AM Receivers These Days

General Radio News and Comments, Satellite & Internet Radio and LPFM

AM Receivers These Days

Postby albertaboy4life » Fri Jul 24, 2015 1:35 pm

TRENT310 wrote:These old "Hi-Fi" receivers of the 70s/80s have great tuners. Plus, very easily serviceable. I love how they had text labels for pots and inductors, and the traces on the other side were silkscreened on the top side as well. Meanwhile, I also have one of those brand new, 7.1 DTS, HDMI everything receivers and the AM tuner in that thing is the worst, if you can pick out any signal from the tons of internal noise it generates. I'm disappointed to see the AM tuner is basically an after thought these days. Onkyo actually was the hold out for AM Stereo, offering that feature in their products well into the 2000s. Sadly, most of them never ever had a chance to receive anything that would trip the light.


Yup, the newer gear sucks especially most OEM car radios.

700 in Calgary reminds me of the poor audio, due to low STL bit rate, aired by Seattle's Classic Country KKXA 1520.

I've got a four or five year old DENON home theatre receiver with a supplied external AM plastic loop antenna and it sounds okay. It doesn't have much high frequency output for FM though. My fifteen year old Harman/Kardon receiver is much better. I've air-checked some local FM stuff for jon on it and he's remarked about how good it sounds.

Radiofan's AM Stereo air-checks are proof of how good things can and should sound.

NAD calls its receivers Stereo AM FM Tuners. Case in point, http://nadelectronics.com/products/tune ... M-FM-Tuner But I can't find any technical references to a Motorola C-QUAM decoder or the like. Never seen one of these in a local shop either to test it out. Buying NAD stuff at VISIONS seems to mean having it shipped to your home after the purchase.
Faster cars, younger women, older cheese, more money . . .
User avatar
albertaboy4life
Advanced Member
 
Posts: 790
Joined: Thu May 18, 2006 5:48 pm
Location: Back in Alberta

AM Receivers These Days

Postby jon » Fri Jul 24, 2015 1:42 pm

I've "always" owned several "Stereo Receivers" as we used to "call" the combo radio/amplifier component of a Home Stereo setup. They are great for running stand-alone speakers for TV audio, computer audio and even for videos watched while exercising. And I've never had anything to complain about on the AM side of the receiver since a Canadian-built Germanium Transistor model in the '60s that my Father bought back then.

Then came the turn of this century. Suddenly some of the otherwise great quality Stereo Receivers would have AM receivers that cut off the highs or lows, or both. I didn't notice for years as I had the luxury of recording AM stations off Shaw Cable FM, so never used the AM receiver. Then Shaw pulled the service because they needed the bandwidth and I started airchecking off a real AM receiver. And found out the hard way.

Otherwise decent "Entertainment Systems" in vehicles have, in many cases, gone the same way, even in high end car brands, e.g. - Acura. Rather than spend a couple of bucks on components to eliminate the RFI from spark plugs and such, it was easier to cut off the highs and lows on the AM section of the car radio. I didn't initially clue in to just how much RFI was involved until I turned the engine off one day on my 2003 PT Cruiser (long since replaced) and discovered how much more sensitivity the AM radio had. Chrysler was quite clever as, when the engine was running, it was almost like a Squelch Control where you could turn up the volume to maximum and only hear what sounded like low level background noise. Turn off the engine and the AM band came alive, especially in the daytime on quiet frequencies with weak signals.

As for the return of AM Stereo as mentioned earlier, in another thread, there is still the possibility but only in some form of "Digital Radio". Unfortunately, in Canada, IBOC appears the most likely approach, initially on FM, which makes it also the most likely method for AM. If you think splatter on FM IBOC is bad, just wait until you try to listen to any frequency near an AM IBOC station.

Lets not forget that some AM stations already have outstanding audio quality. Today, without any need for AM stereo or IBOC. W-14-40 (CKJR Wetaskiwin) is an oft-cited example. Unfortunately, very few people get to hear it properly on an AM receiver. If they are in a vehicle, it is doubtful that they ever will, at least with current technology. Sure, some auto maker could (and maybe already does) make a full range audio option for their AM radio. To avoid you having to turn the engine off to hear it, they could even install Ignition Suppression circuitry on the engine, but that wouldn't do you any good unless all the cars you were driving next to had it too. Which, of course, won't happen unless the FCC and Industry Canada both require Ignition Suppression of all automakers like they did 40 years ago.
User avatar
jon
Advanced Member
 
Posts: 9208
Joined: Mon May 08, 2006 10:15 am
Location: Edmonton

Re: AM Receivers These Days

Postby jon » Fri Jul 24, 2015 3:05 pm

My previous post was written without seeing ab4life's post.

