(RF analysis) FM 100.9MHz Gunung Ledang can interfere Selangor FM 100.9MHz Gunung Ulu Kali coverage in Tanjung Sepat and Sungai Pelek if covers Melaka.

5 years ago, I listed FM 100.9MHz as proposed frequency for Gunung Ledang transmission for Melaka and North Johor. In 2016, I suggested this frequency for Kool FM as Melaka frequency as FM 100.9MHz was vacated in North Johor, meanwhile it was weak signal of RTM Selangor FM from Gunung Ulu Kali.

Look at the spectrum condition, FM 100.9MHz apparently can be used in Gunung Ledang for North Johor and Melaka, but technically it can cause co-channel interference with Selangor FM in critical locations.

Use my old personal proposal. Kool FM 100.9MHz Gunung Ledang for Melaka and North Johor, I know if the expansion is successful will benefit its listeners in Melaka and North Johor, even part of Negeri Sembilan and Pahang, but because Selangor FM 100.9MHz can be listened in costal areas of Northwest Melaka, Kool FM 100.9MHz Gunung Ledang could face serious co-channel interference from Selangor FM badly, mainly in Kuala Sungai Baru, Masjid Tanah, Sungai Udang, Tanjung Bidara, Lubok Cina and part of Melaka city like what happen to Minnal FM 103.3MHz Gunung Ledang which suffers interference from Era FM 103.3MHz Gunung Ulu Kali in part of Melaka.

That's not the biggest point, but the main point is Kool FM 100.9MHz Gunung Ledang can interfere Selangor FM 100.9MHz Gunung Ulu Kali coverage in Tanjung Sepat and Sungai Pelek where are towns in Selangor state. So, Selangor FM's listeners can hear co-channel interference from FM 100.9MHz Gunung Ledang (Kool FM: personal old proposal) badly in Tanjung Sepat, and Sungai Pelek. 

This is because Era FM 103.3MHz Gunung Ulu Kali suffers co-channel interference from Minnal FM 103.3MHz Gunung Ledang in Tanjung Sepat and Sungai Pelek (including Bagan Lalang) badly, but this does not affect Era FM listeners because Era can be tuned on FM 103.6MHz from Gunung Telapak Burok there. 

Era FM has alternative frequency, but Selangor FM has no alternative frequency as it covers the whole Selangor state with only a frequency FM 100.9MHz.

Unless Selangor FM launches alternative frequency to backup Tanjung Sepat and Sungai Pelek (maybe FM 92.0MHz or 102.1MHz) from Sepang, so interference from Kool FM 100.9MHz Gunung Ledang in Tanjung Sepat and Sungai Pelek is not a matter, but it is not worth to do so because RTM Selangor FM needs to pay more transmission fees because of alternative transmitter.

For everyone's information, as there is no terrains between Gunung Ledang and Southwest Selangor, so Gunung Ledang transmitted radio stations can be tuned clearly there, except those Gunung Ledang radio stations cover only North Johor and other non-Melaka region (example: Johor FM 105.3MHz and Asyik FM 95.6MHz).

Following by Era FM 103.3MHz (Gunung Ulu Kali) is having co-channel interference from Minnal FM 103.3MHz (Gunung Ledang) in Tanjung Sepat and Sungai Pelek that I detected few weeks ago, now I realize my old proposal of FM 100.9MHz Gunung Ledang transmission is not safe to be used.

It is quite dangerous if a radio station uses FM 100.9MHz in Gunung Ledang to cover Melaka and North Johor because it can interfere Selangor FM Gunung Ulu Kali coverage in Southwest Selangor (Tanjung Sepat and Sungai Pelek).

Another case, Johor FM is using 105.3MHz in Gunung Ledang which is same frequency as Suria FM from Gunung Ulu Kali, but the transmission never cause interference to Suria FM in Southwest Selangor because Johor FM beams only North Johor areas.

The frequency FM 100.9MHz Gunung Ledang is safe to be used if the radio station does not cover Melaka like Johor FM. If Pahang FM launches Gunung Ledang transmitter to cover Muadzam Shah on FM 100.9MHz by using directional antenna to cover South Pahang only, it is fine because it will not cause interference to Selangor FM coverage in Southwest Selangor.

 

Asyik FM currently broadcasts on FM 95.6MHz in Gunung Ledang for North Johor only, excluding Melaka and Negeri Sembilan, because it is interfering with RTM Negeri FM 95.7MHz Bukit Tampin, actually if RTM Asyik FM Gunung Ledang frequency changes to 100.9MHz without changing its antenna system, it will not interfere Selangor FM 100.9MHz Gunung Ulu Kali coverage.

In conclusion, FM 100.9MHz Gunung Ledang transmission depends on radio broadcaster antenna direction configuration.

==RF interference analysis if FM 100.9MHz Gunung Ledang transmission is occupied to cover Melaka and North Johor==

1. For FM 100.9MHz Gunung Ledang (example: Kool FM)

- Affected listening areas: Tanjung Bidara, Sungai Udang, Kem Terendak, Kuala Sungai Baru, Masjid Tanah, Lubuk China, Tanjung Kling and some Melaka city. (Melaka state)

2. For Selangor FM 100.9MHz Gunung Ulu Kali

- Affected listening areas: Tanjung Sepat, Bagan Lalang, and Sungai Pelek. (Selangor state)

- Alternative frequency: NO

3. Common interference areas: Port Dickson, Rembau, Rantau, Linggi, Pedas, Lukut, Pasir Panjang, Si Rusa, Kuala Klawang, Bera, Kemayan, Teriang, Manchis.

==RF interference analysis between Minnal FM 103.3MHz Gunung Ledang and Era FM 103.3MHz Gunung Ulu Kali==

1. For Minnal FM 103.3MHz Gunung Ledang

- Affected listening areas: Tanjung Bidara, Sungai Udang, Kem Terendak, Kuala Sungai Baru, Masjid Tanah, Lubuk China, Tanjung Kling and some Melaka city. (Melaka state)

- Alternative frequency: FM 90.5MHz Gunung Telapak Burok

2. For Era FM 103.3MHz Gunung Ulu Kali

- Affected listening areas: Tanjung Sepat, Bagan Lalang, and Sungai Pelek. (Selangor state)

- Alternative frequency: FM 103.6MHz Gunung Telapak Burok

3. Common interference areas: Port Dickson, Rembau, Rantau, Linggi, Pedas, Lukut, Pasir Panjang, Si Rusa, Kuala Klawang, Bera, Kemayan, Teriang, Manchis.