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Repeater weirdness in Taiwan

I think I have not ranted for a while, right? Just recently I bought a simple dual band handy transceiver, to be able to use the repeaters here. So far however I have not had a single QSO with it.

Repeaters are a difficult topic in Taiwan. Years ago I had the chance to witness the construction, installation and later failure of a "repeater" in Taizhong. Said repeater consisted of an Alinco mobile dual band transceiver in crossband repeater mode with two linear amplifiers, one for 144 and 430MHz each. That repeater was set up in a back metal box (with fans, but that did not make any difference) and installed on a building roof - directly under the sun. Do I need to elaborate what happened? Probably not.

The local radio law mentions repeaters, but AFAIK it is impossible to apply for one. Besides, 430MHz in Taiwan is only 2MHz wide: 430-432MHz. There are no repeaters on 144MHz (probably copied from Japan). So how come there are repeaters on 430MHz when you can not apply for one and do not have the space to place uplink and downlink within the allowed frequency range?

The answer is "emergency services". When an earthquake or typhoon takes down regular communication networks, these repeaters are supposed to allow communication in a wider area, ideally throughout the whole island. This is however like a China Crisis song - wishful thinking . "C6" is the repeater supposed to cover the Gaoxiong area. So far I could not open it with my handy transceiver, not from Zuoying, not from Sanmin, not from Xiaogang. So I think I better not rely on it in case of a real emergency...

Emergency services was of course only an official reason to get the repeaters approved. They are connected to echolink, and in the Northern part of this island, people even seem to be using them on a regular basis. But now comes the technical side: You may already have wondered how a repeater fits into 2MHz. The answer is simple: It does not. the downlink frequency is 430.980MHz, uplink frequencies are above 439MHz.

Did you notice the use of singular and plural? Good. This is not a joke. There was a time when even the uplink was on the same frequency. Not kidding. People even noticed that this caused problems (Hear, hear...), and I only shook my head when I read about those problems on the local Skype chat. This is FM! Two FM signals on the same frequency will cause interference or you will only hear the stronger one. So, if a station is closer to C5 (the Tainan repeater) than to C6 (Gaoxiong), but can be heard by both repeaters, while a replying station can only reach C6, do you think the calling station will hear the reply? I think not...

So the solution was to use different uplink frequencies, but still use the same downlink frequency. Ingenious. Do you have an idea how much time it takes to set those frequencies up in your transceiver? Usually you would set a shift (say, 7.6MHz in Europe), and then just tell the transceiver to use shift on certain frequencies. If you follow standard frequency assignments, your transceiver may even switch the shift on automagically. Here however...

Let's see if I can convince anyone to fix this mess...

Comments

Right

You are of course right, Hans. The frequencies are a well-kept secret. Which also means: If someone needs to use a repeater in an emergency, they will probably not be able to.

Oh, talking about abilities: I know now why I can not access C6. It is gone. C6 has moved to Tainan, and C5 has moved to Jiayi. And almost nobody here in Gaoxiong knew until I raised the topic...

I heard that the frequency scheme was the idea of someone up high in the CTARL, so short of overthrowing the current rulership this frequency disaster is unlikely to change.

Good rant.

Good rant. I gave up on repeaters: hardly anyone using them up north anyway and if they are used it's usually the same crowd. And what is so difficult about a -1.7 MHz repeater shift? Okay, the cavity filters will be a bit more expensive, but countless amateur groups around the world have got it together, so why not in Taiwan?

You forgot to mention that the uplink en CTCSS info is kept super secret and only available for the in-crowd. You will not find any mention on the web, of these because it might come into the hands of the "sausages" and that would mean the end of the exclusive use of these national treasures for us hams. Sometimes I wish.....

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