The NAD tuner noted is definitely not AM Stereo and I'm sure they would mention it if they did IBOC on AM or FM.

For my money, for audio quality, the finest AM/FM tuner that you can buy today, if you are willing to live without AM Stereo, IBOC or FM RDS, is the CCRadio-EP. Easy to overlook as it appears, at first glance, to be a relatively cheap portable radio with mono speaker and internal antennas. And there are tons of those around, so why buy this one?

It is easy to turn it into "the perfect tuner" though it does have one failing that may not bother you or be a Show Stopper: an analogue dial with a poor track record of being set accurately in the factory. No digital display or station presets. The included AC Adapter also has a less than perfect Factory Build record: I have received one with the cord cut to bare wire and another with significant RFI on AM. Both were immediately replaced by CCrane at no cost to me. Not even a request to return the bad one.

You will also read bad reviews of the -EP based on "Drifting". Although I cannot prove it, everything I've read, coupled with my own experience running these radios for 48 hours straight to record airchecks, is that Drifting only occurs when running on batteries, without the AC Adaptor. As the batteries start to run out and reduce their combined voltage, the receiver will drift a bit off frequency.

Here is why I think the CCRadio-EP is "the perfect AM/FM Tuner":
  1. Earphone output is designed to be completely flat frequency response across the entire audio spectrum, stereo for FM, and Line Out-compatible for recording or running into an external amplifier
  2. EXT antenna setting allows external AM and FM antennas to be used, disconnecting both the internal AM antenna (which overloads the receiver close to high power AM transmitters) and the attached FM whip antenna
  3. Audio preamplifier has a very low noise floor, i.e. - high Signal to Noise ratio, allowing the AM receiver to be used with an unamplified external antenna, when used with an external audio amplifier
  4. Very good RFI (noise) rejection
  5. Very good Station Mixing Product (spurious station images on other than their assigned frequency) rejection
There are certainly better DX receivers, though I haven't seen a better AM DX receiver for less than $500. But my comments above were about audio quality for listening or recording.
User avatar
jon
Advanced Member
 
Posts: 9208
Joined: Mon May 08, 2006 10:15 am
Location: Edmonton

Re: AM Receivers These Days

Postby TRENT310 » Fri Jul 24, 2015 6:40 pm

I was wondering where my reply went. Haha. I see it got split.

I actually like many OEM car radios. The NRSC test actually shows that among a plethora of receivers they tested, the OEM car radios often outperform aftermarket car radios.
http://www.nrscstandards.org/SG/NRSC-G100-A.pdf
Of course what I don't like about that document is that it's recommending that broadcasters narrow down to 5kHz or 7kHz audio instead of NRSC standard 10kHz. It does, however, highlight my regular struggle of trying to listen to 910 CKDQ anywhere close to the greater Edmonton area with 930 being quite strong.

The Visteon OEM radio in my 2011 F-350 has a reasonably wide IF, while the Continental OEM radio in my 2015 Ram 3500 has an automatically switching IF bandwidth which actually drives me nuts. The narrow IF is basically un-listenable, while the wide IF is usable. I get that it may be a listener comfort thing to basically muffle undesirable noise such as when driving under transmission power lines, but in fringe areas where it switches constantly between modes I do find that annoying. I have not had a chance to try out the higher end infotainment systems as I typically buy base model vehicles. On that note, however, many of those higher end systems have built in IBOC HD Radio support which many owners do not yet know about, since Canadian market vehicles are often of similar specification to the American counterparts. It's unlikely that a station today would spend the effort and expense as well as the additional point of maintenance and failure to implement C-QUAM to appease a select few listeners (mostly us here talking about it) who would also go the extra mile to source and use AM-Stereo capable equipment.

The wideband tuner that I use to record audio off-air is the Sony STR-AV790 which I've posted elsewhere on these forums.

