Author: Razvan

DXpedition videos – T33R, T88CJ, VP88SSI, 7J1RL

After the previous post about DXpedition videos, I decided to add some more. Here they are: T33R T33T Banaba Island (1990) T88CJ Palau (2008)  VP88SSI South Sandwich Island (1992) – some of the worst conditions to operate in 7J1RL Okino Torishima (1976) – Huge effort by the Japan Amateur Radio League, taking alot of manpower to the shallow atoll in order to install suspended shacks and towers, in an era before GPS or DX...

Read More

Kenwood TS-990s – inside pictures

Some pictures of the Kenwood TS-990s popped up recently, it’s a real beauty. The pictures are on the QRZ – Ham Radio Facebook page, not sure what is the original source. Also posted on my friend YO3IBW’s...

Read More

A bit of solar activity

Hopefully these days we will finally get a bit of solar activity and of course, a bit of 10m openings. The number of sunspots continuously grew in the last five days (60 > 63 > 88 > 90 to 115 today), the SFI is a mediocre 115 and in the next few days quiet to unsettled  geomegnetic levels are expected. I had the chance to work a bit in 10m SSB and I got 2 new entities (GU3UOQ – Guernsey and XT2TT – Burkina Faso), it still appears to be open right now (about 19:00) as I am recieveing strong stations from South America on JT65-HF (LU5FD, PY2VM etc), as well as ZS1AW from South Africa. Unfortunately 10W doesn’t really cut it for me, I guess JT65 is indeed a low signal mode and not a low power...

Read More

Kenwood TS-990S instruction manual is public

Kenwood has released the TS-990S instruction manual today, so it brings much more info about the contest-class long awaited chunk of iron. I didn’t get the chance to read it yet but I will come back with some comments shortly, in the meantime you can download it here:Kenwood TS-990S instruction...

Read More

V53ARC – multiband WSPR beacon in Namibia

In the last few days my station has been running continuously on WSPR frequency hopping between the 80m, 40m, 20m and 10m bands, and I got the chance to spot on 10 meters the V53ARC WSPR beacon in Namibia. Apparently it is on the air since 2009 and this is the first time I spot it, and by looking the callsign up over the internet I found it’s story. The beacon is maintained by the Namibian Amateur Radio Centre and it is installed remotely on a farm, running on solar power and using a vertical multiband antenna. It transmits continuously with 1W of RF power, cycling trough the 80m/40m/30m/20m/17m/15m/10m/6m bands, meaning it will transmit a WSPR sequence of 2 minutes every 16 minutes on each band. The transmitter is the work of Gernot Frauscher OE1IFM and it’s a smart design, properly built for the purpose, with a CPU controlling the AD9851 DDS, a GPS reciever for precision timing and frequency reference and a 15W final stage with switched LPF. You can find more details about it – including schematics over at OE1IFM‘s website; he also describes the multiband vertical he used for the beacon, wich seems a good solution for the space limited individual. Looking on the WSPRnet website I see it gets a fairly low amount of spots, about 10 each day; there aren’t too many WSPR stations...

Read More

DXpedition videos – VP6T, 3D2C, BS7H, 5A7A, AH1A

 Ever since the beginnings of my ham radio adventures i’ve been curious about operating from parts of the world the civilisation hasn’t reached yet; I guess it’s one of the few ways you can still be a hands-on pioneer these days. Dxpeditions, SOTA, IOTA, you name it, I want to see how it has been done and how was the feeling to do such a thing, what equipment did they use and what challenges they had to overcome, how they laid out their antennas or how much planning was put into. Recently have been published two videos of DXpeditions that took place last year. The first one is 3D2C in Conway Reef, wich doesn’t have an embed option so you need to check this link out in order to view it: 3D2C Conway Reef 2012  The second one is VP6T Pitcairn Island, you can check it out below: There are also older DXpedition videos that I really enjoyed, made just like a documentary with plenty of info: 5A7A Libya (2006) BS7H Scarborough Reef (1997)  And finally, the oldest but best, AH1A Howland Island (1993) I will probably post more of these, I still have alot in my list of...

Read More

Over the Horizon radars and ham radio interference

Since the early days of the cold war and culminating with the Russian Woodpecker, ham radio operators have reported powerful jamming-like wideband signals creating disturbance in the amateur short wave (HF) bands. These are created by powerful over-the-horizon (OTH) radars that use the HF spectrum to “visualize” significant portions of the entire planet in just one sweep by using the all-so-loved (by us amateurs) phenomenon of ionospheric reflexion. Thanks to my geographic location and to the fact that i use a SDR transciever with panadapter/waterfall, it so happens that almost daily i get to identify an OTH signal somewhere in the HF spectrum, so I got a bit interested; and when i saw EI2KC’s post earlier today about the incredibly strong OTH signal recieved by S57S just a few days ago, I thought I should put my thoughts in writing. The most famous OTH radar is of course the soviet cold-war megalomanic station DUGA-3, the fully grown brother of the smaller and experimental DUGA-1 and DUGA-2. This mutant is located in the Chernobyl exclusion zone, the transmitter and reciever being about 60Km apart. The sight of such an installation, taken offline in 1989 and now deserted, brings chills down my spine. The huge array of wideband Nadenenko dipoles and reflector plane coupled with the powerful transmitter managed to put out reported EIRP up to 40MW (!). The signal was...

Read More

WSPR and antenna radiation pattern

WSPR seems to be not just a tool for actively monitoring the propagation status, but it can also help you trace the radiation pattern of your antenna. Of course, for a reasonable trace we would need WSPR stations all over the world using all types of antennas, but I guess we will have to make do with what we have for now. This is the result of about 6 hours of WSPR in the reliable 40m band, from 04:00 to 10:00 local time, running 10W, 10% transmit cycle and a Windom antenna. The north-west / south-east patterns seem to be predominant, but we must also take into account the fact that there are just a very few WSPR stations in Russia, Africa or South America, some of them were active (like PY2FLP) as I could see in the WSPRnet.org spot database, but no spots for me. Then there is also the antenna’s takeoff angle, wich makes the wave “land” at a certain distance from where it’s transmitted; lower angle means your signal will go further, so the fact that I got alot of spots from the East coast of the USA but none from the West means my takeoff angle should be a bit lower if I want to work that region.   This can also be observed by looking at the closest spots, OK3SAM, IK3NLK or USP041 all...

Read More

Archives