Help? SB-101 keeps tripping into XMIT

[Zeiger-Guerra Family]

Newly acquired SB-101 is a great receiver.  Once rig has warmed up and I
begin transmitting (PTT) I only hear 1 or 2 seconds of audio after releasing
PTT and the rig trips back into XMIT.  VOX is OFF and PTT switch, etc. is OK
(even removing microphone connector from rig has no effect).  Cleaned and
examined both relays and tested/replaced tubes in VOX circuits.  Once this
begins to happen, only solution is to power down (for ~10 secs).  When power
back up, stays in RCV until next transmit.

Anyone have this problem?  Ideas?  Thanks!

- Stu KB1QW (Phila., PA)
[long time reader, first time "poster" on this reflector]

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