Posts by DL5CN

    Hallo,

    here is a picture of a dish with beams (read lines) from the mirrors to the focus point. The mirror pieces are cracked from a bigger mirror. Take care not to get injured.

    The reason for this method was a false mounting. The wholes in the dish allowed to mount it wrong, the upper side was at the right side. It didn't work at all, no focus, much frustration. With the mirrors I found my misteake easily. With the top side on top, all is fine.
    It is a little bit difficult to hit the sun but with some trials it will be ok. Follow the beams from the mirrors to the focus, the correct position can be found. It can be used also with a dish and unknown focus point.

    73
    Andreas

    Hallo Jabi,

    take 3 very small pieces of a mirror and glew it in the dish at different places. The mirror surfaces must be parallel to the dish. With thin double-sided adhesive tape it will work. Turn the dish to the sun. With a sheet of paper you will see, where the sun beams meet. With this method it can be seen also , if the dish surface and the paraboloid shape are correct still.

    Have fun.
    73
    Andreas

    Headshaking Modus on

    What a strange discussion?
    Don't look at the bandwith. Take care about the audio frequency response to generate SSB with good readability. Many signals waste much power closed to the carrier. In the literature there is a clear information to increase audio gain with 6dB /Octave. In wireless communication the power densitiy spectrum must be filled everywhere constant to get good reports even with low power and noise. Another question is compression. One can found literature information there also. The readability increases with a specific degree of compression. I don't mean clipping but level control without additional distortion. At least the linearity of the transmitter chain should be good enough for a clear signal with the same bandwith as the SSB-Filter has. Carefully leveling and level control help a lot. All this is implemented in a SDR. Believe me or not, digital technology can be very senseful in transmitters.
    Of course there are newcomers. That is what we want. They need help to optimize their stations.
    Headshaking Modus off

    Let's be good Oms and give support in a friendly and hamlike way. To go forward as an example I wrote a paper (German) about my radio. Send me an email if you like to get it.

    73
    Andreas

    Hallo Manfred,

    über eine Liste der in Frage kommenden Geräte verfüge ich natürlich nicht habe aber schon eine Reihe von Veröffentlichungen zu dem Effekt gelesen. Ganz konkret gemessen habe ich das beispielhaft mal an einem IC706 (weil der grad greifbar war).
    Das wäre mal ein Thema für den Herrn Sherwood aber der kümmert sich nicht um Sender.
    Im Zweifelsfall also probieren. Mit der CW-Tastung einen Speicheroszi triggern und das Ausgangssignal anschauen. Vielleicht noch eine schnelle Gleichrichtung einfügen. Man muss leider erkennen, daß kaum Innovation in etlichen Senderkonstruktionen steckt. Vernünftiger Audiofrequenzgang, sauber einstellbare, geringe Ausgangsleistung und eine Kontrolle bzw. Begrenzung der Spitzenpegel für einen geringen Crest-Faktor fehlen. Mit einem SDR ist das alles ein Kinderspiel. Dabei habe ich die Linearität einiger PAs bewußt nicht gestreift.
    73
    Andreas

    Hallo,
    after playing around a bit with the SAA_2N, I found, the firmware works. It is difficult to calibrate the touch display. After finding the right button and sticking the upper left and the lower right corner, all is fine. Putting the device into DFU, press the left cursor button and switch on. Connecting QT leads to the update menue.
    But, don't update anything until there is more clear information. At present we have some confusion about the display size and the corresponding firmware.
    73
    Andreas

    Hallo,
    please don't talk about power without any information about linearity. Even with a Pluto there is a very useful two tone generator. And with the receiver itself you can have a look to the output spectrum. Use a dummy load and attenuators to feed the signal back to Rx. It is very easy. You can use it as a perfect spectrum analyzer. The absolute power is not important but low intermodulation distortion. It is a good sign to do a sharp limited band in the waterfall display. And it will be estimated from others.
    73s
    Andreas

    Hallo,

    I measured 800ms delay between pressing the PTT at Console Input or clicking on TX-Button and Pluto- GPO-Signal. This was confirmed by Evariste, F5OEO. Hew wrote me, this is the round trip of his firmware_031. He wrote also, this can be reduced to some milliseconds but I don't know if this is done already. Meanwhile, I found the POE-Adapter-Solution and it works well and very fast. And was copied by some friends.

    To avoid missunderstandings, the delay was not caused by the Console or the method how to activate the transmit mode. Keeping the amplifier in TX-Mode, the delay was very low also. So, the Pluto was ready to transmit but the Amps were switched on and off with 800ms delay. Using the Ethernet-Line is very simple and cheap and there is no distance limit.

    73s
    Andreas

    Hallo Christian,

    using the Plutos GPIO-Port to get a PTT-Signal means a delay of 800ms. Look at my report about PTT over Ethernet.
    It is just some postings before. The POE-Adapters are very cheap and can simply be sticked between the Ethernet-Connectors.

    800ms delay are not problematic for DATV but for SSB and CW.
    Beside this the USB-Relays for PTT-Input and output allow a hardware switch may be integrated in a microphon. From my point of view it feels better then pushing the TX-Button with a mouse.

    73s
    Andreas

    Hallo,

    die meisten TRXe mit einer Sender-ALC erzeugen bei abgeregelter Ausgangsleistung einen Spike beim Einschalten des TX, der mit voller Leistung am Ausgang erscheint, genannt ALC-Overshoot. Das kann nachgeschaltete Geräte (PAs, Transverter) übersteuern, musses nicht.
    Eine mögliche Lösung ist die Verwendung einer externen Spannung, um die Ausgangsleistung des TRX abzuregeln, dann wird die interne ALC nicht benutzt. Den overshoot zu messen, ist nicht so einfach, Speicheroszillograph mit der CW-Tastung triggern, schnelles Wattmeter.

