Thxs Griffo for the info. Will try out & monitor the freqs. I also managed to 'dick out' some info from the internet on the freqs used by South East Asia ATC (as below), might serve as a guilde line as well.
SEA-1
3470
5670
6556
10066
13318
17907
Bali, Bangkok, Colombo, Calcutta, Dhaka, Guangzhou, Jakarta, Kathmandu, Kuala Lumpur, Kunming, Madras, Male, Singapore, Yangon
SEA-2
3485
5649
5655
8942
11396
13309
17907
Bali, Bangkok, Guangzhou, Hanoi, Ho Chi Minh, Hong Kong, Jakarta, Kuala Lumpur, Kota Kinabalu, Manila, Seoul, Singapore, Tokyo, Vientiane
SEA-3
3470
5733
6556
10066
11396
13318
17907
Bali, Cocos Islands, Jakarta, Male, Perth, Singapore, Ujung Pandang
Will post soonest on detection of better freqs set.
Regards