Seankw40 makes a strong case for sending a good analog signal, and except for the technical curiousity of digital, I love and prefer analog, and intend staying that way for my regular AM service.
YES, Sean is right that people will hope to find some analog IF and WHEN the dial goes DIG-A-Hole (digital). And there's something else...
Even now, when you can tune back and forth much of the time and find NOTHING worth listening to from the licensed place-holders, there is PLENTY of possibility that people will discover YOUR meezly-watt signal and actually kneel down and thank god for SOMETHING worthwhile.
We know what we're doing, even when we have doubts. Believe it!
I'm staying with AM analog if for no other reason than some little kid out there with a crystal radio needs it.
I grew up with crystal radios and would hate to think about all those broken hearted kids when analog disappears.
I'm slowly moving toward simulcasting DRM and analog. If my transmitter and software allow, I'm planning on simulcasting both digital and analog on a 20 kHz channel. The resulting broadcast could be considered as two separate broadcasts on adjacent 10 kHz channels, one DRM and one analog. I've informally reserved an unoccupied 30 kHz band of which 20 kHz would be used for this purpose. Does anyone forsee any legal problem with this plan?
525-1705 khz you are limited to 100mw input and a 3m meter antenna. that is all, beyond that you can use any modulation scheme your imagination can dream up as long as your input and antenna are legal and you are within the appropriate band limits for the rule part you are operating under. the same for the 1750m band
Of course "AM" is a modulation method, even though for us it also means "medium wave band."
DRM (Digital Radio Mondiale) is a digital encoding method of modulation.
Are any licensed U.S. medium wave stations broadcasting in DRM?
Are any medium wave receivers equipped to listen to DRM?
I know it is being used on shortwave by some stations.
Can it be done on the FM band?
Very useful info from WDCX about the state of DRM.
Also, to remind anyone, DRM is an "open source" digital transmission method, as oppossed to "HD" which requires big time royalty payments.
But, tpreitzel in Post#33 would help us better answer his complex question if he gave more details about what he is planning.
We can gather from what he says that tpreitzel is planning to try DRM on the medium wave band (10kHz spacing), but what method of imposing the DRM signal?
A single transmitter? Several transmitters on side-by-side frequencies?
What about a receiver?
All this talk about digital vs. analong, etc...
I don't recall seeing anyone post this information.
http://www.fcc.gov/document/commission-adopts-nprm-revitalize-am-broadcast-radio-service
Makes for a very interesting read, and for those of us who also work in commercial broadcast radio, it gives us some hope and some new worries.
On the opposite end of the spectrum, I've begun work at my "real" job doing pre-install work for a new 6000 Nautel AM broadcast transmitter that is replacing the stations 40 year old Harris MW-5. The Harris will become the new backup transmitter and I have dibs on the 1000 watt Collins that used to be the backup.
Tim in Bovey
Iron Range Country
Yes, indeed! Digital Part 15 is coming on the MW band to Billings, MT. I now have an AspiSys DRMAX-1 Part 15 transmitter. Unfortunately, I don't yet have a 24v DC power supply, but a cheap, switched 24v DC power supply has been ordered. The power consumption of the DRMAX-1 is ~ 9 watts. Maybe a reader can suggest a good quality 24v DC supply at a reasonable cost.
Since the DRMAX-1's RF output impedance is 50 ohm, I intend to marry the DRMAX-1 to Radio Systems' ATU for their I.AM. Radio transmitter. I don't really want to fiddle with the default settings of the DRMAX-1 since I don't have the necessary test equipment.
More later ...
Carl,
Yeah, I'm a year late and a dollar short ... what's new? Times are hard ... 😉
I'll be using a single ASPiSYS' DrMax-1 transmitter. At the time that I wrote my thoughts, I was planning on using two 10 kHz adjacent channels, but I don't think my software will allow that possibility yet.
Receivers are potentially infinite if one considers using the DReaM software at www.sf.net/projects/drm with a computer and a soundcard. Hopefully, a mobile device with a RTL-SDR running a new version of Android will soon be able to run DReaM so a listener doesn't have to carry a laptop in his car. 😉
Initially, I'll likely be using the Opus codec available in DReaM's transmitter so the listener will need to use the DReaM software with a computer as well. I just ordered a 24V DC regulated, linear power supply to power my DrMax-1. I'll start experimenting within a week or so.
I got too many transmitters AM or FM to have my good time ruined for me by the system going digital some day, maby the FCC will give me refund on my analog gear if that hapens you never know. Ill have to write a letter to the current adminstration im sure they will do this for me if I ask them. I still havent wore out my 8 tracks yet now they want to take my radios.
RadioJoe
Pry my cold dead fingers....
I was reading about how many people actually have "last words" that they want placed on their grave stone. These have always been analog.
Perhaps in the new age someone could etch hexagonal digital code on their monument.
With a weak signal the signal to noise ratio is lowered and the channel capacity (received bandwidth) is reduced. This tells us that one response to a weak signal is to narrow the bandwidth rather than just blanking the signal. This is one approach which can be investigated.
Good observation, but is the blanking threshold for useful reception of signals using digitally-modulated components largely dependent on the design/hardware of the receive system, for a given r-f field arriving at the receive antenna?
I'm not sure why anyone would swith to digital ?
ever listen to a modern cell phone ? Now compare it to the origanal anolag cell phone I used in the 90s .. Uhm Modern Phones sound like Poo and I am being nice.
Digital TV ? Oh that worked out great , no more SF stations in SC because they don't get out worth a poop anymore.
Digital Music ? give me a break already , My Marshall amps will make your Pods and Solid State Amps run away in fear of my tone.
Digital is weak and inferior period .. Ok back to my movie.