All India Radio DRM: Dan notes two simultaneous feeds

All India Radio (AIR) Headquarters in Dehli, India. Photo courtesy of Wikipedia.

All India Radio (AIR) Headquarters in Dehli, India. Photo courtesy of Wikipedia.

Many thanks to SWLing Post contributor, Dan Srebnick, who writes:

While DRM (Digital Radio Mondiale) has long been pronounced DOA (dead on arrival), All India Radio seems to be taking it pretty seriously. Here’s a screenshot of not one, but two simultaneous feeds going out over the same 10 kHz wide 40 meter frequency (7,550 kHz) at 2027 UTC today. The signal on my Perseus was just a tad under S9+5db using my ham band Alpha Delta DX-CC antenna.

image001So what’s the twist, aside from the 2 feeds on 1 frequency? Even at +5 over S9, the feed was only strong enough to occasionally flutter in with some decoded audio. Mostly, it was silence.

[I had] about a 98% successful decode by 2051 UTC when the signal rose to S9+10 db. I could switch between streams by clicking channel button within Dream!

Dan wrote the message above yesterday, I asked him if he could record AIR  today and he kindly sent the following:

AIR DRM recorded today with announcements @ 1930 UTC. Some dropouts as a
great example of the dropout/echo effect heard on DRM when signals are quite
strong enough. This decode was done at S9 signal strength.

Dan actually calls the DRM dropouts, the Max Headroom Effect.”  That is the best description I’ve ever heard, Dan.  Thanks for sharing your notes and recording!

Alexander reviews the Avion AV-DR-1410 DRM receiver

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Many thanks to SWLing Post contributor, Alexander (DL4NO), for the following review of the new Avion DRM receiver:

A review of the Avion DRM receiver

by Alexander von Obert (DL4NO)

The Avion AV-DR-1401 DRM receiver has appeared on the SWLing Post before in a previous review.

Amazon India does not sell the Avion outside of India. As it happens, I found someone who was willing to buy it for me and bring it with him from India to Germany.

The first impressions were quite disappointing. This feels more like a prototype, not a polished product:

  • The power supply produces lots of interference and runs quite hot. Unless I find another power supply, I can either charge the battery or listen to the radio.
  • The handle rattles. Such things often are symptoms for the whole product.
  • The firmware fails in many ways: update errors of the display, very confusing user interface.
  • No acceptable field strength indicator, especially in DRM until a signal is decoded. If you have a selective antenna you need to switch to AM to tune it. And then you tune it by ear or by numbers. No bar of any kind.
Avion AV-DR-1410 DRM

Radio Romania

Radio Romania produced very good signals this evening in southern Germany on 41m. But with the built-in antenna, DRM reception was impossible even in my shack directly under the roof. A Degen 31MS selective active antenna indoors enabled sketchy reception of Radio Romania and All India Radio on 41m. Reasonable reception was only possible with my external antenna.

All India Radio

All India Radio

Just imagine why I took the trouble to get the receiver! It is a far cry from what I really wanted: a modern replacement of my trusty Sony ICF7600D from the 1980s. I had to retire it for mechanical reasons after it travelled with me for 20 years.

In India, they might not have the industrial infrastructure they have in China or Japan, but an intensive firmware update is urgently needed. Software is something they are good at in India. Many problems could be solved that way:

  • The volume knob has no stop and must be pressed for a few seconds to turn the radio on or off. A short press could be used to switch it between volume and tuning.
  • A reasonable field strength indicator should be introduced.
  • The remote control does not work reliably.
  • With the “mode” switch I can select AM, FM, or DRM. But I have not found anything that the “band” switch could be doing.
  • The “scan” switch works on FM and puts all transmitters found into the favorites. But neither is that the function I would expect it to do nor does it work on other bands.

From my preliminary tests I fear the unit has massive large-signal problems. For example, I heard distorted signals of Radio Romania on bands where they were not transmitting at all. I use an active antenna but this is the same I use for the DX Patrol or SDRplay RSP, therefore I know that my antenna is not to blame. I also see this as an indicator about the DRM signal of Radio Romania.

I could not help but open the Avion receiver: [the internal antenna worked so poorly, I wanted to investigate].

I must say that the rattling handle was an accurate indicator of production quality.

