Saturday, July 14, 2018

Chinese DRM!

As has been hinted at in the recent past, China may be on the cusp of a DRM broadcasting revolution.

This may represent the first in many broadcasts, which would certainly break the DRM market wide-open! Great opportunity for Gospell to capture the growing market -  as they have the only DRM receiver in current prodcution and they are located in China.

As seen on Now on the radio BBS "Jul 13, 2018 06:47 UTC CHINA: 6030kHz, Chinese traditional music
("Minzu Yinyue")(DRM) UTC 0230-0700?"

Sunday, June 10, 2018

WINB - further details on their DRM broadcasting

Here is info from the April WINB FCC Construction/Change application. You will see they are using a data amplifier from Amplifier Systems Inc. I don't actually see the quoted model on the ASI website, but I emailed them for more details. It appears that WINB is planning datacasting (in addition to DRM audio and its associated text). 



They are currently testing using 5kHz DRM, so the left half of the 10kHz channel appears to be the datacasting. Zyg has some ideas that he posted over on DRMRX.

Here is an evaluation screen of WINB reception last Friday. See the spiky section on the left half of the 10kHz channel? It looks wrong for a DRM waveform, but it is likely the datacasting stream - hence the 5 kHz DRM to the right side.

This data may represent "Shortwave Trading" that has been written about recently. Completely conjecture so far! Just nice to have some DRM in NA again!



Sunday, June 3, 2018

UPDATED: WINB and DRM

Please find below, Brother Zyg's VOACAP work related to WINB DRM testing (updated with information from Hans about their Rhombic being terminated)

DRMNA Admin

WINB reports : 
"We are testing in DRM 15670 kHz M-F 
try between 1100-1700 UTC"





Here is a preliminary view of the WINB 15670 kHz DRM coverage at 1600z for June 2018.  The coverage is for a receiver using only a 6 foot whip antenna.  Higher gain antennas may produce better results.

The WINB Rhombic antenna parameters are taken from the HFCC files.  Although the transmitter has been stated as "being rated for 15 kW", I'm using a conservative estimate of 10 kW DRM power for the plot. 
From SWL reports the transmitted bit rate has been monitored as being 8.28 kbps, which should help it to be decoded at lower signal levels.

A report in the DRM RX forum indicated that the signal was relatively strong in Newfoundland at this time but with deep fading and then disappeared some minutes later.  This agrees with the plot which shows the listeners location just on the edge of stronger signal coverage.  The propagation does move the stronger signal area eastwards as time progresses.  There were also reports from the UK and France at a little earlier time when the signal would have been at a somewhat higher level in those areas before moving eastwards.


On Friday, I monitored the KiwiSDR web network of receivers at 1600z and found 15670 kHz DRM "waterfall" signals in Houston, Miami (stronger), and Iceland (weak).  I did not encounter any DRM signals in Europe at that time, but Radio France International has a 500 kW broadcast from Issoudun, France, beaming south to Africa on the same frequency and at the same time!  There was also a much weaker, but still noticeable, signal in the Atlanta area (as received on my Kenwood R-1000 receiver and a long wire antenna).


The plot only shows signals that are stronger than S6 (on an S-meter).

Finally this coverage is for "normal" propagation conditions which just happen to have a zero solar sunspot number as we are in the bottom of the 11 year solar cycle.  Conditions have been less than normal in the past few days.


73,
-Zyg

Sunday, May 27, 2018

Great fun at NASB 2018!


Good things were planned at SonSet Solutions in Elkhart, Indiana and those fine folks delivered!


Charles Jacobson served as Emcee and host for two days of fun and fellowship at SonSet, a partial continuation of the services that we all remember as HCJB. SonSet and ReachBeyond are now the heirs to this PRICELESS Shortwave legacy!


As usual, folks assembled from around the globe to discuss, reminisce and plan the future of Shortwave radio. I am always awed at the knowledge and experience of the various attendees. Representatives from all over CONUS and as far away as Asia and Europe were in attendance.

Presentations ran-the-gamut from news, receiver technology, new installations, antennas... the list goes on. Here are just a few highlights!


