Long time no update. A lot has happened.

My last post was in January this year. It’s August now. Lots of things have changed around here.

First of all i changed QTH. I now live in a place where i can mount a larger antenna IF I WANTED TO. In fact, if i wanted to get back into some serious radio i WILL have to build a new antenna because my previous antenna got lost in the move. But do i want to? This i will explain later.

Then i changed job. Where before i was working from home and never left the house, read: lots of time for radio, now i have to travel every week. So when i am at home i want to be with the family, work on the garden, the pool, the BBQ and not lock myself up in my office again to do some radio.

Then, and that’s the most important at the moment, the sun has gone really quiet lately. I know the cycle is going down, but i didn’t expect it to go down this dramatically. This was a very short and very unpredictable sun cycle. So to spend money on a tower and an antenna when there is hardly anything to listen to, no. That’s not the plan.

Let’s see. For the moment i just let my SDR create some daily heatmaps and maybe at some point, when the winter comes and conditions pick up again, i will decide to build or buy something.

UPDATE!

A second heatmap server has been installed. This time i used a leftover Raspberry Pi and a RTL-SDR adapter. This one is going to cover everything from 24MHz to 1.7GHz. At least, that’s what i understand the RTL adapter can handle.

CubicSDR has progressed into a great piece of software

It’s been a while since i wrote on this blog, but that doesn’t mean nothing has happened in the mean time. Things have progressed a lot on the panadapter front.

In my last post i wrote about the SDRPlay only supporting Windows, well that has changed, SDRPlay now also supports OSX. that makes that i can now use CubicSDR on my Mac and specifically CubicSDR has come a long way in it’s development:

  • I wrote about CubicSDR supporting osmosdr, that has changed. CubicSDR has now moved to SoapySDR. SoapySDR is an open-source platform for interfacing with SDR devices and supports the most common SDR devices under which the SDRPlay. More about SoapySDR on https://github.com/pothosware/SoapySDR/wiki

soapy_sdr_info

  • CubicSDR now also supports Hamlib. Hamlib is a library to control radio receivers and transceivers and one of the transceivers supported is my TS-590. More about Hamlib on http://sourceforge.net/p/hamlib/wiki/Hamlib/

Hamlib_design

  • CubicSDR is going to support more modulations, specifically the digital ones. So we will be able to decode digital signals without the need for Windows decoding software. This is not finished yet, but it’s looking good so far.

Screen shot 2016-01-06 at 14.06.16

  • then there are many small new features like multiple SDR support, RTL-TCP, audio device support, automatic and manual gain control, many UI improvements and many, many more enhancements to come. The developer Charles J. Cliffe is really putting a great effort in building a superb SDR program that is going to give HDSDR a run for its money.

So when i add all these new developments up as of now i will use CubicSDR as my panadapter for my TS-590 without the need of having to use Windows. I removed my RTL adapter from my radio and am only using the SDRPlay from now.

Houston, we have an issue with the SDR setup

11-19-2014 11-58-04 AM

So in general i am happy with my SDR setup. I cannot imagine going back to use my radio “in the blind” without being able to see what is happening on the band. Most of the stations i work are stations that haven’t been spotted on the cluster yet. SDR helps me to discover those stations and work them before the pile-up caused by the clusters starts.

I have spent my time mostly on 10m. I am very surprised that this band is so active the last months. I don’t know why that is. I was always under the impression that 20m was the most active band, but when i look at my bandscope i see much more stations on 10m than on 20m. And it’s not my antenna setup that is deaf on 20m because when i look at the cluster stats i also see roughly twice the amount of 10m spots compared to 20m spots. Anyway, band perculiarities set aside. Houston, we have a problem with the SDR setup.

As i mentioned in previous articles when i was building the SDR solution, i pick my IF signal from CN303 which is on the RX-2 path. Why? Because the IF sits on 73.095MHz which is a frequency i can “hear” with my RTL-SDR adapter. The IF on RX-1 sits on 11.374MHz and the RTL-SDR doesn’t go that low. Because i have almost solely been working on 10m i haven’t noticed anything wrong with my SDR setup. After all, everything between 21.5 and 30.0MHz goes through the RX-2 path.

Yesterday i wanted to work a few stations on 20m and i noticed that my SDR doesn’t receive anything unless i set my RX filter wider than 2700Hz, then suddenly CN303 gives me a signal again. In the image above you can see how it looks on the band scope. It’s either nothing (filter narrower than 2700Hz) or the normal bandscope as i am used to see (filter wider than 2700Hz).

In the Service Manual i found a table that shows which RX path is chosen when and as you can see in this table there are quite a few moments where i need to open the filter to be able to hear anything at all. Most significant (to me) are the 15m band and the 20m band. Below 20m there is nothing for me to do anyway because of antenna conditions.

Thinking about it it’s not a huge problem (so Houston, you can get back to work again), but merely an inconvenience. Now that i get used to the TS-590 i started to play with the RX filter and equalizer settings and i found that i get the most out of the radio with the filter set appx 1600-1800Hz wide (300-400 Low and 2000-2200 High) and the RX equalizer to one of the two High Boost settings (HB1 or HB2). Now i need to get used to use a much wider filter setting and change the RX equalizer setting for 14 and 21MHz if i want to continue to use the bandscope to help me find stations that were not spotted yet.

Reading it back, what does this article actually tell you? Not much, really. Many times i just start writing to get my thoughts and priorities straight and fixing this SDR “problem” is now, after writing this article, not a priority anymore.