Greater Southwest Aero Modelers Chat Forum

R/C Electronics => Radio Gear Information => Topic started by: Bill Bradford on June 26, 2019, 04:15:10 pm

Title: Sharing of Receiver Port
Post by: Bill Bradford on June 26, 2019, 04:15:10 pm
When sharing a receiver port with a battery and a servo I have always cut the signal wire on the battery side of the "Y" cable. Is this really a necessary step?

Thanks,
Bill
Title: Re: Sharing of Receiver Port
Post by: Steve Rogers on June 26, 2019, 07:41:08 pm
No.
Title: Re: Sharing of Receiver Port
Post by: Bill Bradford on June 27, 2019, 04:17:07 pm
Thank you, sir.
Title: Re: Sharing of Receiver Port
Post by: Paul Lange on June 28, 2019, 09:15:12 am
Hard to understand a simple answer.....I had to read that response several times before I understood it.

Paul H Lange
Title: Re: Sharing of Receiver Port
Post by: Steve Rogers on June 28, 2019, 07:36:08 pm
The long answer.

As long as the receiver design engineer does his job there should be no problem with having a short amount of wire hanging on the signal line.

It will act like an antenna and that can cause a problem if it is not mitigated in the design. RC equipment designers know what the normal EMI levels are and the good ones plan on making sure that their equipment will work under those conditions.

If you put something unusual in your plane, then there may be a problem. Like if you put a 50 Watt transmitter on board so you can relay data back to you during the flight, that would be outside of the normal RC receiver capability to handle and the interference could jam your signal.

Way back in the old days of RC, when we used 27Mhz signals, we were limited by law to 4 Watts on our transmitters. A few of the CB Radio owners, mostly truckers used an illegal 1,000 Watt transmitter and the signal was so strong it overrode the frequency selection circuits in our little RC radio receivers and would shoot us down.