List of vacant FM frequencies where are not suitable to be used in Gunung Ledang as broadcast transmission

It is normal for those non-broadcast background people who don't have deeper analysis to list out all vacant frequencies which sound suitable to be used in certain sites.

We know that there are very limited vacant FM frequencies for Gunung Ledang. At the same time, MCMC is performing FM frequency re-planning study, the regulator body had released its public announcement on 1st July 2019, therefore none of FM broadcasters' frequency application will be considered and issued until the FM frequency re-planning study is done.

If I choose to neglect MCMC FM frequency re-planning study yet, according to current FM spectrum condition, there are only about two vacant frequencies in Gunung Ledang, mainly FM 91.5MHz and FM 100.9MHz.

As December 2019, Kool FM has no frequencies in Gunung Ledang for Melaka and North Johor like its sister stations Fly FM, Hot FM and One FM due to unavailable spectrum allocation on FM frequencies, but certain people suggest few frequencies on Facebook which "sound" suitable for Gunung Ledang transmission, the frequencies are:

- FM 89.9MHz
- FM 90.7MHz
- FM 94.4MHz
- FM 95.2MHz
- FM 100.8MHz

Generally, these five frequencies sound suitable to be used in Gunung Ledang, but technically they can cause interference to existing radio stations. Therefore, let's analyze these five frequencies.

==FM 89.9MHz==
89.9MHz: BFM Gunung Ulu Kali
89.9MHz: Gunung Ledang
<0kHz, OK>

89.9MHz: Gunung Ledang
90.1MHz: Hot FM Gunung Pulai
<200kHz, OK>

89.9MHz: Gunung Ledang
90.1MHz: Radio Klasik FM Bukit Tinggi (Mersing)
<200kHz, OK>

89.5MHz: IKIM FM Gunung Ledang
89.7MHz: Ai FM Gunung Telapak Burok
89.9MHz: Gunung Ledang
<200kHz, INTERFERENCE>

==FM 90.7MHz==
90.5MHz: Gold 905 Singapore
90.7MHz: Gunung Ledang
<200kHz, OK>

90.7MHz: Gunung Ledang
90.9MHz: Nasional FM Bukit Tinggi
<200kHz, OK>

90.7MHz: Gunung Ledang
91.1MHz: Mix FM Gunung Ledang
<400kHz, OK>

90.6MHz: RRI PRO-1 Bengkalis, Indonesia
90.7MHz: Gunung Ledang
<100kHz, interference>

90.3MHz: Era FM Gunung Ledang
90.5MHz: Minnal FM Gunung Telapak Burok
90.7MHz: Gunung Ledang
<200kHz, interference to 90.5 Gunung Telapak Burok>

==FM 94.4MHz==
94.0MHz: Fly FM Gunung Ledang
94.2MHz: Mix FM Gunung Telapak Burok
94.4MHz: Gunung Ledang
<200kHz, interference> 

94.4MHz: Gunung Ledang
94.5MHz: Mix FM Gunung Ulu Kali
<100kHz, OK>

94.4MHz: Gunung Ledang
94.6MHz: Lite FM Gunung Pulai
<200kHz, OK>

==FM 95.2MHz==
94.8MHz: Best FM Gunung Ledang
95.0MHz: Hitz FM Gunung Telapak Burok
95.2MHz: Gunung Ledang
<200kHz, interference> 

95.2MHz: Gunung Ledang
95.3MHz: Nasional FM Gunung Ulu Kali
<100kHz, OK>

95.2MHz: Gunung Ledang
95.4MHz: MY FM Gunung Pulai
<200kHz, OK>

==FM 100.8MHz== 
100.4MHz: Fly FM Gunung Ledang
100.6MHz: Mix FM Gunung Telapak Burok
100.8MHz: Gunung Ledang
<200kHz, interference> 

100.8MHz: Gunung Ledang
100.9MHz: Selangor FM Gunung Ulu Kali
<100kHz, OK>

According to RF analysis of 5 frequencies above, FM 89.9MHz, FM 90.7MHz, FM 94.4MHz, FM 95.2MHz and FM 100.8MHz will cause interference to Gunung Telapak Burok radio stations coverage in Negeri Sembilan because Gunung Telapak Burok frequencies such as FM 89.7MHz, FM 90.5MHz, FM 94.2MHz, FM 95.0MHz and FM 100.6MHz already have 200kHz frequencies separation from existing Gunung Ledang stations respectively such as FM 89.5MHz, FM 90.3MHz, FM 94.0MHz, FM 94.8MHz and FM 100.6MHz.

