Dave, I always loved the Collins receivers, but they were very poor for AM work, as I guess you know. When AM was in, the technology did not seem to support good filters, xtal filters were in, or low frequency IF stages, both had drawbacks for hi fidelity AM reception. When mechanical filters came out, the move to ssb was already in motion, so Collins concentrated on building a good ssb receiver for ham use. They were very successful.
I don't think Collins ever designed a good audio output stage in anything they built, not like the direct coupled, push pull output amp like the Scott receivers had, or the hi power push pull output some of the Hallicrafters receivers used. They were not alone, and the best sounding audio receivers were built at a time when some of them were used as hi fidelity amplifiers for other things, my Scott has a phono input... The Collins receivers could be upgraded easy these days, with an add on low distortion AM detector, and good filters, into an outboard audio amp. Anything that uses a 455Khz IF frequency can be upgraded quite a bit with the kiwi filters, you can tack on a new detector without any trouble, and all the Collins receivers were very accurate in frequency, very stable, with good frequency resolution. One of these days, I will get around to upgrading a 75S1 for hi fidelity AM reception. Those receivers are still quite reasonable in price, and nice and small. I had one some time ago, but sold it. On AM, it was as broad as a barn door, but I did not know about the kiwi filters then. Way back, when receivers like the NC303 were at fests for $50.00, I don't think you could come up with anything better for AM reception. Some older radios had better fidelity, but had poor (or no) frequency resolution, poor bandwidth shape factors, and other problems. I think only the R390 with outboard audio was in the ball park. Its quite surprising that the NC300/303 still sells for a reasonable price these days....when you see them, they are well under the cost of something like a 75a4. Once and a while, I see them for $200.00 or less. That is a lot of receiver for the price! Brett N2DTS > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of David Knepper > Sent: Friday, October 17, 2003 8:21 AM > To: amradio@mailman.qth.net > Subject: Re: [AMRadio] FW: Homebrew receiver > > > Very fine, Brett. In all the receivers that I have at the > Collins Radio > Center, I like the NC-303, the best for AM > > > Dave, W3ST > Secretary to the Collins Radio Association > Publisher of the Collins Journal > www.collinsra.com
