# GTB Questions



## Maxxratter (Mar 18, 2005)

Just wondering if any one has any info on these items:

I see Novak is advertising new GTB's with "Spread Spectrrum Technology."
Does this mean they will ONLY work with SST radios, or just that they preform better with SST radios? Will they still work with FM, etc? 

Anyone have any idea when the new Novak GTB 4 cell and 13.5 Pro Stock combo #3043 (or any of the new GTB Pro combos) will be available?

Thanks!


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## NovakTwo (Feb 8, 2006)

Maxxratter said:


> Just wondering if any one has any info on these items:
> 
> I see Novak is advertising new GTB's with "Spread Spectrrum Technology."
> Does this mean they will ONLY work with SST radios, or just that they preform better with SST radios? Will they still work with FM, etc?
> ...


The new GTB/SS Pro systems will be shipping to distributors this week.

The #1711 GTB Spread Spectrum Brushless/Brush ESC and the #1715 GTB 4-Cell Spread Spectrum Brushless/Brush ESC are for use only with Spread Spectrum radio systems (2.4GHz radio systems).

http://www.teamnovak.com/products/esc/gtb_spread_spectrum/index.html


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## Maxxratter (Mar 18, 2005)

Thank you for the quick reply!!


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## NCFRC (Aug 4, 2005)

How does the GTB transfer much heat thru the sink as it has a non conductive pad below ?


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## McLin (Dec 5, 2001)

The material is a heat transfer material. Sort of like the white heat sink compound that you get from Radio Shack but much better.


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## NCFRC (Aug 4, 2005)

Are there companies out there that make a replacement top heat sink or can it be removed for 4 cell 13.5 racing ??


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## KenBajdek (Oct 7, 2001)

If you are running 4 cell 13.5 you won't need a heat sink. 13.5 motors are a very low power motor and low amp draw so heat won't be an isssue. We run 4 cell 4300 and 5800 w/o heatsinks and they run fine. Temps on the speedo are around 100 for a 5800 and less than 90 for a 4300.


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## KenBajdek (Oct 7, 2001)

The 2.4ghz based radios (Spektrum, Nomadio and Futaba's 2.4) can use the new GTB's higher drive frequency they are more efficient but may cause glitching with the old style FM and AM radios. The regular GTB's 4 cell and the orginal one operate at a lower frequency to eliminate the glitching issue. If you are looking for a speed advatage with the newer speedo it is highly unlikely. More efficient is less heat but in reality heating is not an issue for 4 cell but if you run 6 cell mod 3.5 and up you may have a cooler esc at the end of a race.


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## trailranger (Feb 9, 2006)

My fairly new GTB just puffed alot of white smoke. Anyone else have a GTB go bad under normal use? I just run 13.5T and the ESC went bad right after I taped my batteries in, connected the plug to the battery and flipped the ESC on.


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## FishRC (Sep 28, 2001)

From experiance, if you get 4 runs out of a GTB or the LRP with no issues you have a good one, if not, its got to go back as bad for replacement.


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## factoid (Apr 8, 2007)

Will it mess up other cars on the track using crystals?

Regardless I am not convinced that generating RF is a good thing or required to achieve performance. Yes switching fast can reduce heat, but good fets switch plenty fast without generating RF if done right. It is not as simple as fast=RF. It is a combination of things that cause it and it can always be filtered out with a little money and effort. 

Novak should be embarrassed that they could not keep their unit from thermal shutdown without generating so much RF that a crystal radio does not work well, and then telling us that this is a neat new feature. 

Sorry, but we put up with so much bull in marketing and I am simply disappointed and insulted by this promo angle. I have always liked Novak products but this is not good engineering. Bugs me enough I did my first posts on several forums.


