I almost don't where to start. At this point I have only made a cursory test of the FM and multi channel, and can't complain about
what I found there. I'm only 7 miles from the downtown Chicago FMs, and FM works fine.
I can hear extended range when the HD FM kicks in, the differences greater or less depending on individual stations.
The time sync was good on all the HD FM-1s here. Probably has the same delay as the AM, but I haven't checked yet.
The AM behavior and the digital signal processing are almost incomprehensible.
Compared to any other radio, ....how do I put this.. it's a sensitive as 5 tube table radio with a "dead" IF tube and a weak or
misaligned RF section. It gets the the big local signals only to any effect. More on this later.
I will briefly repeat my observations from another thread.
I tried listening to my part 15 AM with 20-ish to 20k-ish audio. Real weird. First there's the quarter-second delay in analog.
Either real low modulation or real low power opened up the bandwidth to just under 10khz ( no whine ).
Low, low power (almost off) with full mod turned the audio into huge clots and braps, while "control radios" sounded beautiful if weak.
Raising RF and audio to normal levels is immediately evident as bandwidth shuts down to something aproximately like a telephone.
Full modulation gives the DSP fits. Dancin' Machine by The Jackson 5 and the theme from Dragnet by Ray Anthony are causing
spiky pumps in loudness in any short gaps, which if followed by a percussive sound, appears as a 1/10 of second volume burst
maybe 6db over average which is at all other times is maintained with an iron fist. In a way it reminds me of the short-time constant
AVC setting on a Collins 390, which does not follow music well at all, but is perfect for CW in choppy fading.
Anyway, musical this ain't. It stabs, punches and pumps. The more dynamics and positive-going mod you give this, the more it
staggers like a drunk. It's trying to give a LOT of audio compression on its own apparently.
Spike Jones' "You always hurt the one you love" is causing massive over/undershoots.
I thought I was hearing the bandwidth change only while in the low-to mid levels.
It is most drastic there, but even at full modulation, this effect comes in and out as eventual low-level material appears.
The effect is like hearing the EQ suddenly change on the old long lines, or even like sideband fading on shortwave.
Also much like the sound of tape alignment changing while listening to an old mistracking tape.
I'm not going to pick faults with the speaker/cabinet/size issue. It has enough low end response given its size.
Not too boomy, perhaps a bit. There is a characteristic mantra-like 'ooooooommmm" noise heard on every weak
or "empty" AM frequency, which appears over a second or two and then continues.
At first I thought it was normal carrier beat, but it's the EXACT same on every frequency, like a pitch pipe.
It's down low, maybe 5 percent, but it ain't on the control radios. It may BE a beat freq, if there is something in the
DSP has an affinity for putting that note at advantage, perhaps to extend frequency low end as is done in port tuning of speakers.
As I'm listening, it's becoming clear there is something really wrong in the "release" timing of the AGC.
Removing my compression on transmit and lowerering mod to "adequate" minimizes the defect.
It can't seem to deal with positive-going swing. That sets it a pumpin'.
I don't care for any of tone presets much, but I leave it on ROCK.
There is a nice one called "NORMAL" where the letters NOR are positioned over MAL inside a nice SQUARE box.
Very nice touch.
It's like finding clues in code.
For regular reception it's very hard of hearing, as I mentioned above. WSB, WSM which could be copied easily on the
'62 Mopar radio, 1982 Sony tabletop and Sangean 803 were barely detectable on the Accurian, despite best loop positioning.
Even mid-level signals of what I think of as Chicago stations were too weak to listen to.
The radio was begging me to open it up and see who had fiddled with the IF trimmers.
The big locals sound bad, since their strength shuts the bandwidth down to narrow.
WLS sound great though, because it's I little farther away for me than the others and the weaker signal opens it up.
But even as I listen to WLS in analog, I hear the bandwidth opening and closing.
Copying WCBS 880 here in the basement by turning the loop....the "oooooooooommmmmmmm" is almost as loud as WCBS.
Nothing else going downward until 780 WBBM in iboc, The Accurian hides the giant hissing sound on adjacent frequencies, offering
instead a dull low rasp. The HD AM codec is less troubling on busy music than it is on voice.
On voice, everyone has the smearing rasp on the crisp information in their vocals.
There's nowhere to hide it on voice.
WHAT'S THIS! on AM 670 WSCR we hear the Dan Patrick show, where the decoded AM HD has the exact SAME sound
as good old fashioned FM multipath hiss! After listening a while, this is not only local content, only the Dan Patrick show network.
WSM barely detectable under the ooooooommmmm.
Not much I can think of now....the display hasn't freaked out any tonight as it did last night, when
AM1620 changed into Z?TX.
