Hi all,
on June 16th I posted the following:
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Hi All,
I tested a number of LNBs regarding the quality of their ozillators. To do this I mounted the LNBs in the feed holder of a FUBA DAA 850 A offset dish, monitored the CW beacon with an SDRplay RSP2pro and the software SDRconsole and evaluated the signal in the waterfall diagram.
Out of 50 single LNB's GM-201 the oscillators of 7 pieces have wobbled.
Out of 10 single LNB's goobay 67269 the oscillators of 2 pieces have wobbled.
At 10 single LNB's OPTICUM LSP-02G none of the oscillators wobbled.
Of other LNB types, I only have one or two pieces to test, so I can not say anything about their Oszillaors. With a total of more than 80 LNBs examined, one was included with a remarkably frequency stable oscillator. So there are also outliers for the good side ...
73! Peter, DJ7GP
An LNB useful for narrowband applications is shown in Figure 1. An LNB (wobbeling) unusable for narrowband applications is shown in Figure 2.
I tested all wobbling LNBs for satellite TV reception. Result: No problems!
But also an insufficient stability of the LNB holder can lead to unsightly instability of the received signal. If you knock on the LNB holder, as you will knock on a door, there are vibrations (frequency modulation) as shown in Figure 3.
73! Peter, DJ7GP