DRM (Digital Radio Mondiale) in Asia - possibilities and facts

After being around for 10 years or more as a new technology DRM still remains a technology not viable for mass with many restrictions and failure over years. And most DRM promoter broadcasters are ether closing down or leaving Shortwave. Now we see DRM Consortium and their promoters trying hard to come back with support from some broadcasters in developing countries.

People think Digital short-wave broadcasts would be clearer and could carry bits of text too. The technology (known as DRM) has existed for years. But listeners will not buy pricey new radios without content, and broadcasters will not go digital without listeners.

Regarding the TWR Asia DRM test broadcast to Asia recently I wrote this letter to TWR Asia via their contact page - sadly since then they haven't replied my any further communication


Below is what I wrote to TWR when they tested DRM to Asia from Guam in May 2012, since then they havn't replied any of my mail!!! Did I offended them by my comments? never knew!

posted this via TWR.asia contact us page...

QUOTE

Broadcasting via DRM is useless, yes its just useless, when there is only 2-3 people has DRM receiver or DRM receiving capability in entire South Asia - yes about 1.5 Billion people and 3 Listeners - can't believe it right? Just check out how many (or how many people) reception reports you receive on DRM broadcasts from South Asia! And other listeners just listen nasty noise on the same frequency. DRM receiver - there is scarcity of DRM receiver in the market - now the cheapest one Chengdu Electronics DR111 costs about 120 USD plus freight (48 USD) + import duty - and in South Asia people normally buy a receiver within 25 USD. So no one is going to buy one DRM receiver in that price. And DRM listening via exsisting receivers modified or kits? forget it... those are no portable + hectic.

Sadly we here don't have any DRM capable receiver, and I haven't heard anyone has a DRM radio or setup within 1000 kilometers of my place. So sorry I can't listen on DRM, in my receiver its only noise I receive - nothing to hear.

As per an expert DRM only seems to be of use in Europe where there seems to be a plethora of broadcasts. And what is there has to be perfect or it is not decoded...sort of the shortwave version of digital TV which is a conspiracy amongst cable and satellite TV operators to get those of us in the hinterland to sign up with them.

Another expert quotes - I can't think of another technical project, that has been implemented as badly as DRM. It was tried to push along by force, totally forgetting that radio transmissions need LISTENERS and they need receivers for that and they were not available at the same time. Oh, now I remember another: DAB FM digitalisation in Northern Europe. Fortunately it was only a few transmitters.

And some Radio hobbiest also opines as DRM on SW was a retirement project by the few engineers!! And it haven't successful even after more than a decade!

Finally in the DRM we can not hear or decode a signal below S4 or S3, in Analogue we can even listen to more worse signals. So it is up to you that what you chose - a medium that is up to date but do not reach mass or an old reliable method to reach more people.

UNQUOTE

Reading my letter an experienced SWL & DXer commented as follows

"
When television first came out it was experimental with only a few sets capable of receiving the signals but the networks and industry ensured there would be a demand and they filled that need. Every other advance in entertainment has a similar track record from FM radio through CD players to Ipods. DRM took the opposite route of the cart before the horse and it failed miserably. If TWR was offended it's too bad they took your criticisms the wrong way as you did not attack them, or their programming, but a technology that was badly implemented.
"

In reply I also explained as "Yes I always mean that even with single frequency or lowest power station's first priority should be to reach the mass, but DRM offends the basic requirement, but even my statement may sound that I am against DRM - but that's because no sub-band implementation and causing interruptions to analogue broadcasts"

and then a longtime broadcaster and media analyst opined as follows - "Do not assume that the lack of a personal reply means that they have not read your letter. At RNW, every letter and email was read, but there simply wasn't time to reply to them individually. During times of financial restraint, cuts have to me made in areas that are least harmful to programming. One of these is dealing with listener mail. No broadcaster is going to be offended by negative comments about DRM. Some broadcasters still have DRM tests for the purpose of training engineers how to use it. Then, if it ever does become viable - which I admit is extremely unlikely - they will be ready for it."

I replied - Yes, I am sure they read it, actually I saw after that they issued few QSL/e-QSLs where the listener sent reports via there reception report form. Unlike hardliners I am happy with e-confirmations or merely an email, so when others get some for of reply I expected my other 2 reports and a communication may get some email reply, But I agree to your point, & should add your reply is informative too. And regarding RNW,  RCI and NHK the experience was exemplary always - I was always confident that my letter was read and somehow taken into consideration.

To be continued: In future posts we will see review of Stand Alone DRM receiver(s) and DRM as a technology and implementation with facts and figures...

The Degen 1103 modified for DRM

Originally Written by:
Name: Giampiero Bernardini
Location: Milan, Italy

Continuing the experiments on the small but enthusiastic (and inexpensive) Degen DE1103 purchased on eBay. Daniele Giusti, Lodi's list FMDXItaly linked a portable media card to convert the Intermediate frequency from 455 kHz to 12 kHz. The card is produced by Crispino Messina, I5XWW , The output thus obtained can be brought to the computer's sound card (via the in-line or microphone) and demodulated with a proper application. In case we used Dream . Dream allows you to decode DRM broadcasts.