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## Ralf (Oct 19, 2001)

Factoid? (Interesting choice of names) Two posts? Did you sign up just to bash NOVAK? Novak is just leading the way again as they have in Brushless from the start for RC Oval. More and more people are switching to Spektrum technology and they see some advantages of the system to be used so they are pursuing it, no other manufacturer is advancing the tech as far as I can see. Kudos to NOVAK, hopefully some people will stop bashing brushless in any form and either get on the bandwagon or just quit the hobby and leave the rest of us in peace. My .02 Ralf


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## factoid (Apr 8, 2007)

Been reading for years, finally bugged enough by something to get involved. We all had to do our first post somewhere and had a reason that motivated us.

Bashing? The guy above me is bashing with an unsupported personal opinion. I am stating the fact that this is a design problem that marketing is claiming as a sales feature. I love brushless, but do not like seeing one of the most respected companies in the industry market like a bogus claims infomercial.

What exactly is the advantage? "Does not provide any noticeable performance difference", claimed in their own press release. "Does make the esc slightly cooler", which would not matter if it is was not problem to begin with. Why accept a negative like RF noise unless there is an advantage to offset it? Show me a good design engineer that will say anything different. Prior to this press release Spectrum Optimized would have meant broken to most of us and now it is a good thing? 

Like I said I have always liked Novak products, but this is insulting. Blind loyalty just makes you one of the sheep they are counting on. We will see if any other company offers a Spectrum optimized system or should I say is forced to.


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## KenBajdek (Oct 7, 2001)

The "new and improved" sticker on the latest electronic gear has always played to the oval racer. Go back to the 90's and Tekin made new speed controllers about every 6 months. Same case with a different sticker. But some how it was better. They ran cooler or recharged the batteries when you were off the throttle etc, etc. Novak and Epic and Yokomo made new esc's and motors claiming more power and better this and the like. You didn't here the complaints then. Technology has always going to advance and it is going to cost you money. 


Do you really need a broad spectrum radio to be fast, no but it is really convienient to have it though. At times the new stuff has its advantages but it also has drawbacks due to the cost. 


I think that we need to be open to the new stuff but to also keep and eye on performance too. I do not envy anyone who wishes to get started in today's R/C due to the different choices of what to race and what to buy. The fact is brushed motors are going to be extinict for racing soon and new battery technology will surpass the NIMH and Li-Po packs as well.


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## FishRC (Sep 28, 2001)

Well seeing as theses units are just out and no one knows exactly there performance so there is little fact at this point on the new unit. I just got the shipping notification for my unit and was worth the extra $20 if it even runs a little cooler. Why? Running 4WD buggy we create a lot of heat and in the summer on hot days it can be iffy if you can keep any motor cool. Cool motor = performance. So a little more cooling adds to motor life and performance on the track. That’s why I went for it. 

Brushed motors and AM/FM radios for racing are heading the way of 8-track. Yep, there not going away, but other than RTR and other low end setups, there on the way out.


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## NovakTwo (Feb 8, 2006)

*Adnan Khan (Novak Electronics) GTB Spread Spectrum*

Over the years, the Mosfets used in Novak's ESCs have steadily gotten better and now we have reached a point of diminishing returns as far as the Rds On of the Mosfet is concerned. The GTB uses Mosfets that have a Rds On of 1.2 milli ohm. The PCB and wires have much higher resistance than the Mosfets, so why does the ESC still get hot? That is because most of the heat is caused by the switching losses and not the Rds loss.

In an ideal situation, we would like to see zero switching rise and fall times. Fast rise and fall times cause large current spikes and produce lots of radio frequency interference. In a power supply or piece of industrial equipment, typically the manufacturer encloses the power section in a steel box and uses a large ferrite core to reduce the RFI noise. We don’t have that option!

In the GTB design we have had to slow the rise and fall time significantly so that it would work with ALL the radios out in the field (slowing the switching rate brings the noise floor down by 30-35 dbm). Compared to other high performance ESCs out in the field, the GTB has the fastest switching rate as we use 6 layer power PCBs with lots of ground plane and high frequency capacitors to de-couple noise.

