HackRF and SdrAngel PTT

One of the annoying things about the HackRF is that its only 1/2 duplex. It could be a receiver or a transmitter but never both at the same time as a transceiver. Not anymore. SDRangel now has a new feature, the PTT button that automatically switches from RX to TX and back again. To use it is very easy. Setup your source device, then setup your sink device, click the play button and then when you hit the PTT button you will switch from RX to TX like a pro,

I have been playing with this new feature this morning using a 2m handheld and the HackRF and having QSO’s with myself at the milliwatt level LOL. The received audio in SDRangel sounds rather rubbish, i am sure I have some setting wrong somewhere, but it sounds thin and at times distorted. The transmitted audio does sound a little better.

As far as software goes, its good to see the developers of this continue to improve and expand it. There are also a lot of new demodulation types as well since I last updated it.

IARU Contest

I did not try and make any contacts in the contest, but i did turn on the SDRplay and have a listen for a while. Not that i heard a great deal, but there was enough there to keep me interested for an hour or so. Anyway, mostly i played with settings and the like seeing if i could improve the reception. I was using an outboard bandpass filter for 40m. I know the filter is quite good because i have plotted it with the VNA, but when you are looking at 4Mhz of spectrum, and see the above image, it just reminds you of the job the filter is doing keeping stuff out of the front end. Lastly, take a look at that strong CW station, you can read the dots and dashes, who says morse is not visual HAHAHA.

HF on RTL-SDR

So it turns out, that just by changing a DLL file in SDR# and changing from Quadrature to Q Branch, you can get HF on a dongle without an upconverter or modifications to the hardware. And most surprising of all is it actually works ok. I do have some AM broadcast breakthrough and I will need to add in a Highpass filter to remove it, but other than that, it looks like it works quite ok.

Brisbane Air Band

So i bought an RTL-SDR dongle to play with. And after fighting with windows 10 to install the drivers and then fighting with the software to recognize the dongle I finally got it working and able to receive signals. Connected to a 40m dipole, its not really the best antenna to be receiving VHF and above, but after a few tests listening to a local 2m repeater, a bit of simplex from my HT on 2 and 70cm, i figured it was time to actually look for some signals to listen to.

So with SDR# running, I tuned into Brisbane Air Port air traffic control for a bit of a stickybeak to see whats going on. Also at the same time, I have started to play with screen recording software and video editing software with the plan to start making the odd youtube on what I am doing. Anywho, with all that in mind, I do have some plans for different things to do with the dongle. I have some bits and pieces in the mail already to add to this and well watch this space, more to come. Oh and the reason why i got this was to use it to learn how to use GNU Radio. That is the ultimate plan and to learn some things as we go about doing that.

Here is a little video from earlier: