ph2t

[ph2t]

Yes it *should* but I think you need to re-tune the coupling capacitor and inductor that connects to the ariel.

ph2t.

[ph2t]

uA, what’s the link?

[ph2t]

Since only getting into this stuff at christmas, I’m a newcomer but hope to be old school one day.

[ph2t]

I found this circuit on the net.

This is an RF power amplifier that can be built out of stock parts. I”ll need to do some calculations on the LC networks to confirm the operating freq of this amp. I believe it’s set around the 27MHz range since I got this from a microflight site. Here is the site with more info here.

Ph2t.

[ph2t]

Micro, put the Vcc to the TX chip back down to 3V. No difference. Range is still the same.
I also removed the crip cap from the Car’s PCB and got an extra meter.

So I’m now at 9 meters……….

Gotta get me a better telescopic antenna to put on the controller, the telescopic I’ve got i ripped from one of the clones.

Does anyone know where I can buy these from? (too lazy at tha ‘mo to check my usual haunts…:smiley16:)

ph2t.

[ph2t]

DrQuintezz, welcome to ausmicro, good to have another propellor head onboard, micro and I were getting lonely!:smiley2:

See my thread here about the RX boards on these cars. Also in this thread there are datasheets for all the different chipsets used in these models.

The recievers aren’t very selective, as micro said, more circuitry is required to decrease the bandwidth on the RX’s. Possibly the addition of an extra IF stage, or the inclusion of a PLL (Phase Locked Loop) will make the RX more selective. But in the current config of these cars they only have the single RF reciever stage at the moment.

As for Bensu .vs Microsizer controllers, the TX/RX chipsets might be on a different base oscillator (set by the 220K resistor on the OSCO/OSCI pins on the RX and TX chips respectively) which would then created a different modulated signal. This is a “theory” that I will try (when I get enough time of course) one day to get two cars on the same freq operating together. But then again the Bensu’s might be on a different revision of the same chipset (tx2b, tx2c, etc…) which could then change the OOK (On-Off Keying) encoded signal for each function, Left/Right/Fwd/Rev…..

Cheers,

ph2t.

[ph2t]

OK, Micro and I have been talking and we are going to setup a meet next Saturday 26th April at a pub just to have a meets ‘n greets sorta thing….

Details will be given soon, in the next couple of days.

Cheers,

ph2t.

[ph2t]

Here are some pics of my work in progress. I know it doesn’t mean much for people who don’t wear propellors on their heads, but it’s some info none the less…..:approve:

I just ran out of Solder, *arghhhhh*. I guess I know what I’m doing tommorrow, another trip to Jaycar……..

ph2t.

[ph2t]

Has anyone thought of trying to do this to a Bit?

I’m thinkin magnet ‘n coils, lotsa @#$%^ magnets ‘n coils……

respect!

:approve:

ph2t.

[ph2t]

Surfmy, PM me. I can help you with your webspace.

ph2t.

[ph2t]

wcwl, how much were they selling them at Hobby place in the city? Were they the Japanese BitChar-G’s or the aussie distro version called Compact-Char-G’s?

The aussie version comes in only 2 freq’s, 27 and 40MHz. But the Japanese version comes in 4 freq’s.

bitchargoz.tk has the full range online, so does http://www.toyeast.com. But I dunno about the cost of shipping etc, etc… barrell is the best to speak to about this…..

ph2t.

[ph2t]

On the RX circuit there is a chip that pulls the voltage up from the 1.2V the battery provides to 3V that the RX chip can run on. I thought maybee I can increase the steering power by connecting the steering coils to this 3V source instead of the 1.2V source they were attached to.

Bugger,:angry:. Didn’t work. Once I connected the steering coils to the 3V source their effect on current in that part of the circuit caused the 3V rail to lower to 1V which is below the minimum operating voltage for the RX2 chip. I effectively stopped the RX2 chip from operating.

Oh well, I guess a dual cell mod will help with this…..

ph2t.

[ph2t]

Lets not forget the posts on bitpimps and tinyrc……….

Where do you work man that allows you to post like a pimp? :smiley2:

ph2t.

[ph2t]

Heya Cabo, welcome downunder, represent! Now your in my territory! Most of the post in the techo section are my rants and raves…..:approve:
As to whether (I could never spell that word right!) on not they are legit, that remains to be seen.

ph2t.

