List Of Tuners That Can Properly Filter HD Radio Self Noise?
- Thread starter DKak
- Start date
Is this what the QRM from HD radio sounds like?
https://www.youtube.com/watch?v=I8LSIPe2ZnA
I don't think this is an issue in the Cheyenne area, at least I have not heard anything like it but I don't often listen to over the air radio so this issue is new to me, and very interesting.
https://www.youtube.com/watch?v=I8LSIPe2ZnA
I don't think this is an issue in the Cheyenne area, at least I have not heard anything like it but I don't often listen to over the air radio so this issue is new to me, and very interesting.
The noise sounds like low-level constant hiss of white noise when there should be silence (or near silence). The noise can be heard during quiet classical passages or in between quiet on-air conversation. The road is not a good place to listen for the noise. A quality signal heard in a quiet environment is best. Narrow IF filtering can help some, Hi-Blend can help some, both are a compromise. The post detector filtering/canceling work best, IMHO.
Hopefully "HD Radio" (or other digital data systems piggybacked on FM) goes into the toilet. If not, then snap up a good, post-detection-filter tuner. One way to determine is to look at the schematic of any tuner about to be purchased and look for filtering (typically adjustable coils) right after the detector but before the MPX section.
Hopefully "HD Radio" (or other digital data systems piggybacked on FM) goes into the toilet. If not, then snap up a good, post-detection-filter tuner. One way to determine is to look at the schematic of any tuner about to be purchased and look for filtering (typically adjustable coils) right after the detector but before the MPX section.
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Day-Sequerra has updated their page about how HD interferes with analog:
http://daysequerra.com/ViewProduct.aspx?CurPage=fm reference
Pretty good exposition with a link to a very technical article from Radio World.
For just $2800 you can upgrade your FM Reference to undo the damage done by HD; the broadcast equipment for which is sold by... Day-Sequerra! Arrgh.
http://daysequerra.com/ViewProduct.aspx?CurPage=fm reference
Pretty good exposition with a link to a very technical article from Radio World.
For just $2800 you can upgrade your FM Reference to undo the damage done by HD; the broadcast equipment for which is sold by... Day-Sequerra! Arrgh.
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sKiZo
Hates received: 92644 43.20°N 85.50°W
Ya ... and as soon as you clean up the HD interference, the power company will start installing "smart" meters in the neighborhood. I got a postcard in the mail the other day, and have heard some horror stories about what the RF from those can do to various assorted electronics and signals ...
Can't wait ... <mumble grumble mutter mutter>
Still having fun with my Sony HD car head ... doing an outstanding job. Never really noticed any problems with the Sansui QRX for tuning standard stations either. Only problem here is a steady tick on AM sometimes, probably due to a bad insulator on an electric fence somewhere in a 50 mile radius ...
Can't wait ... <mumble grumble mutter mutter>
Still having fun with my Sony HD car head ... doing an outstanding job. Never really noticed any problems with the Sansui QRX for tuning standard stations either. Only problem here is a steady tick on AM sometimes, probably due to a bad insulator on an electric fence somewhere in a 50 mile radius ...
musician2358
Active Member
HD Self-Noise Over-rated as a Problem?
I have a tuner made in 1982 (Sherwood TD-2010 CP) so I assume it has no HD noise filter just based on when it was made. When I tune to KQAC, a local 5900 watt public classical music station that broadcasts HD, I hear some very low-level white noise during quiet moments that goes away if I switch to mono. It is low enough not to interfere with listening to classical music. While that's subjective, I'm fairly sensitive to noise when listening to FM and a tuner being quiet is my main criterion for selection of a tuner.
I would assume this is HD self-noise based on info in this thread. However, if I tune to KMHD, a local 7900 watt public jazz station that also broadcasts an HF side-band, it is absolutely quiet during silent moments such as the moment after a music selection ends but before the announcer begins talking. Thus, I am inclined to conclude that the noise heard at similar quiet moments on the weaker station is just general noise resulting from the FM decode of a weak signal and that HD self noise is not really an issue, at least where I live.
Anyone more knowledgeable of FM than myself able to refute my reasoning above? I understand that a Kenwood KT-815 has a general noise filter that works well for HD noise, so maybe the tuner in question has a feature like that and is filtering some of the HD noise despite being designed years before HD radio was developed?
M2
I have a tuner made in 1982 (Sherwood TD-2010 CP) so I assume it has no HD noise filter just based on when it was made. When I tune to KQAC, a local 5900 watt public classical music station that broadcasts HD, I hear some very low-level white noise during quiet moments that goes away if I switch to mono. It is low enough not to interfere with listening to classical music. While that's subjective, I'm fairly sensitive to noise when listening to FM and a tuner being quiet is my main criterion for selection of a tuner.
