Noise in KINK's Audio Chain

This topic contains 39 replies, has 13 voices, and was last updated by  cbaravelli 1 year ago.

Viewing 15 posts - 16 through 30 (of 40 total)
  • Author
    Posts
  • #36028

    Andy Brown
    Participant

    First, audio frequency anomalies do not, repeat, do not necessarily come from the program audio chain. Any two signals that are close in frequency can result in an audio band difference. E.g., any two adjacent A.M. stations can beat resulting in a 10 kHz. whistle. On F.M. with IBOC digital, there are lots of possible components within the analog plus digital envelope that could be the culprit, well downstream of a “program audio” anomaly. Unless you hear this problem within the audio feed before it goes into the R.F. chain, there is likely no cause in the program audio chain itself.

    Second, hijacking the thread into a who’s who of what bands you don’t like is sophomoric. Clearly the original poster wasn’t intending to solicit all these posts which have zero value to the topic.

    “Bad cap. My guess in the band stop filter by-pass circuit. Hard to component trouble shoot (if anyone still can).”

    Since many filtering operations are now cooked right into ICs aka ’embedded component technology,’ there really can’t be much TSCL. Only the filters that have to deal with intermediate and high level RF power use individual components. Manufacturers don’t even want anyone trying to replace a suspect IC on one of those multi layer boards. Board swapping began in the 1980’s and completely took over and really began to dominate when switching power supplies took over, as most commonly seen in personal computers but also in other consumer, industrial and broadcast electronics.

    #36034

    Mixmasterdmc
    Participant

    Is it possibe the OP is talking about cranked up PPM encoding? Being in Bend, I can’t tune in to Kink right now, but I know that when we drive to Portland and listen to Live 95.5, it sounds super horrible and very metallic sounding. Of course if this is a constant noise or squeeling, the PPM encoder is probably not the issue.

    #36035

    nosignalallnoise
    Participant

    Second, hijacking the thread into a who’s who of what bands you don’t like is sophomoric. Clearly the original poster wasn’t intending to solicit all these posts which have zero value to the topic.

    No, it is not “hijacking” or “sophomoric” or any other cheap shot you want to take at it. Side topics happen all the time in forum and bulletin board threads and have for probably the entire history of the technology. That’s the nature of it. Doesn’t make it “bad” or “wrong”. I’m sorry if it personally “offends” you.

    #36037

    cbaravelli
    Spectator

    Don’t sound like IBOC hash. KINK-FM shares tower space with five other broadcast FM sources and all run separate co-axial cables.
    Could be a DAC circuit after STL demod or further upstream. Near all audio by-pass capacitors are .XXmfd and physically too large to integrate into a VLSI chip. Use a finger or a can of freeze spray.
    Don’t want to rank on a brother engineer, but he’s more of a studio and remote guy.

    #36043

    Notalent
    Participant

    You might be hearing the Voltair, It is an audio watermarking device which inserts station data for ratings purposes into the audio.

    The latest trend is to increase the level of the watermark so the PPM’s can “hear” it better.

    The side effect is mid to high frequency distortion. Especially noticeable on AM’s playing music.

    • This reply was modified 1 year ago by  Notalent.
    #36045

    jr_tech
    Participant

    “KINK-FM shares tower space with five other broadcast FM sources and all run separate co-axial cables.”

    Are you indicating that they no longer share the “master antenna” through the combiner on the mezzanine at the east end of the transmitter suite?

    #36046

    Alfredo_T
    Participant

    The audio artifacts that I have heard on the Alpha stations definitely do NOT sound like something that could be produced by an analog component. Hearing these artifacts on all the stations is another important clue.

    #36050

    Andy Brown
    Participant

    “I’m sorry if it personally “offends” you.”

    No apology necessary. I am not offended. It wasn’t your post that ‘hijacked’ the thread, it was that your post opened the door for others whom have no clue about what the OP is about to chime in similarly. You know the difference between volts and amps, and can make a worthwhile contribution at some point in the thread if you want to. dork on the other hand, made 3 useless posts that derailed the thread, causing MOD to even chime in as if dork’s hijack was what the thread is about. Sure, over on the other side of the board that is commonplace but if someone (dork) wants to talk about bad music, start a thread. He will soon see (in most cases) that such discussions get moved to the politics and other things side of the board and rightfully so. dork is pretty much known for making worthless posts but in a thread like this one, IMO, they don’t have any merit beyond a one post joke. dork, like others that have come through here and been banished, abuses the lack of moderation. On the politics side I couldn’t care but on this side, I will speak out. I should have been clearer, it was never about your one post joke.

