benny2k

I have a savage 35 and i wish to make a siren for it to go with the mountain rescue shell i have made ( i am an electronic engineer) i need a four channel transmitter for it, is there a car transmitter for it or do i have to use my skysports six (it says specificaly not for model car use, against the law?) i know the savage has a fourth channel on the reciever but where do i get a tranny for it?

Ahab

there is a switch on the transmitter to switch the reverse module, there is also a 3rd channel on the reciever that ,unless you are using a reverse module, should be free. As the transmitter is has a switching 3rd channel not a variable one, it should be perfect for turning on your siren....

the savage 25 (I dotn think there is a 35 yet) rtr comes with a 3ch radio system.
1ch for steering
1ch for throttle/break
1ch for reverse...or anything else if you dont have reverse.

as for wether you can use your Plane Radio I am not sure. I know there are laws about what radios you can fly with but wether you cant use the same radio on the ground I am not sure... I mean, I car cant fly... but a plane can taxi....

lax195

My Feedback: (2)

well, airplane radios are usually 72mhz and it is illegal (in most areas) to run a surface verhicle on that frequency. surface vehicles are assigned 27mhz and 75mhz ONLY. but you can buy a radio for a tank. hehe 9 channels should be enough .

Frost_

My Feedback: (1)

Well, like said, if you don't have/use reverse, there is your free channel. A mechanical switch setup could be easily fabricated using micro switches so that one channel could operate 2 devices (one forward travel of servo, the other from opposite travel).

If you are really an EE you can build a filter circuit to connect directly to the servo output... tailor it to pass signals over X freq. or below Y (the 2 directions that the motor would travel if connected). Use your O'scope to find out the range in each direction. I built a small servo driver out of a 555 timer, this is kind of looking at things from the other end. Take your filtered output to a latching ckt. and use a 2n222 switching transistor. Chain it to a FET if you need more output current. This solution is more power effecient (remeber your effeciency lessons), requires no adjustment once the ckt. is built, will have no wear or maintenence as compared to the mechanical solution, and it's output can be tailored directly to the device.


That airplane transmitter would be a PITA anyway, the throttle stick stays where you put it, that is, it doesn't spring back to neutral...

sarpiparpi

savage comes with 4 channel radio
at least mine did

lax195

My Feedback: (2)

savage comes with a 3 channel radio

tamiya08

My Feedback: (10)

heres my idea, use the 3rd channel for a servo. then use the stock locatoin for the 3 servo and put a servo horn on it and then mount a switch for the siren some where that u can turn it on and off with that servo

Frost_

My Feedback: (1)

Yeah, I kinda had that covered already, maybe skim the whole thread first next time...

tamiya08

My Feedback: (10)

alright its not that big of a deal. now ahab can read through the forum and notice that 2 ppl have said the same idea and then ahab
can pick that idea becuz its been recognized by more than one person.

benny2k

hey guys, i know about the possibility of using the reverse channel, but i do rock climbing with it..and i need it, so does an one know if i can use the fourth output on the reciever, if so how do u use it, and thanks frost but i want it to be realy simple to useso i will have a play about and tinker, have u got an e-mail or some way of cantacting you if i need help?,

Frost_

My Feedback: (1)

There isn't a 4th channel on the receiver.....

If you PM me, it'll go to my email, include your email addy, and I will drop you an re:

[email protected]

72 Mhz is also and old plane frequency coz my old plane has it but i dnt think the 75Mhz is ilegel!!!

lax195

My Feedback: (2)

ehh, not illegal.....but not the greatest idea!

Vortec_Rat

If you guys will look, there is a fourth slot on the reciever. I don't know if it's connected to anything. I can't make anything work when connected to it. The S-25 comes with a three channel radio, not four. I wouldn't doubt that HPI used anything laying around when putting the savage together so it is possible that some of us got a three channel reciever and some got a four channel reciever. I would suggest someone with a four or six channel transmitter with the same frequency try and play with the four(?) channel reciever and let us know. It might come in handy for those of us with the extra plug.

blindguy

The TF-4 radio system in the RTR Savages is made by Futaba. It has a 3-channel transmitter and a 4-channel receiver. I'm sure HPI chose the 4-channel receiver because Futaba does not make a 3-channel AM receiver anymore. Here is the equivalent Futaba 4-channel receiver from Tower.
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXALN9]Futaba 4-channel receiver[/link]

Futaba makes a 4VWD 27mhz am 4-channel stick radio that would work great for the Savage. I think the left stick is spring loaded to the center so you can use it similar to a pistol radio. It even has a picture of a Clod Buster on the front of the transmitter.
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXBCP2**&P=0]Futaba 4VWD[/link]

johny thin

whats a savage 35?

Ahab

a typo

islandflyer

European R/C frequency regulations are significantly different fro the U.S.
Click on this link for reference:
http://ewc2004.users.btopenworld.com...ncySurvey.html