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To HDR16 or not
- Thread starter austingrace
- Start date
More like a micro-boombox.
I was torn between the two but decided that with my traveling,
the SRF-1 would be more practical than the 100.
Platform motion also happens with clear skywave signals.
I do not remember which way it drifts,
but fading in moves the audio to one side
and fading out goes the other way.
I personally don't remember AM stereo. I'm only 29. LOL
Happy Birthday!
I never had platform motion on the SRF 42. It seems some receivers were pretty good at eliminating it. The stereo range was great on that thing. I remember tuning in XEMU 580 in the 90's on it at night, and in mono, there was sometimes barely any trace of a signal on it, but if I switched to stereo, it would pop right out. Any other station on the frequency would stay in mono. The TM-152 definitely had the platform motion with some signals. Lots of time the station would just fade out and the signal would squeal before fading out and the radio would go mono. Stereo would only return if the signal was above a certain point.
Later receivers were sensitive to a 25Hz pilot tone to engage the stereo circuits.
If the receiver could not receive this 25Hz tone, it would revert to monaural
and it could possibly use it as a reference to fight off the platform motion.
Many new HD receivers will decode C-QUAM stereo,
although the left and right channels might be reversed.
Of course, one would be very hard-pressed to find a station upon which to test it.
I said something in a previous post that was inaccurate:
It was a pre-Belar system, not a pre-Harris system that RCA tested in the 1950's over WNBC which used an L-R, FM signal.
Harris, Magnavox, and Motorola were all basically quadrature-phase modulated L-R systems but were mutually incompatible.
If the receiver could not receive this 25Hz tone, it would revert to monaural
and it could possibly use it as a reference to fight off the platform motion.
Many new HD receivers will decode C-QUAM stereo,
although the left and right channels might be reversed.
Of course, one would be very hard-pressed to find a station upon which to test it.
I said something in a previous post that was inaccurate:
It was a pre-Belar system, not a pre-Harris system that RCA tested in the 1950's over WNBC which used an L-R, FM signal.
Harris, Magnavox, and Motorola were all basically quadrature-phase modulated L-R systems but were mutually incompatible.
The SRF 42 also had the ability to "force" a station into stereo if the 25hz pilot tone was missing, but everything was in place. I don't know how it managed to do that, but I remember there were a couple of stations that were in stereo but not transmitting the tone that the radio was able to decode.
I got an SRF42 in 1996 when a store was closing out. So mine is probably one of the later versions.
Fire it up, tune to any DX channel at night, you'll hear platform motion. I'm not sure how it would operate on a local station with AM stereo, because as far as I know, there aren't any.
Ai4i: I"ve also read that many of the newer SiLabs chips have CQUAM decoding capability. But I would think the radio itself would have to also be configured to tell the chip to decode it, and then be configured to produce the results in stereo. Most radios using those chips are set to produce AM in mono.
Fire it up, tune to any DX channel at night, you'll hear platform motion. I'm not sure how it would operate on a local station with AM stereo, because as far as I know, there aren't any.
Ai4i: I"ve also read that many of the newer SiLabs chips have CQUAM decoding capability. But I would think the radio itself would have to also be configured to tell the chip to decode it, and then be configured to produce the results in stereo. Most radios using those chips are set to produce AM in mono.
Well guys. I'm still loving this radio. I'll be in Altamonte for the easter weekend so I'll be able to really put the radio to the test. I'll also be taking it to Palm Bay with me as well. So I'll be able to give you guys a new outlook on it as well.
Hi Austin. I'm glad you're enjoying your new HDR-16! These DSP tuners deliver remarkable FM performance don't they? AM ain't bad either! Here in Palm Coast we have only one AM station WNZF 1550KHz, and it doesn't broadcast HD. I've yet to hear an AM signal in HD and I fear I may never hear one. I read recently that the number of AM stations broadcasting HD is dwindling.