    #36051

    Andy Brown
    Participant

    Here’s a follow up about PPM / Voltair encoding causing audible problems. After rereading all the relevant posts in the thread, and doing some research, it appears that MixmasterDMC and Notalent are probably correct.

    http://www.radioinsights.com/2016/04/nielsen-ppm-making-radio-unlistenable.html

    #36057

    nosignalallnoise
    Participant

    So I’m a bit confused by that audio sample on the page you linked to, since I don’t listen to terrestrial radio so I wouldn’t know what the encoding sounds like. Is the PPM encoding the loud shrill buzzing noise or the alternating beeps that sound like extremely low-speed (~0.5 baud?) FSK in the background?

    From the filename I’m guessing that the PPM must be the beeps that they buried in some white noise then bandpass filtered the noise to 3 kHz to make the sample, and the metallic buzzing must be the filtered noise. Right/wrong?

    #36067

    cbaravelli
    Spectator

    “Are you indicating that they no longer share the “master antenna” through the combiner on the mezzanine at the east end of the transmitter suite?” – jr tech

    You may be referring to the ‘KGON’ Stonehenge Tower with its Stairway [ladder] to Heaven. Cost considerations for Entercom/CBS and subsequent FM broadcasters to use combiner / diplexer technologies. Other radio services use co-axial run inside the chase. But, I don’t think there is room for another ‘pull’ inside.
    https://people.well.com/user/dmsml/stonehenge/
    Sylvan Tower facility south of SW Barnes ‘Cemetery’ RD. has two towers and the KUFO-AM antenna. There are two combining multiplexers inside the main ‘shack’. One for broadcast television (KOIN-DT, KATU-DT & KRCW-DT) and the other for Cellular (Verizon, T-Mobile, AT&T and Sprint). Alpha Media (KXL-FM & KINK-FM) is also there as are other radio services. Alpha Media ‘tray’ was co-axial. Have not been inside the other cellular / public service radio shack.
    Recall KINK-FM was at the KGW-DT / KOPB-DT site until 2010. Thermionic valve transmitter was replaced by a solid state with a Class D final. I like the station’s old tube sound better.

    #36069

    jr_tech
    Participant

    “You may be referring to the ‘KGON’ Stonehenge Tower with its Stairway [ladder] to Heaven.”

    No, I am referring to the installation in the room across the central hall north of the waveguide TV combiner in the new building at the Sylvan site. This is where the former CBS owned FMs (including KINK) and FM combiner reside. To save floor space, the combiner was installed on an elevated platform, above the support equipment for the transmitters.

    #36109

    cbaravelli
    Spectator

    Was told by someone who should know that box is two big FM band notch custom cavity filters. Nextstar insisted to protect KOIN-TV then on-air VHF Channel 6. Saw two Commscope cables go in and two cables go out. But, you could be right.
    Alpha Media PDX does use Telos Voltair ‘watermarking’ audio processing but not on all properties. It works. Arbitron then Nielsen Portable People Meter CBET has issues. So does Voltair.
    Voltair 2.0+ mimics Neilsen enhanced CBET. Short 1000 Hz Frequency Shift Key data bursts at least four times in one minute. Audio levels are selectable depending on expected listening environments (automobile, home, gym, outdoors). and program content.
    “Barking spiders” can be heard on KWEE-FM. Newstalk formats are also susceptible. Bonneville SEA KIRO-FM uses a low almost imperceptible repeating music track to mask CBET code data bursts.
    Diaries with a five or ten dollar bill tucked inside are still better than PPM radios, period.

    #36111

    jr_tech
    Participant

    Different time frame… the combiner installation that I described above was installed after the analog TV shutdown, both the old RCA ch6 transmitter in the old building (off and gutted early 2005) and the new Harris ch 6 transmitter in the new building, which ran till the end of the analog era. The FMs were among the last to occupy the new building before the old building and old towers were demolished several years ago.

    Whatever, I don’t think the noise heard is IBOC interference due to shared transmission line/antenna.

    #36113

    cbaravelli
    Spectator

    By golly, yer right!
    Had to make another phone call. KXL, KINK and KUPL [KUFO] all share the same antenna from top to bottom. KLTH (the big one), KXJM, KBVM, other lower power broadcast FM and translators as well as a bunch of cellulars are on site.
    This asks the question: Is the intermittent ‘chinese chain saw’ noise on KINK cross / over modulation from KXL or KUPL (more likely), or from the often feared but rarely understood Inter-Carrier Phase Modulation interference which plagues my industry?
    It is Spring sweeps.

Viewing 15 posts - 16 through 30 (of 40 total)

You must be logged in to reply to this topic.