Ian Besides casual listening around the HF bands, it turns the K3 into another piece of test equipment in the shack. The K3 calibration is pretty darn good, so you can measure the frequency of a signal and be very close to its absolute frequency. Or just listen to an oscillator that operates outside the ham bands, such as those in a homebrew RX or TX. 73, Bob N6WG
----- Original Message ----- From: "Iain MacDonnell - K6IAM" <[EMAIL PROTECTED]> To: "Ron D'Eau Claire" <[EMAIL PROTECTED]> Cc: "'Joe Word'" <[EMAIL PROTECTED]>; <elecraft@mailman.qth.net> Sent: Monday, July 28, 2008 10:46 AM Subject: Re: [Elecraft] K3: General Coverage Receive Filter > > I'd been meaning to ask for a while; what is the motivation for those > of you who have ordered the general coverage receiver option? i.e. what > makes it worth the extra $129 ?? > > ~Iain > > > Ron D'Eau Claire wrote on 07/28/08 07:35: > > Joe asked: > > > > What is the General Coverage Receive Filter, how does it work? If it is > > just > > another roofing filters, why not just use the 6.0 filter? > > > > ------------------------------------------------------- > > > > It's not, Joe. The KBPF3 provides additional receiver input bandpass > > filters. > > The input bandpass filters are L/C filters that are switched > > automatically according to the frequency band selected to protect the > > receiver from strong out-of-band signals hundreds of kilohertz or even a > > few megahertz away from the desired signal. > > > > The first I.F. "roofing" filters follow later in the signal path to > > provide selectivity within a few kHz or a few hundred Hz of the desired > > signal. > > > > The basic K3 is equipped with input filters covering the 160-6 meter Ham > > bands. These filters also allow reception near the Ham bands but, as you > > tune farther from a Ham band, the sensitivity will drop off as you move > > beyond the edge of the filter bandpass. This is most apparent when > > trying to listen to AM broadcast band stations below 1,000 kHz without > > the KBPF3, but a significant loss of sensitivity occurs whenever the > > basic K3 is tuned far from a Ham band. > > > > The KBPF3 provides additional input filters that are switched in > > automatically to cover the out-of-Ham-band frequencies between 500 kHz > > and 30 MHz. > > > > Ron AC7AC > > > > > > > > _______________________________________________ > > Elecraft mailing list > > Post to: Elecraft@mailman.qth.net > > 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: Elecraft@mailman.qth.net > 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: Elecraft@mailman.qth.net 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