Just a quick post about my newest mobile fun! I went out and bought a 102" steel CB whip (this will keep me out of the garage and the drive-thru!) I had to secure the magnetic mount base with a piece of nylon cord since the wind load is quite high.On my 45 minute commute, reception of RNZI on 17675 kHz was intermittent, but I was able to listen for 3-5 minutes at a time without dropouts. Using my C. Crane FM transmitter, the car stereo sounded great with RNZI's audio. I wished they were playing music, but it was mostly news and talk.
SNR was as high as 25 dB. In the above image you can see 23.6 dB. I must say that I was not disappointed, but wished for my stable steady signals to be sure. The 102" whip was a real improvement and I can see this will be a great addition when it comes to general HF/SW reception in the car. Yesterday, I was using the Pappradio, Asus Eee PC (with HDSDR and DReaM) and 102" CB steel whip antenna.
Overall, noise levels were low unless I passed through a field of high tension power lines or some other odd RFI situation. Propagation was making New Zealand a moving target. Under better conditions (come on solar cycle!) mobile DRM is truly doable, even in North America! I'm not beyond thinking that a properly tuned and filtered preamp might be the answer to more steady decode.