Slowing down the switching rate causes more heating because the Mosfets are in the linear region of operation for longer periods and that accounts for most of the heating in the ESC. Also as you slow the switching rate, the pulse width driving the Mosfets starts to look like a trapezoidal wave form instead of a square wave and that causes the trigger control resolution to go down. 

The last issue is that the dead time between the electronic commutation required goes up as we have to wait for one bank of Mosfet to turn off before we can turn on the next bank. In our Brushless ESCs we have six commutation steps per revolution, so any improvement in dead time reduction and switching efficiency can be significant.

The Spectrum optimized GTB uses a very fast Mosfet drive circuit switching speed (in the order of 1uS or less) and that will translate into significant improvement in efficiency under high loads and much smoother throttle response. We at Novak are committed to bringing the best possible racing Brushless system out to market and we are continually pushing the envelope of technology. Spread Spectrum allows us to improve the system performance without affecting the radio performance. 

One last note on the fast switching ESC: it does not interfere with the radios outside of the car, so you will not be causing interference to the car next to yours whose user has the traditional crystal radio.


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## Stratus54 (Jul 16, 2005)

Hmmm... what happened to Factoid  Sounds like Novak stepped up to the plate and responded to his posts with technical answers... I am waiting to read his responce


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## Ralf (Oct 19, 2001)

I was wondering the same thing, maybe he has to wait for someone to explain it to him? Ralf


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## FishRC (Sep 28, 2001)

Adnan,
Thanks for clearing all that up. Nice to see you drop in here and fill us in on the new design. Now I'm just waiting for mine to arrive. It is going into a 4WD that runs on soft dirt tracks so it is under load a lot, so this new setup will help.


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## factoid (Apr 8, 2007)

Easy boys, some of us have a life beyond being a forum rat. I started this and do not need any coaxing to finish up.

Thank you MR. Khan for taking the time to explain this in detail. It is text book engineering and exactly what the press released claims with more detail and maybe a few unintended admissions. I agree with almost all of it and I have to say you made my case for me nicely. 

I can accept that you had to increase switching speed to the point that there are problems with crystal radios because the unit cannot handle the heavy loads and overheats even with a heat sink and a fan. I guess for marketing purposes that had to be shortened to ‘Spectrum Optimized’. Otherwise it really does not have that ‘I gotta have it’ ring to it.

If it truly makes the unit considerably better, then perhaps the trade off is worth it. If it simply makes it work then I still say it is a Spectrum Bandaid and a marketing spin.

Some may argue that the GTB did not have thermal problems to begin with. I suggest you search the word ‘Thermal’ in the 60 pages on Rctech in the electric onroad section ‘New Novak Brushless system’. It is not like it is a secret that it has been an issue.

I think you should check out the competition a little closer. Many products are switching much faster than you mention. I believe the Castle unit switches in less than 100ns or 10 times faster and so does the Quark unit. I see Tekin does not even have a heatsink on their new unit so they must also be switching pretty fast to pull that off. Somehow they all controlled the RF and do not require the use of 2.4Ghz radio. 

Now that it has been explained (admitted) that RF and heat could not be controlled at the same time for some reason in this circuit I will leave it be. At least that is better than a creative marketing angle to cover up a design problem. However for those in the know I have to say you have lost your position as the technology leader and then tried to tell us it was a good thing and we should be excited about it.


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## swtour (Oct 8, 2001)

LOL @ "New and Improved",

I recently had an old timer tell me the laundry detergent he uses has been "New and Improved" sooo many times since he was a KID..that his MOM must have been using plain WATER to do the laundry.

Years ago I remembered seeing a TRINITY product in a LHS, the store could not GIVE THEM away... some time later - this SAME PRODUCT was available in a NEW and BETTER looking Package..and selling like it was GOLD. (Product didn't change..just the wrapper)

RACERS (not just Oval Racers) buy in part because of the BLING factor and the PERCEPTION something is better. Strangely, so many run exactly the SAME SPEED with the NEW STUFF.