In addition, the distance between Gunung Telapak Burok and Gunung Ledang is 79km only, the height of Gunung Ledang is higher than Gunung Telapak Burok actually. Due to these reasons, it is not recommended to allocate "sandwich" frequency systems in Gunung Ledang and Gunung Telapak Burok.

The concept of sandwich frequency system is a radio station frequency from Site A is located between two radio stations from Site B where frequency separation from Site A and Site B are 200kHz or above. 

Example of sandwich frequency allocation system:

95.6MHz: Perak FM Gunung Kledang (Gardenia Original Classic)
95.8MHz: Fly FM Gunung Ulu Kali (turkey ham)
96.0MHz: Suria FM Gunung Kledang (Gardenia Original Classic)
<200kHz, thin sandwich, but distance between Gunung Ulu Kali and Gunung Kledang is more than 140km, so no interference within coverage area is happened>

Note: I classify it as Sandwich A (thin sandwich with two same breads)

300kHz between is considered as thick sandwich frequency separation, it is perfect because it avoids interference. Example:

96.1MHz: 988 FM Gunung Jerai
96.4MHz: Sinar FM Bukit Larut
96.7MHz: Minnal FM Gunung Jerai

93.0MHz: Hitz FM Gunung Ledang
93.3MHz: 988FM Gunung Telapak Burok
93.6MHz: Radio Klasik Gunung Ledang 

I classify it as Sandwich B (thicker sandwich with two same breads)

Some of "sandwich frequency separation" are using different site, where interference impact is very low, same as two different bread slices with an egg. Example:

87.7MHz: Radio Klasik KL Tower (Gardenia whole meal)
87.9MHz: Radio Klasik Gunung Telapak Burok (egg)
88.1MHz: One FM Gunung Ulu Kali (Gardenia original classic)

Note: I classify it as Sandwich C (thin sandwich, but two different breads' type/flavor or brand).

Although the analysis shows that 87.7 and 88.1 targets Kuala Lumpur, but their transmission sites are different and transmission height of 87.7 is much lower than 88.1, so interference to 87.9 coverage is very low.

Based on RF analysis by mentioning sandwich concept, if the distance between Site A and Site B is more than 130km, so it is ok to allocate based on Sandwich A which is thick sandwich. In addition, if both transmission sites distance is less than 100km, it is highly recommended to allocate based on Sandwich B where frequency separation is 300kHz left right.

Result: It is not suitable to separate again from Gunung Telapak Burok with 200kHz separation for new Gunung Ledang station where Gunung Telapak Burok already has 200kHz frequency separation from another Gunung Ledang station. (Example: 94.0 Gn Ledang>94.2 Gn Telapak Burok>94.4 Gn Ledang), despite the distance between two sites is less than 90km.




Another situation is two same sandwich, but different thickness concept, which never cause interference to the middle.

98.3MHz: Radio Klasik Gunung Ulu Kali (thick sandwich)
98.6MHz: Fly FM Gunung Telapak Burok (egg/ham)
98.8MHz: 988 FM Gunung Ulu Kali (thin sandwich)

Return to the listed frequencies, although all five frequencies are not suitable for Gunung Ledang transmission, but they're suitable for certain sites where is far from Gunung Telapak Burok or much lower than Gunung Ledang.

1. FM 94.4MHz can be used in Bukit Tinggi for Mersing only.
2. FM 100.8MHz can be used in Bukit Sembilan for South and southeast Pahang.
3. FM 100.9MHz can be used in Gunung Ledang transmission for Melaka and North Johor.

Note: FM 91.5MHz may not be suitable to be used for Gunung Ledang transmission because interference to FM 91.4MHz in Dumai, Indonesia.

Allocating FM frequencies in Gunung Ledang does not only need to consider existing stations from Gunung Telapak Burok, Bukit Tampin, Bukit Tinggi, Gunung Pulai and Gunung Ledang itself, somehow we need to consider existing stations from Singapore, Indonesia (Bengkalis and Dumai), Gunung Ulu Kali and Bukit Senggora.