Posts by S57RW
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Last Friday on the 15th Nov Oscar 7 celebrated his half century in space. Wish him to rest operational for many years to come.
73 Andrej - s57rw
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Hi,
Noted on the ARRIS web page there should be a new SSTV event.
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November 6, 2024 — Amateur Radio on the International Space Station (ARISS) announces an SSTV event to be held next week. The event is scheduled to begin on Monday, November 11 at 11:50 UTC and to end Monday, November 18 at 13:40 UTC. SSTV transmissions will be paused during scheduled school contacts on November 15 and 16. Downlink transmissions will be at 145.800 MHz and the mode is expected to be PD 120.
The transmissions will consist of 12 images featuring activities from the 2024 40th Anniversary Celebrating Amateur Radio in Human Spaceflight. If you are a past participant in our SSTV events, please note that we will be using our newly updated gallery at https://ariss-usa.org/ARISS_SSTV/ .
ARISS has a new way to request a special certificate. When participants successfully receive at least one image and submit it at the new gallery, participants will be moved to a thank-you page. There, a person can read text about data protection, and press the button that says “I agree,” and receive an email in two weeks or sooner with a certificate. If a person submits additional images, the thank-you page tells them they have already asked for a certificate.
Thanks to our user community for participating in ARISS.--------
Will give a try to receive few SSTV pictures and in between transmissions make some QSOs on the transponder.
73 Andrej - s57rw
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Hi,
Mine received with handheld arrow yagi.
In between sstv transmissions made 3 QSOs on ISS FM transponder so great fun
73 Andrej - s57rw
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Hi,
Last update and to close this topic, have received from SV1AFN the program for updating parameters to the unit with examples how to generate register files with Clock builder PRO. So all fine now.
Seems he took a break around new year so wasn't replaying
73 Andrej - s57rw
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Hi Martin,
Tnx that can be an easy solution to generate other frequencies from a 10MHz reference. Have several of this Si5351 boards and used for some projects already. Most of the times I don't even need GPSDO accuracy/stability so using them with the 25MHz quartz installed on the board.
For update on above topic, seems I'm a bit lucky. SV1AFN replied to my e-mails today. He asked what frequencies I need so he can send me a sample file. Have replied him to send me also the python script for uploading via USB port to the unit since no longer available on his web site. So hopefully I'm on a good way
73 Andrej - s57rw
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Martin,
Before posting here have e-mailed the guy and searched the internet. Found him also on e-bay and by recent reviews he should be still active. And also found some posts around the internet if you need any support as you mentioned good luck...
Hope somebody here got his unit in the past and have downloaded the tool for programing while the google drive link was still available. Would be an easy solution. Next step send him another e-mail and hope to get lucky and get a replay.
Worst case scenario the eeprom is I2C so can try to read data from it by connecting SDA and SCL lines to an exetnal programmer. Knowing the actual parameters, reverse engineer the binary file where the prescaler divider for the SI5342 is and later program new ones. Acceptable solution if required not to do very frequently. Otherwise write new firmware for the STM32. Libraries for the SI5342 PLL are available so should not be to difficult and implement my own serial protocol to program it and store to eeprom for keeping the data in after power resets. Can be done but will wait if can get an easier solution prior messing and lose a weekend to do that
73 Andrej - s57rw
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Martin,
Tnx for the above. When got the unit it arrived without any instructions, software or whatever. The only one are on his web site. I got so far that I've installed the ClockBuilderPro and I'm able for the device used get the parameters based on input frequencies and other parameters you specifiy. So far so well. Than how to put that to the unit is the main question.
SV1AFN is mentioning to use a python tool to program the parameters to the eeprom in the unit via USB port. Eeprom is connected trough a STM32 MCU which controlls the unit. This part I'm missing. On his web site is a link to a google drive where you probably could download this. But the link isn't working any more.
