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Got to be careful ----

R

rbrucecarter5

Guest
what I say about HD radio on here! I might be getting a job related to HD. Maybe I can do some good at designing advanced antenna systems to solve the dropout problems. Nobody has done much new in AM or FM antennas in quite a while. There are a lot of new tricks!

If I don't hear from those folks in a few days, they probably don't want me - so I'll be back to my same old iconclastic self.

Actually, I've done them a lot of research already - 70 mile reception with a dipole isn't bad, and the Godar antenna might extend that a bit. AM is problematic no matter what, but I've advocated re-allocation of the band for years to help alleviate the problem and give HD AM a chance. Give HD the part of the band from 1200 to 1500, you limit daytime scattering for the most part, and leave the rest of the band untouched. 30 kHz channel spacing from 1200 to 1500, no protection outside of COL, lots of power. Or use the almost completely wasted longwave band for AM HD. Make it all digital - give current owners a concurrent license like they did for the expanded band, and the option to abadom AM for LW completely, or vice versa, after enough years to allow HD radio to shake out in the marketplace. People need new radios for HD anyway - time to intelligently re-allocate spectrum like LW or channels 5 and 6.

The only problem with HD radio is first adjacent (and second adjacent on AM) interference. Solve that, and there is no opposition. And it would go a long way to solve the coverage problems, at least on AM. Combine that with advanced antenna technologies on FM, it is probably a workable system.

Will consumers ever buy it? Not without coersion - like HD has to be included on all radios over $50. When people hear it, most people like it. It has quality problems on AM especially, but the iPod generation doesn't care. The FCC used coersion on teletext for the deaf - why not for HD?

There - that is cutting some slack for the HD folks. As much as I can!
 
"....Or use the almost completely wasted longwave band for AM HD..."
Is there a Chinaman's chance in hell we could get 10 channels re-purposed for AM from 1700 to 1800? If we could it would be a acceptable place to do local AM HD that would work a lot better. I still think the 5 and 6 idea would be best, but if we can't get that, at least 1700-1800 could be used for pure iBuz in straight digital mode. One real positive thing about going that direction is that current HD-AM stations could probably buy some combining components and tell their current main HD transmitters to go all digital on the new channel. If they had a backup rig it could spit out the AM signal. The costs associated with the change could be not that bad really.
 
I would think that even a D-A could be lit up with digital on one tower while the rest of the array was pumping out a directional pattern on the main analog channel. I think several stations are doing things like this with combining sites so the technology it out there to do it right now.
 
Good Luck!! Hope you can get in and fix it!
 
I think you'd find that propagation characteristics at 1700 - 1800 kHz would be problematic. You're getting into shortwave territory there and skywave night interference could stomp on local digital detection causing receiver muting. The only way I would theorize this working would be if a very limited number of stations were allocated with, as you prescribe, 30 kHz spacing. And they would have to be almost TRUE "clear channel" high power stations - one to a frequency, like the original 1930s plan, or at the least highly separated (like co-channel in Boston and Spokane, for example.)

There would have to be careful antenna design at those frequencies. Local groundwave isn't so efficient up there, at least compared with the skywave, which would be one giant honkin' signal.
 
OKCRadioGuy said:
"....Or use the almost completely wasted longwave band for AM HD..."
Is there a Chinaman's chance in hell we could get 10 channels re-purposed for AM from 1700 to 1800? If we could it would be a acceptable place to do local AM HD that would work a lot better. I still think the 5 and 6 idea would be best, but if we can't get that, at least 1700-1800 could be used for pure iBuz in straight digital mode. One real positive thing about going that direction is that current HD-AM stations could probably buy some combining components and tell their current main HD transmitters to go all digital on the new channel. If they had a backup rig it could spit out the AM signal. The costs associated with the change could be not that bad really.
Click to expand...

How about 1700-1770, we don't want no hissing, whooshin' and a-buzzin' on the bottom of the 160M ham band. It would be worse than BPL.
 
HDmeltdown said:
The FCC has only limited jurisdiction over equipment manufacturers
Click to expand...

The FCC could use the All Channel Receiver Act of 1962 to require it. They've done it before.

