Sunday, October 20, 2019

KONG39 Report Day Two (Oct 19)

Overnight conditions towards North America were not spectacular, but some stations noted, such as KCSF Colorado Springs CO 1300. Another surprise was KARN Little Rock AR 920. KXPN Kearney NE 1460 has been noted on several occasions, too often for only 56 watts at night we think.  Very strong signals from Hawaii from around 09:00 and into the afternoon.

Also a few NZ showed up at around 10:00, but after signal levels did a deep dive, NZ never recovered. Australia did show up with some stations at excellent signal levels - 2RN Wollongong 1431 was the only noteworthy.

The rest of the day was rather uneventful, except we tested a few nice beers, such as Djævelsk Fruktig Double IPA, Survival of the Hoppiest Double IPA and Oppigårds New Sweden IPA.

Dinner is something we always look forward to. For starters we had bruscetta consisting of fresh, no-knead bread with small tomatoes, fresh basil and parmesan cheese (and a handful of garlic).
Bruscetta


The main course was fresh salmon with carbonara (and a handful of garlic), and we ended up with assorted cheese (without garlic). Calles's Riesling for the starter and main course, and a Niepoort port wine for the dessert.

Temperatures from 0 to -2 Celsius, snow showers but otherwise sunny as you can see below.




The other picture shows a view, although limited, to the north. Two beverage antennas actually cross the dirt road but you probably can't see them.

Sunday morning status: Weather much the same. Good signal levels overnight!

View to the south

View to the north

Saturday, October 19, 2019

KONG39 Report Day One (Oct 18)

Participants:
OJ Sagdahl, Ole Forr, Bjarne Mjelde (host)

KONG39 started a bit earlier than expected. Ole had made the 1000-km drive from Andøya in record  speed, and in winter conditions, and arrived at 06:00, as Bjarne was driving to Kirkenes to pick up OJ at the airport. At 11:20, when we were stuck in a road maintenance queue, Ole texted a New Zealand alert! We were quick to pick up our laptops and connect to our KONG SDRs. Amazing signal levels! Alas, later analysis revealed that most stations were heard before - still it was by a large margin the best NZ opening so far this season. It's always nice when 2-kW 1XX in Whakatane, NZ dominates over 100-kW JOLF!

Remote NZ DX in the car



















We arrived in Kongsfjord around 13:00 and went directly to our Mount Loran 1000-metre site to replace the battery and other equipment. Asia conditions in the afternoon and evening was rather uninspiring, and we had the traditional first-day meal, home-made fish gratin with chocolate pudding & custard for dessert, in the evening.

Temperatures around 0 Celsius, a "refreshing" breeze and mostly dry between the occasional snow shower. Icy roads much of the drive. In the morning of the 19 it's sunny, but snow showers looming outside the coast to the north. Superb signals from Hawaii right now. More to come!

Saturday, October 12, 2019

QSL: CHRN Montreál, QC 1610

CHHA Voces Latinas usually dominates 1610, but in mid-September, another voice dominated, that of Radio Humsafar. CHRN caters for the South Asian communities in Montreál, with programming in Punjabi, Hindi, Urdu and English. Short but friendly email response from the station's President today. Quebec verie no. 25 and North America X-band verie no. 50.

Tuesday, October 08, 2019

QSL: KXXX Colby KS 790

KXXX has been on my wish list since I saw it logged several times in the 1980's in Sweden and Finland. But did I ever hear it? No! Until a few days ago, when excellent spot conditions appeared for a little while during the onset of a solar disturbance. The Mount Loran 1000-metre beverage was able to pull in a rather weak, albeit legible signal. The next full hour, the signal was gone and KGHL/KFGO again dominated the frequency. Thanks Paul Walker for submitting the contact address.

Friday, September 27, 2019

Recording and Playing Back MW IQ Files: A Software Comparison

Recording and playing back IQ files is a vital part of the MW DX-er's hobby. With lots of SDR software available, how do we do it? What are the pros and cons? In this article, I have tried to make a (relatively) unbiased comparison between the most popular programs today. If anyone do not agree, that is fair enough, mileage and preferences vary.

Saturday, September 21, 2019

Chrome Remote Desktop - An Alternative to Costly Remote Control Programs?

I was advised by Swedish DX-er Stefan Wikander that Chrome Remote Desktop worked very well with his remote Perseus location. Now really, I thought, I tested Chrome's remote solution several years ago and it was a complete disaster at the time.