Charles gave an informative tour of the plant at SonSet Solutions. He then detailed projects including work with the SonSet Radio (a rather robust and efficient fixed-tuned ministry receiver).


Ever the popular presenter, Dr. Kim Andrew Elliott presented Digital Broadcasts on Analogue Shortwave Transmitters. He is the producer of "Shortwave Radiogram" and is recently retired from VOA. Dr. Elliot wowed the audience with live decodes (transmitted from WRMI and WWCR) of Shortwave Radiogram via a SonSet radio. Presentation of foreign characters (Cyrillic, Chinese and Arabic) really showed the power of this novel broadcasting technology!


Gerhard Straub Director, IBB Broadcast Technologies Division presented and engaging talk on International Broadcasting Bureau Shortwave Projects with continued good news about our CONUS powerhouse in Greenville, North Carolina.


Jerome Hirigoyen of Telediffusion de France (TDF) offered details of the 360-degree Rotatable Antenna System known as ALLISS. I'd take one for my house, but the neighbors might complain!


NASB is known for excellent food and our dinner at "Das Dutchman Essenhaus" in Middlebury, IN (an Amish style restaurant in the middle of Amish country) was tasty and great fun.

Of course, if you are reading this blog, you want to know about DRM! Well the news was plentiful and I'd call it GREAT! Both George Ross of TWR and yours truly presented on DRM topics.


George had more news about the Titus II receiver. It is nearly ready from prime-time and will be using Fraunhofer MMPlayer. This is great news and should make for a very versatile receiver. Although there have been numerous false-starts with the release of the Titus II, it is nearing release and is still promised at the sub $100 price tag.


In "fly catching mode" I am seen here presenting the DRM global update  and extolling the virtues of the Gospell GR-216.






After my presentation, we moved to SonSet's hamshack to attach the Gospell to an external antenna. We were then treated to an hour of nearly flawless reception of Radio Kuwait in DRM stereo! It was really a joy and attendees that had never experienced DRM were awestruck at the audio quality and signal clarity from so far away.


NASB members gave brief reports about their efforts. Of particular interest is the work that J.D Tayloe of Strategic Communications Group shared regarding reviving an old KOL Israel site.


The business meeting handled NASB elections and plans for 2019. The location wasn't finalized but should be shortly. Stay tuned! Another great NASB conference! Thanks to the host, SonSet Solutions for another memorable and informative meeting!

Monday, May 21, 2018

CONUS-wide Gospell GR-216 review!

Special thanks to Haochun of Gospell for the demo unit. As you will read below, we really put it through its paces. Haochun allowed us a test unit and this single radio was all over the USA in states from the West Coast to the East Coast in 6 months.

We were particularly fortunate to present the demo unit at NASB 2018 at SonSet Solutions in Elkhart, Indiana. Kuwait DRM came through for a solid hour on two frequencies from 7000 miles away! Here is a short clip as an example. If this doesn't convince you that we have a winner here, then nothing will!


It is a pity there is so little DRM available in North America. After our experience with Kuwait, the consensus is that the GR-216 works well overall and very well with DRM (remember, this is an early release with early firmware) and I believe it represents hope that tabletop DRM reception is now within reach!

Fibber:

I have been taking my time to enjoy the new GR-216. The unit is a full featured table top with traditional AM and FM offerings plus Shortwave and DRM (for AM and Shortwave bands). Build quality is really nice. It is a solid feeling radio, with a crisp looking LCD display. It sports BNC connectors for antennas and RCA and 1/8" jacks for audio output. It has a physical switch for using internal versus external antennas.

I'm going to quickly cover AM and FM reception. Here in the Pacific Northwest, DRM is just about non-existent currently. Shortwave reception is fair this time of year so here is an example of daytime VOA Korea.


On a quick trip to the Oregon coast, I caught this Classical music station transmitting full RDS. Nice to see the scrolling text descriptions on such a nice, bright display.



