Friday, January 12, 2018

The RSP1A - Some Conclusions

After a few weeks of use in Kongsfjord and Smøla island, here are my impressions of this inexpensive, but quite able SDR.

Thursday, January 11, 2018

QSL: JO-- NHK-2 Nagano Relay, Matsumoto 1512

Every now and then, a frequency dominant fades and gives room for less common stations. Like late October when the usual JOZB NHK-2 Matsuyama gave way to the 1-kW relay of NHK-2 Nagano in Matsumoto. A custom-made QSL, obviously printed on an inkjet printer, was received today.

Wednesday, January 10, 2018

QSL: CBQT Wrigley NT 1280

"This is CBC Radio One. 98.9 FM in Yellowknife" was the rather unexpected announcement on 1280 kHz one evening in November last year. CBQT Wrigley is one of CBC's low-power repeater stations, and the only one on 1280. An email from CBC North confirmed my reception, thanks to Ole Forr who first spotted it. The distance is 4975 km, so even 40 watts can travel great distances when propagation is right.

Wrigley has around 130 inhabitants, and is the end point of the Mackenzie Highway. There is even an air strip at the east bank of the Mackenzie River. Canada MW verie #220.

Tuesday, January 09, 2018

QSL: JO-- NHK-2 Kagoshima Relay, Naze 1602

This relay of JOHC 1386 was heard with surprising clarity one day in late October, and I received a friendly letter today. Naze is a 1-kW relay, located on the island Amami Oshima, 350 km southwest of Kyushu island. MW verie  #110 from Japan.

Sunday, January 07, 2018

New Radio(s) - Pt. 3: Evaluation

I'm currently spending the weekend at an extremely stormy Smøla island together with OJ Sagdahl, Ole Forr and the host, LA2XPA Rolf Torvik. I have had the chance to compare the receivers mentioned before, and the results were not very surprising. Inexpensive SDRs may in some instances be a good alternative for the dedicated MW DX-er, but if the signal levels are high, the Perseus shows its might. That said, the HF+ did remarkably well. Here's the write-up.

Thursday, January 04, 2018

New Radio(s) - Pt. 2

As mentioned in a previous post I also got hold of the new SDRPlay RSP1A just before Christmas, so two novel SDRs with rather different architecture were purchased the last month. Below are the two together, the HF+ to the right. The RSP1A, no monster size itself, brings perspective to the credit card sized HF+. There are no LEDs on the SDRPlay. The HF+ has a tiny orange LED for power, and a blue LED for running.

What I want to do at Smøla island the coming weekend is the following:
- Test the SDRs against the Perseus as a reference SDR in a period with the highest signal levels.
- Test the SDRs against the Perseus in a period with the lowest signal levels.

Hopefully, I will be able to note any differences with regards to overloading, and the ability to separate weak signals next to very strong ones. I should also be able to note how they resolve very weak signals. The SDRs will be connected to an efficient beverage antenna, and being a MW DX-er, I will focus on MW and possibly a bit on SW. I won't tune above 30 MHz! Promise!

Wednesday, January 03, 2018

New Radio

In the series "You Can Never Have Too Many Radios" the next chapter is Airspy HF+ which I picked up at the post office today. Its MW capacity will be tested the coming weekend. It's small, as you can see, but quite heavy. 90 x 55 x 12 mm excluding the antenna ports, and 187 grams. More to come.

Monday, January 01, 2018

KongSDR Finances - December

Despite wintery conditions, the KongSDR has been online practically every hour of December, thanks to excellent hardware and a broadband mobile connection without outages. In December, the manufacturer Seeed finally offered a metal enclosure for the KiwiSDR, which adds a little physical and RFI protection. Here it is, rather out of focus, standing next to one of my Perseus SDRs.

The financial support for the KongSDR is still strong. I am thankful that many users find it useful and want to contribute to its existence.  Happy New DX-Year!

Monday, December 25, 2017

The SDRPlay RSP1A: A Closer Look

After I had done my first test of the RSP1A I realised that the comparison I did was rather unfair. The SDR was connected to a cheap laptop, and cheap laptops usually have awful audio cards. Especially in comparison with the Cakewalk UA-16 I use on my main PC! So I moved the radio to the main PC and decided to do another test.

This time, I recorded 20 seconds of audio from a very weak KONP 1450 kHz to the RSP1A, the Cloud-IQ and the Perseus (Jaguar software).

So you can listen for yourselves. Sorry that the line level of the Perseus came up a bit louder than the other two. The sequence is: 20 seconds RSP1A, 20 seconds Cloud-IQ and 20 seconds Perseus/Jaguar.  Software used with RSP1A and Cloud-IQ was SDR Console V3, USB mode, 2.8 kHz bandwidth (Perseus 3.2). The audio is recorded today at 12:30:00 to 12:30:20 UTC.

Apart from this, I have compared the RSP1A to the Cloud-IQ on various frequency ranges, various software (HDSDR and SDR Console V3), but only with the 2,048 kHz bandwidth. It does in fact fare well.

Below are the RSP1A (left) and Cloud-IQ when connected to a 500-metre, 50-degrees beverage (the Asia-Pacific antenna).

Friday, December 22, 2017

New Toy: SDRPlay RSP1A

First 10 minutes of use: Not bad for USD 100. Setup was ok, I chose to use HDSDR and when default setup was chosen, it was up and running. I needed to push LNA all the way up (which turned out to be UP towards zero!) for best sensitivity though.

Speaking of which: Not at the Perseus level, but not too far behind. Here's an audio file from KLAM Cordova Alaska 1450 with a relatively strong interfering signal on 1449. RSP1A is set up with USB, 2.7 kHz bandwidth. The Perseus is also set up with USB, but 3 kHz bandwidth. Antenna: 340 meters long beverage directed towards western North America. When I tested on KHKA Honolulu 1500 (below), the difference in sensitivity was noticeable with KHKA having audio and being partly readable on the Perseus. The RSP1A could only barely hear audio.

For sure not an SDR to replace the Perseus-grade SDRs. The price-performance ratio is good though.

More as it happens.