Author Topic: Transmitters  (Read 1050 times)

0 Members and 1 Guest are viewing this topic.

Offline soninja8Topic starter

  • Robot Overlord
  • ****
  • Posts: 136
  • Helpful? 1
Transmitters
« on: May 15, 2011, 07:10:37 PM »
Any good 75mhz FM 4 channel (or more) transmitter under $40??? Im tired of a 2 channel one.

Thanks!  :)

Offline garrettg84

  • Robot Overlord
  • ****
  • Posts: 187
  • Helpful? 8
  • Armchair Roboticist Extraordinaire
Re: Transmitters
« Reply #1 on: May 16, 2011, 09:17:52 AM »
Any reason you are sticking to 75mhz? I understand that you may have a receiver that is 75mhz, any reason you wouldn't switch both?
-garrett

Offline Conscripted

  • Robot Overlord
  • ****
  • Posts: 291
  • Helpful? 10
Re: Transmitters
« Reply #2 on: May 16, 2011, 10:28:39 AM »
75Mhz is legal for ground use in the US. 72Mhz are restricted to aircraft if one is wanting to stay legal.

http://rcsource.hobbypeople.net/faqs/freqlist.htm

Conscripted

Offline garrettg84

  • Robot Overlord
  • ****
  • Posts: 187
  • Helpful? 8
  • Armchair Roboticist Extraordinaire
Re: Transmitters
« Reply #3 on: May 16, 2011, 10:43:15 AM »
I was aiming towards the 2.4ghz spectrum. There are some CHEAP rc style transmitter/receivers for about $40 shipped from www.hobbyking.com. I use the hobbyking brand tx/rx in some of my messing around, and it seems to have pretty excellent range.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9042
That tx/rx combo shipped to my door is $40.99.
-garrett

Offline soninja8Topic starter

  • Robot Overlord
  • ****
  • Posts: 136
  • Helpful? 1
Re: Transmitters
« Reply #4 on: May 17, 2011, 07:14:01 AM »
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9042
That tx/rx combo shipped to my door is $40.99.


why is this so cheap? is it chinese plastic crap? or is it good? I see that it is programmable....do i need to program it or would it work right out of the box?

Offline garrettg84

  • Robot Overlord
  • ****
  • Posts: 187
  • Helpful? 8
  • Armchair Roboticist Extraordinaire
Re: Transmitters
« Reply #5 on: May 17, 2011, 07:23:49 AM »
It is chinese plastic, I don't feel it is crap. There are purists out there that won't touch anything but name brands. It's your call on programming out of the box. It works fine for me out of the box. I made some tweaks to add exponential curve to the throttle and steering for a project in the past. The 'programming' consists of an app with a few check boxes and some sliders, very simple to visualize and understand. I did like them enough that I have two of them, one I keep for RC, one I keep set up for more 'robotics' style projects.

One note on the chinese plastic crap, one of the thumb sticks 'end piece grip' came loose and I popped some super glue inside and all was well. I would imagine they are skimping on it somewhere, but I've opened it and checked out the electronics. Inside it all looks good, machine soldered, where some of the really cheap crap from china looks hand soldered. So far, I've been happy with just about everything i pick up from hobby king. Read their reviews - they are a world of help in determining if a product is crap.
-garrett

Offline soninja8Topic starter

  • Robot Overlord
  • ****
  • Posts: 136
  • Helpful? 1
Re: Transmitters
« Reply #6 on: May 17, 2011, 07:29:29 AM »
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15140
I was thinking of getting this since I live in the United States, but they dont sell the programming cable in their U.S. warehouse....any suggestions?

Also, do i need to buy a module for this? or does it come with one?
« Last Edit: May 17, 2011, 07:31:04 AM by soninja8 »

Offline rbtying

  • Supreme Robot
  • *****
  • Posts: 452
  • Helpful? 31
Re: Transmitters
« Reply #7 on: May 17, 2011, 07:49:41 AM »
You don't NEED a programming cable, they're nice if you fly different types of aircraft - the various surfaces often require exponential throws and suchlike.

Also, do i need to buy a module for this? or does it come with one?

What do you mean by a module? It does come with a receiver.

Offline soninja8Topic starter

  • Robot Overlord
  • ****
  • Posts: 136
  • Helpful? 1
Re: Transmitters
« Reply #8 on: May 17, 2011, 08:06:41 AM »
You don't NEED a programming cable, they're nice if you fly different types of aircraft - the various surfaces often require exponential throws and suchlike.

Also, do i need to buy a module for this? or does it come with one?

What do you mean by a module? It does come with a receiver.

I thought 2.4ghz is just like 75mhz where you have to get a certain channel module or something...


And also, how do I trim or reverse servos without programming?

Offline garrettg84

  • Robot Overlord
  • ****
  • Posts: 187
  • Helpful? 8
  • Armchair Roboticist Extraordinaire
Re: Transmitters
« Reply #9 on: May 17, 2011, 08:15:06 AM »
You don't NEED a programming cable, they're nice if you fly different types of aircraft - the various surfaces often require exponential throws and suchlike.

Also, do i need to buy a module for this? or does it come with one?

What do you mean by a module? It does come with a receiver.

I thought 2.4ghz is just like 75mhz where you have to get a certain channel module or something...


And also, how do I trim or reverse servos without programming?

