• 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

DXing with the Boston Acoustics HD radio

A

autopaint-1

Guest
I have a B.A. HD radio and in many ways it is the most interesting radio for DXing I've ever used. I live near NYC. I've connected a Radio Shack loop to it and between 6:30 AM and 8 Am this morning, here is a list of stations I've heard.

550 WGR - Buffalo
580 WHP - Harrisburg
630 WPRO - Providence
640 WHLO - Akron
680 WRKO - Boston (Received in full daylight in NY)
700 WLW - Cincinnati (Received at 7:45 full daylight in NY)
780 WBBM - Chicago (received in fulll daylight NY)
830 WEEU - Redding PA (Local 820 WNYC had their IBOC running at the same time)
890 WLS - Chicago (Full daylight NY)
890 WKNV - Fairlawn Va (Received at 8 AM local full daylight)
940 WKGM - Smithfield Va
960 WEAV - Plattsburgh, NY
1040 WJTB - North Ridgeville Ohio (presunrise - Also heard re-seunset at 2500 watts)
1120 KMOZ - St Louis, 7:50 AM Local full daylight NY)
1200 WCHB - Taylor Michigan
1260 WWRC - D.C.
1470 WJDY - Salisbury, Md. (6:40 AM Pre sunrise 43 watts)
1630 WRDW - Augusta Ga
1700 WEUP - Hunstville Ala.

The point of this list is that in NYC where we have many 50 KW radio stations I was able to listen DX the AM Broadcast band even after the IBOC exciters where turned on with this radio. The same can not be said for other radios I've used.
 
Astonishing given that the Boston Acoustics MUST have a wide bandwidth IF to accomodate the IBOC envelope. I would have expected that many of the first adjacents would be covered by splatter from the analog channel coming into the wide bandwidth IF, let alone the digital sidebands.

Could you post some MP3's? I am sure there are a lot of sceptics on here!
 
> Astonishing given that the Boston Acoustics MUST have a wide
> bandwidth IF to accomodate the IBOC envelope. I would have
> expected that many of the first adjacents would be covered
> by splatter from the analog channel coming into the wide
> bandwidth IF, let alone the digital sidebands.
>
> Could you post some MP3's? I am sure there are a lot of
> sceptics on here!
>

Enough talk...WHERE DO I GET ONE????????? :) HD AND the ability to DX? Sign me up!
 
> > Astonishing given that the Boston Acoustics MUST have a wide
> > bandwidth IF to accomodate the IBOC envelope. I would have
> > expected that many of the first adjacents would be covered
> > by splatter from the analog channel coming into the wide
> > bandwidth IF, let alone the digital sidebands.
> > Could you post some MP3's? I am sure there are a lot of
> > sceptics on here!
>
> Enough talk...WHERE DO I GET ONE????????? :) HD AND the
> ability to DX? Sign me up!

There's a link in December Radio News:
http://www.univox.com/radio/2005december.html#2

(Not in the Gifts For Radio Geeks section, but
a little further down, in section 2, just below
Joyce Kaufmam.)

If you buy one through my site, you help
support the South Florida Radio Pages.

Now that the price is going down, I may
think about one myself.

73s from 954 -- DXer since 1965
 
If there is space to store an MP3 here I'll get the recorder out and put something together. I was shocked at the results myself. I can only imagine that the skirt selectivity is very tight. In other words it might go out to 10 Khz bandwidth but if the skirt is nearly 180 degrees, dropping 40 or more DB outside of the 10 K bandwidth, then you'll in effect have great selectivity. I'll do some recording and if they'll allow it put up some MP3's.
 
> If there is space to store an MP3 here I'll get the recorder
> out and put something together. I was shocked at the results
> myself. I can only imagine that the skirt selectivity is
> very tight. In other words it might go out to 10 Khz
> bandwidth but if the skirt is nearly 180 degrees, dropping
> 40 or more DB outside of the 10 K bandwidth, then you'll in
> effect have great selectivity. I'll do some recording and if
> they'll allow it put up some MP3's.
>
Upload to www.yousendit.com and post the links they give after its done uploading. That's what most people around here (especially on the aircheck board) do for MP3s.

