Posts by DD1US

Hello Riri,
I do not know. It might be glued. In any case I do not recomment to disassemble it.
If you want to use a different LNB then I would rather add another POTY feed to it
and let the Feed with LNB as it is.

Regards

Matthias

Homepage DD1US

Hello Riri,

sorry I did not anwer your last 2 questions:

I am not 100% sure how your LNB looks like but many LNBs from AMSAT-DL

were LNBs with 2 outputs (one for the NB transponder and one for the WB transponder).

The reference frequency input was at the WB transponder output port.

Thus if you want to use such an LNB for NB operations you have to supply indeed a supply
voltage to both ports and in addition supply the reference frequency for the PLL in the LNB

on the WB output port. By choosing the supply voltage you can select the polarization e.g.
12-14V one polarization and 14-18V the other polarization. You can indeeed supply the same
voltage e.g. 12V to both outputs and then get on both output ports the same polarization.

I do not have a SG labs transverter but I think they are of very good quality and the only
configuration you need to make is setting the local oscillator frequency (to chose which
part of the 13cm band you want to operate e.g. 2320 MHZ for EME or 2400MHz for satellite
uplink). I am not aware of any modifications you need to do at this transverter but maybe
other can chime in who are using such a transverter.

Kind regards

Matthias

Homepage DD1US

Hello Riri,

You have to not only supply the supply voltage to the LNB but also the reference frequency.

Both are supplies as "phantom feed".

Are you doing that ?

Kind regards

Matthias

http://www.dd1us.de

Ja, ich denke das Datum passt zu der Einführung der neuen Lizenzklassen Mitte nächsten Jahres.

Viele Grüße

Matthias

http://www.dd1us.de

Hello Nicolas, I assume you meatn you are using a helix feed in the 88cm dish. The minimum uplink power you will need for SSB will be about 500mW and the maximum uplink power will be about 3W.
Kind regards
Matthias

http://www.dd1us.de

No, the ground mod is no longer needed with the rev C/D Pluto.

Kind regards

Matthias

http://www.dd1us.de

Hallo Michael,

vielen Dank für Deine tolle Arbeit.
Der Downlink funktioniert leider nicht.

Es kommt die Fehlermeldung "Die Datei befindet sich im Papierkorb des Eigentümers".

Viele Grüße

Matthias

http://www.dd1us.de

If I remember right you need to restart SDRC after changing the setting as Martin proposed.

Kind regards

Matthias

http://www.dd1us.de

Hello George,

excellent, congratulations!

Kind regards

Matthias

http://www.dd1us.de

Dear Alexandros,

you are very welcome.

Enjoy the satellite.

Kind regards

Matthias

http://www.dd1us.de

Alexandros,

the beacons are back at the nominal level.

Kind regards

Matthias

http://www.dd1us.de

Dear Alexandros,

thank you very much for your kind offer.

As the construction obstacles should be removed by tomorrow Monday I do not think it is necessary.

Nevertheless I have forwarded your offer for support to the operators of the groundstation in Bochum.

Kind regards

Matthias

www.dd1us,de

Hello,

there is some heavy construction work ongoing at the groundstation oinm Bochum.

Some of the equipment is presently shading the dishes for QO-100.

This should be corrected the latest on Monday and all beacons and LEILA back to
nominal operation.

Kind regards

Matthias

http://www.dd1us.de

Hi George,

I am sure you will be able to optimize the design.

Good luck.

Kind regards

Matthias

http://www.dd1us.de

Dear all,

I measured the filter with my HP8753E.

Below please find the results.

Kind regards

Matthias

http://www.dd1us.de

Hi George,

you have apparently a calibration issue of your measurement setup.

I do not think the ripple in the passband of your filter is real and so is the S11 curve.

If you do not have the proper measurement setup I can offer to you that you send it to me
and I will characterize the filter for you.

Kind regards

Matthias

http://www.dd1us.de

Hi Georg,

more than 3dB insertion loss is in my opinion way too high.

Not only close to the cutoff frequency but even down at 1GHz.

Hopefully soldering the contacts will help. Probably clamping the discs
would be better (lower loss) than soldering them but as you have chosen
this path I wish you good luck.

Kind regards

Matthias

http://www.dd1us.de

Hi Georg,

that looks very professional, it seems you have a very nice workshop.

It will be interesting to see your measurement results.

I got the primer and the glue but have been away from home for the last 2 weeks.

I might get back home next week or the week after and then plan to make some tests.

Kind regards

Matthias

http://www.dd1us.de

Hi George,

Kurt DJ0ABR built a very nice 2.4 GHz LPF and documented it here:

https://projects.dj0abr.de/doku.php?id=en:sat:filter2400

I guess it is quite similar to yours.

You may compare your results to his.

Kind regards

Matthias

http://www.dd1us.de

Hi Stefan,

I have been using the LimeSDR USB (not mini) for several years with good results.

I also have a Pluto and cannot confirm one or the other is more sensitive / better.

Kind regards

Matthias

http://www.dd1us.de