27 April 2016

Looking for clean SS HF PA w/QSK - part 3

Hi all,

there I am sharing the findings and latest informations about this topic done by my friend Rudi, DK5FD...

"I own for many years an EXPERT 1K-FA PA and I am quite contented with it, up to the QSK operation. Because, the QSK operation is very loud, due to the relais noise; it's a nerve shattering clacking.

In January I had the opportunity to test for one day the new EXPERT 1.3K-FA, but what a disappointment the 1.3K-FA from EXPERT is also annoying, only a little bit quieter as the 1K-FA is.

Up to now I have also not found a suitable QSK amplifier.
I had written up the following companies:

ACOM for ACOM1200S, answer:
"Regretfully there is no good news for you. ACOM 1200S is not designed as a QSK amplifier.
TX/RX switching there is done in the same way as in ACOM 600S or ACOM 1010.
Regretfully there are probably not many hams that are interested in QSK rigs."

JUMA for PA1000, answer:
"PA1000 is using a quite high speed SMD relay for T/R switching. The max operate time is 4ms and max release time is 6ms.
Although the relay is quite fast the lifetime of 100x10e6 mechanical operations is limiting the endurance in QSK.
So it is not a vacuum or a solid state relay and it is not fully noiseless."

Linamp for Gemini HF-1K, answer:

http://www.linamp.co.uk/gemini_HF.html
"The QSK switching is fully solid state. No relays. Diode switched turned of hard by a 300V rail."

Therefore the Gemini HF-1K seems to be only QSK PA on the market, but the Design is not very nice, hi.

From the HAM's there should be a stronger demand for real QSK equipment and asking for, e.g. by eMails like you do."



Well, so we decided to share all our findings including Rudi's items over here, because we have to force the demand for SSPA QSK ability. It's a pitty that only one manufacturer (Gemini) offers a SSPA with real QSK... it seems.

Linear Amp Gemini HF-1K 1.8-50MHz 1kW Solid State Linear Amplifier:
http://www.linamp.co.uk/gemini_HF.html
Download brochure for Gemini amplifier:
http://www.linamp.co.uk/images/user/LinearAmp_Gemini_HF_lr.pdf


73 - Petr, OK1RP
"auf die Dauer hilft nur Power" (Erich, HB9FIH)

21 April 2016

Looking for clean SS HF PA w/QSK - part 2

Hi all,

there I am sharing additional informations about my research and findings regarding the "highly reliable, clean, compact, solid state HF-6m bands PA with 100% working, smooth QSK at around 1-1.2kW heavy-duty output and standard radio interface".

In the preview article I talked about the Juma PA1000. Unfortunately I got the feedback from Juma guys regarding the QSK system as follows:

"Hello Petr,
Sorry for the slow response. JUMA PA1000 is using quite a fast and quiet mechanical T/R relay with max Operate/Release times of 4ms/6ms. That means you can implement quite a fast QSK but it is recommended to configure TRCVR "TXon" timing so that the relay is closed before transmit. I hope this will help you.
73 Matti OH7SV"
 
...in another words:
 
"PA1000 is using a quite high speed SMD relay for T/R switching. The max operate time is 4ms and max release time is 6ms. Although the relay is quite fast the lifetime of 100.10e6 mechanical operations is limiting the endurance in QSK. So it is not a vacuum or a solid state relay and it is not fully noiseless." (tnx to Rudi, DK7FD)
 
So it looks like Juma PA1000 is out of the game for the moment.
More informations coming soon...
 
73 - Petr, OK1RP
"auf die Dauer hilft nur Power" (Erich, HB9FIH)