RC Slope Soaring in Hong Kong

其實我只係度緊 chassic power, ERP 會再低 D。呢個方法最大既問題係將條 RF cable 接到發射個部份, 呢度有幾多 power reflection 就真係唔知﹐只係可以肯定真實既 power 會比我度到既高。

真正去度 ERP 好難架﹐要有間 anechoic chamber



香港只有幾間 lab 同大學有咋﹗

剛剛收到挪威 F3X 發燒友 Jojo 既回應﹐佢都話 100 mW 無問題渦﹕


Hi there!
I did not read you links to documents but...
In Norway there is a maximum of transmitted power of 100mW. And a
channel separation of 10kHz. This is stated in the rules from the
Norwegian government and is what most producers of Tx's are aiming
for. This should be enough for 5km over water and atleast 2-3km over
land. Actually I flew 1,6km inland in the military on 41mHz with no
problem with standard Tx and the other pilots claimed that they had
reached 5,5km over water (with binouculars).

All Tx's I have checked with my clubs scanner is apx this power. And
I have been checking (by being on Eurotour events) most of the Tx's
that is being used by top pilots in F3B and F3J in Europe on bands
from 27-41mhz.

Good luck
Regards Jojo
www.grini.no

It is a good news. I think what we need to do is to confirm with OFTA that the 100mW they specified is the ERP value. (In fact, I still do not know what is it.) Then we can start flying legally.

Chassic power 係指個 Tx module 產生既 RF power 而 ERP 係指真正射左出空氣既 power. 兩者唔一定一樣。

Tx module 產生既 power 可唔可以全部射出空氣就要睇條天線係唔係 match 個 Tx module 既線路。一般黎講都有 D 唔 match, 結果就係部份 RF power 會被反射番入個 module 度﹐變成熱能。所以 ERP 一般都係低過 Chassic power.

譬如我個 JR Tx module 既 Chassic power 係 100 mW, 如果我將條天線完全縮晒﹐條天線就會好唔 match 個 Tx module, 結果大部份既能量都被反射番入個 module 度﹐摸下個 module 會覺得好熱。只有小部份能量可以射出空氣﹐所以控制距離好短﹐係呢個狀態下﹐ERP 就低得好緊要﹐但 Chassic power 仍然係 100 mW.

掉番轉頭如果我將條天線完全拉晒出黎﹐ERP 就會高好多﹐但高極都只係會等同 Chassic power。實制既情況下條天線係好難完全 match 晒個 module, 就算 tune 到 match 到﹐只要周圍既環境一變﹐譬如你改變條天線既傾斜度或者係同自己既距離, 就會即刻影響 matching , 降低 ERP. 所以 ERP 低過 Chassic Power 幾 dB 係好閑。如果低 3 dB, ERP 就只有 Chassic power 一半﹐即 50 mW.

Hi you guys are wonderful with all sorts of professional knowledge.

Y.C., did you measure the power level with 50 ohm termination in the power meter?

I think ERP is a more effective measure than just the transmitter power. The antenna will play a more important role in this measure. I believe the antenna we are using has a gain lower than that of a half-wave dipole (0 dBd), so effectively the ERP should be much lower. I don't know the antenna gain for those rubber duck antennas for which some people are using. I think they should be less than 0dBd also.

On the other hand if we use high gain antenna such as Yagi or parabolic type antenna (directional), we can control our model several kilometers away - but this will break the 100mW limitation as ERP is measured on the main beam.

In conclusion I think we can accept 100mW ERP limitation. If one day you are challenged by the OFTA staff for over power and creating potential interference with other telecom users, you may simply cut short your antenna and the radiated power will be much lower then!

I have just talked to the guy in OFTA asking them to change the 100mW to 100mW ERP in the schedule.
He said that the specification is already in ERP.

So I looked at the schedule again and indeed found out the specification is in Maximum Effective Radiated Power, so I have no further complain and that is. We have our legal channels. Enjoy and play safe!

今朝發現尋晚用既 power sensor 既 range 唔合適﹐所以讀數唔可靠﹐今日班左另外一部 power meter 再度﹐讀數合理好多﹐41 MHz 同 35 MHz module (歐洲用)既 chassic power 係 100 ?180 mW, 72 MHz (美國用)就明顯高D﹐有成 410 ?470 mW. 睇黎 JR 既 module 出幾多 power 係要睇出口去邊個國家。

講開又講我都得部機用72MHz嘅module時啲電去得快啲。

Hello Y C & Stanley,

現在是否 35MHz 及 40MHz 的 ERP 限制在 100mW 內，而 72MHz 的則維持 ERP 500mW? 因剛看過 licence 的 schedule，內裏列明 Maximum Effective Radiated Power : 0.5Watt，如一律限制在 100mW，則按 Y C 的測試結果，72MHz 的 RF module 會否很大機會超標?

Good news!

I just received an email notice from OFTA that they have already started the legislation process to license-exempt the use of radio control equipment with specification as defined in the new schedule of our OFTA license.
If everything is ok, the new legislation will be effective by 1 Jan 2005. By then we do not need a license to operate our r/c gear.

What a wonderful news that we have been waiting for many years!

Cheers

Dear Stanley,

Hats up to you! Let's hope they'll add more frequencies to the list in the future.

CT
In anticipation of Mini Nyx... just a kind reminder

Hi CT,

I will remind OFTA again to ask them to open up the whole 35MHz and 40MHz bands.
To my understanding they have difficulties too.
35MHz band is largely used by outdoor wireless mic so they do not have much space to manipulate. For the 40MHz band, I was told PLA is currently using 40MHz (large power tx) for communications between HK and Beijing. The OFTA guy said they will negotiate or trade with PLA to relinquish the 40MHz link. In that case they might open up the whole 40MHz band afterward. Let's see!

