R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 06-30-2013, 02:57 PM   #1
Tech Initiate
 
Join Date: Jan 2013
Posts: 29
Questions?? how to shorten a receiver antenna?

How can I shorten my sanwa rx-461 receiver antenna without cutting it ?
Ivelin. is offline   Reply With Quote
Old 06-30-2013, 03:52 PM   #2
Tech Elite
 
303slowdown's Avatar
 
Join Date: Sep 2008
Location: Rapid City SD.
Posts: 2,299
Trader Rating: 24 (100%+)
Default

You might be able to open the case and coil the wire up in the case.
__________________
Ryan Borgheiinck
303slowdown is offline   Reply With Quote
Old 06-30-2013, 03:55 PM   #3
Tech Adept
 
C@T's Avatar
 
Join Date: Oct 2012
Posts: 189
Default

This is a 2,4 GHz receiver. The antenna is a coax cable with a cetain length of a bare inner conductor at the end.

This portion is the antenna. The rest of the length is only a cable.

You can shorten the total length if you are able to strip the end to same length as before.

It is much easier to just hide it in the receiver box. The exposed length of the unstripped cable should be same as the bare one.
C@T is offline   Reply With Quote
Old 06-30-2013, 04:01 PM   #4
Tech Adept
 
C@T's Avatar
 
Join Date: Oct 2012
Posts: 189
Default

Quote:
Originally Posted by 303slowdown View Post
You might be able to open the case and coil the wire up in the case.
Not a realy good plan. Might easily cause interference.

Cutting and stripping is possible if you are skilled enough.
C@T is offline   Reply With Quote
Old 06-30-2013, 04:51 PM   #5
Tech Fanatic
 
Join Date: Jan 2012
Location: Carrollton, TX
Posts: 902
Trader Rating: 27 (100%+)
Default

I fold mine up tight and heat shrink it all together. Never had a problem with interference. I only race on a small/medium carpet track though. Never raced on huge tracks.
__________________
Xray | Airtronics | R1Wurks LiPo | Hobbywing
hyujmn is offline   Reply With Quote
Old 06-30-2013, 07:43 PM   #6
Tech Addict
 
Join Date: Jun 2007
Location: Canal Fulton, OH
Posts: 597
Send a message via AIM to JimmyMack12
Default

It is *never* recommended to cut an antenna, either receiver or transmitter. The length of the antenna is determined by what frequency range it needs. Longer antenna - lower frequencies (you'll see longer antennae with your older-style AM/FM radios with crystals). Shorter antenna - higher frequencies (2.4gHz).
JimmyMack12 is offline   Reply With Quote
Old 06-30-2013, 07:55 PM   #7
Tech Adept
 
Andy w's Avatar
 
Join Date: Jul 2011
Location: utah
Posts: 236
Trader Rating: 7 (100%+)
Default

Quote:
Originally Posted by 303slowdown View Post
You might be able to open the case and coil the wire up in the case.
This is what I have done with mine. I never had a interference or a glitch.
__________________
Andy Wade
Andy w is offline   Reply With Quote
Old 06-30-2013, 08:19 PM   #8
Suspended
 
Join Date: Jun 2011
Location: Brisbane
Posts: 1,696
Trader Rating: 6 (100%+)
Default

Quote:
Originally Posted by JimmyMack12 View Post
It is *never* recommended to cut an antenna, either receiver or transmitter. The length of the antenna is determined by what frequency range it needs. Longer antenna - lower frequencies (you'll see longer antennae with your older-style AM/FM radios with crystals). Shorter antenna - higher frequencies (2.4gHz).
This is only kind of true. In the pic below, the actual antenna is the clear part right at the end, the rest of it is just extension lead. As long as you are taking out the grey section of lead you can cut that baby up into 100 pieces if you so choose and the antenna, the clear part at the end, will work as it is intended to. As long as the OP knows what is antenna and what is lead, he can shorten it up with no ill consequence at all.

RogerDaShrubber is offline   Reply With Quote
Old 07-01-2013, 05:39 AM   #9
Tech Adept
 
C@T's Avatar
 
Join Date: Oct 2012
Posts: 189
Default

Quote:
Originally Posted by RogerDaShrubber View Post
This is only kind of true. In the pic below, the actual antenna is the clear part right at the end, the rest of it is just extension lead. As long as you are taking out the grey section of lead you can cut that baby up into 100 pieces if you so choose and the antenna, the clear part at the end, will work as it is intended to. As long as the OP knows what is antenna and what is lead, he can shorten it up with no ill consequence at all.

Good information, right on the point. The only thing you forgot to tell is that the tricky part is under the grey outer isollation. There is a second lead woven around the inner clear part called shield.

To do it well you need to have a clean round cut where the grey does end. Not so easy with a cable that thing.