I've seen a few LRP's shut down, and a lot of NOVAK'S shut down...but usually the gearing is SO wrong when they do. Just like NiMh battery technology, the Brushless Motor and Speedcontrol technology will keep getting better (And do you really think ANY Mfg. is showing 100% of their BEST ideas early in the game?) If they did - HOW would they ever have improvements?


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## FishRC (Sep 28, 2001)

All I know is form what I have experianced. With the Novak brushless I have had far more on track time than I ever did with a brushed motor. When I am in the pits I am able to focus on setup work other than the motor. Yes they thermal but like swtour put it, its usualy bad gearing or pushing it to the edge. So they thermal, with a brushed motor its called "Cooking the motor". Insted of killing a set of brushes and tearing the copper off the com, the unit just shuts down. Yep, there are others making units, but what do you see at the track. a few of the others and a lot of the Novak.


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## brian0525 (Jan 17, 2005)

The thermal you guys keep referring to is a motor thermal and isn't what Novak or Factoid is even talking about! They are talking about speed control thermal which I would guess most if any aren't having that issue. I have only seen speedo thermal one time and it was from a 4.5r and a speedo with no heatsink or fan and some toher mods that I won't mention!

Don't confuse motor thermal with speedo thermal, they are very different!


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## swtour (Oct 8, 2001)

When I watch a guy with a GTB and a 3.5 on a 100+ ft Carpet Oval track run 3:30 and STOP I never asked whether it was the SPEED CONTROL or the MOTOR causing the shut down.

When I watched guys with the LRP and a Novak 3.5 run the same distance and have a similar concern..and switch to the GTB and MAKE time...I have to assume since the MOTOR and GEAR RATIO didn't change...it must have the the Speed Control shutting down.

However, this brushless thing is still VERY NEW to me and I'm learning NEW STUFF every day...thanks to great discussion boards like Hankster has here...


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## LARCGuy (Apr 18, 2004)

The very few shut downs (thermals) I have had are speed control. I cut the blue lead on my two motors (3.5 & 4300) when I got them.


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## brian0525 (Jan 17, 2005)

LARCGuy said:


> The very few shut downs (thermals) I have had are speed control. I cut the blue lead on my two motors (3.5 & 4300) when I got them.


That is a motor thermal not speedo!

the blue wire sends the temp from the motor to the speedo.

SWTOUR: The LRP may have been a speedo problem cause the LRP wasn't made to handle the 3.5R and The GTB was but they were discussing the GTB not the LRP.


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## LARCGuy (Apr 18, 2004)

I know what the blue wire does.


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## Ralf (Oct 19, 2001)

NO matter what they are told, some people will continue to abuse their equipment to try and get "that edge", and some people due to whatever their "thinking" will refuse to listen to the facts. Their bad. Ralf


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## brian0525 (Jan 17, 2005)

LARCGuy said:


> I know what the blue wire does.


Then please explain why you think cutting the blue wire will prevent the speedo from thermal problems!

Blue wire has nothing to do with speedo thermal only motor thermal so your statement makes absolutely no sense!


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## Stratus54 (Jul 16, 2005)

brian0525 said:


> Then please explain why you think cutting the blue wire will prevent the speedo from thermal problems!
> 
> Blue wire has nothing to do with speedo thermal only motor thermal so your statement makes absolutely no sense!


Unless he means that he cuts the blue wire when he gets the motors (before he runs them) so the thermals he has experienced would then be ESC thermals?


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## brian0525 (Jan 17, 2005)

Stratus54 said:


> Unless he means that he cuts the blue wire when he gets the motors (before he runs them) so the thermals he has experienced would then be ESC thermals?


Maybe! Not the way I took it but maybe?


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## swtour (Oct 8, 2001)

...I think what Scot (LARCGUY) was talking about is that he didn't have SPEEDO shutdowns, his thermals were (in ref. to my comments, because he's one of only a small handful of our racers running a 3.5/4cell) MOTOR shutdowns...and so when he gets it close and is confident in his set up, he cuts the blue sensor wire on the motor..so IT can't shut down.

