[hpsdr] PennyWhistle MOSFET's

[Rod Brink]

Sounds like there is insufficient feedback signal for PureSignal to  work properly.

Sent from Mail for Windows

From: Riho B., ES7AAZ
Sent: Tuesday, November 9, 2021 4:42 PM
To: Hpsdr Mailing List; Helmut Oeller
Subject: Re: [hpsdr] PennyWhistle MOSFET's

P.S. To be correct they are rising in any order - sometimes only 3rd, sometimes only 5th, etc., sometimes all together. It looks like a code stuff is doing that.

Kontakt Riho B., ES7AAZ (<es7aaz at gmail.com>) kirjutas kuupäeval K, 10. november 2021 kell 02:00:
Helmut, how to explain this kind of Penelope behavior? I observing Penelope output only in the two tone test @ 250mW. Sometimes there are no visible IMD products, sometimes IMD products are rising, 3rd order abt. 10db.

Kontakt Riho B., ES7AAZ (<es7aaz at gmail.com>) kirjutas kuupäeval T, 9. november 2021 kell 14:40:

HI Helmut,

yes, the adaptive predistortion is a very good thing, but as far I know Ozy+Mercury+Penelope doesn't support that thing. This setup performs more than good for me and I don't want to upgrade it. Recently I've seen wierd SSB signals on 20m. Signal itself looks good and 2700Hz BW, but the bottom side is very wide and looks like the ocean waves. That's why I started to explore how does my setup do and I found that my setup does exactly the same wierd thing on SSB. I only need a good 160-6m amp, not the perfect one. I hope that this 2xRD70HVF1 amp is exactly what I need for my setup.

--
73,
Riho ES7AAZ


Kontakt Helmut Oeller (<dc6ny at gmx.de>) kirjutas kuupäeval T, 9. november 2021 kell 14:07:
Riho, most PA designs are using the fundamental work of Helge O. Granberg, OH2ZE/K7ES, who published in the 80's a lot of ANs in the famous Motorla 'cook book'. Helge - sk meanwhile - was a impressive engineer and I gladly recall  some meetings with him.
Nevertheless physics is incurruptible. If you go for IMD optimization you have to consider a lot of details. To produce 'dirty' power is no big deal. But even 'dirty' amps can be cleaned using Warren's fine adaptive predistortion algorithm.
73, Helmut, DC6NY
Am 09.11.2021 um 11:59 schrieb Riho B., ES7AAZ:
Hi Helmut,

thank you for your remarks. I'll take a look into the bifilar choke for DC feed. This amp is designed by OH7SV, OH2NLT. It should be a working thing and give a quite flat 22dB gain from 1 to 60MHz. The same guys who designed the JUMA DC TRX and state-of-art LDMOS 1kW amp JUMA PA1000 - http://www.jumaradio.com/ But yes, I built it from quite a scratch. There was no big story about this amp - schematic, PCB 2400dpiPDF image, PCB layout, some pictures and their measurement results on their website. 

--
73, 
Riho ES7AAZ














-- 
73,
Riho ES7AAZ
www.qrz.com/ES7AAZ



-- 
73,
Riho ES7AAZ
www.qrz.com/ES7AAZ

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