You better do some training with the peace you cut off before going for the final cut.
C@T is offline   Reply With Quote
Old 07-01-2013, 12:53 PM   #10
Tech Apprentice
 
Join Date: Apr 2012
Posts: 79
Default

With my older fm rx, I would go to donsrc.com and get the short antenna for helicopter..never had a problem with range
ttsquirrel is offline   Reply With Quote
Old 07-01-2013, 01:48 PM   #11
Tech Elite
 
valk's Avatar
 
Join Date: May 2011
Location: Victoria, BC
Posts: 2,025
Trader Rating: 13 (100%+)
Send a message via ICQ to valk Send a message via AIM to valk Send a message via MSN to valk
Default

anyone who says its ok to cut your antenna, you should not associate with them on your rc business cause they aint winning lol.

ive tried to open the rx box and tuck it around inside but that causes a little interference. another thing you could try is wrapping it around the antenna tube like a pancar. wont cut the lenth drastically, but a few inches for sure. you could loop it around the chassis pan and have a little sticky uppy bit for the end. the end has to be exposed and preferablly not obstructed by anything that emits emi. some antennas are shorter than others. my airtronics ones were stupid long. replaced with hpi/spectrum antennas which were quite shorter.
the orange rx antennas are very short as well. buy rx for $10 and snipe the antenna.. about the only thing those orange rx's are good for anyway.
__________________
My stuff
| Team Associated - Reedy - Reflex Racing/RSD - ProAMPS RC |
My RC
www.irocc.ca - www.wcics.ca - www.vrcworld.com - http://proampsrc.com/ - www.teamassociated.com
valk is offline   Reply With Quote
Old 06-02-2014, 06:59 PM   #12
Tech Addict
 
Cadman1981's Avatar
 
Join Date: Nov 2012
Location: Montreal, Quebec
Posts: 551
Trader Rating: 1 (100%+)
Default

I have a Sanwa RX-471 that i cut the antenna tip, and i didn't remove the sheilding, i kept having glitches until i read this thread! So it's a Coax cable. I re-exposed just the tip - i left 1 inch of the grey area (the center core), i'll let you guys know after next race if the glitches continue.



I also have a Airtronics 92524, the antenna wire looks different, it's still 2.4ghz, but does anyone know if the wire is the same? I opened the case and it looks like the same old wire from my AM/FM radios. Can i put a coax type wire?
__________________
Arc R10 2015
Awesomatix A700L
Exotek F1R3
1990s Futaba FXT stadium racer - Mint condition!
And a bunch of other RC kits for me and my kids...yeah...my kids...
Cadman1981 is offline   Reply With Quote
Old 06-02-2014, 07:25 PM   #13
Tech Elite
 
Johnny Wishbone's Avatar
 
Join Date: Feb 2006
Posts: 3,419
Trader Rating: 6 (100%+)
Default

Quote:
Originally Posted by [email protected] View Post
This is a 2,4 GHz receiver. The antenna is a coax cable with a cetain length of a bare inner conductor at the end.

This portion is the antenna. The rest of the length is only a cable.

You can shorten the total length if you are able to strip the end to same length as before.

It is much easier to just hide it in the receiver box. The exposed length of the unstripped cable should be same as the bare one.
This is 100% true. I have done this to countless Airtronics receivers and have had no issues with any of them. One tip though, once you get the grey outer layer off just push the shield down and it will accumulate at the base of the cable that hasn't been stripped. This then makes it really easy to trim the shield without knicking the center conducted. If you use really small side cutters or preceded flush cutters you can then cut the shield nice and close to the main cable which will look like factory.
__________________
Gary Lanzer
Johnny Wishbone is offline   Reply With Quote
Old 06-02-2014, 07:27 PM   #14
Tech Master
 
Join Date: Feb 2014
Location: Kirkland, WA
Posts: 1,035
Trader Rating: 6 (100%+)
Default

The total length of the wire is the antenna, not just the exposed tip. Has to do with the frequencies traveling down the wire being tuned to a specific length. I'll see if I can find a decent article on it.

Edit: Here ya go

http://www.rc-cam.com/ant_exp.htm

Long story short, antenna length directly affects wavelength. You may not notice it so much if your receiver can pick up a signal at 100ft and you're only driving 50ft away. But going farther away you'll notice the signal drop off really fast and lose control.
__________________
-Mike B.
Carnage9270 is online now   Reply With Quote
Old 06-02-2014, 07:39 PM   #15
Tech Master
 
Geezatec's Avatar
 
Join Date: Oct 2007
Posts: 1,460
Default

Sanwa manual tells you not to cut or extent antenna. The may void warranty. just follow your manual of location. These antenna are only 5" long.
Geezatec is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 05:58 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net