Yeah, I have a PTC as well plus a TTM which is probably the best monitor mix for your TT if you don't use a graphics card.
If you want a reasonable picture from your TT go for a graphics card or at least an Overscan TT which will boost your TTs video chip to its full capacity (more colums and lines) while making the picture fit onto you monitor nicely.
Btw:
This picture (from ST-Computer 10/1990) shows how to make up a cable to use any monitor with TT Hirez.
If you have a TFT that supports 1280x960 you might want to try that.