Inside the Avion

Inside the Avion

See “Inside the Avion” image above (click to enlarge). The back side on the left was originally covered by an aluminum shield. I had to remove it as the wires are quite short–one cannot put the two parts flat on the bench otherwise. You see that they tried to improve the shielding on the right.

AVION internal antenna preamp

Avion internal antenna preamp

See “Avion internal antenna preamp” above (click to enlarge). The circuit board at the lower left corner of the first picture is the preamp for the internal antennas. In the lower left corner is the telescopic antenna connection. The wire here was extremely short–either it broke before and made contact by chance or I broke it when I dismounted the circuit board. At least I did not force it (still a bad manufacturing practice).

If you examine the circuitry, you see very bad practices: C2 directly connects the antenna to the base of Q2. It must be a bipolar transistor considering R3/R4. At least there is DN1 which seems to be protection diodes. On the whole board I can find no inductivities at all. There is absolutely no band limiting.

AVION broken shilding wire

Avion broken shilding wire

See “Avion broken shielding wire” above. The shielding wire had broken from the soldering. That was definitely not my fault. At the yellow isolation, a second wire is connected. That is the wire routed around the backside without any connection. This doesn’t make sense to me.

Avion crushed battery holder

Avion crushed battery holder

See “Avion crushed battery holder” above. The battery holder is fixed together with the aluminum shielding. The worker crushed the lug of the battery holder while mounting the shield. A few other threads were torn, too. A typical case of too much strength.

Avion seems to know about the inherent RFI problems of this receiver, but could not solve them. No wonder I have to use an external antenna.

Perhaps I will replace the antenna preamp with something reasonable.

Otherwise this radio will gather dust here.

Thank you for your report, Alexander–I’m sorry to hear about your experiences with the Avion, especially after the trouble you went to obtaining it.

So far, I’ve heard no truly positive reviews of the Avion AV-DR-1410. Sadly, it sounds like a radio to avoid.

A review of the new Avion receiver and a few thoughts about DRM

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Many thanks to SWLing Post reader, Mike Barraclough, for sharing a link to this review of the new Avion DRM receiver by DRM Radio Forum user PhilipOneL. I’ve pasted his evaluation of the Avion below–you can read this, along with the full discussion thread, on the DRM Radio Forum:

I received my Avion AV-DR-1401 this afternoon and have had it up and running for a couple of hours. There is no instruction booklet with it so I am puzzling over the 41-button remote. It is not as user-friendly as I hoped.

First impression: somewhat cheap feel to it. I have put a small bend already in the thin but long aerial. But that is just the outside (handle, volume control, master power switch, and aerial); I hope it works well anyway. But that cheapness hurts when the price of the radio was fairly high to begin with and I paid more than I wanted for a private company to ship it (Fedex).

The radio arrived with its battery fully charged: nice. (But I need to get an adaptor for the AC adaptor’s mains plug which has tubular prongs rather than the North American blade prongs.) I like a lot the fact that it runs normally with its internal battery rather than plugged into mains. This means I can carry it away from noise sources. And it is very carryable — it reminds me of a small 1965-era beach radio in size.

Turned on, it scanned the local FM spectrum well and registered all the local stations. But I cannot get the Scan function to operate on MW and SW, nor in DRM mode. With an outside antenna (8 metre wire) attached, it was able to get the AIR DRM broadcast on 7550 kHz and decode it. It didn’t seem to be able to get enough signal with just the extending aerial.

I have not figured out yet how to make it register a medium-wave, shortwave, or DRM station in its memory; it does not happen when the button labelled “Delete / Store” is pushed. Among the 41 buttons, there is no other likely candidate for that function.

Shortwave sensitivity in AM mode seems to be poor. I was listening, for instance, to ERT Greece on 9420 on the three receivers now on my desk: Satellit 750, MorphyRichards 27024, and the Avion DR-1401, each in turn connected to the same outdoor antenna. The MR27024 produces the best sound and greatest s/n ratio. It seems far more sensitive than the Avion. But who knows? I may discover I am doing something wrong with the set.

