Posts by DD4YR

    By the way, the PLL from GOLDEN Media locks in stable over a very large area. Better than the RCA's in the OCTAGON's. I went so far up the GPS stabilized PLL frequency (26.335 MHz) so I could still receive the 10706 MHz beacon at 435 MHz. The S / N was not worse. The same way in the other direction to convert the 10.5 GHz transponder to 1286 MHz.

    The best PLL I've ever had in my hand. :-)

    pe1chl , I understand that, and you're right. But, the housing with PLL and quartz stabilized stickers to label and then obstruct other hardware is already brazen ....

    I will act as Remco recommends...

    @YL3ACK, I still work with a single PLL LNB from GOLDEN Media (GM-201), removed Quarz, drilled hole for coax with GPS sync clock. Works perfect.

    The only problem is the weather resistance and waterproofing, certainly not long-term stable... :-)

    DD0KP wrote: Raf I am just discussing with the company b.e.s.t. in Germany. They have rocket LNBs with PLL!!

    Definitely not! I have procured such a LNB, and behold: No PLL to recognize, no Quartz ... Only two DRO :-(

    Be careful with LNB´s from B.E.S.T

    73's Robert

    Has anyone already measured the broadband nature of the LNB? The ZF of 739 MHz is already clearly out of specification ... Is it possible that the transponder signals then turn out to be significantly weaker than the beacon on 10706?

    73 Robert

    That is indeed the case. I have here 40m Coax, a 4-way splitter with 12 dB attenuation. In addition, then an attenuator with 20 dB is required to have the signal for a SSB receiver in the correct level ... :-) The fat 65 dB gain from the LNB must first be adjusted ...

    Hi Peter,

    that's the right choice! :-) I have run here on my RPi 3B+ GQRX under VLC watching on my WIN10 computer, the utilization of the processor including VLC is around 38%. Power consumption 6.5 watts when decoding ...

    I think so. Do not confuse circular and linear polarization! Linear polarization is a momentary segment of circular polarization. The turning of the polarization is of course inverted by the mirror, with two mirrors inverted twice. However, considering only the instantaneous moment of a linear section, the angles in a two-mirror system are identical.

    For a Cassegrain, standing behind the dish and looking at the satellite you've to turn it anti-clockwise.

    Hello Remco,

    I don´t think so. Cassegrain is a two mirror system. The signal is upside down and reversed. But, the angle from the signal is still the same.

    Interessanter Ansatz, ja. Bei geostationärem Orbit auch durchaus vorstellbar. Ich hab die Idee bisher noch nie erwogen und wegen Doppler und Antennennachführung ausschließlich im Duplex Betrieb gearbeitet...

    Bin ich ja gespannt inwieweit uplinkabhängige Leistungsregelungen im Transponderbetrieb ein Anpassen / Nachregeln der Sendeleistung notwendig oder überflüssig machen.

    Es wird sich zeigen.... :-)

    73s de Robert

    The way to use a specially made for this case quartz I've already gone ... Unfortunately not with the desired success. As Remco already suspected, the frequency stability for SSB operation is hardly sufficient, for digital operation not at all. When watching the beacon of Es'Hail in CW, the frequency is constantly drifting, moreover the sound is "jammering" in the loudspeaker. A quartz heater improves the frequency drift, but the jammering remains .....

    73s de Robert

    Yep, aber, das 23cm Modul vom FT-736 läuft von 1240 bis 1300 MHz. Der Plan war zunächst den Transponder ans obere Ende zu legen (1289 MHz) da das Signal/Rauschverhältnis beim FT-736 am oberen Bandende besser zu sein scheint.

    Sicher kann man aber auch runter auf 1249 oder so.

    Im Moment hab ich ein Single LNB von Golden Media im Einsatz, das rastet die PLL noch gut bei 23,5897 MHz. Ist halt mechanisch schwieriger den LO Input mechanisch fest und dauerhaft wasserdicht zu realisieren.....