Just five years ago, the FCC mandated that TV manufacturers begin installing digital receivers, approved by the DC Court of Appeals.
 
Rbrucecarter--

Coupla things I see wrong with your proposals:

Cramming all the mediumwave IBAC broadcasts into the upper part of the band and keeping analogue transmissions below 1190, while I imagine could potentially be pulled off easily here in the western US, would be a nightmare in parts of the area where the band is already overcrowded, like the East Coast. (Ever tried to DX mediumwave while in Philly? Not fun, as I found out the hard way in 1997.....)

And with longwave, what you have there is not so much broadcast crowding (obviously) but rather navigational radio-beacons used by airports. I'm not too certain the FAA would be too hot about IBACing what to some pilots may still be seen as a vital service. (But then again, you never know; they might not even care.) And of course, you have the perceived potential for health problems associated with living near a sufficiently powerful, lower-frequency LW transmitter tower..........

........although I bet if it's powerful enough, night-time IBAC DXing on longwave would be KILLER because of the band's propagation characteristics.

(And with that you'd have potential interference to brodcasts in Europe and possibly Asia, assuming any of those nations are still broadcasting on LW [*coughcough*Beebeecee*HACKcough*] but I'm not getting into that now. No sense for the FCC to provoke international conflict because they want to push DAB in the USA, I think. But then again, given what we've seen happen within the last eight years already, it might just end up being par for the course.................... ;o)

Don't get me wrong, I wouldn't completely be against putting IBAC on longwave. In fact if it came to be, I might consider buying a compatible receiver specifically for DXing that band. Just *cautious*.
 
There are still Broadcast stations in Europe on longwave which are logged here on the E coast quite often as well as the beacons which are quite numerous. There is also an experimental CW ham band between 506 and 509, I know it's actually above LW but still there is a lot of stuff down there.
 
MotoMuzak said:
And with longwave, what you have there is not so much broadcast crowding (obviously) but rather navigational radio-beacons used by airports. I'm not too certain the FAA would be too hot about IBACing what to some pilots may still be seen as a vital service.
Click to expand...

I had assumed that those beacon signals were anachronisms in the age of GPS. And they would be pretty much useless if there is a thunderstorm anywhere in the area.
 
As a general-aviation pilot I can assure everyone that the NAV beacon functions are built into the avionics in every plane and are routinely relied upon in IFR and even VFR navigation. You can choose the NAV beacon or key your autopilot to a MW broadcast station (like mine when it's not being obliterated by WBZ-HD.) Thunderstorms or no the system works fine. And you shouldn't be flying around thunderstorms anyway unless you're a commercial pilot flying a 737 or something.

Sure, there's GPS, but actually I think the NAV LW beacons are more robust. They're no fuss-no muss. Just check the airport charts and dial in the frequency and fly to it. We've been doing it for decades. It works fine.
 
The USofA needs to have working backup systems to GPS, for if/when the 'bad guys' strike us again, and if they are successful at "taking-out" both the Internet and GPS birds, it would cripple the USA if we don't have working backups, AKA, RADIO, for both navagation beacons and broadcasts for information.
It would be foolish to abolish old systems this day in age.
 
Savage said:
You can choose the NAV beacon or key your autopilot to a MW broadcast station
(like mine when it's not being obliterated by WBZ-HD.)
Click to expand...

Now that's a first-class skewering of the devil.

The devil in this case being the product and the entity using it.
 
JohnnyElectron said:
The USofA needs to have working backup systems to GPS, ... It would be foolish to abolish old systems this day in age.
Click to expand...

This debate boils down to what to do with the LORAN system. The options are: (1) Fully implement an upgrade called eLoran, (2) Maintain LORAN-C as is, or (3) Decommission it.

Google "eloran" for details.

- Jonathan


P.S. -- Loran broadcasts at 100 kHz with transmitters a few hundred miles apart, at powers in the 100's of kW.
 
Re: Got to be careful ---- well I ain't gonna get the job!

Kid gloves are back off. They didn't want just HD, they wanted other stuff as well. Sounds like the committment to HD is fading --- so much for my idea of three separate receive paths to defeat the gain / bandwidth product - one for the main analog signal, and one for each sideband. Easy on silicon ---
 
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