Posts by DD1US

Quote from dm4im

I agree. I just wanted to point out, that even with a cumbersome antenna, you will have good results with a dish that diameter. My first antenna was the 4 element yagi pointing into the dish , the 2nd was a linear polarised patch feed without waveguide for the lnb and the one i'm using now is a poty . Learning by doing, improving over time. It is more important to have a clean signal, may it be not so strong. The LEILA triggering signals are for later, and even those are clean, if you overdrive NONE of your gear......

Regards

Martin

P.S. : I don't encourage anyone to trigger LEILA.

Hi Martin,

yes, we should not overpower.

Looking at the transmit side for the narrowband transponder a smaller dish is clearly enough.

The big benefit of such a large dish is on the receive side especially for the wideband transponder and for transmitting
DATV signals.

See you soon on QO-100.

Kind regards

Matthias

http://www.dd1us.de

Ronni,

with the 1.5m dish you will not need more than 500mW transmit power at the dish.

Kind regards

Matthias

http://www.dd1us.de

Hi Ronni,

a 1.5m PFD is a nice dish. Go for it. You will then also have a good basis for receiving and eventually transmitting DATV signals via QO-100.

I am using a 1.8m PFD (old Kathrein dish which I refurbished). My dish is quite deep (f/D=0.29) and therefore a POTY feed is fits well. I do not use a lens in front of the 10GHz waveguide, just leave it open.

Do you know what the f/D of your dish is?

Most PFD dishes are between 0.3 and 0.4 and a POTY feed will then still serve you well.

On my website http://www.dd1us.de you can find some information about my setup incl. the feed-holder I built.

If you do not find it plase send me an Email and I will give you more details.

I kindly disagree with Martin: if you setup a 1.5m dish you should try to get out the optimum of it. Otherwise it is a waste of
time and material ...

Kind regards

Matthias

http://www.dd1us.de

Hello,
there has been some maintenance work ongoing in the last 2 days at AMSAT-DL in Bochum.

Kind regards

Matthias

http://www.dd1us.de

Hello Wilhelm,

in SDR Console the function "writing text in the spectrum" is already built in.

Kind regards

Matthias

www.dd1us,de

Hallo Wilhelm,

vielen Dank für Deinen Vorschlag.

Ich werde es mit Kurt diskutieren.

Viele Grüße

Matthias

http://www.dd1us.de

Hi Rudi,

Nico PA0DLO, who is quite experienced in tracking and identifying satellites, thinks that

CAS 5A is object 54684 (2022-167C).

This might change over time but presently those keps seem to match best.

Try these keps:

1 54684U 22167C 22343.84789909 .00012645 00000-0 80776-3 0 9992

2 54684 97.5368 118.8404 0014186 263.7133 96.2527 15.08701216 88

Kind regards

Matthias

http://www.dd1us.de

Hello Andrew,

you wrote: "The program starts and the command window opens. It runs through many items with no errors and the command window closes."

The command window should not close. It stays open here. I minimize it manually but do not close it.

Kind regards

Matthias

http://www.dd1us.de

Hello Jean,

thanks and regards

Matthias

http://www.dd1us.de

Quote from DJ0VL

Hello Matthias,

I did some bias-adjustment tests on the PA that was sold as „ …4x BLF8G27LS-140V – STEREO ..:)“, assuming this is the PA we are talking about.

This PA uses a programmable 8bit potentiometer for the bias adjustment of the main and the peak transistors (as part of an analogue temperature compensated bias network). Unfortunately, the programmable bias voltage range of the peak transistor is limited to 0.4-0.6V.

As the PA uses the same transistor type for main and for peak channel, I simply connected the bias of the peak transistor in parallel to the main transistor and set the bias current to 1A per transistor.

73 Jean DJ0VL

PS: the other PA (2x BLC9G22XS-400AVT-2) that use the LMP92066 for the bias generation can be programmed to set the peak transistor to mode AB without any hardware modification.

Display More

Hello Jean,

thank you for your answer.