The receiver module comes with the transmitter. For trim, there are manual sliders next to the controls, but they are limited. For serious differences in servos you'll need the cable, otherwise, for minor adjustments the mechanical trim sliders are good enough.

These are frequency hopping around 2.4ghz. There are no channel modules/crystals that must be changed. They find unused channels and just keep on rolling. I have seen multiple 10s of 2.4ghz tx/rx in the same park with no issues. These things are digital radios.
-garrett

Offline soninja8Topic starter

  • Robot Overlord
  • ****
  • Posts: 136
  • Helpful? 1
Re: Transmitters
« Reply #10 on: May 17, 2011, 08:17:57 AM »
if it is digital, do i need a digital servo? or are my analog ones fine?

And you said you can trim without programming, what about servo reversing?

Offline garrettg84

  • Robot Overlord
  • ****
  • Posts: 187
  • Helpful? 8
  • Armchair Roboticist Extraordinaire
Re: Transmitters
« Reply #11 on: May 17, 2011, 08:20:05 AM »
Analog servos are all I've ever used.
-garrett

Offline Razor Concepts

  • Supreme Robot
  • *****
  • Posts: 1,856
  • Helpful? 53
Re: Transmitters
« Reply #12 on: May 17, 2011, 09:05:40 AM »
if it is digital, do i need a digital servo? or are my analog ones fine?

And you said you can trim without programming, what about servo reversing?

Digital and analog servos work with any type of radio, the specification of digital or analog is just regarding the internal mechanics of the servo. On the outside, they both work exactly the same, with the same signal protocol. Analog servos will be fine.

Basic functions such as trim and servo reversing are located directly on the radio transmitter.

Offline georgeecollins

  • Full Member
  • ***
  • Posts: 58
  • Helpful? 3
Re: Transmitters
« Reply #13 on: May 17, 2011, 12:03:57 PM »
I just got one of these Hobby King 6 channel Rx/Tx combos to see what you get for the low price.  I have had a Futaba, a HiTec, a Viper, a GWS, and a Tactic 404 rx/tx combo before so I think I can make some comparisons. 

- It took a long time to be delivered.   
- It's 2.4 Ghz, so the transmitter and receiver are mated (they don't have to be on the same channel).  At Robogames they won't let you participate anymore with an FM transmitter.   At this price I don't know why anyone bothers with FM anymore.   
- The receiver is a bit bulky and has a large antenna for 2.4Ghz setup. 
- It won't accept Futaba servos unless you trim the plugs. 
- It's cheap in feel and missing some features, most notably the ability to reverse channels or change the way you mix channels.  I connect my rx to a micro-controller board, so I can reverse or mix channels in software so that doesn't really matter to me. 

Overall, it seems like I am going to use this radio to control one of my walking robots.  The price is right.  If you felt like spending a little more I would think about a Tactic 404 which is a little nicer. 

Offline soninja8Topic starter

  • Robot Overlord
  • ****
  • Posts: 136
  • Helpful? 1
Re: Transmitters
« Reply #14 on: May 17, 2011, 01:25:46 PM »
Ok, so can someone point me to the best 2.4ghz transmitter and receiver that would be good for a ground robot and is under $50  :)

Also, im using it for my robot, with a wireless camera, so i need it to go far. Will it let my robot be controlled farther away than my original 75mhz FM transmitter and receiver?

« Last Edit: May 17, 2011, 01:38:09 PM by soninja8 »

Offline garrettg84

  • Robot Overlord
  • ****
  • Posts: 187
  • Helpful? 8
  • Armchair Roboticist Extraordinaire
Re: Transmitters
« Reply #15 on: May 17, 2011, 02:13:21 PM »
Ok, so can someone point me to the best 2.4ghz transmitter and receiver that would be good for a ground robot and is under $50  :)

Also, im using it for my robot, with a wireless camera, so i need it to go far. Will it let my robot be controlled farther away than my original 75mhz FM transmitter and receiver?



I think the Turnigy tx/rx are the best of the 'value' brands. They can be had for about $50 (+ shipping) and most Turnigy transmitters can be programmed via on device LCD+Buttons. I have a buddy who uses one of these.

-garrett

Offline soninja8Topic starter

  • Robot Overlord
  • ****
  • Posts: 136
  • Helpful? 1
Re: Transmitters
« Reply #16 on: May 17, 2011, 02:42:20 PM »
I dont agree, all the reviews say that it took 3-4 months to arrive, and it was defective...I kinda want one that is shipped from the U.S. and isnt defective...im deciding between http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15142
and
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15140

any suggestions?
Thanks! :)

Offline putz

  • Beginner
  • *
  • Posts: 2
  • Helpful? 0
Re: Transmitters
« Reply #17 on: May 23, 2011, 09:05:02 AM »
I recommend the Spektrum dx5. Look around ebay and you could probably get one cheap. Pair it up with any full range receiver and you will get great range.

Offline Razor Concepts

  • Supreme Robot
  • *****
  • Posts: 1,856
  • Helpful? 53
Re: Transmitters
« Reply #18 on: May 23, 2011, 09:27:28 AM »
I dont agree, all the reviews say that it took 3-4 months to arrive, and it was defective...I kinda want one that is shipped from the U.S. and isnt defective...im deciding between http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15142
and
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15140

any suggestions?
Thanks! :)


Those should work fine.

 


Get Your Ad Here