    73
    Andreas

    Hallo,

    look to this thread.
    PTT over Ethernet

    SDR-Console supports PTT-IN (USB to TTL Adapter) and PTT-OUT (HID kompatible USB-relay).

    The USB to TTL-Adapter should contain a FT232 Chip from FTDI. A status line can be configured and used with a microfon button. It works with VOX also.
    The output relay must follow the HID-Rules (Human Interface Device).

    To bring the PTT-Signal to the amplifier use two POE-Adapters on each end of the Ethernet cable. There is no distance limit.


    The GPIO-Port of the Pluto gives a PTT-Signal also. This requires firmware from F5OEO. Unfortunately there is a delay of about 800ms between Tx on and PTT-out at the GPIO-Port. Evariste, F5OEO told me, this can be reduced.
    There is no matter for DATV. But fast SSB-Talking is much better without this delay.
    That's why, I prefer the POE-Adapters.

    73s
    Andreas

    Hallo,
    CN0417 Cool Down.
    With the help of a very kindly Applications Engineer of AD the Rev C of the CN0417 is clear to me now. The additional chips are a temperature switch U2 and a tri state buffer. The buffer U3 has an output enable pin. It is clamped to 5P.


    This is the backside of CN0417. Remove R6.

    Patch 1k from Pin1 of U3 to GND. Patch a pull up from Pin4 to 5P. The PTT-Signal to pin1 of U3 changes between 0 (Rx) and 5P (Tx).
    The current consumption goes down from 600 mA to 40mA and is good for stby.


    Again, the help of the Applications Engineer from Analog Devices must be higly appreciated.

    Save current, avoid heat.
    73s
    Andreas

    Hallo,

    I did a direct coupling with my first and also with the second Pluto. Both devices (host and client) need a fixed but different IP in the same adress range 192.168.1.xxx (example). The USB-Ethernet-Adapter is an ICY Box IB-AC510 with OTG.
    But the most important thing was to put the adress which is assigned to the Pluto in the standard gateway mask at the host PC. This was succesful with two total different PCs.
    Please note, this is not DHCP.
    73s
    Andreas

    Hallo,

    CN0417.
    There are differences between Rev B and C. My board (RevC) shows more components U2 and U3 on the backside. My idea is to use the enable Pin2 of the ADL5606 to reduce standby current. The AD-Documents "Design-Support" show Rev B. No infos for Rev C.
    In Rev B Pin 2 is grounded, very clear. Not so in Rev C.
    May be, the circuit to use the enable function is there already but I can not use it without any info about U2 und U3. I think it is difficult to find the right person at AD which can help. I will try parallel.
    I am pretty sure, there is a chance to switch the amp on and off. It is designed for mobile communication with fast time slot operation.

    Does anybody have infos about Rev C? Circuit or layout?

    Thanks in advance

    73s Andreas

    Hallo Oms,

    please remember, any infomation about power should be combined with attention to linearity. One can watch the transmit Signal with the Pluto itself. Use a dummy load and/or directional couplers with the right attenuation and look to the spectrum. The Console in combination with the Pluto gives a rather clean two tone signal with 0dBm PEP. This all is possible without a spectrum analyzer.
    At least the transponder will show if the transmitted signal is ok. From my point of view there is a great general improvement compared to the beginning more than a year ago. Don't forget the equalizer and the compressor.

    The goal must be to find a transmitter chain without unneccessary intermodulation. The Pluto followed by the CN0417 delivers +20dBm
    (100mW) with good linearity.
    @Oliver: Why don't you stick all the attenuators together and place it behind the last amp? With 36dB of gain of a two tone signal there is no danger for the attenuators. From 0 dBm of the Pluto you achieve 36dBm PEP (4 Watts PEP), the 2 W dummy load will withstand it keeping the transmission short. I would try to bring an damped signal back to the receiver to control intermodulation.

    73s
    Andreas

    Hallo,

    wir sind uns doch alle einig, daß der Empfang des Transpondergrundrauschens, wenn es denn deutlich über dem des LNB
    liegt, keine weitere Verbesserung benötigt? Das bedeutet bei den gängigen LNBs einen Mindestgewinn, den ich jetzt mal salopp
    als Spiegelgröße (z.B. 80cm) bezeichne. Korrekte Montage und Polarisation vorausgesetzt. Damit ist der empfangbare Signal-Rauschabstand der Benutzer definiert und nur noch von deren Sendeleistung abhängig, das bedarf eigentlich keiner weiteren Erwähnung.
    Daher ist die Frage nach der Art einer Gewinnerhöhung nach Veränderung des Koppelstiftes in der Tat interessant.
    Welcher Art ZF-Rx ist das und wie äußern sich 5 dB Gewinn durch die Filterung der 739,xxx ZF ?

    danke
    73

    Andreas

    Hallo,

    I can confirm, the Maximum LNBs include DROs.
    What to do? Send it back or keep the lenses?

    I added a patch to a Megasat Twin Daivolo. The Waveguide is nearly the same like the rockets. This could be an alternative.


    The Horn isn't very deep. It can be cutted with a lathe. Take care not to get in trouble with the cutter holder.
    Then stick the waveguide to a wood core for further work.

    No idea how the case will look like. And how to mount it. Depends on the dish and the LNB holder.

    I didn't expect a cylindrical wave guide. If there will be further production, wie don't need the rockets anymore.

    73
    Andreas

    Hallo,

    Mike, fully agree. There are more hints to stabilize the system. Pluto must be modified because of EMV too. I grounded the connectors to a cupper plated board below. Beside grounding there is more mechanical stability to the connectors. Take care to power supply and USB-to Ethernet -Adapter also.
    73s
    Andreas