21 April 2016

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

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)

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