• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

HD Radio Interference in SW Michigan

A

audioguy

WAUS-FM (90.7) is the only classical station that reaches my area reliably. It is an outstanding station with great programming and a good sounding audio chain, and normally comes in well. But during the summer months when there is enhanced tropo propagation in the mornings, the HD sidebands from NPR station WKAR-FM (90.5) bury WAUS in hiss at my location. Normally WKAR is too weak to cause a problem, but whenever propagation is enhanced, reception of WAUS is impossible. Although WKAR interferes with WAUS, the reverse problem does not occur because WAUS does not broadcast in HD. I hope they never do, because they have one of the best sounding stations anywhere.

I have listened to many different classical stations worldwide on a variety of receivers, and I can honestly say that HD degrades the quality of the any station's sound. You get hiss in the background, or distortion on high frequencies, or both. Personally, I find the high frequency distortion much more objectionable than the hiss.
 
There may not be a lot you can do - unless you are willing to install a directional antenna (assuming they are coming from different directions and you haven't already installed one). Sideband interference with first adjacents is the main reason why some of us on this board object to HD-FM. If you are in a city, and stations are spaced 800 kHz, you don't usually have a first adjacent situation. But suburbs and rural areas do, and HD sidebands are limiting choices nationwide. The problem is so bad - the HD mafia obviously paid off or threatened off "digitaldisaster.org", which was the first web site to warn of the problem. Fortunately, there are web archiving services that retain information, even after it has been suppressed by sinister intentions:

http://web.archive.org/web/20040926102459/http://digitaldisaster.org/
 
Um, no conspiracy here. The guy who set up digitaldisaster.org had the domain point to an AOL Hometown build-yr-own website. When AOL discontinued it, Chris didn't migrate the content anywhere else, because he had his fingers in so many other pies (such as LPFM and public-access TV in his hometown).

He did, however, file some interesting comments with the FCC during the comment and reply-comment periods of 99-325.
 
I recently installed a new Pioneer car radio. Made a major improvement on 1st adjacent signal reception. You might try another radio?
 
The HD carriers are ON the adjacent channel. There's no way to get rid of that interference, regardless of the selectivity of the tuner.
 
With all due respect, I know what I hear. The radio has a different detector or something that makes it receive very well on 1st adjacents with an HD station. It seems to not detect the digital. This is only on FM. AM IBOC is a mess on all radios.
 
I found out the same thing; it appears that some of the makers of HD radios realized what HD crud could be thrown on the adjacents and I had an HD radio that actually had some sort of "HD Filter" in it that allowed me to receive 1st and 2nd adjacents again - but ONLY on the HD radio, but not on an analog tuner! No lie, they actually had some sort of an HD filter that filtered-out the HD junk just enough to allow you reception of your station again. It was a Directed Electronics tuner, and it also died an early death (2 years of use), thanks to lead-free solder and excessive heat generated by the unit.
 
I've noticed the same thing with my Tecsun PL-380. It certainly doesn't get rid of the HD interference, but it makes it easier to null out. Maybe just a better capture ratio? Or maybe the DSP detector is slightly more immune? I'm not sure what it is, but the phenomenon is definitely there.

The newer space-diversity car radios are better at rejecting HD interference too.

Dave B.
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.
Back
Top Bottom