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"hi-end" AM tuner

EXACTLY, Kent ! All this new, hi-falutin' Rootin'-Tootin' Digital stuff is USELESS, because it typically has SO much internally generated noise that effectively drowns out any far-away DX AM stations..An R-389, R-390 or R-390A, typically is an EXTREMELY "Quiet" receiver, down close to the atmospheric level of what's attainable.. My NRD-545, while being a Top-Notch receiver otherwise, has a HIGH noise floor because of CPU & fluorescent display issues..
 
1TUFSS said:
Carver TX-11.

AM stereo, near-flat 20-20 response, absolutely no noise to speak of, pulls in distant stations like a freight train. I've only heard one, and it fooled me.

The FM stage kicks just as much butt.
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umm... it's impossible to get more than about 9kHz out of (analog) AM.
 
Hi Q AM

Ya sorry for involving FM in the discussion.
Am stereo? It still exists? I do not know of any stations still adopting this method of transmission. Having AM hi-fidelity is questionable to me at least, due to the nature of the source and the ability of the remove the noise.
If Am stereo is the norm, then the ? remains, why would Silicon Labs, not incorporate this feature into their products? I think I know the answer, AM stereo is dead in the water, has been for some time now.
And I hope that HD FM goes the same way. Just like ATSC?, it sucks or does not exist at fringe signal levels.
I do agree that digital electronics and AM radio frequencies are an issue, but that is the way it is these days with electronic noise saources, i.e. fluorescent ballasts/fixtures/lamps spraying RF. You need an external antenna and mount it far away from the noise sources, if you can. Ain't so easy, in a metropolitan area.
My NRD-545, while being a Top-Notch receiver otherwise, has a HIGH noise floor because of CPU & fluorescent display issues.
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Well maybe they did not do such a good job at shielding,filtering these noise sources? Like most are saying, AM is a second thought with most tuners.
To think that a DSP is of no use in a AM receiver, is what I'd call short sighted. Maybe you are correct, Silicon Lab's do not know what they are doing, NOT.
If $ permits, like on a Carvier budget, you can design very low phase noise VCO's, PLL's etc as it is done with hi-end Signal generators.
Before people shoot down a DSP radio for AM, have any of you actually designed, listened to a Si4770 part that has been implemented correctly?
 
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speaking of antennae for AM - the wavelengths are long so external antennae can get kind of... big :-)

Indoor (or outdoor) loops are still value-added for AM reception - unfortunately the popularly priced option (the Select-a-Tenna) is NLA as new production. I think C. Crane & Co. still has a high-performance AM antenna but it is fairly 'spensive.

EDIT:
http://www.ccrane.com/antennas/am-antennas/

http://www.ccrane.com/antennas/am-antennas/twin-coil-ferrite-am-antenna.aspx
http://www.ccrane.com/antennas/am-antennas/terk-am-advantage.aspx
http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=SM100
 
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Yes, and before that, 15 kilohertz response could be achieved. AM Stereo is not totally dead, some stations use it and reinstalled it instead of HD Radio on AM.
 
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KT -

Since I don't know from nuthin' on this subject, but am really interested, a question: if bandwidth is now limited to 9khz on the a.m. side, what's the point in having a wideband (if I'm using the term right) a.m. receiver?

tks,

s.
 
Sound quality, even news and talk shows sound much better, like they're on FM(If the station is broadcasting a good signal like WBZ in my area). Wish AM car radios had good fidelity, to make it easier listening above the noise, instead of the typical muffled sound.
 
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mhardy6647 said:
speaking of antennae for AM - the wavelengths are long so external antennae can get kind of... big :-)

Indoor (or outdoor) loops are still value-added for AM reception - unfortunately the popularly priced option (the Select-a-Tenna) is NLA as new production. I think C. Crane & Co. still has a high-performance AM antenna but it is fairly 'spensive.