Tuning can be done by inputting a frequency on the remote. Alternatively, the volume wheel can be pushed (this takes two hands) to convert it to a tuning knob. Two problems are apparent. One is that the signal is muted as you tune until you wait on a frequency for four or five seconds. Thus it is a slow and aggravating experience to try to tune across a band looking for signals. Secondly, as soon as a station is tuned and producing audio, the knob goes back to being a volume control. Grrrr. (I think there is a professor at all the design schools who seems to be telling all her/his students to be visually minimalist in design and to give every knob multiple functions. That professor should be publicly shamed until she/he recants and causes all the students to go back to multiple knobs each of which does one thing well.) When the radio gets itself ready to produce audio it seems to ramp itself up to full audio in a series of four steps, each a half-second or so after the last — it is an odd-sounding process. It is like a faulty AGC circuit; perhaps it is.

Sound quality is mediocre at best on AM (both mw and sw). I didn’t listen long enough to the DRM signal from AIR before it signed off to get a good idea of DRM audio quality; I was busy cooking supper. FM audio is mediocre too on the internal speakers but, piped out through the headphone jack to external speakers, it is quite good. When I piped the AM audio out it still seemed mediocre.

Why the AM sound is mediocre seems to be related to two things: the tiny speakers (about 8 cm or 3.3 inches) and the bandwidth at the radio stage. Even comparatively strong (and clean) signals like RHC on 6000 kHz have what may be adjacent signals mixing in — perhaps even internal mixing products? I heard a splash of a local FM station at one point while listening to a shortwave band.

I have written my contact at Avion (Ankit) asking for an instruction booklet, or a pdf of one. I hope I’ll get that early next week (if indeed they have one).

I hope over the next week I will get some chances to check out more DRM signals. I am also hoping that my gradual love affair with the MorphyRichards radio will be replicated here. When I first got the MR27024 I was very cranky about its weird ways of doing things. But once I got a good antenna on it, and got used to its ways, I prefer it to all my other radios as a table-top radio (that is, one useful for listening to specific regular stations). The MR’s radio-stage DSP is quite lovely and makes for good sound. I doubt the Avion will seduce me to quite the same extent, but it may grow on me in other ways.

I understand the problems with DRM but I am still a fan of of the system. I bought this Avion set partly in hopes that I would encourage the manufacturer in some small way. I will use it but I suspect that the minimalist design features (which were also a part of the MorphyRichards design) will turn off users of the Avion.

I’m not terribly surprised by this reviewer’s assessment. Just looking at some of the preliminary info on the Avion receiver last year made me think of previous DRM portables like the Newstar DR111 and the Uniwave Di-Wave 100.

The UniWave Di-Wave/Di-Wave 100.

The UniWave Di-Wave/Di-Wave 100.

I have a hunch all of these designs were fleshed out by engineers and entrepreneurs who had not gotten customer input in advance.

It’s sad, too. While I know DRM (via the shortwaves) was a “cart before the horse” innovation–meaning, broadcasters adopted the technology well before consumer receivers were on the market.

I really wish the medium would’ve gained traction.

While I prefer the rich sonic texture of amplitude modulation, I love listening to DRM broadcasts well. Last year, during my presentation at PARI, I played a recording of a piano concerto I heard on one of Radio New Zealand International’s DRM broadcasts. If memory serves, the audio clip was taken from this recording I made on June 21, 2104:

Through the presentation room’s hi-fi system, the music sounded absolutely brilliant.

To put what this audience was hearing in perspective, I told them:

“We’re listening to a radio station some 8,300 miles away without the use of the Internet, mobile phones, satellites, or any sort of subscription service. We’re hearing FM-quality audio, streamed wirelessly and originating from the other side of our planet.”

I then received a number of questions like: “How is this technology possible?” and “Do they make car radios that can receive these broadcasts?”

There’s magic in DRM. Sadly, I feel its deployment was awkward and its window of opportunity may have already passed. An affordable, effective, and simple DRM receiver (combined with serious, viral publicity) could turn the tide somewhat–but it doesn’t seem like this will happen anytime soon. Each new DRM portable is only a slightly improved iteration of its predecessor and the price tag continues to be too high for effective market penetration.

I want to be proven wrong, though.

Avion DRM Receiver now shipping via Amazon India

Avion

The Avion portable DRM receiver is now available on Amazon India (click here to view). It’s being sold for 14,999.00 INR (roughly $230 US).

