Category Archives: Mediumwave

Pacific Island Results from Gary DeBock’s Hawaii Ultralight DXpedition

Clearing the southern coastline of Maui en route to the Big Island. (Photo by Gary DeBock)

Many thanks to SWLing Post contributor and intrepid Ultralight DXer, Gary DeBock, who shares this DXpedition summary with recordings:


Kona, Hawaii DXpedition– Pacific Island Results

by Gary DeBock

From December 17-20 a Mini-DXpedition was conducted in Kona, Hawaii with a 5 inch (13cm) “Frequent Flyer” FSL antenna and a 7.5 inch (19cm) loopstick C.Crane Skywave Ultralight radio.

The FSL antenna was a new type designed to easily pass through TSA security checkpoints at airports, and provide inductive coupling gain roughly similar to that of a 4 foot air core box loop. South Pacific island reception was generally good from 0630-0800 UTC daily, but usually became problematic after that when powerful Asian stations tended to drown out the exotic Pacific island stations as sunset progressed over Japan, Korea and China. By 0900 daily only the most powerful Pacific island stations on 621, 846, 1098 and 1440 had much of a chance of surviving the Asian signal onslaught, and even some of those were drowned out. During a similar visit to Kona, Hawaii with identical gear in April (DXing at the same motel) the Pacific island stations were generally stronger, and had no co-channel competition from the Asians from 0800-1030 UTC. As such the South Pacific results during this trip were slightly down from April, although there were still plenty of strong signals to record.

The new 846-Kiribati on Christmas Island was a star performer as the strongest island DU station, with local-like signals shortly after the Hawaiian sunset each evening. Despite this it had an intermittent transmitter cutout issue, with the signal failing to transmit at odd intervals (including one stretch with six signal dropouts within one minute, as documented in an MP3 linked below). In addition 846-Christmas Island’s programming had a variable time delay with that of distant 1440-Kiribati in Tarawa, with both a 19-second and 35 second time delay noted. This may be related to the transmitter cutout issue, with the time delay changing after a major dropout. DXers looking for a parallel with 1440 should keep this programming quirk in mind. Although both 846 and 1440-Kiribati signed off at the usual 0936 UTC time on the first couple days of the trip, they had both switched to a 1009 UTC sign off on the last couple of days. Whether this is a permanent programming change is unknown, but the loud 1000 Hz audio tone is still being broadcast before power is cut, resulting in a very easy way to distinguish the stations at sign off time (even in heavy domestic QRM).

846 and 1440 weren’t the only exotic DU’s with transmitter issues. 621-Tuvalu came down with distorted audio on December 18th, a problem which got worse and worse on the remaining two days. By the last day it was sounding very garbled, making a bizarre combination with 621-Voice of Korea’s buzzing Japanese service transmitter. Whether 621-Tuvalu has repaired its garbled audio is also unknown.

540-2AP was somewhat weaker than it was in April, while 558-Radio Fiji One was MIA during the entire trip (probably because of Asian QRM). Efforts were made to track down 630-Cook Islands but only a weak UnID was recorded. 801-Guam was possibly received during a Pyongyang BS/ Jammer fade, but 990-Fiji Gold was given a golden knockout by 990-Honolulu. 1017-Tonga showed up for a couple of good recordings, but got slammed by Asian co-channels after 0830. Efforts to track down 1035-Solomons ran into heavy 1040-Honolulu splatter, while 1098-Marshalls became the only Pacific island station to have stronger signals than in April. Its overwhelming signals after 0700 daily were one of the bright spots in Pacific island reception. Finally the new 1611-DWNX in Mindanao, Philippines was received at a strong level at 0855 on December 19th, apparently with a major boost from sunset skip propagation.

540 2AP Apia, Samoa, 5 kW Christian worship music at a good level through the T-storms at 0751 on 12-17, but not nearly as strong as in April:

Click here to download audio.

621 R. Tuvalu Funafuti, Tuvalu, 5 kW This station had very strong signals until around 0800 on most evenings, when it usually began to be pestered by Asian QRM (China, N. Korea and NHK1). It also came down with a garbled audio issue on December 18th, which continued to get progressively worse until I left Hawaii. Sign off time is still around 1006, but by that time it ran the gauntlet of powerful Asian co-channels during the December propagation.
Local employment offers read by the usual lady announcer at an S9 level at 0750 on 12-18. This was the last undistorted audio signal recorded from the station during this trip; after this the audio went “south”:

Click here to download audio.

Guest speaker in Japanese-accented English, followed by local island-type music at 0835 on 12-18– the first sign of audio distortion:

Click here to download audio.