I have a relative of the HDR-16. I have a HDR-18, which is a tabletop model. I suspect it has the same tuner as the HDR-16. It's a nice HD radio, but there is one thing that annoys me somewhat. It has a bandwidth filter that narrows automatically when tuned to weaker signals thus degrading audio fidelity. In my opinion, bandwidth selection should always be user selectable. The HDR-18 is a fun radio though with very pleasant audio especially when tuned to HD signals. By the way, WPOZ broadcasts four discrete HD carriers!
One unfortunate thing I've observed with some HD broadcasters is that they severely limit the bit rate on transmissions to the point that broadcasts sound like low bit rate MP3 files.
Let's hope HD stays around for many years to come. While the internet is fun, there's a certain mystique associated with terrestrial radio! Happy scanning and listening!
I have a relative of the HDR-16. I have a HDR-18, which is a tabletop model. I suspect it has the same tuner as the HDR-16. It's a nice HD radio, but there is one thing that annoys me somewhat. It has a bandwidth filter that narrows automatically when tuned to weaker signals thus degrading audio fidelity. In my opinion, bandwidth selection should always be user selectable. The HDR-18 is a fun radio though with very pleasant audio especially when tuned to HD signals. By the way, WPOZ broadcasts four discrete HD carriers!
One unfortunate thing I've observed with some HD broadcasters is that they severely limit the bit rate on transmissions to the point that broadcasts sound like low bit rate MP3 files.
Let's hope HD stays around for many years to come. While the internet is fun, there's a certain mystique associated with terrestrial radio! Happy scanning and listening!
As an owner of the SANGEAN HDR-18, your comments regarding the HDR-16 affirm without a doubt that they share the same tuner and functionality. I too am annoyed that my HDR-18 will not retain its HD assignment beyond the first HD carrier when powered off and back on.
I'll bet the HDR-16, as with the HDR-18, narrows its bandwidth filter automatically on weaker signals thus degrading audio fidelity.
Incidentally, my favorite portable FM/AM radio is the C. Crane CC2E. No radio is perfect, but the CC2E is darn close!
I'll bet the HDR-16, as with the HDR-18, narrows its bandwidth filter automatically on weaker signals thus degrading audio fidelity.
Incidentally, my favorite portable FM/AM radio is the C. Crane CC2E. No radio is perfect, but the CC2E is darn close!
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When you say it has a narrow bandwidth, are you talking about AM, FM, FM HD, or AM HD?
I have a PR-D5, and the bandwidth is fixed. I would guess it is fixed on their other radios as well -- unless it is selectable.
What you may be hearing that sounds to you like "bandwidth narrowing" is the DSP tuning to the signal, and adjusting when it weakens and strengthens (please see the Superadio thread here, where RBruceCarter talks about the software in DSP chips adjusting to AM signals). But if your radio has no bandwidth switch, it is undoubtedly fixed.
Also, your HDR-18 may have muting, which some other popular Sangean DSP equipped radios (like the PR-D5) don't have. Soft muting is where the DSP chip drops the signal reception to near zero when the signal drops below a certain threshold. SiLabs DSP IF chips can do this -- my Radio Shack Pocket Radio, which has a SiLabs DSP chip, does this. When AM signals drop below a certain threshold, the chip "sees" it as a form of "noise", and drops the signal Waaaaaaaaaay down in the mud. Then, when the AM signal fades back up over the threshold, it's up to full strength again.
LIke I said, not all DSP chip equipped radios do this. My Sangean PR-D5 doesn't, and I think a few of their other radios don't, but some reviews I've read hint that some Sangean radios do have soft muting.
If your HDR-18 has soft muting, that may be what you are hearing.
I have a PR-D5, and the bandwidth is fixed. I would guess it is fixed on their other radios as well -- unless it is selectable.
What you may be hearing that sounds to you like "bandwidth narrowing" is the DSP tuning to the signal, and adjusting when it weakens and strengthens (please see the Superadio thread here, where RBruceCarter talks about the software in DSP chips adjusting to AM signals). But if your radio has no bandwidth switch, it is undoubtedly fixed.
