Looks good George!
MY QO100 SETUP
-
-
-
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 George,
on the NB TPX the bandwidth is limited to 2.7 kHz. Thus Spread Spectrum makes no sense.
On the WB TPX you can try Spead Spectrum Schemes but please make use of the chat channel in the WB Spectrum Monitor to announce your tests.
Kind regards
Matthias
-
On the WB TPX you can try Spead Spectrum Schemes
??
Matthias, present not included in the bandplan ..... -
Hello Robert,
yes and no. It will be difficult to allocate part of the transponder to new modes as long as those have not been implemented.
In my opinion it was never out of the question that AMSAT-DL encourages new wideband modes.
Testing those modes should be announced on the chat channel of the spectrum monitor to avoid interference with other users.
If we see that a new mode is getting adopted by more user we can of course still adapt the band plan and allocate part of the spectrum of the wide band transponder to such new modes. Yet I think it is too early to do this. Let us see the results of the tests first.
Kind regards
Matthias
-
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,
Simplified block diagram.
-
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.
-
-
hello help pll ADF4351 PIC12F675
i made the converter 433 mhz / 10489 for qo-100 as LO I use pll ad4351 with controller pic12f675 i as a reference I use external 10 mhz of the isotemp 131-100 it is very good problem that if I turn on the pll the lock does not turn on if I turn off then I turn on first the external reference 10mhz and then I turn on the pll so does any idea work?
i used this project;
http://www.f5ubz.fr/adf4351/ADF4351_F5UBZ.html
thank
73 de iw5bsf Roberto
-
Hi Roberto,
If you do not connect the 10MHz, power on, see that the PLL doesn't lock, then pulse the MCLR on the 12F675, does the PLL lock then?I've made something similar, but with attiny13, it can be found elsewhere on this forum. I don't have the problem you have: PLL always locks when 10MHz is connected.
-
hello not lock only if I first turn on 10 mhz connected then of lock I had tried with attiny 13 usual problem
-
12f675 pic
I noticed that touching the pin mclr pic 12675 with the finger of the hand restarts the lock
-
I found I was able to reproduce the "non lock" with an eval board, and I have a theory of what is happening
Looking closer at the datasheet of the ADF4351, it seems that "programming the registers" does more than just load values it it, a number of circuit selections happen inside the chip while the programming process is happening. This is why the registers must be programmed in a certain sequence: R5, then R4, then R3, ... last R0.
If there is no reference frequency during the process then it will fail.
If you power-up the adf4351 with a reference, then remove it, then connect it again, the PLL will lock. The problem is if the PLL is that if the PLL is programmed when the reference frequency is missing, the programming doesn't seem to work.
My suggestion would be to make sure that your programming includes correct programming of the Lock Detect output, then change the programming of the 12F675 so that after programming you wait a bit, wait for Lock Detect to go active, and if not, re-start the programming process. I have not tried it, but your "touch the MCLR" suggest this will work.
I'm nervous about the "touch MCLR" comment. Does this pin have a pull-up resistor? -
Thanks for the answer, I use the pickt3 as a programmer following some indications on the net I put a resistor between VDD and MCLR for programming
the sequences in the asm file up to these:
EEPROM LOCATION
DE 0x00, 0x7D, 0x80, 0x10 ; register R0 2514,000Mhz // ok
DE 0x08, 0x00, 0x80, 0x29 ; register R1
DE 0x00, 0x00, 0x4E, 0x42 ; register R2
DE 0x00, 0x00, 0x04, 0xB3 ; register R3
DE 0x00, 0x85, 0x00, 0x3C ; register R4
DE 0x00, 0x58, 0x00, 0x05 ; register R5
therefore the sequences must be reversed
-
I took a look after reading your directions datasheet 4351 page 22 it says register 3 also serves to determine TIMER AND FAST LOCK REGISTER SEQUENCES TER
-
hello
I found this information interesting
on pic 12f675 -
Hi,
Any experience using echo mode WSJT-X for 10 GHz EME operation? I plan to test using a PF 60 cm dish and 10W.
-
Hi,
A modification is applied to a modified twin Octagon LNB with 25 MHz insertion using a 2.2 uH & 18 pF as OZ2OE proposed, that replace meander with a 5.6 uH (have more that 75*10 ohm resistance at 25 MHz). The existing 10 ohm in series with meander is replaced with a 0805 one in order to solder the 5.6 uH.
The result is that in NB similar performance exist as before. But in WB the MER for beacon is improved about 0.3 to 0.4 approaching the LNBs performance with XTALs MER but with GPSDO accuracy and stability. Replacing 25 MHz source with lower noise OCXO as mentioned before , a very small increase must occurs, must be about 0.1 (may be ...) .
It must mentioned with this modification the required 25 MHz signal in order to lock the LNBs PLL, is a lot of dB less, but for optimum performance the previous level is required (in my case about 13-15 dBm).
This idea is generated while discussing with SV1UI about the loss of 25 MHz signal due the 950 MHz HPF that exists in LNBs output.
Also the output signal of some LNBs is measured from 350 MHz to 850 MHz. As the results is not very accurate a typical performance is a few dB less signal at 740 MHz and about 10-15 dB at 430 MHz. The attached screen is from an unmodified twin green Octagon LNB.