Hello Glenn_911,
Intelsat 805 @55,5°W is much stronger and easier to catch as NSS 806 @40,5°W.
On linear Satposition with H and V frequencies as on 55,5°W, you don´t need Dielectricum plate in the C-Band LNB.
On cirkular Satpositions with L and R frequencies as on 40,5°W, you "must" use it. -> But more better is for circular Transmission to use a waveguide. I use it since 2 years now and it brings you much more good signal, especially with smaller dishes. Dielectricum plates looses more from signal.
You know, 120cm are not much for C-Band! I would say: To get every regular program on Intelsat 805 you need about 240cm. For NSS 806 you need 300cm.
But you can try the following frequencies. Here with mesh 366cm the quality of signal is between 90-100% and 9-10,5dB on Openbox X-810 receiver. * means strongest signals!
NSS 806 @40,5°W:
3803 L 27500 3/4
3860 L 2600 3/4
*3965 R 1844 3/4 in DVB-S/MPEG-4
*3967 R 1844 3/4 in DVB-S/MPEG-4
3977 L 3979 3/4
3986 L 3179 3/4
Intelsat 805 @55,5°W:
3591 V 10128 3/4
3603 V 6655 3/4
3612 V 3798 3/4
3683 V 11358 3/4
3727 V 3000 3/4
*3935 H 3255 2/3
3966 V 2963 3/4
*3971 V 3703 2/3
4080 V 4341 3/4
4093 H 2500 3/4
4111 H 3333 3/4
4134 H 6111 3/4
4145 V 2000 3/4
Good luck!
Best Regards
Edgar.