https://alexnld.com/product/latest-v9-version-1-10d-malachite-radio-dual-antenna-malahit-dsp1-stereo-sdr-receiver-50khz-to-250mhz-400mhz-to-2ghz/?hilite="100K-50MHz RTL-SDR Supporting long Antenna 9:1 Impedance Transformer Balun HF"