Radio control interferrence myth and reality

[Babylon5]

Hi, having design Fm and AM receivers for decades I would like to let fellow RCer know what is myth and reality.

Myth:
1.) I have a PCM digital radio systems . People with AM or FM transmitter with same frequency will not interfere a more superior systems.
Wrong: Try this and I can guaranteed the PCM systems will go into fail safe mode or your RC model will fall off from the sky.

2.) If I am 200 meters away playing my buggy , guys flying at that far distance would not be affected by my transmitter.
Wrong again: When aircraft is in the air, the RF receiving range is greatly extended. If the flying model is at 40Mhz and depending on the height of the flying model it can pick up the same 40Mhz several hundred metres away

Safe tips in RC playing field.

1) Never turn on your transmitter without checking with fellow RC whether you are playing with boat/car or even the cheapo RC toy car that you bought for your 6 year old kid. I have seen adult bringing in kids with their cheapo short range RC toys into the flying field.

2)Always check your frequencies with fellow Rcer although he has been flying with you everyweek. One day he change his crystal or radio gear...oops

3) Always use approve and legal frequencies band.




Have a safe flying

Babylon5

[Art]

Thanks for the reminder...sometimes we just take it for granted that our flying buddies are using the same frequency every week.....

[Babylon5]

Radio interferrence at Bukit Batok Aero-modelling Club.

Last week a few members(at least 3 ) from the BBAC on the 29Mhz experience unknown glitches and planes keep falling off the sky without any reason.
Not sure what is the cause but a member reported some modeller are flying at Bukit batok west near the field at the temple which is less than 1 km away
from the sanction club to-day

Guys I have post the myth and reality of radio interferrence please read it again.

Guys ,If you are flying near the temple ,I suggest you join BBAC . We will welcome you and at least has some frequency check and controls.
If not I suggest you fly further away . This is no winner situation.

If our club member turns on their Tx and interfere with your models and planes start falling from the sky. Moreover, the fields is near a busy traffic junction.
Accident is just waiting to happen.

I do hope RC hobby to exercise due consideration and caution . Maybe they are ignorant and not aware there is a RC club neaby.

I urge fellow modellers to pass the message around especially the RCer flying at the field near the temple.

Babylon5

[Babylon5]

Hi again, the BBA club is at Bukit Batok west ave7 near the site where a new school is under contruction or Princess Elizabeth School.


Babylon5

[muduck]

What about Sunspot activity?

taken very seriously by Jet Jockeys...big article about it in the latest issue of Australian Äirbourne"magazine....

[Babylon5]

Hi Muduck, you are right with regard to sunspot activities . Our 29Mhz or the 10 meter short wave band is smack right in the middle of the sunspot activities.
If sunspot activities hit us ,you will know because many modelers plane operating within the 10 meter short wave will start falling from the sky one by one.
However, the real culprit are usually people who flies without consideration to other fellow ...don't check frequencies. Indifferent and don't fly within the group.

On the other hand, we have fellow flyer who are kind and really helpful and considerate and are always mindful of safety first.


Cheers

[protyne]

Hi Babylon5,

What is in reality a safe frequency "difference" between 2 users on the same band?

29.800 and 29.850 is safe?

Thanks

[Babylon5]

Hi Babylon5,

What is in reality a safe frequency "difference" between 2 users on the same band?

29.800 and 29.850 is safe?

Thanks

29.800 and 29.850 is very safe provided you are using original Futaba ,JR or any other reputable brand.
Usually the better receivers are narrow band high selectivity characteristics.

I have evaluated the older Futaba receiver. This long range receivers has amazing adjacent selectivity of (if I can recall) over 70dB per 5Khz apart.
The Futaba frequencies allocation per crystall frequencies is 25Khz apart.

Example 29.800Mhz vs 29.825mhz or 29.775Mhz is 25Khz apart is very safe.
Therefore the minimun safe frequencies distance apart is 25khz or 0.025Mhz although some claim as near as 15Khz apart.

How ever, I have not evaluated the new park fly range receivers so cannot tell how good is the channel selectivity performance.

hope this will help
cheers

[P4cm4n2000]

Hi Babylon5,

can you let me know where to buy non-orginal Futaba TX ? I'm interested to get the 2.4GB non-orginal one leh....pls PM me

thanks!

29.800 and 29.850 is very safe provided you are using original Futaba ,JR or any other reputable brand.
Usually the better receivers are narrow band high selectivity characteristics.
hope this will help
cheers

[protyne]

Hi Babylon5,

can you let me know where to buy non-orginal Futaba TX ? I'm interested to get the 2.4GB non-orginal one leh....pls PM me

thanks!

Bro he talking about receiver issit? hehe

[protyne]

Thanks for explaining

29.800 and 29.850 is very safe provided you are using original Futaba ,JR or any other reputable brand.
Usually the better receivers are narrow band high selectivity characteristics.

I have evaluated the older Futaba receiver. This long range receivers has amazing adjacent selectivity of (if I can recall) over 70dB per 5Khz apart.
The Futaba frequencies allocation per crystall frequencies is 25Khz apart.

Example 29.800Mhz vs 29.825mhz or 29.775Mhz is 25Khz apart is very safe.
Therefore the minimun safe frequencies distance apart is 25khz or 0.025Mhz although some claim as near as 15Khz apart.

How ever, I have not evaluated the new park fly range receivers so cannot tell how good is the channel selectivity performance.

hope this will help
cheers

[Babylon5]

Hi Babylon5,

can you let me know where to buy non-orginal Futaba TX ? I'm interested to get the 2.4GB non-orginal one leh....pls PM me

thanks!

Hi P4CM, I think you want a 2.4GHz radio systems. As far as I know there is no 2.4GHz Futaba Radio in Singapore yet.(maybe there are some people who bought it overseas).

The closes you can get a 2.4GHz is the Dx6 and DX7 spectrum.

However, once you switch to 2.4Ghz, you cannot use the existing Reicevers be it Futaba, JR or other brand. It got to be a 2.4Ghz receiver design to receive the particular brand of 2.4Ghz TX.

Sorry to say the existing 29, 35,40 and 72Mhz receiver cannot be used. I am
afraid you have to "lelong" these RX .

Only some(not all) of the existing Tx can be modified to 2.4Ghz by replacing the Tx module or "rework or modified". I don't have the details so I cannot say much about this modification.

Cheers