I have the KIWA filters in the homebrew, and for my money, they work as good or better then a mechanical filter. 4.5 or 5.5 Kc is just that, outside the passband its gone! I like AM qso's every 5 kc as long as the signals are clean, if someone is distorted and splattering, nothing helps.
Brett N2DTS > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Jim Candela > Sent: Sunday, October 01, 2006 6:50 PM > To: Discussion of AM Radio in the Amateur Service > Subject: Re: [AMRadio] Best AM BoatanchorReceiver or AM > RiceboxReceiverDiscussion > > Jim, > > I lover your term, 'Aflak'! Pardon me, but I am going to use it..:-) > > That Sx-117 is a pretty neat receiver. I was just looking > at the specifications at the following sight: > > http://www.dxing.com/rx/sx115.htm > > The IF selectivity at .5, 2.5 and 5 khz @ -6db is pretty > tight for AM, and I bet that is why you did pretty good on 75 > yesterday with 3 AM signals spaced 5 Khz apart, and a duck on > either side. My Sp-600 with a 3 and 8 and 13 khz options just > did not have the right bandwidth position for the conditions. > There was also an Aflak at 3918 Khz running an amplifier, and > was about 150 yards from my home. The SP-600 could not handle > it, S-meter would go down about 1/2 what it was, and > undetected SSB came right through the speaker - loud too. The > R75 with preamp off, and attenuator off had no trouble with > the 3918 Aflak. > > In defense of that SP-600, later during the traders net the > QRM subsided, and I opened the Super Pro to 8 Khz, and turned > up the audio. It was clear as a bell, and the audio from > those guys really came through nicely. Then the signals > faded, QSB, selective fading, noise, etc. came in. > > The R75 sync detector has issues, and many complaints. That > said, if you use the passband tuning (say +/- 2.4 khz), with > AM sync ON, it locks every time. With normal AM tunining mine > seldom locks. The Kiwa mods take care of that, and several > other issues. > > http://www.kiwa.com/R75.html > > Jim > JKO > > > > > > ----- Original Message ---- > From: Jim Wilhite <[EMAIL PROTECTED]> > To: Discussion of AM Radio in the Amateur Service > <[email protected]> > Sent: Sunday, October 1, 2006 11:33:28 AM > Subject: Re: [AMRadio] Best AM BoatanchorReceiver or AM > RiceboxReceiver Discussion > > Jim I listened to the same groups as you yesterday on an SX > 117. I did not > have any trouble copying each of the groups. While some of > the aflack noise > could be heard, it did not affect my copy that much. I > turned on the HRO 60 > with the D coil in the General Coverage mode and was able to > copy very well > with it. > > I am about 500 miles North of you and was using a dipole and > an inverted L > on both receivers. I didn't try the NC 183D but it tends to > be almost as > selective as the HRO. I also have an R 75 and I really don't > see that much > of an improvement in reception. I do not have all the > filters in it as you > do, but the S- AM mode does not help that much. Also my R 75 > does not have > any modifications. > > 73 Jim > W5JO > > > > > Hi All, > > > > Yesterday morning on 75 meters we had at least 3 AM QSO's going on > > simultaniously. It was glorious! I heard QSO's on 3880, 85, > and 90. At the > > same time there were SSB groups on 3878, and 3894. > > > > At my QTH (central Texas) with my equipment, my SP-600 was > useless. Yes I > > could use the 3Kc IF bandpass position, and tune off center > to favor one > > sideband or another. As soon as the audio midrange would > brighten up I'd > > hear QRM from an adjacent channel. Switching in the 8kc > position resulted > > in > > a maddening array of signals besides the one I was wanting to hear. > > > > Then I switched to my Icom R-75 with 3 mechanical filters > that are about > > 2.4, 3.5 and 6 khz in bandwidth. I could hear all 3 QSO's > Q5 in AM with > > the > > 3.5 Khz filter, but it was no fun because the upper mids, > and all highs > > were > > gone. Then tune off 1 Khz, and much better or turn on the > synchronous > > detector, offset the passband tuning 2.4 khz (or 3.5), > select the 2.4 > > filter > > (or 3.5), and golly Gee! Nice sounding AM on all 3 QSO's so > long as you > > pick > > the better sideband. > > > > As the morning went on the QRM went away, and all we had > was the traders > > net > > on 3890. Now the SP-600 ruled until the signals started > dropping from > > daytime propagation kicking in. Now I was experiencing QSB, > selective > > sideband fading, and occasional impulse line noise. Switch > back to the > > R-75, > > turn on the noise blanker, and synchronous detector. Back > to Q5 again!! > > > > This is not a tube versus solid state issue. Chuck Wa0zhh > has a all tube > > HB > > receiver that has most of the modern features, and his receiver can > > probably > > blow the doors off my R-75. Chuck likes old style octal > tubes too like the > > 6L7 in his noise blanker circuit. > > > > So how would a R-390 have done yesterday, or a NC-183D, > Bretts HB tube > > receiver, or one of Darrel's HB tube receivers?? Just curious. > > > > Jim > > JKO > > > ______________________________________________________________ > AMRadio mailing list > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] > > > > ______________________________________________________________ > AMRadio mailing list > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] > ______________________________________________________________ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:[email protected]