I did have several brief opportunities to compare signal levels on DRM brodcasts. Kuwait and Romania both presented on the radio, Kuwait with bits of audio. I ran these concurrently with a recent build of DReaM and found the Gospell comparable to what I was getting via the ELAD FDM-S1 using DReaM.

I must say that the variable AM bandwidths have quickly become my favorite feature. The wide settings are more than generous for high-fidelity listening. The medium and narrow settings provide the ability to avoid adjacent squawk in even the overcrowded 49M bands on my West Coast mornings.

If I had any suggestions with would variable AGC options for AM and possibly speaker modifications as the AGC seems to on-occasion clamp and then release on deep fades to big signals, causing physical speaker distortion or almost rattle even. No doubt some of the problem is simply a firmware adjustment.

This is by far the most stout and robust feeling DRM receiver I have encountered. Once the price-point approaches that of conventional (but high-quality) tabletops, we will have a global winner here. xHE-AAC compatibility on DRM too, so this one will be ready for my Global DRM Domination plan!

BRENDAN:

First Impressions: after the box arrived, I carefully pulled out all of the contents and studied the radio itself. Larger and heavier than the DR111, it has a sturdy plastic case and knobs. A separate 110V power supply with Euro-style pins had been sent along, but a pin adapter fixed that issue. Plugged it in and was greeted by the radio as it booted up. It worked!

But what kind of radio is this? Is it a geek's radio or a consumer's radio? It's a bit of both actually. You can choose to just set and use the memories and be happy, or manually tune it and listen to DX. With both internal antennas and BNC connectors for external ones, you can choose to use it as a tabletop receiver in the kitchen or living room.  Think of it this way: the looks of an MW/FM receiver, with a decent HF SDR receiver inside.

Build quality is something I'd like to talk about before my operating observations. The case is sturdy, but the knobs and buttons need a better mechanical foundation. They are wiggly when they're not supposed to be and feel cheap. The sub-assembly that the front control buttons are attached to is not very strong, since a single button push would move them all within their casing holes. All controls actually worked fine, so the electrical aspect was good, just not the structural assembly. The main tuning knob is used for several functions just like the DR111, but it too needs some work. It often overtunes (too fast), even in 'slow' mode, so manual tuning has to be carefully done, and the detents in the knob's action don't help either. There is an extensive frequency/channel memory system built-in, but I did not use it.

Operating the radio, I found not all controls to be entirely obvious, nor did the instruction booklet provide much help actually. I still don't really know what "VF/VM" means, outside of perhaps meaning "Visible Frequency/Visible Memory." Never did function that I could tell...

However, most of the other control functions were easy to understand and/or figure out, so I was able to get it working reasonably quickly. Analog FM reception is quite good, and I was pleased at the fringe reception results for my location. The GR216 has a good speaker, and you can separately adjust the treble, midrange, and bass using the button control commands, a neat touch (no extra knobs). Stereo outputs are available on the back plane, so you can connect the radio to an ouside stereo system. A 3.5mm headphone jack, 2 RCA connectors for both channels, and power inputs.

Analog MW/AM operation was very straight forward, and proved to be quite good with external antennas connected. The internal antenna was not that good in my experience, due to AC hum like I have not heard in years. The FM band was only somewhat affected by the hum, but the MW/AM band was virtually useless. Not even the local MW stations located only about 5miles/8Km away completely overwhelmed, making listening very difficult. Connect an external antenna and the noise disappears, WITH the same power supply. Hmmmm...

HF analog reception was good, especially with an external antenna connected, but the internal rod antenna was not that effective for HF purposes.

A very neat feature that works on all modes is what appears to be an automatic filter bandwidth  setting, and it works well. I could set the radio to FM, tune a local station which would then show a wide(r) bandwidth, while moving to what is a DX station showed a narrower width. Very effective, even on HF.

While I could not 'catch' any DRM signals during my review period, I have no doubt that the GR216 would work well, based on my previous experience with my own DR111. I would also rate the GR216 as a better all-around radio than the DR111, given the higher quality speaker and more refined operating controls.

