AMSAT-DL 2.4 GHz / 6W Power Amplifier für QO-100 mit ADALM-PLUTO

Hi

Vielleicht ist es besser, 2x SKY66292 durch Transistoren zu ersetzen 2x LD-MOSFET PD85004 ?

73

Artur

Quote from DB2OS

Ja Andreas, man hat es nicht einfach.. ich hab mir schon in den aller wertesten gebissen..

Aua! (Das ist nicht gut für die Wirbelsäule!)

Quote from DB2OS

wenn es tatsächlich in den nächsten Tagen im Shop steht, werde ich es erst dann hier schreiben..

Solche Wirbel-Säulen können wir als Allerwerteste ja nur schätzen. Ich wünsche Dir guten Wirkungsgrad und bleibe in guter Hoffnung

Bestellt! Danke.

Gibt's auch eine Schätzung für Gehäuse und LNB?

(Ok. Banner im Shop gesehen)

übrigens der Link auf die Produkte: https://shop.amsat-dl.org/produkt/ baucht noch etwas Pflege (Err 404)

Quote from HB9SKA

Andreas, wo ist denn dieser Link ?

Hier:

Hallo,

is there any information about intermodulation distortion and power of a DB4UM-Amplifier. It is a single SKY66292. I tested one and the results were disappointing a bit. I don't know why yet. The push pull amp with these chips runs much better.
Any kind of information will be highly appreciated.

Thanks in advance
73
Andreas

Hi all,

today I could test several samples of the amplifier with one SKY66292. All showed rather pure intermodulation results. So, it seems like it can not be recommended as a driver. I am very interested in getting some information from other testers. Once more, saturation power is not usable for linear operation.
A driver stage should be minimum 6 dB better in IMD3 than a final. Otherwise the overall intermodulation gets worse.

Thanks
73

Andreas

Hello Andreas

The Skyworks data suggests that the device has a maximum power dissipation of 1.25W.
I do not really see how they can claim "4W Output" other than that is the maximum saturated output with everything on or slightly over the limit. Looks like it may be just acceptable at 500mW but even then the response is not ideal. Probably a device to avoid.

Thanks

David

Hallo David,

unfortunately I don't know where differences between a single sky-amp and the push pull Version come from.

This is an Intermodualtion spectrum of the push pull Amp. Two single carriers with one watt give four watts PEP. IMD3 reaches around 40 dB PEP. From my nonessential point of view, it is very good.

The next shot is captured from a single SKY66292 designed after DB4UM with the help of a chinese board. This is about one watt PEP and IMD3 is 10 dB worse. May be, my expectation is wrong.

A friend and I try to get some hybrid couplers to test the push pulls again.

Regards
73
Andreas

Hallo,

here is another amplifier-question. I ordered an amplifier from Alieexpress with SZM2166 (Sirenza, now QORVO) so see how it works. I am very satisfied with the SZA2044, this is the "little brother" of the SZM2166.
But unfortunatley the SZM2166 board didn't work. Extrem low idle current and less gain. The datasheet says 800mA idle current. The dialog with Alieexpress is difficult and will continuing...

Is there anyone who owns a good working amplifier board with this SZM2166. I am interested in information about current cosumption (quiescent and power) and linearity of course. QORVO says the chip is obsolete. Some suspect dealers report about chips in stock. Not sure if they will sell me something as a privat person.

Thanks
73
Andreas

Servus alle die günstige China Verstärker kaufen....

Zitat aus: https://www.hb9afo.ch/histoire…TV%20Rptrs%20Rptr-115.pdf bezüglich: SZM2166

Hi Jim ---- Hi hi hi hi hi 8-) my condolences ! You're not the first to notice that
this PA doesn't work. I also bought 6 pieces for 2.4GHz and 4 pieces for 5.6GHz. I
haven't tried a 2.4GHz yet, all the others work from very poorly to not at all. The only
relatively good thing is switch down power supply.... the rest ended up in the trash.
These PA's are built with fake China parts or chips discarded by manufacturers as not
good enough. Unfortunately, we customers are still blinded by the price and buy it.
If anyone needs good all mode amplifiers for 2.4GHz, with throughput gain above 50dB,
I have a few for sale. with 0,008mW input PA give 2,0 Watt output DVB-T
or with -14dBm input PA give 16 Watt output CW SSB ATV
Vy 73 de OE7DBH, Darko, Pians Austria

Zitat ende.

In https://www.hb9afo.ch/histoire…TV%20Rptrs%20Rptr-114.pdf wurden diese günstige

China Verstärker behandelt.

Vy 73 de OE7DBH

Hi Darko, my name is not Jim,
your infos about Chinese amps are confusing a bit. The SZA2044 works great with 200 mWatts and very good linearity. I would like to get more information about the fake Chips. Many amps from China work as expected. And many Oms appreciate the prices and the wide range offers. What is about your famous amps? Is there an intermodulation spectrum available?

Thanks
73
Andreas

Hallo,

now I am sure, stay away from SZM2166-Boards from China. I tested another one from ebay. The seller has good references. The yesterday arrived board showed less idle current and no amplification at all, just like the first one I tested from Alieexpress. By the way, they gave back the money. I will send the ebay example back too.
What a pity, the smaller chip SZA2044, as I wrote above, works great.
At least, it seems like the obsolete chips SZM2166 from Sirenza/Qorvo are fakes. I will explore the board and compare it with the evaluation infos in the datasheet. But there is not much hope. This is very sad, most of the offers from Asia are ok. And we can save time and work to use it.

The picture shows the quick Setup. The idle current is about 140 mA. The data sheet says much more.

May be, there is a chance to get correct working chips? It should be possible to change the chips with hot air soldering. Any information about a reliable distributor, who is ready to sell some parts, will be appreciated.

Enjoy the Christmas Time
73
Andreas

Hallo,

both Asian dealers sent back the money very fast. May be, they know already whats wrong with the chips.
No further loss for me beside the frustration. Trying to get in contact with Qorvo support, I received a quick reply. A field applications manager told me, the lot code of the SZM2166 is 5 digit normally instead of 6 digits I watched through my microscope. He recommended me the RFPA5208 as a replacement. Unfortunately there are no boards with this chip.
All this couldn't fix the Problem but I was surprized about the quick and friendly reaction of Qorvo. From my point of view it has to be highly apprecciated.
73
Andreas

The RFPA5208 is used as the PA of the HiDes BU500 upconverter.

https://www.oe7forum.at/viewtopic.php?t=284&start=150#p2045

,

73s

Hallo,
thanks for the information. I am looking for single amps as driver stages behind the Pluto. I own a BU500 from the very beginning but do not use it anymore. My example showed a poor LO surpression. It's up to everyone but the SDR-solutions bring so much advantages. An article will be published in the German Magazine "Funkamateur", I hope soon.
73
Andreas