<P ID="signature">______________

</P>
 
.
> >
> Upload to www.yousendit.com and post the links they give
> after its done uploading. That's what most people around
> here (especially on the aircheck board) do for MP3s.
>
Thanks, I'll do it in the next few days hopefully.
 
> Now was this ANALOG or were you getting the HD?
>
> Powell
>

Yes, to hell with the analogue stations!
Show us a list of the HD signals you were able to hear.<P ID="signature">______________
Proud 2 B a pioneering satellite radio subs¢riber
Ai4i is always on the trailing edge of technology
______________</P>
 
> > Now was this ANALOG or were you getting the HD?
> >
> > Powell
> >
>
> Yes, to hell with the analogue stations!
> Show us a list of the HD signals you were able to hear.
>
Those were analog stations. In NY I can hear WOR, WNYC & WADO in HD. Stations outside of the NY area have illuminated the HD light but as of this time no fringe stations have been received in HD. When the weather improves maybe I'll put up a long wire and see what I can receive in HD. The point of my findings is to point out that the claim that HD causes interference to second and third adjacent is bogus. I have tape that I recorded and once I have concerted it to MP3 I will post the examples. On my analogue receivers it would appear that WOR, 710 interferes with fringe WADS 690 at my location 25 miles north of Manhattan. On the B.A. receiver there isn't a hint of "splash" from WOR on the low power 690. I also recorded the sound of WOR and WNYC switching from analogue to digital. The audio improvement is remarkable. On the FM dial, the following NY stations are operating in HD. WBGO, WFUV, WNYC FM, WPLJ, WQHT, WHTZ, WCBS FM, WNEW, WKTU, WWPR. WLTW. WQHT, WHTZ, WCBS FM, WNEW FM, WKTU, WWPR & WLTW are broadcasting seperate audio on their second HD channel stream. WFUV, and WNYC show a second channel but contain no audio. WBGO & WPLJ are not broadacsting a second data stream.
 
> point of my findings is to point out that the claim that HD
> causes interference to second and third adjacent is bogus.

> at my location 25 miles north of Manhattan. On the B.A.
> receiver there isn't a hint of "splash" from WOR on the low
> power 690. I also recorded the sound of WOR and WNYC

This is difficult to believe. Unless the B.A. offers some kind of lower-sideband only mode for analog reception. (I can get rid of the WLAC HD interference to WCKY-1530 by selecting upper sideband on my FT-1000MP, but I think we can reasonably assume the number of listeners using SSB-capable receivers is negligible!)

I can tell you that on a typical car radio, WCKD-1490 (Lebanon, TN) is *completely missing* in western Wilson Co. about 20 miles from the transmitter, and the HD QRM from 1510 is very noticable even at points within the Lebanon city limits. (less than five miles from the 1490 transmitter)
 
>
> This is difficult to believe. Unless the B.A. offers some
> kind of lower-sideband only mode for analog reception. (I
> can get rid of the WLAC HD interference to WCKY-1530 by
> selecting upper sideband on my FT-1000MP, but I think we can
> reasonably assume the number of listeners using SSB-capable
> receivers is negligible!)
>
>

Bob is right ...
I also have the Boston Acoustics radio and there is no "splash" from strong stations on adjacent frequencies, whether it's AM or FM, or whether the strong station in question is analog or HD ...
<P ID="signature">______________


New Jersey Radio Board moderator
</P>
 
> >
> > This is difficult to believe. Unless the B.A. offers some
>
> > kind of lower-sideband only mode for analog reception. (I
>
> > can get rid of the WLAC HD interference to WCKY-1530 by
> > selecting upper sideband on my FT-1000MP, but I think we
> can
> > reasonably assume the number of listeners using
> SSB-capable
> > receivers is negligible!)
> >
> >
>
> Bob is right ...
> I also have the Boston Acoustics radio and there is no
> "splash" from strong stations on adjacent frequencies,
> whether it's AM or FM, or whether the strong station in
> question is analog or HD ...
>
Thanks Jim, this afternoon I am goingt o attempt to post a link to audio samples which I recorded the other day. AM propagation has calmed somewhat however, I do have some examples to prove my points and you will be able to hear what the radiuo sounds like switching from analogue to digital modes.
 
