Here is a video of the system being bench tested. It works !!!!  . I have to still work on the RF front end though, it needs to be tuned. I'll have to find a spectrum analyzer for that. Ill also have to find joysticks and a suitable case for this as it is a little difficult to test like this.

Thank you for the kind offer, I have built a receiver using mc3361 before, but I din't have a transmitter to test it with, I have only one tx on 72mhz and the receiver was built for 35mhz. MC3361 in not so good for 72mhz and the 35mhz version required fixed value and easily available inductors, therefore I built it but could not test it. I will let you know if I require the chips and may be even send you a complete rx (i.e. if i get it to work)   !!

try to contact your local HAM guys, should help u out with RF stuff easily !

No need to send me an Rx, I'll be glad to just see them getting some use than gather dust here with me. I don't see myself doing any RF project on these frequencies in future.

On the 3361 there are versions from other manufacturers (Toko if my memory is correct) that works at higher frequencies.

yes the toko tk83361 works at higher frequencies !

hey buzz_rc

which compiler are u using and how are u reading the pots (i.e A/D-voltage or Resistor-Capacitor mode) ?

http://www.elektor.com/news/mcus-feature-integrated-wireless-interface.1220375.lynkx?utm_source=UK&utm_medium=email&utm_campaign=news

http://www.atmel.com/dyn/products/product_card_mcu.asp?part_id=4692

this can be a good way to implement RC transmitter/receiver for indoor to parkflyers range !

sahil

hello sahil i'm using PBP complier from the link below:

http://store.melabs.com/prod/software/PBP.html

i'm reading the pots using A/D voltage. I'm planning to make a very light weight rx using surface mount components n use it for indoor flying purpose also.I just need to find a way to put the entire system together so that I can test it properly !

okay,also what tools are u using for testing RF stuff ??

build yourself a simple sound card based PC-Scope if you don't have one already !

sahil

I have made a simple rf detection probe using two diodes .It can detect RF strength and display the readings on a multimeter.I have a soundcard scope (see my video). I am now trying to make an LC meter but cannot locate the reed relay required. Once I have an lc meter I will be able to wind my own inductors.
I did see your thread on a similar project as well (the one in which you've used the micro star encoder), how's it coming along ??

the micro-star thing is a huge ocean in itself, i still need to do lot of work,wiring etc also have a look at Frequency counter/meter 50Mhz range unit (this is the simplest unit i know)

http://freenet-homepage.de/dl4yhf/freq_counter/freq_counter.html

http://www.hamradioindia.org

you can get the reed relays in cordless phone base and are you by chance building an LC meter using 16F84A and 16X2 LCD display ?

http://electronics-diy.com/electronics/lc_meter.php

sahil

Thanks for the links Sahil, I have a relay (I took this out of a cordless phone base), but am not sure if it would work. Yes I am planning to build the LC meter using pic16f84a and 16x2 LCD.

here is a link to the relay I have:

http://www.daiichiparts.com.hk/product/reed/rl108n_700.htm

if I'm not wrong that guy is using reed relay because it can be driven directly by the PIC !
all you have to do is make sure it matches with current ratings !

assume the 3volts relay is a 3volt led and you are applying 5v supply with a limit resistor in series

R-limit = supply voltage - led drop voltage ( 3 volts ) divided by current consumed by led (relay)

now you can calculate the current consumed by reed relay by V = I X R

the value of R/V will be printed on the relay from that get "I" now from the "I" you can get R-limit which u can use to replace  10kohms resistor in the circuit and please beer in mind the current limits of pin (PIC)

sahil

oh i think i might have one of those 700ohms stuff let me check !

i have been reading your postings it seems you are using an Bit-char circuit for the TX stage and what about the receiver system ?

sahil

hey if you need any partners let me know I'm getting bored doing stuff alone  

we can share results n resources and i'm particularity interested in the Radio Frequency part!

here is a link to my project    http://www.indiarc.com/forum/index.php?topic=2242.0

Its a standard AM ckt that I made using the reference circuit given in the book 'principles of communication'. it consists of an oscillator, a mixer and an amplifier stage. The receiver is a superregen.

Hello Sahil,
I did see the link of your project, your encoder circuit seems to be the one given here:  http://users.picbasic.org/projects/RcEncoder/radio_control_encoder.htm, and also you've used standatd RF modules available in the market. My approach is different, the current prototype uses low powered basic version of the tx and rx, this is only for test purposes and to Check whether the concept works or not. a lot of tuning will be required and also amplifier design will have to be modded for the final version. Once I find an old radio case with joysticks, I will assemble the entire circuit on a new pcb and test it further...

yes the circuit part of it is correct but there code is wrong and i have modified the circuit to work with my own code plus one can use different pots/range not just 5kohms and planning to add a LCD display with voltage indicator/trim options !

regarding the RF stage there are two main reasons one simpler to implement and two i was more interested in indoor/light weight RX system ! hence off the self stuff.

and you are planning to build any FM systems ?

After finishing this project, I definately have plans to build a FM system. In my previous post I have mentioned building a FM receiver but I could not test it. I have also ordered Xbee pro modules for my final year project, so after i'm done with that, I might end up experimenting with 2.4 Ghz also !!

great 

do help...me....

pls share ur knowledge..

Hi Buzz_rc,

Try with relaytronics, mumbai for the relay, i'm sure it should be available with them.
Last year I had built a PIC based LC Meter with 16*2 LCD Dispaly & I hope I have a spare PCB of it with me.
Let me know, if you need it.

Sanjay

Hi buzz
how is ur work on
the tx rx going ?

Hello,

I am still working on it, The other day I blew up the rx circuit while testing. My power supply had developed a fault that caused it to output a higher voltage. A couple of other circuits also stopped working due to this. I need to find a convenient way of testing the system. I am looking out for the following stuff, can anyone help me out ? I will pay for it.

Old/unwanted/broken radios (will use this for the case and joysticks + to salvage hard to find components+ for testing the receiver)
A pair of tx/rx crystals on 27mhz band.

Hi Buzz,

Since i couldn't locate the spare PCB, I have got it fabricated again, but with a new circuit.

http://ironbark.bendigo.latrobe.edu.au/~rice/lc/index2.html

It seems to be better than the earlier one (not tested by me). PCB is ready with me.

Please PM me your address.



Sanjay