But not only DRM, it can be used to demodulate the signals received in Am, USB, LSB and CW
using a variable filter as you like and then get a much better reception than the receiver used in the traditional way.

Of course to make the demodulation you can use other programs, which are available mostly free downloadable from the Internet. Just noticed something wrong with the fact that the Degen is not shielded. The connection cable (preferably made with coaxial cable) between the degenerate and the conversion board 455/12 should move as far away as possible from the attack by the ferrite antenna and stylus. All information, with the pictures of the modification, can be found on the site FMDX Italy .

More information about changes to portable receivers for DRM can be found on the German site (in German) www.funkerberg.de , segnalatomi by Andrea Borgnino, whose website is certainly visited.

DRM on the Degen 1103

Originally written by fmdxITALY, all rights goes to them. We are giving a English version for your help.

This argument is a bit 'off topic, but since the group moving more than 70 Degen 1103 here are some notes on the evidence of change (by attaching a small card) to receive the DRM.
Daniele Giusti has installed a card that makes a conversion from 450 kHz to 12 kHz. The card works fine, unfortunately there is little space in the receiver and interface interference, but the results are exciting. Anyway here's how he made the change Daniele.

Here, illustrated by some pictures, how to proceed:
after the connections tab

it takes the signal to 450 kHz within the Degen 1103 (but the same thing can be done in any conversion receiver with a 450 or 455 kHz)

In this case, the point at which the signal is a "jumper" located near the ferrite antenna (this "closeness" Unfortunately, because of interference compromising the final results). In the picture we see him first with the radio reception,

then closer

Finally, even with the cable soldered. The jumper can also be extracted to make peace with the welding


Then the mass is also connected

.
To release the cable from the receiver does not need to drill holes in the chassis: you can get him out of the hole for short rope canvas that serves to challenge the receiver.

The radio signal is taken from the card that converts it from 450 to 12 kHz. With another cable sends the signal to 132 kHz audio input of the PC.

On the computer, through the DREAM program (supplied on CD with the card), proceeds to decode the digital signal

Here are the views of Dream, which displays the stations received from Daniel.

Here are the first experiences of Daniel:
Unfortunately, there is a small problem in the audio converted and sent to the headset, there is always a "noise" background, that along with the music or the decoded speech, you also feel the 12 kHz signal that "passes" through the circuit of the computer.
I also heard perfectly only 3995 kHz radio Deutsche Welle, while the other three issuers have decoded so bad you can only photograph the logo, almost without having to understand audio.
This means that this ticket requires an input digital signal very strong and clean, is also often necessary to act on the trimmer that controls the width of the input signal (the receiver's volume to 0 and then go left or acts mechanically on the trimmer, or on the level of the audio mixer of Windows) to avoid distortion or loss of "packets".
In the coming days I will try again to receive the DRM, trying to clean up the audio from the digital noise in the background.
Still on the subject of the photos, please do not post them because I took the exclusive list FMDX, so that if someone would Fabrizio decided to publish the exclusive (I know, is a detail, but somehow we have to reward F. work for us!).

In case any of you interested in more information or to buy the converter card (which costs a few €), you may contact e.mail address Fabrizio staff.

To reduce noise

Crispino Messina, designer of the card, sent some notes to reduce noise. In fact the main problem is the shielding of the receiver (because it's cheap) and the ferrite antenna connection near by.
To pick up less noise, the connection to the converter must be as short as possible, made with two loose wires or even a small piece of coaxial cable, which is central to the hot side withdrawal from the radio and goes to the sock mass nearby, inside the radio, where the signal is taken to indicate I do not know what these points because I never added the converter to a radio or another Degen. so I just theoretical information considering that there are these problems, the drive will put the opposite side to where there is the antenna input on your receiver or even away from the antenna in radio's internal ferrite, because even if it does not work , it may pick up some 'unwanted radio frequency the radio will be operated initially with internal batteries. The converter will, at least initially, be operated with a 9 volt battery, which will be connected to appropriate pins on the card drive on the computer too, if laptop will run on its batteries if there is a switching power supply, will be the case to unplug from the network, in addition to not let him feed the computer a general rule: the links longer than is strictly necessary should be made with shielded cable, although they may pick the same disorder neon lamps, switching power supplies and other gadgets that pollute at the level of radio frequency output of the converter must be made with coaxial cable to the microphone input or line-in computer microphone input is mono and will generally use a mono input jack is stereo line-in and connections with the cable will be made: the mass of the shield of the cable jack stereo, central wire of the cable to both the tabs on the left and right channels of the same stereo jack on the trimmer drive is put in a central position or at least set in place medium-high (clockwise) then you must act on the commands of the Windows mixer to get an adequate signal level for the Dream program can be developed if the adjustments made are not sufficient you can try to change the input on your sound card (which take into account the mic input is more sensitive than the line-in and therefore requires less signal) in extreme cases you can also try to adjust the trimmer on its lowest values ​​(setting counterclockwise), but it is counterproductive: the ' input impedance change much, it becomes low and the circuits of the radio can be loaded too. So the radio does not go out enough signal to the drive and even other circuits of the radio no longer work correctly

Created: 30/12/2006 - 17:08
Last updated: 06/05/2007 - 11:25
Category: DRM