Hi LF
I'm puzzled with the readings of bandwidth at the Op32 correlation detection grabbers
As source I'm using a GPS generated signal, which is coherent in phase and works for EbNaut
So I tested this at 20x frequency to drive an small D class PA and modulated in Opera32
The OOK was achieved by enabling/disabling a divider by 10 just after GPS
Sourprisingly, my decodes at DF6NM and DL0AO varied in width, but always showing width of a non coherent signal
2018-09-24 16:55:09 EA5DOM 1500km 137485.051Hz 71mHz -99.9dBOp 78% 17.6dB
2018-09-24 15:35:10 EA5DOM 1500km 137485.026Hz 114mHz -99.9dBOp 100% 17.3dB
2018-09-24 14:13:18 EA5DOM 1500km 137485.039Hz 164mHz -37.2dBOp 100% 20.7dB
2018-09-27 19:08:06 EA5DOM 1536km 137485.013Hz 110mHz -38.3dBOp 94% 18.8dB
Last night I tried without PA. Using just a mosfet driver this time getting
about 1W output. The GPS generates the 10x frequency and the OOK is controlled
by enabling/disabling the divider by 10. Got a couple of decodes at DF6NM
2018-09-29 02:17:39 EA5DOM 1500km 137485.007Hz 5mHz -46.4dBOp 85% 15.4dB
2018-09-29 00:37:50 EA5DOM 1500km 137484.986Hz 112mHz -43.2dBOp 100% 19.6dB
So, 5 and 112mHz, for the same signal. I'm thinking that the problem is caused
by glitches when the signal goes off. A synchronous off would be needed to
cut signal at zero crossing ?
Reports to other stations, like SM2DJK, show just 2 to 3mHz
Any ideas ?
PS: Stefan. Your Op32 correlaton detector is not working actually
73 de Luis
EA5DOM