For this reason my question was if somebody has this GPSDO and knows how to do it
73 Andrej - s57rw
P.S. Sorry for the smaily above on your post. Wanted to put it bellow in my text and pressed the wrong thing...
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Hi,
Years ago I've got the SV1AFN GPSDO and arrived with 2 pre programmed frequencies I've need at the time. Most of the time was sitting on a shelf since got another one from Leo Bodnar and was using that one. Now would need to change the output frequencies of the sv1afn unit to use it as a signal source for some testing. On his web site the instructions how to do it are not very clear. Have send him 2 e-mails but never got a reply.
Does anybody have this unit and knows how to program it?
73 Andrej - s57rw
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Hi!
Tried today with the pass starting at 14:01 at my location and surprisingly got trough H/u transponder easily. Soon after above horizon received the CW beacon strong. For 70cm downlink the arrow 7el hand held yagi was used. After transmitted on 15m uplink and could receive imediatelly my signal back on 70cm strong. TX power was 40W which was enough for low angle at AOS and guess still too much for CW. HF antenna is a end-fed 30m long oriented to nord-south as the sat trajectory was. Good results when the SAT was rising from the north and worse when above and toward south. But this confirms what I know about radiation pattern of my end-fed. On HF could allways work easily stations from norden directions but not same easy from southern.
Short clip on YouTube about the test. Sorry for bad video. Not so easy to hold the arrow in one hand, correcting for doppler and holding the camera in other Should put the phone on a tripod...
External Content www.youtube.comContent embedded from external sources will not be displayed without your consent.Through the activation of external content, you agree that personal data may be transferred to third party platforms. We have provided more information on this in our privacy policy.After some break working LEO sats maybe time to install back the egg beaters in the garden and have some fun
73 de Andrej - S57RW
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Hi Thomas,
Tnx for info. Will give a try tomorrow around 1400 UTC I have a good pass. Hopefully during the day the ionosphere won't reflect most of my signal back to earth. Need to try, have never tried to transmit on HF into space at least intentionally Alternatively can try on a night pass when the 15m band is closed.
Will report if managed to pass trough.
73 de Andrej - S57RW
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Hi!
Will give a try on FO-118 H/u mode since never tried so far uplink on HF. To have less veriables to think about and didn't notice this info in the manual for this sat, are all transponders operational at the same time or if somebody for example is using the V/u mode than other transponders are off?
73 de Andrej - S57RW
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Hi Phil,
Pluto will work and you can use it also for receiving at the same time. One thing you should know about Pluto as it comes out of the box its local oscilator isn't that stable for narrow band modes. It is not that it is completly useless and for start will do but with time gets a bit annoying your correspondents have to adjust the frequency for your drift. Inside the house when it warms up is stable enough for SSB but you will most probably like to put all the stuff outside close to the dish to avoid long coax cable runs. Of course there is a solution you can change the TXCO with a more stable one but involves soldering a very tiny SMD component. If you are not comfortable with that find a friend who has experience with soldering SMDs to do it for you. Than you will need 2 stages of amplification to get few watts out, an dish illuminator and you are ready to go. Most of this stuff are commercially available and quite plug and play
Personally don't have the Lime so cannot tell about. Maybe some others here who are using it can. But as have red it has some drift problems as well with original TXCO.
You can check this channel on Youtube from M0DQW, he has a series of videos about making the setup and he tried both with a Pluto and Lime. https://www.youtube.com/c/TechMindsOfficial/videos
In the case you have a 2m and/or 70cm SSB rig you can consider using an upconverter instead of the SDR.
73 de Andrej - s57rw!
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Hi Phil,
Glad to hear it works. Welcome the club Now as you mentioned you have to think about TX side. Don't be affraid you will make it. For any thing ask on the forum here are planty of hams whit experience how to do it. Also if you are a member of your local club check if there is somebody with experience in microwaves and can give you a lot of support making cables, connectors, good advices etc.
