SDRs and Tuning knobs

I am going to get an Elad Tmate-2 tuning accessory for my SDRPlay RSP2Pro. This device is a bit pricy, but it will make using the RSP2Pro much easier. Couple that with a good desktop running SDRUno, and I thing I will have a great receiver, when coupled to the mag loop set up I am designing (Mounted high, with a rotor for nulling and remote control).


When I get it, I will let everyone know how it works out.


73 de KD1IT


Yesterday, I received a ZUMSPot modem that plugs into a RaspberryPI. I opened to have it in a Raspberry PI3 B+, with integrated WiFi. After setting up PIStar on the unit, I started having conversations with people in England, Canada and the East coast of the United States. Basically, the ZUMSpot is a hotspot for Data/DMR/etc digital voice modes. It can connect to reflectors to allow you to see other people listed and make a call to them. Very cool. I am trying to get a friend in NH to get one, and get on it, so we can chat while the solar flux is at its lowest. HF hasn’t been too good lately.


Will say more on the ZUMSpot and MMVDM as I get more and more used to using it.




So, I am interested in building a MMDVM (Multimode Digital Voice Modem) for hooking into DSTAR. So, I spent 8 hours working on a PI-Hat similar to the ZumSpot Pi Zero. Since ZumSpot seems to be dead, I decided to build my own. I finally have the schematic done, board placed and routed. Now, to get them built.

FWIW, I love the ST Micro STM32 MCUs. I use them in our professional work, through I am using a less powerful one on this design.

Here are photos of top and bottom:




MMDVM HS bottom

New SDRPlay RSP-2Pro

Well, I have received a SDRPlay RSP-2Pro and I love it. Such a beautiful SDR. The folks at SDRPlay really did a nice job on this thing. I run SDRUno with it on a (ick) Windows 10 installation in BootCamp on my MacBook Pro and it is a nice combo. (Hey SDRPlay, you should have me port SDRUno to macOS!). What I like about the RSP-2pro is the metal case, and that it has 3 antenna inputs. a Hi-Z, a standard SMA antenna connection, and a bias-t SMA antenna connection (to power those LNAs, etc). The thing really shines, and compared to the RSP-1, the difference is amazing. Another SDR for the shack!


OpenWebRX and SDRPlay

My day job keeps me busy (I run a company and also try to be one of the engineers). Anyway, I was playing around this weekend with OpenWebRX. I have an SDRPlay RSP1. I decided to do a little hacking/configuration and build a remote receiver. I used, originally, a Raspberry PI 2, but found that the CPU would get maxed out. I switched to a Raspberry Pi 3 and discovered it has plenty of horsepower to do this. I downloaded OpenWebRX and then used HB9FXQ (Frank Werner-Krippendorf)’s SDRPlayPorts code to build play_sdr and feed it to OpenWebRX. The result, a nice running remote SDR.