Full Radio Tuvalu sign off routine at 1003 on 12-18, but with China QRM initially. Tuvalu’s signal prevails during the national anthem, but the audio distortion is quite noticeable. The carrier apparently stays on for over a minute after the audio stops:

Click here to download audio.

630 UnID While trying for the Cook islands (Rarotonga) I came across this weak Christmas music with English speech at 0742 on 12-17, although this could just as easily be a west coast domestic station playing the “exotic” to fool a hopeful DXer. Walt says this station is a notorious underperformer:

Click here to download audio.

801 UnID (Guam?) Apparent Christian female vocal music received during Pyongyang BS/ Jammer fade at 0931 on 12-18, but no definite ID clues:

Click here to download audio.

846 R. Kiribati Christmas Island, 10 kW This newly rejuvenated station had awesome signals, and was overall the strongest Pacific island station received. Of all the Pacific island DU’s it faded in at the earliest time after sunset, and maintained its strength even during strong Asian propagation — as long as it managed to transmit without its signal dropping out. Unfortunately this seemed to be a pretty common occurrence while I was in Kona. Island-type music at typical S9 strength at 0735 on 12-18:

Click here to download audio.

This segment at 0620 UTC on December 17th features 6 signal dropouts within one minute:

Click here to download audio.

This segment at 0944 UTC on December 18th is even worse– 9 dropouts in 90 seconds:

Click here to download audio.

After a prolonged 846 transmitter dropout it seemed like the programming time delay between the distant 1440-Kiribati on Tarawa Island and the new 846-Kiribati on Christmas Island would change. On December 17th I recorded two different time delays– 19 seconds, as in the following recording (the MP3 starts out on 846 at 0635, switches to 1440 at the 1:02 point, then switches back to 846 at the 1:34 point, with a 19-second time delay evident between the 1440 and 846 programming (846 lags behind):

Click here to download audio.

Later on the same evening there was a 36 second time delay between 1440 and 846, with this MP3 starting off on 1440 at 0645, and switching to 846 at the 11 second point:

Click here to download audio.

1017 A3Z Nuku’alofa, Tonga, 10 kW Female native language speech at a very good level at 0858 on 12-19:

Click here to download audio.

Somewhat weaker through the T-storms on 12-17 at 0734:

Click here to download audio.

1098 R. Marshalls (V7AB) Majuro, Marshall Islands, 25 kW This station was very strong in Kona with its island music every night, and rarely had any Asian co-channels.
S9 Island music and native language speech (and possible ID) across the 0700 TOH on 12-17:

Click here to download audio.

Equally strong island music and native speech at 0813 on 12-18:

Click here to download audio.

1440 R. Kiribati Bairiki, Tarawa, 10 KW Somewhat weaker than its rejuvenated 846-Christmas Island parallel (which has variable programming delay times, as explained above), this home transmitter could hold down the frequency until around 0800 every night, after which it was usually hammered by JOWF in Sapporo. Despite this it often put up a good fight until its new sign off time of 1009, and it continues to use the loud 1000 Hz tone right before the power is cut (an awesome aid for DXers hoping to ID the station through heavy QRM).

Typical island language speech and strength level at 0830 on 12-18, just as it is starting to get jumbled by JOWF (a Japanese female “Sapporo desu” ID is at 25 seconds):

Click here to download audio.

Full sign off routine at 1005 on 12-19, including the National Anthem and the 1000 Hz tone before the power is cut. The tone gets through the JOWF QRM like a DXer’s dream:

Click here to download audio.

1611 DWNX Naga City, Mindanao, Philippines, 10 kW (Thanks to Hiroyuki Okamura, Satoshi Miyauchi and Mauno Ritola for ID help) Received at 0855 on 12-19, this station was a mystery until the Japanese friends matched the advertising format with that of a new, unlisted station which just came on the air in the Philippines. The propagation apparently got a major boost during sunset at the transmitter:

Click here to download audio.

73 and Good DX,
Gary DeBock (DXing at the Royal Kona Motel with a 7.5″ loopstick C.Crane Skywave Ultralight+
5 inch (127mm) “Frequent Flyer” FSL antenna.

Demo video of the “Frequent Flyer” FSL antenna:

Click here to view demo on YouTube.


Thank you for sharing your Hawaiian DXpedition with us, Gary! Your mediumwave DX catches with modest equipment reminds us all that when HF propagation is poor, there is still so much signal hunting below 2 MHz!

Interested in Ultralight DX? Check out archived posts in our Ultralight DX category.

XHDATA D-808 modification to allow an external mediumwave antenna

Many thanks to SWLing Post contributor, Rolf Snijder, who writes:

I have added an external antenna capability for mediumwave on the XHData D-808.