[ph2t]

A little Shypo, but not much man. I’m gonna try some more tensile springs to keep the front end up higher. Too much pressure on the wheel knuckle kills the steering though….

ph2t.

[ph2t]

They ride well. Biggest difference is that when I hit a bump the car doesn’t change direction as great as before, turning is still the same I think, didn’t notice much . I’m experimenting with removing the stabiliser bar as well and trying slightly stiffer springs.

I want to try the full wheel mod for the front section using the rear wheels from a clone to see if that improves steering and overall handling as well.

One tip though, if your magnet falls out of the arm it’s encased in make sure you put it in the correct way. I had to stuff around for an hour wondering why my steering was so crap 🙁 , put the magnet in the right way and all is sweet again. 8)

The Hi-8 tape mechanism is similar, I have only 3 tapes that my wife and I use for our camcorder so I ain’t gonna rip them apart:smiley2:. The DDS tapes were gathering dust in a storage cupboard at work, hence the opportunity. Let us know how you go SurfmyStrat.

Micro, if ya want a pair just PM me. As for rear suspension I dunno. I believe you would need to remove the whole rear end to make it happen since you would need to keep the motor/gear/axle assembly together. If the car had a differential (yeah right!) axle setup you might be able to do something but I dunno.

Hmmmmmmmmm…….

ph2t.

[ph2t]

I might have a few spare :). If anyone is interested PM me.

Cheers,

ph2t.

[ph2t]

Been doin a bit of research to do with this timing problem that diets pointed out and have found some info that might help me get over this problem.

The pdf located here, was found on a website somewhere, I can’t remember where…… So I thank that person for doing all the ground work.:)

So to take this info futher and converting the timings in to a frequency we have the following:

Function_______________Cycle____________Max Freq
_______________________(ms)_____________(Hz)

Forward Only…………18…………..55
Reverse Only…………48…………..20
Left Only……………66…………..15
Right Only…………..74…………..13
Forward + Right………44…………..22
Forward+ Left………..38…………..26
Reverse +Right……….56…………..17
Reverse + Left……….62…………..16

So, given this data I guess the max frequncy I can run the PWM at and NOT cause conflicts is 13 Hz. I would then remove the triangle wave generator from the steering circuit and drive both circuits (Steering and Throttle) off the same oscillator. This would keep both circuits in time and not cause the conflicts.

Now I know what I will be doing this Easter Weekend. :approve: Just hope my theory isn’t full of crappola!:smiley2:

Edited by – ph2t on 17 April 2003 15:42:00

[ph2t]

Yeah, true micro. I’ve only been around since Christmas and have no plans to stop pressing refresh every 30 seconds……..:)

ph2t.

[ph2t]

Yeah, I missed the boat on this one. I only got into bits after christmas. I bought 2 clones for $20 a pop.

ph2t.

[ph2t]

Is this metre measured from a moving start? Or is it from stop to go? The times will vary wildly given the differnces in the two.

It would be good to do this measurement along with what gear ratios you’re using. If this would be done for all stock bits / motors we could compile it into a table and for once have a good quick and accurate way to rate clone motors! 🙂

ph2t.

[ph2t]

Quote:

Back to the drawing board…………..

ph2t.

Edited by – Shypo on 15 April 2003 22:53:56

I wonder what Shypo edited in my post?:question:

[ph2t]

uA, I was writing my previous response as you posted yours, so I missed that in my reply.

I will test this for you no sweats. Gotta crash now though, got an early start tomorrow.

Cheers,

ph2t.

[ph2t]

So far I’m at 9 meters (27ft) without re-tuning the variable inductor. I will do this tomorrow. I’ve managed to put everything back into the MS controller (quite happy with myself):D:D
The batt compartment doesn’t fit the 9v batt very well even after getting rid of excess plastic.
At least with this setup I could charge a daul batt combo without too much difficulty. I’ve lost the timer function though, it was too tricky to isolate the charger circuit from the rest of the circuit because the PCB I have is newer than the schematic I’ve based my design on. EG: The timer circuit uses a LM293 Comparator chip, whilst the original schematic uses a transistor based timer instead. (Thanks for the heads up on that one uA:))

ph2t.

[ph2t]

Hey Efarel, you make some good points, but I still wanna get as much as I can out of this as possible.:)

Hey Micro, where is the cripple cap on the RX board? This news to me?:shock:

ph2t.

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