[TenTec] HELP! Eagle Tuning Problem

[1291jim at gmail.com]

Happy New Year All,

I have had an issue with my Eagle happen twice now.

Issue:
-  Eagle loses tuning and SWR starts going crazy and jumping all over the
place
-  Will not tune with inboard or outboard tuner
-  Returns to normal operation after I shut in down for a while

Background:
- Has only happened when I have been operating for several hours and during
a 20 min+ QSO, (so lots of sending) and both times on 40M
- Eagle felt warm but not hot
- Antenna is an EndFed (Alpha Antenna J-Pole Sr)
- Without tuning on 40M SWR is 2.6 : 1 
- Normally tunes to 1.0 or 1.1 : 1 with outboard or internal tuner
 
1st occurrence:
- I had been operating for 3-4 hrs
- Eagle was running 100W through an MFJ Intellituner Model 993B that tuned
SWR to 1.1 : 1
- SWR started jumping all over the place
- MFJ could not tune it
- I assumed it was the MFJ Tuner, shut it all down. 

2nd occurrence: (last night)
- Had been operating several hours at 100W
- Eagle again through MFJ Tuner when SWR started jumping all over
- This time I bypassed the MFJ tuner and tried to tune with the Eagles
internal tuner
- The internal tuner could not tune the antenna and SWR continued going nuts
through the attempted tuning process

This morning after a rest, rig tunes FB with outboard or inboard tuner.

Pulling it from service now.

Any advice would be appreciated.

HNY ES 73 DE W6JIM