Also, your HDR-18 may have muting, which some other popular Sangean DSP equipped radios (like the PR-D5) don't have. Soft muting is where the DSP chip drops the signal reception to near zero when the signal drops below a certain threshold. SiLabs DSP IF chips can do this -- my Radio Shack Pocket Radio, which has a SiLabs DSP chip, does this. When AM signals drop below a certain threshold, the chip "sees" it as a form of "noise", and drops the signal Waaaaaaaaaay down in the mud. Then, when the AM signal fades back up over the threshold, it's up to full strength again.
LIke I said, not all DSP chip equipped radios do this. My Sangean PR-D5 doesn't, and I think a few of their other radios don't, but some reviews I've read hint that some Sangean radios do have soft muting.
If your HDR-18 has soft muting, that may be what you are hearing.
I'm mot especially technically inclined, but I can tell you that, at least with the HDR-18, I clearly observe on both analog FM and AM, a distinct narrowing and widening of the audio frequency response depending on the strength of the received signals. It's not a muting issue. It's very bothersome to me as one who enjoys DXing. This auto bandwidth adjustment results in muffled audio on weak AM signals and nasty sibilants on weak FM signals. The audio response is wide and pleasant when the set is decoding HD. I'll bet the HDR-16 has the same DSP as the HDR-18. If you have a HDR-16, compare the audio of a strong signal to one of medium strength. I'm not talking about noise or loudness of the received signal, but specifically the audio frequency response.
By the way, I have two C. Crane CC2E (SANGEAN) sets that do not exhibit what I perceive to be automatic bandwidth switching. They maintain a consistent range of audio even when pulling signals close to the noise floor.
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Must be something either wrong with the radio (no other review of this radio I've read mentions that issue), or perhaps it is some form of noise reduction programming of the DSP chip that isn't used to the same degree in other radios.
I don't know that the HDR-16 would have that issue or someone else here would have noticed it on the AM band, as most the folks who hang out here are DXers of some sort.
A few other reviews of the HDR-18 mention pretty good AM and great FM reception.... some on Amazon say the clock sucks, though.
EDIT: I stand corrected here!
Radio Jay Allen notes exactly what you are describing here, in his review of the HDR-16: "Automatically variable bandwidth".
Where weaker AM stations have their treble reduced for apparent noise reduction reasons. You can read it on his HDR-16 review here:
https://radiojayallen.com/sangean-hdr-16-amfmhd-stereo-radio/
Ya learn something new every day.
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On FM,
Could you be hearing a blend from stereo to mono?
That would knock off some of the brightness.
No sir, it is variable automatic narrowing of the bandwidth filter on weaker FM and AM signals resulting in loss of audio fidelity. The radio is working as intended.
As for the clock issues with the HDR-18, and I suspect this includes the HDR-16 as well, there are none. When the clocks are set to auto set, they rely on time signatures sent by radio stations. Many radio stations, and I do mean MANY, are woefully negligent at accurately setting their clocks. I have witnessed the clock in my HDR-18 resetting seconds after I tune in to various different stations. Some stations' clocks are off by more than an hour! Many stations send no time signature whatsoever. Therefore I recommend setting the clocks manually. There is, however, a big flaw associated with the clock in the HDR-18 and I suspect in the HDR-16 as well. If the radio is disconnected from its power source for even a fraction of a second, the clock loses its settings and must be reset. SHAME ON SANGEAN!
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Hey guys. So had some more fun with the hdr-16. I know what you are referring to on the whole weak FM signal thing. It is a bit annoying but I have learned to live with it. I did hear HD AM. The station that I heard was WMMB 1240 in Melbourne. It sounds similar to a skype call. But it drops out very easy and defaults back to the analog signal. I see why a lot of the operators dropped the HD AM service. I still love this radio. I like HD radio more than what I thought.
Lucky you! Was WMMB 1240 rendered in stereo?
Austin, do you have an external passive loop antenna? If not, I highly recommend getting one. With the exception of a very few high-performance radios, a tunable passive loop can significantly increase the AM sensitivity of your radios. Their effectiveness is very apparent during daytime DX sessions. Passive loops are inexpensive and well worth the investment!
Hey guys. Does anyone know if amazon carries a replacement power cord for this radio? I have misplaced mine and cannot find it and i use the power cord a good amount. Thank you.
Prepare to dial!
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