[Amps] Sequencing an Alpha 87a

jsternmd jsternmd at earthlink.net
Tue May 22 17:18:11 EDT 2007

Hi All,

Recently there have been reports of a number of PA failures in recent manufactures of the ICOM IC-7800.  Reasons are unclear but one concern is poor sequencing when the IC-7800 may be keying an amp and the IC-7800 may experience very high transient SWR while the Amp antenna relay is switching on CW or FSK.  They say the 7800's PAs are much more "fragile" than others.  The Alpha 87a has a Key IN and OUT where I could wire in the PTT/Key but looking at the schematic it seems it would work on the key down OK but the xcvr would be susceptible to the same issue on the key up where the amp would start switching the antenna relay while the xcvr lags slightly behind.  Anyone have any experience to share?

Tnx es 73

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