No, I was referreing to the board with the BLC9G27XS-380AVT transistors.

Kind regards

Matthias

http://www.dd1us.de

Hello,

meanwhile I also built a DATV-PA based on such a 250W pallet from Ampleon. I am getting 230W output and the bias point is quite stable over temperature.

Here is a description (sorry it is still in German but you will probably understand based on the many pictures):

http://www.dd1us.de/Downloads/…0BPC2425M9X250%20v1.2.pdf

If there is enough interest I might translate it to English.

Kind regards

Matthias

http://www.dd1us.de

Hello Gerhard,

nevertheless thank you very much for your answers.

Kind regards

Matthias

http://www.dd1us.de

Hello Gerhard,

ok, no problem. I was just wonderingas this PCB looks promising.

Are you aware of any information with respect to the adjustment/programming of the board?

Kind regards

Matthias

http://www.dd1us.de

Hello Gerhard.

have there been meanwhile any results in the evaluation of these 2.6GHz PA boards?

Kind regards

Matthias

http://www.dd1us.de

Hallo DL8YF,

also meine Rechnung sieht anders aus:

Downconv 286 Euro

Upconverter 214 Euro

Gehäuse Surplus/Flohmarkt selbst angepasst 20 Euro

Kleinteile 40 Euro

Isolator 30 Euro (damit ist der Sendezug incl. Endstufe auch bei nicht angeschlossener Antenne oder Kurzschluss 100% geschützt)

Damit komme ich also dann auf Kosten von 590 Euro und wenn man gerne bastelt hat man viel Spass beim Aufbau.

Es gibt sehr viele OMs die über QO-100 mit den AMSAT-DL Komponenten qrv sind, incl. DP0GVN in der Antarktis
mit sehr guten Signalen. Ich selbst nutze sich auch in meinem Portabelsetup. Der Downconverter hat in der Tat
recht viel Verstärkung um auch längere Kabelstrecken überbrücken zu können. Wenn das jemnd zu viel ist dann
reicht ein kleines Dämpfungsglied aus 3 Widerständen und Du kannst das entsprechend an Deinen Transceiver
anpassen. Ein passendes kommerzielles Dämpfungsglied kostet gebraucht ca. 15 Euro.

Du hast es aber richtig gemacht, wenn Du mit den Kompoenten nicht klar kommst dann nicht ewig ärgern sondern
etwas fertiges kaufen und sich daran freuen.

... suum cuique ...

Viele Grüße

Matthias

http://www.dd1us.de

Hi Tom,

thank you very much for your great work.

Could you please issue a pull request in Github and we will include your changes in the next official version.

Kind regards

Matthias

http://www.dd1us.de

Henry,

I think it should be 9-10dB MER of the DATV-beacon if the wideband transponder is empty.

Regards

Matthias

http://www.dd1us.de

George,

there is no reason why this should be forbidden.

As long as you use SSB and stay within 2.7kHz transmit bandwidth it is ok.

Go ahead and try it. I wish you a lot of fun.

Kind regards

Matthias

http://www.dd1us.de

George,

well, we have to acknowledge that not all radio amateurs are able to actively contribute to science and society. This may be due to a lack of technical knowledge or a lack of free time besides the daytime job.

For such people there is still the option to support organizations like AMSAT by money (by membership fees or by donations) and thus enable those organizations to forster contributions to science and society.

But for sure there are also quite some, who do not contribute anything but only benefit from the knowhow, time and money others are spending. As long as they value what they are enjoying it is fine for me but those who are only complaining without contributing are a real PITA.

Kind regards

Matthias

http://www.dd1us.de

Quote from SV1BDS

Hi,

A SDR based system must use the capabilities of software based solutions in order to do things that can not be done or is very complicated to do with hardware. All of us try to replicate hardware solutions into the software solutions and not think what new features can be implemented.

Good point George, but you still have to be compliant with the regulations in your country and according to your license.

Regards

Matthias

http://www.dd1us.de