Should I make some recordings of this? It's pretty like a car wreck.
what I found there. I'm only 7 miles from the downtown Chicago FMs, and FM works fine.
I can hear extended range when the HD FM kicks in, the differences greater or less depending on individual stations.
The time sync was good on all the HD FM-1s here. Probably has the same delay as the AM, but I haven't checked yet.
The AM behavior and the digital signal processing are almost incomprehensible.
Compared to any other radio, ....how do I put this.. it's a sensitive as 5 tube table radio with a "dead" IF tube and a weak or
misaligned RF section. It gets the the big local signals only to any effect. More on this later.
I will briefly repeat my observations from another thread.
I tried listening to my part 15 AM with 20-ish to 20k-ish audio. Real weird. First there's the quarter-second delay in analog.
Either real low modulation or real low power opened up the bandwidth to just under 10khz ( no whine ).
Low, low power (almost off) with full mod turned the audio into huge clots and braps, while "control radios" sounded beautiful if weak.
Raising RF and audio to normal levels is immediately evident as bandwidth shuts down to something aproximately like a telephone.
Full modulation gives the DSP fits. Dancin' Machine by The Jackson 5 and the theme from Dragnet by Ray Anthony are causing
spiky pumps in loudness in any short gaps, which if followed by a percussive sound, appears as a 1/10 of second volume burst
maybe 6db over average which is at all other times is maintained with an iron fist. In a way it reminds me of the short-time constant
AVC setting on a Collins 390, which does not follow music well at all, but is perfect for CW in choppy fading.
Anyway, musical this ain't. It stabs, punches and pumps. The more dynamics and positive-going mod you give this, the more it
staggers like a drunk. It's trying to give a LOT of audio compression on its own apparently.
Spike Jones' "You always hurt the one you love" is causing massive over/undershoots.
I thought I was hearing the bandwidth change only while in the low-to mid levels.
It is most drastic there, but even at full modulation, this effect comes in and out as eventual low-level material appears.
The effect is like hearing the EQ suddenly change on the old long lines, or even like sideband fading on shortwave.
Also much like the sound of tape alignment changing while listening to an old mistracking tape.
I'm not going to pick faults with the speaker/cabinet/size issue. It has enough low end response given its size.
Not too boomy, perhaps a bit. There is a characteristic mantra-like 'ooooooommmm" noise heard on every weak
or "empty" AM frequency, which appears over a second or two and then continues.
At first I thought it was normal carrier beat, but it's the EXACT same on every frequency, like a pitch pipe.
It's down low, maybe 5 percent, but it ain't on the control radios. It may BE a beat freq, if there is something in the
DSP has an affinity for putting that note at advantage, perhaps to extend frequency low end as is done in port tuning of speakers.
As I'm listening, it's becoming clear there is something really wrong in the "release" timing of the AGC.
Removing my compression on transmit and lowerering mod to "adequate" minimizes the defect.
It can't seem to deal with positive-going swing. That sets it a pumpin'.
I don't care for any of tone presets much, but I leave it on ROCK.
There is a nice one called "NORMAL" where the letters NOR are positioned over MAL inside a nice SQUARE box.
Very nice touch.
It's like finding clues in code.For regular reception it's very hard of hearing, as I mentioned above. WSB, WSM which could be copied easily on the
'62 Mopar radio, 1982 Sony tabletop and Sangean 803 were barely detectable on the Accurian, despite best loop positioning.
Even mid-level signals of what I think of as Chicago stations were too weak to listen to.
The radio was begging me to open it up and see who had fiddled with the IF trimmers.
The big locals sound bad, since their strength shuts the bandwidth down to narrow.
WLS sound great though, because it's I little farther away for me than the others and the weaker signal opens it up.
But even as I listen to WLS in analog, I hear the bandwidth opening and closing.
Copying WCBS 880 here in the basement by turning the loop....the "oooooooooommmmmmmm" is almost as loud as WCBS.
Nothing else going downward until 780 WBBM in iboc, The Accurian hides the giant hissing sound on adjacent frequencies, offering
instead a dull low rasp. The HD AM codec is less troubling on busy music than it is on voice.
On voice, everyone has the smearing rasp on the crisp information in their vocals.
There's nowhere to hide it on voice.
WHAT'S THIS! on AM 670 WSCR we hear the Dan Patrick show, where the decoded AM HD has the exact SAME sound
as good old fashioned FM multipath hiss! After listening a while, this is not only local content, only the Dan Patrick show network.
WSM barely detectable under the ooooooommmmm.
Not much I can think of now....the display hasn't freaked out any tonight as it did last night, when
AM1620 changed into Z?TX.
Should I make some recordings of this? It's pretty like a car wreck.