Hello I've tried to remove the L-band gap on my E4000 tuner by changing the divisors. Please see the patch below. I don't have a signal source to test today, so i'm not sure if it works, but the pll locks. I will try to test tomorrow. Without my hack: E4K L-band gap: 1093 to 1233 MHz With my hack: sq5bpf@dellix:~/gnuradio/rtl-sdr/src$ ./rtl_test -t Found 1 device(s): 0: ezcap USB 2.0 DVB-T/DAB/FM dongle Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle Found Elonics E4000 tuner Supported gain values (14): -1.0 1.5 4.0 6.5 9.0 11.5 14.0 16.5 19.0 21.5 24.0 29.0 34.0 42.0 Benchmarking E4000 PLL... [E4K] PLL not locked for 51000000 Hz! [E4K] PLL not locked for 2186000000 Hz! E4K range: 52 to 2185 MHz E4K L-band gap: 0 to 0 MHz Regards Jacek / SQ5BPF --- tuner_e4k.c.orig 2012-11-08 22:08:07.000000000 +0100 +++ tuner_e4k.c 2012-11-08 23:01:05.000000000 +0100 @@ -35,6 +35,7 @@ /* If this is defined, the limits are somewhat relaxed compared to what the * vendor claims is possible */ #define OUT_OF_SPEC +#define HACKED_DIVISORS #define MHZ(x) ((x)*1000*1000) #define KHZ(x) ((x)*1000) @@ -357,7 +358,14 @@ {KHZ(350000), (1 << 3) | 1, 8}, {KHZ(432000), (0 << 3) | 3, 8}, {KHZ(667000), (0 << 3) | 2, 6}, - {KHZ(1200000), (0 << 3) | 1, 4} +#ifdef HACKED_DIVISORS +/* the original settings seem to be ripped from some Elonics driver, + * however changing them a bit removes the L-band gap + * change this to a bit more then the end of your L-band gap --sq5bpf */ + {KHZ(1270000), (0 << 3) | 1, 3} +#else + {KHZ(1200000), (0 << 3) | 1, 4} +#endif }; static int is_fvco_valid(uint32_t fvco_z)