Over the years I have used LogMeIn (became very expensive), Teamviewer (kicked me out of my free, Personal account) and Splashtop (present choice, excellent tool, USD 100/year). And tested many more. Anyway, I know Stefan as a sensible man, so I decided to test CRD. It has in fact come a long way.

CRD is a "free" extension in Chrome (you pay with your user data), so obviously you need the Chrome browser, and you need a Google account. Chrome needs to be synchronized over the PC or PCs you want to control. Setup is relatively straightforward. I set up one PC to access two other PCs, and when I opened the extension, I was met with this "welcome" page:


When I clicked on the "Smøla 290" PC on top, it opened as a new tab in Chrome, and the PC displayed like this:


It actually loads very quickly, faster than Splashtop. Audio quality is on par, video quality a bit better than Splashtop. What really surprised me was there was no noticeable lag, much better than both Teamviewer and Splashtop. Your remote PC can be bookmarked for even easier access.

CRD doesn't have many features, so for a professional user CRD may not be the optimal solution. For the DX-er however: Good video, good audio, file transfer (to and from the unit), copy & paste. Windowed and full screen. Not much more to ask for!

October 2019 update: On one occasion however, one of my remote PCs refused to connect. I was able to connect via Splashtop, so the connection was ok. I restarted the PC several times with no effect. It turned out that Chrome on that particular PC had disabled its server function, so I had to set it up again. This casts some doubt over its reliability. I'm going to keep Splashtop, and use CRD as backup. See comments below.

Thursday, August 29, 2019

QSL: 4KZ Innisfail, QLD 5055

The 4KZ 1620 kHz 400-watt relay is quite easy to hear at my location, despite the 12,800 km distance.

Not so with their 1.3 kW station on 5055 kHz! After a few futile (albeit random) attempts, I decided in February to monitor and record three top of the hours every day. I also wanted to do an A-B comparison between the Airspy HF+ and the SDRPlay RSP1A. So both were connected to the same antenna, two different PCs with HDSDR running on both. After quite a number of days, the signal was finally readable.

The HF+ is known to be a very sensitive SDR, while the RSP1A is more average when microvolts are measured. So, there "should" be a difference in audio recovery, at least on threshold signals. There was. When signals are very weak and the noise floor is low, better sensitivity is indeed audible. Here is how 4KZ was heard at the time. Headphones recommended.

The 4KZ General Manger Al Kirton is a DX-friendy guy, and sent off a proper QSL card with a sticker and info in the mail.


Friday, August 23, 2019

Airspy HF+ Discovery: Sensitivity Measurements

Time to find out how sensitive the HF+ Discovery is! Since it is basically the same receiver as the HF+, with preselectors, I expected sensitivity on MW to be roughly the same. Which turned out to be true.
On 500 kHz, I measured -110 dBm, on 1000 kHz -111, and on 1500 kHz -110 dBm. Using SDR#, v.1708, 6 kHz bandwidth with AM mode, and a 30 % modulated, 400 Hz signal from the signal generator.

The "Receiver Sensitivity Measurements" table has been updated accordingly. Excellent numbers.

Tuesday, August 20, 2019

Airspy HF+ Discovery Has Landed

Well admittedly, the Norway transport was on road, taking twice as long as from Shanghai to Oslo. But it arrived! Just fired it up at my home in Tana, no antennas available, so only to get a feel of it (feels warm to touch) and do the latest firmware update. Sensitivity measurements will be done on Friday.

My kitchen weight says 32 grams. By a good margin the lightest SDR I've had so far.

Sunday, July 28, 2019

Antenna Test: The NTi MegaDipol MD300DX

Not much is happening DX-wise during the light Arctic summer, but I had the opportunity to check out a dipole antenna sold by bonito.de, the NTi MegaDipol MD300DX.
For the time being, you can check it out yourself on my KiwiSDR, see link on the right hand side.

Beverage antennas are the norm at my KONG (Kongsfjord, Arctic Norway) location, because I and my co-users are exclusively MW DX-ers. For general listening, especially on SW, other antenna designs may be better, and for some time I have had a 70-metre longwire up as an all-purpose antenna for use with my KiwiSDR. Many years ago I tested a Mini-Whip antenna, and also the venerable Clifton Labs Z1501 active whip. Two years ago I bought a Wellbrook ALA1530LF for noise detection, and made a comparison with the longwire.
There is no doubt that a properly installed longwire antenna is very efficient on a broad frequency spectrum and may be the preferred alternative if space is not a limiting factor. But often space is restricted, necessitating more compact antenna designs.