As far as abusing equipment...isn't that what OVAL races do best?

IF it's perceived that OVER GEARING may kill the motor..but WIN the race - you don't think guys will OVER GEAR it anyway...and take that chance? MOTORS are CHEAP - WINS might not come every day~



Ralf said:


> NO matter what they are told, some people will continue to abuse their equipment to try and get "that edge


Exactly what scares me about LIPO -


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## Ralf (Oct 19, 2001)

One place to start would be for the sanctioning organizations to disqualify anyone who cuts the wires to the speedo. All oriiginal wiring needs to be in place or they are not allowed through tech.. Ralf


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## FishRC (Sep 28, 2001)

Not much differance with cutting the wire compared to brush cutting, com drops, special oil, springs, motor chilling, etc. As long as any one easily can do it as well, how bad you abuse your own equipment to get an edge is what you do. The all mightly $ is true in all forms of compitition and RC is no different. Cutting a wire to allow a motor to overheat does not harm any other racer on the track and is not a danger to any one at the track. Brushed motors cook all the time and and even some times flame out, so a over heated brushless is no different. Thats like saying you can't cut a brush becasue it might over heat the motor as you work to get the most out of it. Though that might lean to the original brush must be in the can becasue again its an unfair and unsafe modification to the brushed motor.


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## ta_man (Apr 10, 2005)

On the other hand, ROAR has specific rules saying what wires must be present and what they must be used for on a sensored brushless motor. So by cutting a wire, you are violating that rule.


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## FishRC (Sep 28, 2001)

I had to check on that .... heres the rule on it.
8.7.5.3 If the motor is sensored:
It must use a six position JST ZH connector model number ZHR-6 or equivalent
connector with 6 JST part number SZH-002T-PO.5 26-28 awg contacts or equivalent.
Wire sequence must be as follows:
Pin #1- Black wire-ground potential
Pin #2- Orange wire-phase C
Pin #3- White wire-phase B
Pin #4- Green wire-phase A
Pin #5- Blue wire-temp control, 10 k Thermistor referenced to ground potential
Pin #6- Red wire-+ 5.0 volts =/- 10%
For clarification pin #1 is on the left hand side of the above connector with the wires
exiting the top of the connector and the plastic tangs that hold the contacts in the
housing are facing forward.

So the rule only states the requiremt of the connector and the order/use of the wire and not that it may not be modified or removed. So cutting the blue wire is legal. The rule only sets the order and color of the wires.


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## Ralf (Oct 19, 2001)

Guess they need to change the rule. Ralf


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## swtour (Oct 8, 2001)

I've got a old style 4300 that I bought here a while back...I've never done any mods to it...and have only run it twice...

I was just moving it from my VELO car to my short track car and noticed the BLUE wire has been pulled out of the plug and taped back under the spiral tube.

If not for this thread...I would have never even looked...


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## NovakTwo (Feb 8, 2006)

Since this is a GTB thread, I thought this would be a good place to announce that both 6 cell GTBs---the original and the Spread Spectrum version---have been upgraded to include the lipo cut-off circuitry.

NOW WITH BUILT-IN LI-PO CUT-OFF CIRCUITRY!


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## swtour (Oct 8, 2001)

NOVAK2, 

Cool, will there be an available upgrade for the ones we have?


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## NovakTwo (Feb 8, 2006)

I know that an upgrade policy is under discussion. It's kind of complicated because the lipo update---I think---requires both a firmware and a hardware change. I'll check and post info as it becomes available.



swtour said:


> NOVAK2,
> 
> Cool, will there be an available upgrade for the ones we have?


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## swtour (Oct 8, 2001)

...great, I bought my Lipo today...so if I could get both the GTB's updated that would be cool..and I wouldn't need to put that UGLY deal in the car.


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## ta_man (Apr 10, 2005)

I'm sure you could get them updated, but with Novak's prices for updates, it will probably cost you less to sell the one you have and buy a new one.


