Joe, W4TV > > > >> >> Hi K3-folks, >> >> What would be the best RTTY roofing filter for the K3? Is the >> 400Hz 8-pole >> filter too small and the 500Hz 5-pole filter the better choice? >> >> Thanks in advance for your answers. >> >> 73 de >> >> Axel, DL3ZH >> _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
