Looks like buying the FM filter and lying to the rig gives me the maximum flexibility with a minor inconvenience. Being that I won't be TXing in those modes all that often I'm not too worred but I just want to have a true All mode tranceiver.
~Brett On Thu, 2009-07-09 at 11:35 -0400, Joe Subich, W4TV wrote: > > > > This is as expected since the FM filter should be at least -60 > > > dB at +/-23 (2:1 shape factor) with an ultimate attenuation > > > of at least -100 dB. > > Correction ... +/- 26 KHz or a 2:1 shape factor. However > for comparison, Inrad's six pole front end filters for 40 > meters are 15 KHz wide (+/- 7.5 KHz) at 1 dB and 32 KHz > (+/- 16 KHz) at - 60 dB or 20 KHz ((+/- 10 KHz) at -1 dB > and 45 KHz (+/- 22.5 KHz) at - 60 dB. Converting to a 6:60 > framework makes the shape factor around 1.8:1. > > 73, > > ... Joe, W4TV > > > > > > -----Original Message----- > > From: Stewart Baker [mailto:stew...@baker.nildram.co.uk] > > Sent: Thursday, July 09, 2009 10:35 AM > > To: li...@subich.com; 'Brett Howard'; 'Bob Cunnings' > > Cc: elecraft@mailman.qth.net > > Subject: Re: [Elecraft] K3 Filter Question > > > > > > I agree. > > The cost of the K3 filters is now so high in the UK, that I > > want to get away with the minimum number necessary. > > > > 73 > > Stewart G3RXQ > > On Thu, 9 Jul 2009 10:00:42 -0400, Joe Subich, W4TV wrote: > > > > > >> I wonder if there is any possibility of allowing AM TX and/or ESSB > > >> via the FM filter... > > > > > > It is theoretically possible to transmit AM and ESSB through the FM > > > filter but the K3 is currently configured to prohibit AM and ESSB > > > transmit unless the 6 KHz filter is used. I have transmitted using > > > the FM filter by setting the K3 as if the FM filter was an > > AM filter > > > but then I can not transmit FM without resetting the filter set-up. > > > > > > Elecraft will argue that the 6 KHz filter is necessary to prevent > > > transmitted images (the DSP IF is 15 KHz, the image is 30 KHz away > > > from the transmit frequency). However, I can not measure > > any image - > > > to -120 dB from the CW level - when looking at the > > transmitter output > > > with a directional coupler using the SDR-IQ as a spectrum > > analyzer. > > > This is as expected since the FM filter should be at least -60 > > > dB at +/-23 (2:1 shape factor) with an ultimate attenuation > > > of at least -100 dB. > > > > > > It would certainly be nice if the "6 KHz" restriction was removed. > > > > > > 73, > > > > > > ... Joe, W4TV > > > > > > > > >> -----Original Message----- > > >> From: elecraft-boun...@mailman.qth.net > > >> [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Brett Howard > > >> Sent: Thursday, July 09, 2009 2:21 AM > > >> To: Bob Cunnings > > >> Cc: elecraft@mailman.qth.net > > >> Subject: Re: [Elecraft] K3 Filter Question > > >> > > >> > > >> I forgot to go back to that... I was thrown off by the comment on > > >> the order page that said you only need one of each filter for > > >> transmit. I know that doesn't fully say what I was hoping for > > >> though.... > > >> > > >> I wonder if there is any possibility of allowing AM TX and/or ESSB > > >> via the FM filter... As I'd like to have maximum flexibility but > > >> only have one slot left because of the way I have setup > > the radio for > > >> what I spend most of my time doing. > > >> > > >> Thanks for the assistance gentlemen. > > >> > > >> ~Brett > > >> > > >> On Thu, 2009-07-09 at 00:13 -0600, Bob Cunnings wrote: > > >> > Manual, pg 74: > > >> > > > >> > "Rule #1: If you plan to use a particular filter for both > > >> transmitting > > >> > and receiving (main receiver), you'll need to install it > > on the RF > > >> > board. You can optionally install a filter of the same > > or similar > > >> > bandwidth on the sub receiver for receive-only use. (This is > > >> > recommended since it will keep the receivers identical.)" > > >> > > > >> > Bob NW8L > > >> > > > >> > On Wed, Jul 8, 2009 at 11:31 PM, Brett > > >> Howard<br...@livecomputers.com> > > >> > wrote: > > >> > > Ok so I'm curious if I'll be able to do what I'd like. > > >> I'd like to > > >> > > setup my K3 for maximum flexibility. At the moment I > > have these > > >> > > filters. > > >> > > > > >> > > 2.8Khz > > >> > > 1.8Khz > > >> > > 1Khz > > >> > > 250Hz > > >> > > > > >> > > These 4 filters are duplicated in the lower 4 slots of both > > >> > > receivers. I'd like to have the ability to do AM and FM > > >> both TX and > > >> > > RX in this radio. Can I add the AM filter and KBPF into > > >> the main RX > > >> > > and then put the FM filter into the KRX3? > > >> > > > > >> > > I'm hoping that I can then use the MainRX for broad frequency > > >> > > coverage and AM broadcast receive. Then if I ever > > want to do FM > > >> > > work I simply have to use the sub receiver to do so. Will TX > > >> > > through the FM filter work with it in the sub RX... To > > >> the best of > > >> > > my knowledge it appears that I can set the rig up in > > this fashion > > >> > > but that doesn't always mean it will work how I expect it to. > > >> > > > > >> > > Am I all wet here? > > >> > > > > >> > > Thanks > > >> > > > > >> > > ~Brett > > >> > > > > >> > > ______________________________________________________________ > > >> > > Elecraft mailing list > > >> > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > >> > > Help: http://mailman.qth.net/mmfaq.htm > > >> > > Post: mailto:Elecraft@mailman.qth.net > > >> > > > > >> > > This list hosted by: http://www.qsl.net > > >> > > Please help support this email list: > > >> http://www.qsl.net/donate.html > > >> > > > > >> > ______________________________________________________________ > > >> > Elecraft mailing list > > >> > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > >> > Help: http://mailman.qth.net/mmfaq.htm > > >> > Post: mailto:Elecraft@mailman.qth.net > > >> > > > >> > This list hosted by: http://www.qsl.net > > >> > Please help support this email list: > > http://www.qsl.net/donate.html > > >> > > >> ______________________________________________________________ > > >> Elecraft mailing list > > >> Home: http://mailman.qth.net/mailman/listinfo/elecraft > > >> Help: http://mailman.qth.net/mmfaq.htm > > >> Post: mailto:Elecraft@mailman.qth.net > > >> > > >> This list hosted by: http://www.qsl.net > > >> Please help support this email list: http://www.qsl.net/donate.html > > >> > > > > > > ______________________________________________________________ > > > Elecraft mailing list > > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > > Help: http://mailman.qth.net/mmfaq.htm > > > Post: mailto:Elecraft@mailman.qth.net > > > > > > This list hosted by: http://www.qsl.net > > > Please help support this email list: http://www.qsl.net/donate.html > > > > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