Simply add a 27 pF capacitor on the backside of the PCB on C10 to the the ferrite antenna.

The mod causes no loss on FM or shortwave!

I also replaced the Ferrite antenna with a bigger one so I now have more performance on MW!

Longwave is not good in my radio, even with an external antenna, it is not performing well.

Thanks once again, Rolf! I must assume that the Digitech AR-1780 could be modified in the same way as the radios appear to be near identical. Perhaps someone can verify this at some point!

Short Videos: the XHDATA D-808 Portable SSB Receiver on MW and SW

I recently received a new XHDATA D-808 SSB portable receiver, after AliExpress had a $69 USD introductory sale. I’m intrigued by this new model, as it uses the SiLabs Si4735 DSP chip, the same “brains” that powers the Eton Satellit (and Executive version), and C. Crane Skywave SSB. I believe the same Si4735 is found in Tecsun’s PL-880 and the CountyComm GP-5/SSB. A key feature found in all of these radios is USB/LSB modes and 10-Hz tuning step in SSB.


It would be a mistake to assume that all portable DSP receivers with the same SiLabs chip will perform equally; quite the opposite! They all have reception differences that owners will notice. I certainly noticed differences in sensitivity, AGC action, audio quality, and (to some extent) variations in adjacent channel (splatter) rejection between receivers using the same bandwidth. I made these observations when I owned the PL-880 and GP-5/SSB radios. Differences in the circuitry surrounding the SiLabs chip, as well the sizes of MW ferrite loopstick antennas and SW/FM whip antennas contribute to each receiver’s personality.

Below are four videos showing the D-808’s reception of three weaker daytime medium wave stations from indoors at my suburban Seattle-Tacoma (WA) home, plus one video of a shortwave reception in the 41 meter band. The XHDATA D-808 is compared to C. Crane’s newest Skywave radio, the SSB model, and the Eton Executive Satellit. Although brief, these tests show how the new XHDATA portable is a welcome competitor to the field of modern, compact SSB-capable radios:

What about single sideband? These four videos show reception in AM mode only, but rest assured the D-808 is very capable on the SSB modes of LSB and USB! A separate fine tuning rotary wheel on the right side of the radio’s case offers adjustment in 10 Hertz increments. The effect feels very similar to tuning CountyComm’s GP-5/SSB “walkie-talkie” style receiver. The plus or minus (+/-) offset is displayed in multiples of 10 Hz steps as “-1”, “-2”, “-3”, and so on.

I hope to post some future videos showing SSB usage of the D-808.

Soft mute. The dreaded soft mute is present in AM and SSB mode to some degree, but I do not feel it is excessive. Like most radio hobbyists I’m not a fan of soft muting and prefer uninterrupted tuning with no sign of “chuffing” or lowering of noise or audio.  The amount of soft mute on this radio seems the same as the Eton Executive Satellit in my opinion.

What else to like? My take–

Audio. I find the D-808’s audio quality to be slightly more mellow or warmer…I like that, especially on FM! Audio on the MW and SW bands still has a crispness that aids in DXing on those bands, however.

18650 Li-Ion battery. Not all may agree, but I like this style of battery. The D-808’s internal circuit shuts off when the battery is fully charged, or after 10 hours of charging. The radio comes with a 18650 battery and a USB cable; the owner supplies a common 5V USB charger.

RDS on FM. This is a feature lacking on the Skywave SSB, but it is present and performs as expected with the D-808. The XHDATA radio lacks the Skywave SSB’s NOAA weather presets, however.

AM filter bandwidths. Interestingly, this receiver supplies two additional narrow AM mode bandwidths lacking in the Executive Satellit: 1.8 kHz and 1.0 kHz. It’s good to have options, although such narrow filters in AM mode sound a little muffled (offset tuning helps). The Skywave SSB does offer 1.0 kHz in AM mode, but has a 2.0 bandwidth in place of 1.8 kHz.

Backlighting. If desired, the D-808’s easy-on-the-eyes white backlight for the display can remain illuminated continually. Bravo, XHDATA! Now, if we could persuade more manufacturers to add backlighting to the keys themselves (a la the Degen DE1103/Kaito KA1103/Eton E5), we’d have more choices use in low light conditions like camping or bedside use.

Handy size. Probably a third larger than the diminutive Skywave SSB, the D-808 is still a very handy size that will fit most coat pockets, and is a smaller receiver than the Eton Executive Satellit. As you can tell from my videos, reception doesn’t suffer due to the smaller size.