At time of posting, The Avion DRM receiver only has one review by someone who has (obviously) never used the radio. They give one star then state: “price is very high. so i hate this product.

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While I dismiss reviews like this, I must believe that this price is, indeed, high for most Indian consumers; especially when compared with alternate forms of media consumption (smart phones, analog radio, FTA satellite TV, etc.). It would be high for me, too.

I hope, at least, that the Avion performs well. I have no plans to review the Avion DRM receiver at this point simply because it’s challenging for me to find and decode DRM here in North America with my SDRs hooked up to large external antennas. Don’t get me wrong–occasionally, I do get amazing copy–but it’s typically when conditions are favorable. Listeners in Europe, Asia, and Oceana would have better results, no doubt.

Has anyone seen an objective review of the Avion DRM receiver? Please comment.

Click here to view the new Avion DRM receiver on Amazon.in.

The Avion AV-DR -1401 DRM receiver to ship in October

DRM-Avion

Many thanks to several SWLing Post readers who shared this RadioWorld article about the new Avion AV-DR -1401 portable DRM receiver. According to RadioWorld, the AV-1401 will be sold through Amazon India as of October 2015 for approximately $175 US.

Click here to read the full article.

Special DRM broadcast to Europe

drmlogoMany thanks to Mauno Ritola who shares a link to the following schedule from the DRM Consortium via the WRTH Facebook page:

During IBC, Babcock will be transmitting DRM service from the UK, towards Europe.

[Friday September 11, 2015 to September 15, 2015]

  • 1600-1700 local Amsterdam time (1400-1500 GMT), BAB Woofferton, 100 kW, 6040 kHz, 114 degrees (Programme TBA)

  • 1700-1800 local Amsterdam time (1500-1600 GMT), BAB Woofferton, 100 kW, 6040 kHz, 114 degrees (BBC WS English)

Happy Summer/Winter Solstice: Listening to New Zealand and Australia

Australia-NewZealand

I’ve been on the road a lot lately. A lack of time resulting from this, combined with frequent afternoon and evening thunderstorms when I am home, has meant that I’ve not had the radio time I often enjoy.

This morning,  I woke up around 5:50 AM determined to get a bit of time on the radio. After all, today is the first day of summer here in the US, and a special day for me. I walked outside and hooked my antenna back up; I had been forced to disconnect it yesterday as pop-up thunderstorms persisted throughout the afternoon and evening.

I then brewed a cup of coffee and settled into my “listening lounge” for some early morning tuning.

Elad-FDM-S2-Coffee

I started off this morning off by tuning the Elad FDM-S2 to Radio New Zealand International on 9,890 kHz in DRM (Digital Radio Mondiale). I was treated to one full hour of Peter Fry’s Saturday Night music; the DRM lock was completely stable.  Though I prefer the sonic characteristics of AM over digital modes, I’m most impressed with the audio quality DRM affords coming from a 50 kW signal being broadcast on the other side of the planet. The quality is so exceptional that, if you listen carefully, you can even hear the news reader shifting papers at the top of the hour.

That got me thinking: I’m flawlessly receiving and decoding a wireless digital audio signal from 13,500 kM away. Amazing. Especially considering that my laptop struggles to receive Wi-Fi in many hotels.

RNZI signed off after an hour, so I switched modes to AM and tuned to Radio Australia on 9,580 kHz.

BombersAs I had hoped, RA was broadcasting the second half of the AFL match featuring the Essendon Bombers who ultimately held a nine-point win over the Adelaide Crows. Alas, Radio Australia dropped the signal before the end of the final quarter, but I was able to watch the results roll in on my iPhone while making waffles in the kitchen. If this had been a World Cup match, I would have scoured the shortwaves for another Radio Australia frequency.

Immediately after tuning in RNZI, I hit the record button on the FDM-S2 (around 5:55 EDT/9:55 UTC) and didn’t stop the recording until after Radio Australia signed off, so there is a 30 second silence in the middle while I tuned and switched modes from DRM to AM.

Click here to download my full 2+ hour morning recording, or simply listen via the embedded player below:

Depending on which hemisphere you live in, I hope you enjoy this summer–or winter– solstice.

As for me, I’m looking forward to a happy birthday with my family.  Cheers!