Forum.PowerSDR.de

Just another general remark

Completely agreed with Rene opinion : original Hermes lpf is not the best you can find. But using an 9th order filter would have taken quite a lot of place on the board.
some real improvement could be done, using T68 -or T60 at least- toroids. The original filter uses ...

... just a short note to DC9EO

Please Edwin, keep on writting in German. I really can read your language (und ein wenig Bayerisch also) without difficulties (6 years of German at school) but I would feel ashame if you could see how much bad my German grammar is.
VY 73'
Marc f6itu

Hi
in fact, the "Alexiares" structure of the lpf section is in the TX path, and the 6m lpf filter is permanently "in circuit". In other words, when receiving, the signal goes thru a first "toroid based" antialiasing filter AND the MCL integrated lpf located at each RX input, just before the ADC ...

Hi Rene

>gibt es eine möglichkeit den SPI für Alex und den I2C fürs Audio gleichzeitig zu nutzen?

as far as I know, the I2S is sharing the same output with the Alex SPI bus... so I'm affraid it's not possible

>Betreibt von euch jemand den RP mit einem Alexsystem?
yes, I do

>Wenn ja, funktioniert ...

Answer to myself : the power variation of the "drive" cursor in PowerSDR gives a constant delta of 20 dB, and the "PA Gain" gives the possibility to "offset" these 20 dB, thus controling the max and min output power delivered by the Red Pitaya board.

If PA Gain is set to 38.8dB, the RP will deliver ...

Hi Red Pitaya Hams

I would like to know which power level do you use to reach the best tradeoff when transmitting with the Red Pitaya.

By default, if all TX params remain unchanged, the "full throttle" output power is around 0 dBm. The max output power reaches between 9 and 10 dBm when "power ...

<r>I've probably read more than 100 times Pavel's notes... how could I have missed this. Or, worst, refuse to see it. <br/>
"<I><s>[i]</s>slow analog inputs can be used for the forward (Analog input 0) and reverse (Analog input 1) power measurement<e>[/i]</e></I>"<br/>
<br/>
I really feel ashame not ...

Hi Ralf and Chatt

I'm afraid nobody can answer your question. In fact, everything depends on “what” you intend to measure, and “with which precision”.
In other words, basic applications are perfect to explain instrumentation and measure to students. But not more. Let’s just give an example: you ...

Thank you, Siegfried and Yevgueni

I was just remembering something like that, but couldn't retreive this info.

I'll try to add some buffering or limitation (Zener ? ) to avoid killing the gpio. Thanks again to both of you, you make my day :- DD

Marc f6itu

Hi

Amongst the many way PowerSDR mRX manages the forward and reflected power display, one consists using 2 analog input (plugged to a so called "commodity ADC on HPSDR hardware), those two lines comming from the FWD and REV power voltages delivered by a simple VSWR tandem bridge.
I'd like to know ...

Hi Winfried
- did you configure PulseAudio to "connect" the linhpsdr input on "simultaneous output to audio internal analog stereo" ? as long as PulseAudio don't "see" linhpsdr, you won't be able to ear anything... you'll have to fiddle a little bit (output and input peripherals etc... try the ...

Hallo Thomas

I would say "no" if you are not using the VNA function, if you don't intend to use the FT8 digital mode, and if you regularly update your local system (with the "apk" utility)

from a more general point of view, I will upgrade anyway.... for security reasons. A new version of the ...

Hi

Just a stupid question : what is the impedance on the sma fwd connector when something is plugged on it ?

the input Z of the AD8307 is 50 Ohms. The output network of Loftür's coupler is 50 Ohms also
https://3f7d437a-a-62cb3a1a-s-sites.googlegroups.com/site/lofturj/power-and-swr-meter---rev ...

Bonjour Alexander

Did you check the email address written at the end of the article (dc2pd at darc.de) ?

73'
Marc

Hi Uli
The simplest way to analyze a I2C bus is to plug an entry level logic analyzer on the output of the Red Pitaya
https://www.amazon.fr/AZDelivery-Logic-Analyser-compatible-version/dp/B01MUFRHQ2/ref=sr_1_fkmr0_1?ie=UTF8&qid=1530609637&sr=8-1-fkmr0&keywords=logic+analyzer+fx2

If you are in a ...

Oh, certainly Sigy
I’ll try to be as precise as possible and will always answer (or try to answer) to any question
In a few words : We are a group of French hams who decided to build a series of “HPSDR compatible” rigs. Some decided to build an angelia pcb (anan 100D) from component level, others ...

Hallo Red Pitaya Freunde

This Red Pitaya transceivers is using the SPI bus (Thanks to Pavel for this incredibly nice feature) and a personal retrofit of the Alexiares frontend, offering all the functions controlled by PowerSDR or LinHPSDR (filter section of the Setup menu)

red pitaya small.jpg ...

Hi Manfred
Never heard of "alpha & omega" before. And these FET are definitely better than FQP13xx. Thanks for the tip and the reference.
The 416 is hard to find in Europe, but TME is selling the AOT412 which is very close in term of characteristics
Seems nice for low cost RF amps :-)
Thnks agn ...

Hi Manfred
That's not frightening at all... it is strongly encouraging and tempting

just a stupid question : did you try to change the pair of IRF FET with a couple of FQP13N10 ? these are very cheap switching FET, same category of the IRF series, but have a lower input capacitance

anyhow, this ...

Pavel marks a point (and I feel stupid indeed)
you can't control a master/slave I2C dialog without connecting both

Marc