Posts by DD4YR

DK5FA Danke! Ich hab den gleichen

DK5FA und ein Bild vom Filter, ich glaube ich hab den gleichen... Danke auch!

Quote from DK1ML

For DATV transmission you will need a 300w (real linear) pa and a dish >2m.

That´s not correct. Take a look here: https://wiki.batc.org.uk/QO100_DATV_Users

73s de Robert

Hello Heiner, have you already tried the MiniTiouner Pro V2 from R.E.F? I would be interested if he needs less pc performance than the Express ....?

... and custom clearance....

But.. I would still participate...

Robert

Zu NB Transponder: setzt voraus, dass die ATV Station Horizontal und Vertikal gleichzeitig empfangen kann. Also BATC NB mitlaufen lassen, was wieder Abhängigkeit der Infrastruktur bedeutet, oder zwei LNB mit Hohlleiter H/V Weiche betreiben ....

Wenn überhaupt, dann sehe ich nur eine Option für einen Rückkanal innerhalb des WB.

Robert

DD0KP which Transistor is on this board. Can not read on the picture ...

that's it. Thanks for your help!

PA3FYM

thanks for the explanation.
Are the IDQ = 1200 mA given in the data sheet sufficient for the 30 Watt and DATV linear operation? I always thought, "Mode A" amplifiers need significantly higher IDQ?

Ahh, I understand. I know the 6 dB rule.
I'm just not sure about that with the Channel Bandwidth = 3.84 MHz.
Thanks for the explanation.

Hello together, can someone help me to interpret the specifications in a technical data sheet?

The FET´s data sheet specifies two performances. In the case of the MRF6S21140HS it shows:

Typical 2 - carrier W - CDMA Performance: VDD = 28 volts, IDQ = 1200 mA,

1.: Pout = 30 Watts Avg., F = 2112.5 MHz, Channel Bandwidth = 3.84 MHz,

2.: Capable of handling 10: 1 VSWR, @ 28 Vdc, 2140 MHz, 140 Watts CW Output power

Does this mean now that you can load at a bandwidth of 3.84 MHz only with 30 watts (may), in narrowband operation like CW probably 140 watts.

How is it with DATV? Is it possible to load more than 30 watts with a correspondingly lower bandwidth (for example 500 kb/s)?

Is the maximum load between narrowband and 3.84 MHz bandwidth linear, from 140 watts down to 30 watts?

What can I accept?

73´s de Robert

Quote from DD4YR

So,

at 60 watts of DATV signal, the connectors are very hot .... at both ends. PA and Wattmeter ...
Maybe a bad quality of plugs?

Or wrong way to work with SMA plugs ...

73s de Robert

Display More

... problem solved.

Its not the SMA plug, its the cable who is heating.

I have now exchanged the thin coaxial cable for an RG-142. The heat development is now much lower. The 40cm piece still has a loss of about 4 watts at 60 watts of power. With a longer transmission passage, the heat development of the cable is well visible on the thermal scan ....

So, be careful with high power on 2,4 GHz and thin cables ...

73s de Robert

Quote from DD0KP

Did today my first transmitting tests with KG-STV. If you have two soundcards then you can run the program twice and then you have full duplex. You can receive what you send out in parallel. nice feature..

Hello Heiner, congrats for success!

You need only one soundcard to receive your own signal during transmitting.

BTW, you can also ad an secondary receive channel via BATC NB Monitor and can take a look of your correct tx frequency ....

And, make a mouse-click in the waterfall, and you get an other better rx-monitor ...

73´s de Robert

dj0abr

you have to adjust the TX buffer in the video codec settings drop down...

Reduce the video bitrate twiddle in small steps... until you do not have a TX buffer overflow...

dj0abr

what version of DATV Express software are you using?

125lp14 works good, oder version did not work fine with the Pluto at lower symbol rates ...

Is appreciated.

It´s a 50 Watt slug. (2400-2500 MHz)

I get at 1,5 watts input power 50 watts output power. My driver is only 1.75 watts.
With 1.75 Watt the pointer of the Wattmeter goes to right "stop". Should be estimated then 60 watts .. (by 15,3 dB gain)

So,

at 60 watts of DATV signal, the connectors are very hot .... at both ends. PA and Wattmeter ...
Maybe a bad quality of plugs?

Or wrong way to work with SMA plugs ...

73s de Robert

Thanks for the answers, why did not I find that?!?

And for DATV I think 6 dB less?

<100 watts is OK?

73´s de Robert

DB8TF

Hi,

how much power does an SMA plug-in handle?

I can not find any manufacturer information on the internet ...

73 de Robert

VU3BCN ...

Hello, did the sprectrum of the SDR signal change in any way if you switch from V to H polarisation?

Your screenshot looks like you still receive only vertical.

73s de Robert