Keeping off topic ;-)
I’m also making QRP tests over QO-100
Currently using 150mW to a biquad linearly polarized antenna. Apparently Hpol works better than Vpol for unknow reasons
I’m getting decodes in Opera but the WebSDR is not good enough for weak signals
There is still room for decreasing power. And using an omnidirectial RHCP antenna like cuadrifiliar helix would be also
much better
I’m thinking about EbNaut over QO-100. An ADF4351 PLL can be used to generate the signal directly from GPSDO reference
The Rx chain may be a problem. The downconverters in the chain may introduce phase changes. But there are I/Q downconverters
to get the signal directly at baseband using just one LO
Any ideas ?
This may be little bit more focused on topic. Would be amazing to transfer a message trought the sat using minimal power
and
small omni antennas
73 de Luis
EA5DOM
That is what I am doing the PLL LNB is manageable without modification for cw and ssb and most of my equipment is left on 24/7 so no warm up problems.
I do have a high spec satellite RX with selectable digital or analogue reception plus various outputs, IF, BASEBAND etc. also manual frequency and parameter settings.
This could be an alternative method of reception and maybe more stable than the more common LNB/DONGLE method and avoids a T bias module
Sent: Wednesday,
March 06, 2019 5:18 PM
Subject: Re: Not
LF: Opera via QO-10
Most of the LNBs designed for HD TV have a PLL for low phase noise. These have 'acceptable' drift for CW and SSB QSOs......Just let them warm up for 10mins before you
use them. (or fit a TCXO instead of the 27 / 25MHz crystal)
No set top box required. Just small dish + LNB into a dongle. Trying to get an output directly at 70cms is a bit hit and miss as you are well below the lower 750MHz
limit of the LNB.
There must be a way to modify a satellite RX to receive the AO 100. The SAT BOX would have AFC built in to avoid LNB drift in normal use.
One method would be to set up the RX box to analogue reception and tune across the base band, another to tap off the IF 480 Mhz and tune across the IF with a 70cms
amateur RX or SDR dongle and computer
Maybe someone has tried a similar method
Sent: Sunday, March
03, 2019 4:51 PM
Subject: Re: Not
LF: Opera via QO-100
Hi Mal,
my 2.4 GHz TX is fairly improvised and may not be easy to reproduce... I've extracted the LO from an old Sat-TV receiver, followed by a small Minicircuit amplifier and a 60 cm dish indoors. The PLL consists of the 1/64 prescaler output fed to a CD4030 XOR phase
comparator, along with a 18.75082 MHz Rubidium-controlled reference.
There are surely much better ways to generate a decent 13 cm signal. PA1SDB mentioned that he uses an Adalm-Pluto SDR from Analog Devices.
You might be able to pick us up on the web-sdr, using 10489603.5 kHz USB dial, and Opera SW set to Op-05 speed by selecting e.g. the 1296 MHz band. Yes we could try a crossband contact, but not today. To count as a valid QSO, we'd probably also need to set
up our own receivers, both for 10.5 GHz and 472 kHz.
Best 73,
Markus
-----Ursprüngliche Mitteilung-----
Von: mal hamilton <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: So, 3. Mrz 2019 16:24
Betreff: Re: Not LF: Opera via QO-100
How about a XBAND qso AO100/MF on CW
You TX via satellite to me and I tx on 472.5 Khz CW
Sent: Sunday, March
03, 2019 1:44 PM
Subject: Not LF:
Opera via QO-100
Listening to the below-mentioned Goonhilly web-sdr, I noticed an interrupted carrier on 10489.605 MHz, which turned out
to be 10 mW Opera-2 and Opera-05 transmissions from PA1SDB. Peter has been well known in the LF group for running a VLF-Grabber in Appingedam.
During the last week, I had managed to built a rudimentary but stable 2.4 GHz CW transmitter, allowing me to add in another Opera signal on Es'hail-2. Anyone else to join in?
Best 73,
Markus (DF6NM)
-----Ursprüngliche Mitteilung-----
Von: VIGILANT Luis Fernández <[email protected]>
An: [email protected]
<[email protected]>
Verschickt: So, 17. Feb. 2019 22:21
Betreff: LF: MF/LF chat over QA-100 Geostationary Satellite ?
Hi All
May be someone has the equipment and is in the footprint of Es'Hail-2, formely AMSAT QA-100 satellite?
Nice place for chats working as an HF band permanently open and with outstanding sensibility
Anybody (appart from David, G0MRF) interested in joining an MF/LF/VLF chat ?
You need just an SSB rig at 144 or 432, an upconverter to 2.4GHz and a WiFi PA and antenna and you are in
For Rx you can even use the WebSDR at Goonhilly
Unfortunately the footprint of the satellite do not cover America (only the extreme East of Brazil)
nor Australia (reaching up to thailand). But sites like Reunion are in the footprint
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