In summary, I found the GR216 to be a good consumer-oriented radio. The bells and whistles that we enthusiasts like are there, but this is a radio even my 88 year mother could use once set up. She is not a tech whiz, and has difficulty with a smartphone, and I do cut her a lot of slack (she is my mother, after all!). For most people, this radio will be enough for them, and it certainly would be for my mother.

A good effort, now make it smaller!

MEL: 

My reception of DRM has always been with a ham transceiver (Flex 5000) and DREAM software which meant I had to boot up a computer and load software. With the GOSPELL, power up is immediate and ready to receive. For me, this was nice.

As we know, there isn’t much DRM available now due to poor propagation and the loss of stations on this continent. But I was able to decode the State of Kuwait well here in the Midwest. A couple times I decoded a few words from Radio Romania International on 6030 kHz. The GOSPELL displays the sending stations transmission parameters including SNR which tracks within a few dB of what DREAM reports.

There was little difference in the decoding sensitivity between the Flex/Dream and GOSPELL. The dropouts are handled eloquently with soft fade out/fade in vs. the more abrupt off/on of DREAM. Audio fidelity was very good. The front firing speaker was great and headphones worked well using the rear “socket” connection.

Functionally, all the controls and memories worked as described in the GOSPELL user manual. Programming the memories was not real intuitive (stores up to 20 frequencies across 5 banks) but I soon got use to storing/recalling them. The radio’s confirmation “beep” is not set as a default but I believe would make memories easier to use. The two alarm timers are very loud so no fear of missing a scheduled time to listen!

For antennas, I used a “ham bands only” Yagi and 52 foot vertical. There are separate BNCs jack for connecting both FM and AM(DRM) antennas. I found the whip antenna adequate for medium wave and some shortwave listening and great for local FM stations. I did very little listening on AM shortwave, however the sensitivity/selectivity was good for the bands I scanned. Both slow and fast tuning is available on 15 bands (530 through 26100kHz). Status of the AM signal is given too. At the push of a button RF level in dBuv, frequency offset/bandwidth in kHz and carrier modulation in percentage is displayed.

It’s 12 push buttons appear to be physically mounted on one inside panel. All these buttons slightly wiggle when any one is pushed as if they were “loose.” This may be by design, however to ensure they will never stick. They have good tactile feel so I do not believe there is any reason for concern.

I had one issue with the radio. The display froze once on the station it was receiving (in this case, “Galeni TX1”) and I could no longer change frequencies or recall memories on DRM. This was easily fixed using the radio’s “Reset” command but at the sacrifice of losing all presets and memories.

Would I buy one? Yes, I would. The radio has good aesthetics would look fine anywhere in the house and it sounds great. Thanks to Fibber for loaning me the radio to try out.

ZYG:

The radio doesn't have an attenuator but I did try the BW settings. As I have not seen the schematic or even a block diagram of the receiver the following is only speculation on my part.

The radio needs a wide band IF filter to allow for the 10 kHz DRM signal. This IF filter appears to have a fixed (non-adjustable) bandwidth, and the adjustable menu BW filter appears to affect only the audio, as the adjacent strong station splatter can still be heard at the narrowest BW setting.

 A good test for a MW receiver during the day, here in the metro Atlanta area, is to tune to 50 kW station WSM 650 kHz in Nashville, Tennessee, 308 km away from my house. With an outside long wire antenna the station can be heard by a good receiver, even though there is an adjacent local 50 KW station WGST on 640 kHz (31 km away). The radio in my wife's car (Subaru, Forrester) can clearly pick up WSM, without splatter during the day, in our driveway with just the stock car antenna! Similarly, during the night hours with a good receiver I can receive 50 KW station CFZM 740 kHz near Toronto, Ontario, Canada, without adjacent channel splatter even though the adjacent channel of 750 kHz is occupied by local 50 KW station WSB (25.5 km away).

The Gospell can hear WSM with the long wire but unfortunately underneath the very strong splatter of WSB. The same occurs with CFZM. As for shortwave, I compared the GR-216 using its internal telescoping whip antenna side-by-side with my Tecsun PL-880 using its telescoping whip. I find the Tecsun to be a little more sensitive than the Gospell.