Ive been looking at either a wellbrook loop

http://www.wellbrook.uk.com/antennashop/

Or a pixel technologies loop
http://www.pixelsatradio.com/product/shortwave-magnetic-loop-antenna/
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I've been thinking about making a loop for AM (MW) for a long time.

I've gotta say that I don't understand the physics of getting 15 kHz out of AM in the US any time in the last, oh, I don't know... seven decades. How was there enough channel bandwidth to accommodate it without spillover to adjacent channels? I don't doubt that a receiver could accommodate such a signal, but how could it be transmitted and who ever did?

FYI and FWIW, my father engineered the first AM-FM simulcast stereo FM broadcast in Baltimore, MD in the 1950s... but I don't think that the AM channel had the bandwidth of the FM...
 
G'day mate, the channel spacing in Australia is nine kilohertz and believe me even a nine kilohertz audio bandwidth sounds great if received in a low distortion set up. :yes: Regards, Felix (vk4fuq) aka catman.
 
Oh, I hear you on that! My venerable Sherwood S-2000 probably does 8 or 9 kHz in "wide" and it sounds very good even with whatever the real bandwidth of the local AM stations is (what, maybe 4 or 5 kHz, on a good day?) :-)

9524518138_99f1337c58_b.jpg
 
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mhardy6647 said:
umm... it's impossible to get more than about 9kHz out of (analog) AM.
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That might be the case where you live, but not where I live. We use 9khz spacing, but the spectrum bears absolutely no resemblance to the over-crowding of U.S. radio; Adelaide gets so few stations that most of them are 90khz apart.
 
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In this month's edition of "Electric Radio" magazine, there is an article on constructing a homebrew BCB/MW/DX 7 tube radio, along w/how to build a Loop for it..I'm WAY too stupid to build it, if I want to DX AM, I just go flip on my R-389..
 
Dwartz said:
In the late 70's, or perhaps early 80's, I used to see magazine ads for an AM-only tuner that made some pretty fantastic claims about its performance. I can't recall the brand, although it wasn't a brand you'd see in stores. Anyone recall what it was? Were they any good?
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My wife and I regularly listen to AM but reception is problematic. If your research finds a few tuners w/ good AM reception let me know by posting your findings here. Thanks.

mhardy6647 said:
Oh, I hear you on that! My venerable Sherwood S-2000 probably does 8 or 9 kHz in "wide" and it sounds very good even with whatever the real bandwidth of the local AM stations is (what, maybe 4 or 5 kHz, on a good day?) :-)

9524518138_99f1337c58_b.jpg
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That Sherwood looks quite spectacular.
 
A wideband AM tuner with full response will give you AM sound quality as good as what the station you are listening to can broadcast. Listen to some of these recent car radios who have such sharply filtered AM audio and compare. On the McIntosh MR 74 tuners at work, the AM is superb sounding and pleasant on a good station. On those new car radios the AM reception is barely more than strong locals and the audio telephone quality at best. Even sports and news/talk sound better on a good set. Most non HD AM Stations have 10 khz bandwidth, HD AM analog 4-5 khz.
 
Great thread. I have three receivers, one less vintage (1990 Pioneer), and a KT-6007. All four units pick FM well (some better than others), but AM is almost non-existent although they all have AM antennas. I wouldn't mind getting better AM but I get the feeling the juice ain't worth the squeeze.
 
I have been using a Denon TU-680NAB AM Stereo/FM tuner for nearly 30 years, at home. It's usually being fed by a McKay-Dymek DA-5 antenna.

A couple of years ago, I pulled out an old McKay-Dymek AM-5 tuner from work (KSL Radio), cleaned it up and repainted it, changed all the light bulbs and electrolytics, and took it home for the weekend.

Listening to a SportsTalk feed from one of the locals was like hearing the direct satellite feed from Dallas....I could tell which anchor was sitting in the chair with the squeaky wheel. Local music stations (only two of them) were great sounding, and I was surprised how a couple of out-of-town stations sounded.
 
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