Looking forward to hear you calling CQ one day over the QO-100
73 Andrej - s57rw!
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Hi Phil,
Looking for your results. Think will do. If not we will check next steps how to make it work. At the end this is one of the functions of this forum. If you give up at certain point won't never work
73 Andrej - s57rw!
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Hi Phil,
Yes if you set the scale at 26-27 deg elevation and 149 deg for azimuth you should be in about right position. Of course you will have to make some fine adjustments by azimuth and elevation to find the right spot. Do it azimut and elevation separately by not releasing all screws wobbling the dish all around. You have to assume probably your mast isn't perfectly at 90 deg, the printed scale for elevation is more for indication and also you didn't point the sun exactly. But you are in the area so make small adjustments by few deg. Take also in consideration when receiving with a sdr dongle that it has some small delay. But when you move the dish if you are doing it slowly you will get it at the right place.
Once you will fix it at right position you are done. Just make sure the mast is stable and not wobbling in the wind with a 80cm dish on it
73 Andrej - s57rw!
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Hi Phil,
You have a offset dish which is mostly used nowdays for SAT TV. Check on google difference betwen offset and prime focus dish and you will get the idea. Anyway your dish being offset type means when the dish faces exactly vertical means the dish is looking abt. 26 deg up (depends on the dish model but is here around). So trust the printed scale. If you used a level and pointed the dish at 26 deg means your dish is looking probably 50 deg up.
Set it using the dish scale and than search for azimuth. After you find the sat make fine adjustments.
After some time you will get practice. I can find the sat with a dish holding it in my hands so it isn't that hard
Make sure also as mentioned above that you mount the LNB to vertical polarization -19 deg of skew angle. On the LNB flange usually is printed a angle scale. 0 deg on the scale is vertical than rotate it to -20 deg for your location. You will se this scale is quite rough but the setting isn't critical at all. Just don't be off by 45 deg or more Before messing with that you can set it to 0 deg and after you point the dish adjust. Better not to have too much parameters at one time...
For 1st test you can check ask mentioned above receive with the LNB alone. You should hear the beacons, quite weak but you will if the rest of the setup is working properly.
73 de Andrej - s57rw!
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Hi,
For pointing the dish if your mast is leveled vertically than for elevation you can use the angle scale which most dishes should have printed on the mount. It will bring you close enough. Than search for azimuth and after you find the sat do fine adjustments to azimuth and elevation to get the strogest signal.
Just to try if your hardwere is working and assuiming you are on right frequency span you can just point the LNB in the direction of the sat. The LNB alone isn't very directional. So +/- 15-20 deg off the direction would still receive. You should hear the beacons and maybe also some strong SSB stations. The signals will be weak but you should hear them. I can elasily copy the lower CW beacon just with a LNB.
Make sure you oriented the LNB in right polarization. For NB transponer should be vertical. If you mounted it in horizontal probably you won't hear anything. Than adjust it also for the skew angle which should be -19 deg for your location. This angle isn't that critical to be set very precise. Even 10 deg off you won't notice much difference.
73 Andrej - s57rw!
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Thomas tnx for posting about the SSTV transimission from ISS. Usually I miss them...
Receivied three pictures today.
Best 73 Andrej - s57rw!
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Hi!
I've ordered from DX Patrol the version with down converter since for portable operation prefer to have the rx on the rig not needing to carry the laptop around. Generally it works fine. If the unit is inside in the shack the frequency stability is fine. If operated outside there is some drift due temperature changes, but still not a big problem for SSB or CW operation. In any case a big improvement over the previous LNB with an 8ppm reference.
When used with a FT-817 as RX even with its gain set to minimum have to use a 20dB attenuator to get better S/N ratio.
Have still to test digital modes like KG-STV where stability is a must. I suspect for this a GPSDO as external reference will be necessary.
Dirk tnx for the information that the bias is not short circuit protected. Usually is difficult to make a short when screwing the F connectors but you never know. Better have the unit switched off when screwing cables on it or LNB.
Best 73's Andrej - S57RW