Enter the NTi MegaDipol MD300DX. The MegaDipol, priced at EUR 400, comprises of an external antenna unit with two detachable 2.5-metre PVC-coated steel wire elements, and an internal power inserter which powers the external unit via the coaxial cable. The inserter can be powered from a 10-15 VDC supply, or from a 5 VDC supply such as a USB port with slightly less IP values. It is worth noting that the MegaDipol is an E-field antenna, so it should be placed in an electrically quiet environment. For omnidirectional reception, the elements should be placed vertically.


My first test of the MegaDipol was done well away from any potential noise sources, 170 meters away in fact. It was fed from a DX-Engineering coaxial cable. I later added a ground connection to the external unit. At my location, the added grounding did not change the noise floor or signal levels, but the general recommendation is to ground the antenna.
Later, I moved the antenna to a pole much closer to the house. The move from 170 meters away to 30 meters away did not change the noise floor or signal levels.


During the comparison, both antennas were connected to DX-Engineering 75-ohm coaxial cables. The longwire in addition had a matching transformer from DX-Engineering and was grounded on both ends. The MegaDipol was also grounded. The antennas were connected to two KiwiSDRs to facilitate accurate comparisons with identical hardware. Both feedlines had RF isolators inserted; The NTi GI 1000 galvanic isolator for the dipole, and the Wellbrook AFI-5030 for the longwire.
So, how does the MegaDipol compare to the longwire?

Longwave:

I was surprised to see the exceptional performance of the MegaDipol on Longwave. The lower down, the better. On my semi-local NRK 153 kHz, gain was typically 20 dB or more higher than the longwire, and the noise floor was a bit lower. So, all in all up to 25 dB better SNR. The difference decreased with higher frequency as my semi-local NDB “BV” on 399 kHz noted “only” a 10-12 dB difference in SNR.

Mediumwave:

While I had groundwave signals on LW for the comparison, summer daylight limited my comparisons to late evening skywave signals from the south – in the longwire’s lobe. Generally, the longwire does seem to have stronger signals, but the noise floor on the MegaDipol was lower. So, in effect, the difference was only slightly in favour of the longwire.

Shortwave, up to 7 MHz:

A bit like MW performance. The noise floor on the MegaDipol is lower, but so are signal levels. The net result isn’t very different, and one should note that the longwire’s length of 70 meters is very well matched with this part of the spectrum. A shorter longwire would likely not perform as well.

Shortwave, above 7 MHz:

The MegaDipol’s performance compared to the longwire increases with frequency. On a 31-metre band signal, the MegaDipol and the longwire were practically identical in SNR values. From there and up to 30 MHz, the MegaDipol performed increasingly better than the longwire. Skip on 27 MHz was mostly undetected on the longwire. A shorter longwire would probably fare a bit better than the long one, though.

VHF:

The MegaDipol claims to hear up to 300 MHz. I compared the MegaDipol with a 3-element FM antenna on the FM and DAB frequency ranges. On FM, I only had one rather weak Finnish station to compare. It was fair on the FM antenna, not heard on the MegaDipol. On a 225 MHz DAB channel, both antennas heard the signal, although the FM antenna had a 10-dB better signal level. Noise levels were identical.

Directionality:

By mounting the two elements horizontally instead of vertically, it is possible to add directionality to enhance or reduce signals from chosen directions. Late in the test, NTi supplied me of 5-metre elements, one of which was placed semi-horizontally (sloping from 2.5 to 1.6 meters) off the direction of a wind park a few km away. The signature RFI of the Siemens wind turbines, increased noise levels from around 750 to 500 kHz, was reduced into general noise level when I pointed the horizontal element in its direction. The signals from 153 kHz and 399 kHz were also reduced a few dB, although a deeper null might have been possible if I had placed the direction of the horizontal element more precisely.

Overall:

It’s a shame that I don’t have the Z1501 active whip anymore. It would have made a very interesting comparison. Since the Z1501 is out of the equation and considering previous comparisons I did with the ALA1530LF, the longwire and the Mini-Whip, I can safely say that the MegaDipol is an excellent overall performer, and the number one compact antenna I have tested so far.  The price tag may be discouraging for some. However, the Wellbrook loop checks in at GBP 225, and even the cheap longwire’s matching transformer is USD 60. So, small, active antennas usually come at a price. Longwires are cheap – if you have the property to fit one.