Design. OK, this one’s very personal! As a graphic designer I have a real soft spot for any receiver that looks as good as it sounds, no matter what the technology or vintage. The D-808’s look really appeals to me and adds to my enjoyment while operating it. There are no unnecessary protrusions, ridges, or visual do-dads on this XHDATA model. In fact, I seem some design clues from the stylish Tecsun PL-880 in the D-808. The radio also has a quality feel to the plastic case and buttons, giving it a more “upper class” impression during use.

Antenna jack. The D-808 has the standard 3.5mm antenna port on the left side of the receiver. This is an addition I appreciate, and wish that C. Crane had included one on their Skywave SSB model. I tried this external antenna jack with an amplified PK Loops’ shortwave antenna and the combination performs excellently.

Minor annoyances

So far, the list is short! As a sacrifice to style, the manufacturer has kept all front panel buttons almost flush with the case. The effect looks great, but they are almost too low and close to the front panel. Those with larger fingers may find operation awkward or frustrating. Also, entering a shortwave frequency with less than five digits (i.e., below 10,000 kHz) requires a trailing push of the Frequency (FREQ) button.

I encourage other new owners of XHDATA’s D-808 to leave their comments below. Where does this portable rate among other radios you may own?

 

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington.  He’s a regular contributor to the SWLing Post.

Addendum: More Notes on the HF+ SDR on Medium Wave & Long Wave

In my recent post on the AirSpy HF+ vs Elad FDM-S2, I commented on medium wave reception only.

This past weekend I swapped out the Wellbrook ALA1530S+ for another Wellbrook loop, the ALA1530LN Pro. This LN Pro model is less likely to overload receivers at my suburban Tacoma, WA location. Both AirSpy and Elad radios performed admirably with the LN Pro and it was nearly impossible to find any reception differences on medium wave.

Before the antenna swap though I experimented with inline attenuation modules (“bullets”), typically used in cable TV installations. I used the same sample rates on the SDRs as described in the previous article. After some tests with different attenuation levels, I came to the following conclusions during daytime comparisons:

FDM-S2 with ALA1530S+ loop, medium wave: needs a minimum of 6 dB attenuation to avoid overloading. Anything less causes saturation of the spectrum & waterfall, “crunching” overload noises, and minimal or no received signal.

HF+ with ALA1530S+ loop, medium wave: I had to search diligently to find any signs of false signals or overloading, but finally noticed a weak image or spur of a S-9+60 dB (-13.5 dBm) local station on 1560 that was appearing very weakly on 1270 kHz, mixing with the station on that frequency. Sometimes it was there, other times the spur or image would drop down and disappear, leaving the 1270 signal alone. If I added just 3 dB of attenuation in the antenna’s feed line, the interference from the 1560 station was gone for good. The S-9+60 dB station is a very strong signal; it’s impressive that the AirSpy HF+ deals with this and similar powerhouse signals so well.

Long wave: Below are two screen captures from my local long wave reception in the evening, made moments apart with each receiver.

FDM-S2

HF+

As you can tell, there are a half dozen or so additional signals seen on the HF+ below 200 kHz that do not appear on the FDM-S2. These extra spikes are images or spurs from medium wave signals that were missing from the FDM-S2’s reception–bravo Elad! However, the remaining spikes on both radios below 200 kHz seemed to be noise or interference.

Each receiver had roughly equal performance in the bulk of the long wave spectrum, when I did A-B comparisons on the same beacon signals. I’m not a LW or NDB DXer however, so I can’t claim any expertise on these frequencies. In short, though, both radios seem neck-and-neck from about 200 to 500 kHz.

The DXer of LW frequencies may want to look elsewhere for a better performing radio than either the FDM-S2 or HF+. SWLing Post reader Tudor Vedeanu has commented that the SDRPlay RSP1A  and the Eton E1 work very well at long wave.

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington.  He’s a regular contributor to the SWLing Post.

Radio Moscow: New Year’s Day, 40 years ago

Happy New Year SWLing Post community!

A few months ago, I published a post about Colin Anderton’s excellent Radio Moscow recordings from the late 1970s. Being a space flight enthusiast, all of Colin’s brief off-air recordings feature news from the 1977-1978 Soyuz 26 mission to the Salyut 6 space station.

Recently, I started posting Colin’s recordings on a schedule so that each recording is being published exactly 40 years from the original broadcast date. Check out the Shortwave Radio Audio Archive each day (or subscribe via iTunes) to listen to the recordings.

Below, I’ve embedded the recording from New Year’s Day 1978 where we learned that Yuri Romanenko and Georgi Grechko toasted the New Year with fruit juice (for obvious reasons, champagne was not allowed on the station!).

Click here to listen via the Shortwave Radio Audio Archive.