I would assume this is HD self-noise based on info in this thread. However, if I tune to KMHD, a local 7900 watt public jazz station that also broadcasts an HF side-band, it is absolutely quiet during silent moments such as the moment after a music selection ends but before the announcer begins talking. Thus, I am inclined to conclude that the noise heard at similar quiet moments on the weaker station is just general noise resulting from the FM decode of a weak signal and that HD self noise is not really an issue, at least where I live.
Anyone more knowledgeable of FM than myself able to refute my reasoning above? I understand that a Kenwood KT-815 has a general noise filter that works well for HD noise, so maybe the tuner in question has a feature like that and is filtering some of the HD noise despite being designed years before HD radio was developed?
M2
musician2358:
Your Sherwood may have a post-detection filter; some older tuners do. The Marantz 2130 and Sumo Charlie preceded HD by years, but according to Brian Beezley's website they do have such filters.
I have two stations that broadcast multiple HD streams with strong signals; one is noisy and one is not. I suspect it has to do with the way their HD is set up but I can't be sure.
I suspect your analysis is correct for your local stations. You might want to contact their engineers for assistance. Good luck!
Your Sherwood may have a post-detection filter; some older tuners do. The Marantz 2130 and Sumo Charlie preceded HD by years, but according to Brian Beezley's website they do have such filters.
I have two stations that broadcast multiple HD streams with strong signals; one is noisy and one is not. I suspect it has to do with the way their HD is set up but I can't be sure.
I suspect your analysis is correct for your local stations. You might want to contact their engineers for assistance. Good luck!
Schotz or Carver TX11 noise reduction and HD noise?
I'm curious whether anyone can please speak to their experiences.
Both of these technologies were created long before HD; do they provide any benefit on HD noise? I know they were mostly designed to quiet weaker stations.
Schotz-equipped tuners include the Proton 440 and Nakamichi ST-7. One reviewer long ago said he couldn't find much noise to reduce - I guess those were the good old days!
http://www.fmtunerinfo.com/shootouts.html
Since it is easy to switch the NR in and out, does anyone have any observations?
Thanks!
I'm curious whether anyone can please speak to their experiences.
Both of these technologies were created long before HD; do they provide any benefit on HD noise? I know they were mostly designed to quiet weaker stations.
Schotz-equipped tuners include the Proton 440 and Nakamichi ST-7. One reviewer long ago said he couldn't find much noise to reduce - I guess those were the good old days!
http://www.fmtunerinfo.com/shootouts.html
Since it is easy to switch the NR in and out, does anyone have any observations?
Thanks!
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Yamaha blend and HD noise? CT-1010 experience?
On other threads I see some praise for the high-blend feature on Yamaha tuners. Does anyone have any observation on this helping with HD noise on Yamahas in general and the 1010 in particular? There's one on my local CL. Thanks in advance.
On other threads I see some praise for the high-blend feature on Yamaha tuners. Does anyone have any observation on this helping with HD noise on Yamahas in general and the 1010 in particular? There's one on my local CL. Thanks in advance.
What it sounds like
This link here
http://ham-radio.com/k6sti/kpbs.wav
which is at the bottom of
http://ham-radio.com/k6sti/hdrsn.htm
has an audio sample of HD noise. These are the sites of Brian Beezley who has a lot of technical expertise on this topic.
This link here
http://ham-radio.com/k6sti/kpbs.wav
which is at the bottom of
http://ham-radio.com/k6sti/hdrsn.htm
has an audio sample of HD noise. These are the sites of Brian Beezley who has a lot of technical expertise on this topic.
larryhardin
New Member
Magnum-Dynalab FT 101A
My Magnum-Dynalab FT 101A does not suffer from self noise on either of the stations to which I normally listen, despite the fact that both have subcarriers. Neither does it overload even though two FM transmitters are about four blocks away.
My Magnum-Dynalab FT 101A does not suffer from self noise on either of the stations to which I normally listen, despite the fact that both have subcarriers. Neither does it overload even though two FM transmitters are about four blocks away.
I've been listening to a restored Fisher TFM-300 and it is one of the quietest tuners I have ever heard. My local classical station, KBAQ, is noisy as hell on many tuners because their HD radio broadcast causes IBOC noise. No problem on the TFM-300. Stereo imaging is good but not up to my Scott 310E, but the 310E is awfully hard to beat.
monkboughtlunch
Super Member
How is it that the FCC allows HD Radio to be broadcast considering the havoc it wreaks on many tuners and receivers?
PabloTincho
Well-Known Member
DBX Tx-1 is also immune to HD noise, The DBX is the tuner as the Nad 4300, Audio Dynamics T-200 and Sumo aurora
