[TenTec] Popping Noise from Orion and Centurion

[Toby Pennington]

I am experiencing an annoying popping noise in my speaker when keying and unkeying the orion with the Centurion amp in the line.  This does not occur with the Orion standalone, but only occurs when the amp is being keyed up and unkeyed.  The popping can be heard using the keying loop or just using the PTT line to the amp.  This is someting new which is occuring and I am wondering if anyone else has experienced this problem and how you fixed it. 

I have checked all keying cables and tried three different sets of cables with the same results.  I can also hear the popping when running the amp into a dummy load but the noise is greatly reduced.  Turning on the preamp on the Orion brings the noise back up when using the dummy load. 

There appears to bo no other sign of feedback other than the popping noise, so don't think it is a timing issue.  

Any suggestions would be appreciated!          Toby  W4CAK