Lightning Affecting AM HD Radio IBOC signal - KLIF AM 570 DFW area

Sony XDR-F1HD AM/FM Digital receiver connected to a Heathkit AR1500A amplifier, Sony is tuned to AM 570 kHz and shows the affect a thunderstorm over 3 counties to the east (and well away from the DFW area) has on an AM HD Radio signal.

The lightning discharges were able to knock KLIF AM 570's IBOC HD Radio digital bit stream down to the point that the Sony XDR-F1HD lost it and reverted to lower-quality analog twice in minute.

It should be noted that the Sony XDR-F1HD receiver has an unneccessarily narrow IF (Intermediate Filter) severly limiting the audio reponse when tuned to and receivcing a straight AM signal or when it 'reverts' to analog from Digital when the Digital is interfered with.

References:

http://www.rbr.com/features/viewpoints/12024.html

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Category:

Science & Technology

Tags:

• HD Radio
• AM IBOC
• IBOC
• Ibiquity
• DFW area
• Dallas radio market
• Lightning interference
• AM Broadcast
• XDR-F1HD
• Sony
• HD

[harleykman]

The folks over at AVS (audio-video science) Forum claim Sony's radio has the best sound

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I'm surprised to hear you criticizing it, unless they just meant the Sony had the best FM sound

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[uploadJ]

@harleykman

I think you missed the entire point; AM IBOC is not suitable as a broadcast medium on account of the effects even mild thunderstorm activity can have on it (AM HD or "IBOC").

Thanks for your comment.

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[Cringle84]

It does not show the transmitter location, Due to AM transmitters needing a generous amount of real estate for their huge antennas and the regulations on radiation near residential areas, transmitters are usually situated on the outskirts of town. so the transmitter can be anywhere on that map. but mind you, it is still not good for those dropouts. Leave AM analogue and bring back C-QUAM with noise blanking, and wheel out DAB+ like here in Australia.

[uploadJ]

@Cringle84 -

The location of KLIF is well-known to those in the broadcast industry and to many hobbyists as well; for the record, KLIF transmitter facilities are near the 'DFW" indicated on the map early in the video and as such only about 15 miles from the receiver location, 'X', in this video. The storm, by contrast, is quite a ways of to the northeast, yet affects AM IBOC quite severely.

BTW, Thanks for joining the discussion. I agree, dump IBOC and bring back C-QUAM.

[spunker88]

@Cringle84 The transmitter is actually to the northwest of Dallas, right above where it says DFW. So the storm is totally out of the path to the transmitter. The coordinates for any transmitter can be found on the FCC's website.

[uploadJ]

@spunker88

And your point is???

(I am well within the 'class A' coverage area of KLIF, yet, a T-storm some distance away is able to render AM IBOC unusable. How viable is this technology really? That is what this quick video aims to demonstrate ...)

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[djEvilDude]

And that's AM?

It sounds pretty damn clear to me, so as long as the AM station is HD it'll sound like that?

[Cringle84]

@uploadJ I have a C-Quam receiver, a Sherwood TD130SB, When I diagnosed it and did repairs to it for a faulty controller tuner chip, I noticed a strange chip next to the C-Quam chip on the decoder board which turned out to be a "noise blanker chip" it being a simple gatering chip. The performance was quite good, lightning strikes although audible was not very loud, and 50Hz hash from electrics was absent. Using a pirate transmitter I managed to achieve near CD quality sound.

[marc1178]

It also shows the difference between the sound of AM and Digital. If the HD would recover MUCH more quickly than that, it would be too bad.

[Madness832]

I remember reading somewhere that the backlight is stuck on (even when switched off) & it loses all programming if power is interrupted.