I have added two more MiniNYXs to the order, and the manufacturer replied me few days ago that they are pretty busy and my order needs two more weeks to produce.
I will let you know as soon as the shipment arrived.

Cheers

各位師兄請留意下列今日明報一項即時新聞報導:
新增電訊器具豁免領牌[15:44]

2005/03/04



政府今日刊登憲報，建議數項電訊器具可豁免領牌，豁免令將於三月九日提交立法會。

豁免在指定無線電頻段內操作的領牌規定的電訊器具產品包括：

-無線電頻率識別（RFID）器具 :865至868 兆赫及920至925兆赫

-流動衛星服務流動地球站:1518至1525兆赫及1668至1675兆赫

-無線區域網絡設備:5470至5725兆赫

-汽車雷達系統:76至77吉赫

-模型飛機控制器具:35.145-35.225兆赫、40.66至40.70兆赫、72.00至72.02兆、72.12至72.14兆赫、72.16至72.22兆赫及72.26-72.28兆赫

工商及科技局發言人表示，無線電頻率識別（RFID）應用系統在全球供應鍊管理系統上的應用日趨普遍。海外和本地物流業均廣泛使用這項技術以識別及追蹤產品。豁免RFID器具領牌有助推動該系統在香港使用，對本地物流業的發展亦十分有利。

豁免令將於三月九日提交立法會，若通過立法會先訂立後審議的程序，將會盡快實施。

各位師兄請留意下列今日明報一項即時新聞報導:
新增電訊器具豁免領牌[15:44]

2005/03/04



政府今日刊登憲報，建議數項電訊器具可豁免領牌，豁免令將於三月九日提交立法會。

豁免在指定無線電頻段內操作的領牌規定的電訊器具產品包括：

-無線電頻率識別（RFID）器具 :865至868 兆赫及920至925兆赫

-流動衛星服務流動地球站:1518至1525兆赫及1668至1675兆赫

-無線區域網絡設備:5470至5725兆赫

-汽車雷達系統:76至77吉赫

-模型飛機控制器具:35.145-35.225兆赫、40.66至40.70兆赫、72.00至72.02兆、72.12至72.14兆赫、72.16至72.22兆赫及72.26-72.28兆赫

工商及科技局發言人表示，無線電頻率識別（RFID）應用系統在全球供應鍊管理系統上的應用日趨普遍。海外和本地物流業均廣泛使用這項技術以識別及追蹤產品。豁免RFID器具領牌有助推動該系統在香港使用，對本地物流業的發展亦十分有利。

豁免令將於三月九日提交立法會，若通過立法會先訂立後審議的程序，將會盡快實施。

各位師兄請留意下列今日明報一項即時新聞報導:
新增電訊器具豁免領牌[15:44]

2005/03/04



政府今日刊登憲報，建議數項電訊器具可豁免領牌，豁免令將於三月九日提交立法會。

豁免在指定無線電頻段內操作的領牌規定的電訊器具產品包括：

-無線電頻率識別（RFID）器具 :865至868 兆赫及920至925兆赫

-流動衛星服務流動地球站:1518至1525兆赫及1668至1675兆赫

-無線區域網絡設備:5470至5725兆赫

-汽車雷達系統:76至77吉赫

-模型飛機控制器具:35.145-35.225兆赫、40.66至40.70兆赫、72.00至72.02兆、72.12至72.14兆赫、72.16至72.22兆赫及72.26-72.28兆赫

工商及科技局發言人表示，無線電頻率識別（RFID）應用系統在全球供應鍊管理系統上的應用日趨普遍。海外和本地物流業均廣泛使用這項技術以識別及追蹤產品。豁免RFID器具領牌有助推動該系統在香港使用，對本地物流業的發展亦十分有利。

豁免令將於三月九日提交立法會，若通過立法會先訂立後審議的程序，將會盡快實施。

公告全文
http://www.gld.gov.hk/cgi-bin/gld/egazette/gazettefiles.cgi?lang=c&year=2005&month=3&day=4&vol=09&no=09&gn=22&header=1&part=0&df=1&nt=s2&newfile=1&acurrentpage=12&agree=1&gaz_type=ls2

好呀！搞咗咁多年卒之可以等到今天，唔駛擺牌都可以合法玩遙控飛機！

Cheer!

I was informed by OFTA people today that
the vetting period by LegCo is 28 days, counting from 9 March 2005.
By 8 April 2005, all model control hobbyists can use the 18 channels freely.

Cheers

詳情見 Telecommunications (Telecommunications Apparatus)(Exemption from Licensing)(Amendment) Order 2005, http://www.gld.gov.hk/cgi-bin/gld/egazette/gazettefiles.cgi?lang=e&year=2005&month=3&day=4&vol=09&no=09&gn=22&header=1&part=0&df=1&nt=s2&newfile=1&acurrentpage=12&agree=1&gaz_type=ls2

I received a letter from OFTA yesterday saying that the exemption from licensing of model control frequencies will be effective as soon as possible, that means we no longer need to apply for a license to operate our r/c transmitters at the specified frequencies.



Cheers

豁免已在2005年4月15日生效，見 Telecommunications (Telecommunications Apparatus) (Exemption from Licensing) (Amendment) Order 2005 (Commencement) Notice, http://www.gld.gov.hk/cgi-bin/gld/egazette/gazettefiles.cgi?lang=e&year=2005&month=4&day=15&vol=09&no=15&gn=49&header=1&part=0&df=1&nt=s2&newfile=1&acurrentpage=12&agree=1&gaz_type=ls2

Dear Stanley,

Maybe it's a good time to bring up the issue.
Below is an extract from the consultation paper:

現時當局作出管理頻譜的決定，可能會對經濟及