LNB downstream and LO upstream over 1 coax
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Hi,
Can you provide the link of the ON4CJQ solution? Also keep us informed about your progress. I use 25 MHz+740+bias and 430 for the other cable. I run about 60 meters. A Lab testing can be personal run from September. Also I use a second cable for H. Maybe a combiner can be used also to use a single cable for NB and WB signals. One question to the designers of QO100 is why NB and WB use different polarization?
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Johan,
many people are using the cable from the LNB to the receiver to send 3 "signals" over the single cable:
- the receive IF signal e.g. 740 MHz
- the supply voltage for the LNB including the information to switch between V and H polarization (14v / 18V)
- the reference frequency signal for the LNB (typ. 24, 25 or 27 MHz)
Sending the local oscillator signal for the LNB upstream will be very difficult as it is a rather high frequency
and the attenuation of the cable will be very high.Triplexers for the above mentioned 3 signals are built into the AMSAT-DL downconverters and can be bought
stand alone for instance in the BATC shop in UK (design by Mike Willis G0MJW). Here is a descrition of my built:http://www.dd1us.de/Downloads/…from%20G0MJW%20rev1.2.pdf
Kind regards
Matthias
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Hi,
Maybe I am not understud. The proposal is to send also 430 MHz, not LO. Also my proposal is to combine also Rx NB&WB signals. Now I use one for 25+739+13V , one for 740-750+18V and one for 430 MHz. The proposal is 3 to 1 cables.
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Hi George,
I am also not sure whether I understood what Johan wants to accomplish. So we need his response.
In any case I think there are 2 "links" where multiple signals can be combined.
1.) One is the receive path as I had described above,
2.) The other is the path from the transverter to the transceiver where the RX-IF-signal, the TX-IF-signal and the reference signal can be combined. For the second topic I am using a triplexer from Diamond.
You can find a description of ma portable setup (where both "links" are using multiplexing) here:
http://www.dd1us.de/Downloads/…0English%202020-09-26.pdf
Kind regards
Matthias
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DB2OS
Moved the thread from forum Hardware to forum LNB for RX. -
Looks like DD1US Matthias has the solution already.