2nd and 3rd adjacents

No IBOC splatter on 2nd adjacents? Maybe not on third, but making that claim on second is bovine excretion. Given that the IBOC response uses amplitude modulated components from 10 to 15 kHz - you are talking center frequency plus 15 kHz - into the bandwidth of second adjacent channel by definition:

High 1st adjacent is 10 kHz +/- 5, or 5 to 15 kHz (if the station has been "Littlejohned". The high second adjacent is 20 kHz +/- 5, or 15 kHz to 25 kHz. Now add in that high IBOC sideband going up to 15 kHz, which is the exact limit of the lower sideband of a second adjacent, and you would need a brick wall filter to get rid of the IBOC on the second adjacent. When is the last time you saw a "brick wall filter"? If you have one - I can sell it for you!

I have a number of excellent AM tuners, and can tell you that the splatter is definitely on 2nd adjacents. The ____ with trendy things like Boston Acoustics - I have a well maintained and aligned Hammarlund SP-600 JX, perhaps the best AM / Shortwave receiver ever made. Variable IF of 13, 8, and 3 kHz - as well as some crystal controlled narrower IF's. You would expect splatter on second and third with the wide setting, and you get it. But the shocker is splatter on the narrow setting as well - 2nd adjacent for sure, and I suspect some third. The nature of the third adjacent seems to be harmonics, probably that is much of the second as well.

I have been saying all along that the $5 radios that the majority of people use these days are wide band AM by design - not to give good fidelity, but to strip out all but one cheap AM ceramic filter in the IF. I have seen radio after radio with hellacious +/-30, even +/- 40 kHz IF bandwidths - look inside it is one IC, tuning cap, AM ferrite bar (small, one ceramic filter for AM, one for FM). Wideband - and self jamming with AM IBOC. Probably self jamming on FM as well. So even if Boston Acoustics somehow magically doesn't have 2nd adjacent jamming on AM, it is irrelevant because the vast majority of radios will. I even hear self jamming on narrow band AM radios like the GE Superadio 1 and 2. Because the IF can't roll off fast enough to keep the 5 to 10 kHz phase modulated sidebands out - and phase modulation does no good whatsover if the response in the radio's IF is not perfectly symmetrical (when is the last time you saw THAT?)
 