For most DXing, I run a CCRadio 2E which I love for the auto-switching loop antenna - it will automatically switch coils depending on signal strength to prevent receiver overload. However it does not bring through wideband audio or have any controls to switch filter modes. It also has a fixed line output in addition to the variable earphone jack output so you can record and monitor simultaneously. Apart from that, I like the integrated power supply which is of decent quality and doesn't wipe out AM when you use it, the fact that it switches power sources based on actual AC power supply and not merely physical cord insertion presence (like oh so many portable radios out there).
The clock also seems accurate, which is more than I can say for any of the Tecsun/Eton/Grundig ones I have which all drift over a few minutes a month. I also have a few Eton G5, S350DL, and S450DL scattered around - mostly impulse buys when they go on clearance at The Source electronic stores. I was going to purchase a S550 "Field" however the reviews on line including the tear-down show that not much has changed apart from adding RDS and a nicer display. Of course, as many noted I did also experience the drift on the S350/DL model which is characteristic of a mechanically tuned radio with digital counter. I then got the S450 which was a true PLL design, however the audio response was very muddy. There are documented modifications out there online from guys who change out the reactive components to open up the bandwidth on those radios.

I loved the audio on 1440 CKJR. I listened to CKJR all the time back during the Cat Country days, but since 2007 less so after the format switch. Back when all the Cat Country stations were perfectly synchronized, you could definitely tell the difference listening to the same audio via their various outlets - Could compare with 1370 CFOK, 850 CKBA, 830 CKKY, 1400 CKSQ, 910 CKDQ, 1310 CHLW easy enough. CKKY was always plagued with having to switch power levels 4 times a day often in the middle of newscasts, and CFOK always had on and off pattern switching trouble all the way up to the day they flipped to FM.
TRENT310
Advanced Member
 
Posts: 235
Joined: Tue Aug 07, 2007 11:40 pm
Location: Whitecourt/Edmonton, Alberta, Canada

Re: AM Receivers These Days

Postby TRENT310 » Fri Jul 24, 2015 6:54 pm

I looked at the NAD C427. The RS-232 control is what sets it apart from regular tuners, which would open possibilities to schedule recordings from various frequencies and allow full remote control. But at that price tag, I'd be looking at anything broadcast grade... I've been keeping an eye out there for any used Inovonics 525, 634 or something similar. Those have selectable IF, selectable de-emphasis, and remote control on some modelsl. I thought the audiophile-grade tuners would have excellent RF characteristics but again those are so much more biased over FM receiver quality and HD Radio support these days. I had a chance to play with a McIntosh MR88 and basically they were highlighting the FM, HD, and XM capabilities front and foremost. (I also have no idea why satellite radio has any place being in audiophile-grade equipment either, being a low-bitrate, highly compressed audio stream...)
TRENT310
Advanced Member
 
Posts: 235
Joined: Tue Aug 07, 2007 11:40 pm
Location: Whitecourt/Edmonton, Alberta, Canada

Re: AM Receivers These Days

Postby jon » Fri Jul 24, 2015 8:48 pm

Satellite radio may be bad but I was really shocked doing a side by side comparison with their Internet service back in mid-2010. The Internet version at that time was truly awful.

To borrow a line that deeply offended a co-worker at my last job, who ordered his new car from the factory so he could get the high-end sound system: "Why would you worry about the sound system in an acoustic environment with the characteristics of a phone booth?" That explains why I actually don't mind listening to satellite radio in a vehicle, but I don't have it at home.

Since your last post, I received an e-mail from Portland DX'er Mark West wondering about a new kind of DX'ing that he thought might be interesting. He wondered if this receiver would do the job:
P-SB7 Spirit Box ITC Research Device - 2015 Version - FM/AM equally balanced -Noise Cancellation

Product Features

P-SB7 FM - created with intent of hearing voices from the departed in real time
The P-SB7 utilizes a milli-second adjustable Forward or Reverse frequency
FM and AM frequency sweep equally balanced which includes an additional 119 new frequencies from 76MHz to 87.9MHz from original version.
Used with great success by professional paranormal researchers
Comes with a GWS-200 amplified external speaker and FM Noise Reduction for clearest reception

You can find it on amazon.com, with pictures, "Ships from and sold by Ghost Hunting Source." at http://www.amazon.com/P-SB7-Spirit-Box- ... B00AEYS74I
User avatar
jon
Advanced Member
 
Posts: 9208
Joined: Mon May 08, 2006 10:15 am
Location: Edmonton


Return to General Radio News

Who is online

Users browsing this forum: No registered users and 3 guests