Hi,
If produced 25 MHz from 100 MHz it is 12 dB less and from10 MHz is 8 dB more. So for 10 MHz the Lo(9750) must be 50+8=58 dB more and for 100 MHz must be 50-12=38 dB more.
Hi,
If produced 25 MHz from 100 MHz it is 12 dB less and from10 MHz is 8 dB more. So for 10 MHz the Lo(9750) must be 50+8=58 dB more and for 100 MHz must be 50-12=38 dB more.
Hi,
Lets suppose that we have two OCXO one in 10 MHz and one in 100 MHz with the same phase noise at the same offset.The phase noise is increased by 20log(N) dB) where N is multiply factor. In our case N=10, so we have 20 times dB larger noise. It meens in simple words that if we create 10 MHz from 100 MHz it will have 20 time dB less phase noise or if we create 100 MHz from 10 MHz it will have 20 dB times larger phase noise. It is obvious that when we produce 25 MHz from 100 MHz the phase noise will be less than produced from 10 MHz. One calculation that I have done is that phase noise produced by multiplying by 390 (9750/25) is about 50 dB times bigger!!!
The ECOC-2522-100.000 existis in various versions with similar prices and different ppB, so a small ppB is prefered as has better stability... PA3FYM AOCJY1-100.000MHZ seems a good choise for GPSDO available from Mouser at half the price.
Is there any duplicate in address?
If you unplug the PCB, is there any other device using the same address?
DL5LF it seems that you have the right PCB and it seems that you have the right address. Do not try to burn it again. It seems OK. I have no idea for the moment.
Can someone point to a working usb HID relay?
I bought one (HW-343) which does not seem to work on Win10.
Hi,
Can you provide us a picture to verify that you have a correct one?
The 'good' ones are the red.
My first red one was missing burning the firmware.
When I bought the second it was possible to read the code and burn to the 1st one and it worked!
Can you see in USB info if it see it and if yes in what address?
Hi,
Maybe I am not understud. The proposal is to send also 430 MHz, not LO. Also my proposal is to combine also Rx NB&WB signals. Now I use one for 25+739+13V , one for 740-750+18V and one for 430 MHz. The proposal is 3 to 1 cables.
Hi,
Can you provide the link of the ON4CJQ solution? Also keep us informed about your progress. I use 25 MHz+740+bias and 430 for the other cable. I run about 60 meters. A Lab testing can be personal run from September. Also I use a second cable for H. Maybe a combiner can be used also to use a single cable for NB and WB signals. One question to the designers of QO100 is why NB and WB use different polarization?
Hi,
Even OCXO is temperature affected!!! When I build Lars GPSDO and use modified code by PA3FYM when I open or close the air condition it was loosing lock and the code was modified in order to handle such changes. This GPSDO was compared to Cesium and a drift of +-2 Hz at 10 GHz was noticed. It is not perfect but such a stability is more than enough for QO100.
Hi,
In order to measure phase noise your instrument must measure less phase noise than the signal measured. Are you sure about that?
Hi,
Frequency hopping lab tested. It seems that relative wide bandwidth can be archived. Also 3500 hops/sec works fine (1 symbol per hop)!!! This hoping capability seems a dream for a PLL based FH system.
Hi,
Simplified block diagram.
Hi,
A lab flowchart without RF is build that create digital voice, modulate them using QPSK, then DS them *10 using a random noise source and then successfully de-spread it etc producing again voice !!!
In the photo the 1st graph is the produced QPSK signal, then after spreading it and then as received after a LPF.
Hi,
DB2OS is spread spectrum can be operated at NB or/and WB ? Is definitely not or it is a matter of discussion?
My thought is that with GNURADIO and GPSDO Pluto, old hardware solution US expirements described in ARRL publications, can now be software iplemented. At QO100, development can be done 'easy' as the received signal can be monitored.
Hi,
Poll and testing Tx ended.
Thanks everyone participating in any way.
I hope that this experiment was useful.
pe1hzg I am happy that it it was useful to you !!! 0 is my highest power. All the project is experimental, not fully calibrated. It is a try to see it in practice. The biggest personal challenge is that my station operated 25% duty cycle at 43 Celsius roof (environment) temperature !!! ... it still working ...
Well, i can tell that i hear level 24 , even 27, but only that it is there, just a bit over the noise. If i was meant to understand level 24, i would fail. So I voted 21.
So to really determine how deep you can hear in the noise, random words do the trick. 73, martin
I vote 18 but 21 is Q3 ...
Hi Ernst,
I can not confirm or say it is not so regarding your measurements as I have to stop the testing. As I said files has been normalized.
Hi
Any idea what is these 'lines'?