Re: 2nd and 3rd adjacents

> No IBOC splatter on 2nd adjacents? Maybe not on third, but
> making that claim on second is bovine excretion. Given that
> the IBOC response uses amplitude modulated components from
> 10 to 15 kHz - you are talking center frequency plus 15 kHz
> - into the bandwidth of second adjacent channel by
> definition:
>
> High 1st adjacent is 10 kHz +/- 5, or 5 to 15 kHz (if the
> station has been "Littlejohned". The high second adjacent
> is 20 kHz +/- 5, or 15 kHz to 25 kHz. Now add in that high
> IBOC sideband going up to 15 kHz, which is the exact limit
> of the lower sideband of a second adjacent, and you would
> need a brick wall filter to get rid of the IBOC on the
> second adjacent. When is the last time you saw a "brick
> wall filter"? If you have one - I can sell it for you!
>
> I have a number of excellent AM tuners, and can tell you
> that the splatter is definitely on 2nd adjacents. The ____
> with trendy things like Boston Acoustics - I have a well
> maintained and aligned Hammarlund SP-600 JX, perhaps the
> best AM / Shortwave receiver ever made. Variable IF of 13,
> 8, and 3 kHz - as well as some crystal controlled narrower
> IF's. You would expect splatter on second and third with
> the wide setting, and you get it. But the shocker is
> splatter on the narrow setting as well - 2nd adjacent for
> sure, and I suspect some third. The nature of the third
> adjacent seems to be harmonics, probably that is much of the
> second as well.
>
> I have been saying all along that the $5 radios that the
> majority of people use these days are wide band AM by design
> - not to give good fidelity, but to strip out all but one
> cheap AM ceramic filter in the IF. I have seen radio after
> radio with hellacious +/-30, even +/- 40 kHz IF bandwidths -
> look inside it is one IC, tuning cap, AM ferrite bar (small,
> one ceramic filter for AM, one for FM). Wideband - and self
> jamming with AM IBOC. Probably self jamming on FM as well.
> So even if Boston Acoustics somehow magically doesn't have
> 2nd adjacent jamming on AM, it is irrelevant because the
> vast majority of radios will. I even hear self jamming on
> narrow band AM radios like the GE Superadio 1 and 2.
> Because the IF can't roll off fast enough to keep the 5 to
> 10 kHz phase modulated sidebands out - and phase modulation
> does no good whatsover if the response in the radio's IF is
> not perfectly symmetrical (when is the last time you saw
> THAT?)
>
Well, if I have the time later this evening or tomorrow, I will post some 2nd adjacent audio for you to ponder. Say what you will about what you obviously think you know but are not aware of. Have you looked at an IBOC signal on a spectrum analyzer? I've attended IBOC demonstrations given by Ibiquity and Harris at one of our local SBE meetings. I've seen it in the real world not some imaginary setting. By the way, the way they get 15 k response out of a limited bandwidth is through a compression scheme. You can't equate analogue technology with current digital codec schemes. I'm not alone in this by the way. Another user of a B.A receiver has come to the same conclusions.
 
Hi everyone:

> If there is space to store an MP3 here I'll get the recorder
> out and put something together. I was shocked at the results
> myself. I can only imagine that the skirt selectivity is
> very tight. In other words it might go out to 10 Khz
> bandwidth but if the skirt is nearly 180 degrees, dropping
> 40 or more DB outside of the 10 K bandwidth, then you'll in
> effect have great selectivity. I'll do some recording and if
> they'll allow it put up some MP3's.

Just store them somewhere and post links. Need space? Check out FreeWebTown @ http://www.freewebtown.com/ (They'll even STREAM the MP3s for you if you make a playlist out of it).

Hope this helps :)

Cheers :)

Pat
<P ID="signature">______________
patspodcast03a.jpg

http://patspodcast.blogspot.com/
Radio? Uhh.....What's THAT?? :)</P>
 
Hi everyone:

> > If there is space to store an MP3 here I'll get the
> recorder
> > out and put something together. I was shocked at the
> results
> > myself. I can only imagine that the skirt selectivity is
> > very tight. In other words it might go out to 10 Khz
> > bandwidth but if the skirt is nearly 180 degrees, dropping
>
> > 40 or more DB outside of the 10 K bandwidth, then you'll
> in
> > effect have great selectivity. I'll do some recording and
> if
> > they'll allow it put up some MP3's.
> >
> Upload to www.yousendit.com and post the links they give
> after its done uploading. That's what most people around
> here (especially on the aircheck board) do for MP3s.

As I just said, FreeWebTown is also good. They give you 2 GB worth of bandwidth AND disk space. Not only that, but they'll also STREAM the MP3s for you if you make a playlist out of them.

BTW...Wouldn't such recordings be considered HD airchecks? Just wonderin' :)

Cheers :)<P ID="signature">______________
patspodcast03a.jpg

http://patspodcast.blogspot.com/
Radio? Uhh.....What's THAT?? :)</P>
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom