[hpsdr] Pure Signal and ARC FAULT of linear amplifier

[Tokio Endo]

Hello,

So far I enjoy the Pure Signal function of PowerSDR v3.4.9 with a linear amplifier TL-922, 2 x 3-500Z. My SDR board is Hermes and the 100W amp is an old TS-940S.

Recently I’ve begun to use ACOM2000A, manufactured in 2009 with original EBS, instead of TL-922. The other equipment remains the same as TL-922 configurations, including a directional coupler, Xtronic XDC-4SO. The reason why I preferTL-922 is EBS of ACOM2000A which changes the bias during transmission which causes the abrupt change of amplifier behavior which I think it is not good for Pre-distortion.

Using ACOM2000A with Pure Signal, more precisely the PS button ON of PowerSDR, ACOM2000A trips due to ARC FAULT while I have SSB QSO. In CW and FT8, ARC FAULT never happens even with 1.5KW. FYI I don’t use 1.5KW for FT8.

With PS button OFF, NO ARC FAULT occurs with SSB QSO. I am obliged to think that the CAUSE of ARC FAULT is Pure Signal due to a very short period of spike of an exciter power, maybe, during the period when EBS works as well as the adaptive functionality of Pure Signal.

If you have the similar phenomenon, your comments would be much appreciated.

73,
Tokio
JA1CCA