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## badassrevo (May 8, 2006)

I just bought another GTB today, how do I tell if it has the LIPO cut off.
I have two older ones and the only difference is the color of the screws that hold the heat sink on. The instruction sheet does not mention the new upgrade. I am very interested in the mail in upgrade for my older units.


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## FishRC (Sep 28, 2001)

I have one of the new units, there is a sticker on the bottom of the units that says it has the LIPO cutoff.


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## LARCGuy (Apr 18, 2004)

Stratus54 said:


> Unless he means that he cuts the blue wire when he gets the motors (before he runs them) so the thermals he has experienced would then be ESC thermals?


Exactly. Sorry if that was not more clearly stated in my earlier post.


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## badassrevo (May 8, 2006)

FishRC said:


> I have one of the new units, there is a sticker on the bottom of the units that says it has the LIPO cutoff.


Thanks, I guess my "new" one is not that new. I did not see any sticker.


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## badassrevo (May 8, 2006)

I guess I got a bad one because it smoked the first time I ran it. I have two older ones that work great. I guess I will see if the customer service is as good as everyone says it is.


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## tow jockey (Apr 28, 2006)

i had a new one not new enough for the lipo cut off and mine melted on the stand. i diddn't even get to make the car move under its own power. i put soldered new power poles on taped it down was setting the controller, and it smoked aqs soon as i pulled the trigger, novak said i must have shorted it but i diddn't, no shorts in any leads either. made me a little mad. but they replaced it tested the motor said it was fine. when i got it back that was december its back in the car but has not even had connectors put on it to power it yet. some fear!!!!!!!!


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## badassrevo (May 8, 2006)

badassrevo said:


> I guess I got a bad one because it smoked the first time I ran it. I have two older ones that work great. I guess I will see if the customer service is as good as everyone says it is.


Customer service is great, Novak says my replacement will be shipping today or tomorrow.


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## NovakTwo (Feb 8, 2006)

*GTB Different Model Exchange Program*



swtour said:


> ...great, I bought my Lipo today...so if I could get both the GTB's updated that would be cool..and I wouldn't need to put that UGLY deal in the car.


The Novak GTB exchange program information that I mentioned in an earlier post has been posted to the TeamNovak website.

The enhancements to our regular, non-warrantee exchange program are explained here:

...Different Model Exchange Program

The new replacement chart with prices can be found here:

Service Replacement Options

Novak has added these NW service options to allow customers, whose racing needs may have changed, to easily exchange products---ESCs, BL Systems, and Brushless motors---for other items within the same categories.

Examples:

Return an original Novak GTB and exchange it for a Spectrum-optimized GTB, or for a 4-Cell GTB.

Return a SS4300 and exchange it for a Novak Velociti 6.5T brushless motor, or for a SS13.5T Pro Stock motor.


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## ta_man (Apr 10, 2005)

swtour said:


> ...great, I bought my Lipo today...so if I could get both the GTB's updated that would be cool..and I wouldn't need to put that UGLY deal in the car.


Well, now that you see the prices for the upgrade program, it looks like I was accurate when I said:



ta_man said:


> I'm sure you could get them updated, but with Novak's prices for updates, it will probably cost you less to sell the one you have and buy a new one.


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## NovakTwo (Feb 8, 2006)

Your suggestion might work well if you are planning to sell a _still-working_ product.

Novak's exchange program was originally designed for customers returning _non-working_ products for replacement. 

We recently added the upgrade options.



ta_man said:


> Well, now that you see the prices for the upgrade program, it looks like I was accurate when I said:
> 
> 
> Originally Posted by ta_man
> I'm sure you could get them updated, but with Novak's prices for updates, it will probably cost you less to sell the one you have and buy a new one.


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## BEACH (Oct 13, 2002)

NovakTwo, I sent an email to the work email address. I have my hobby shop owners GTB, it is only one race old and it quit working. Can you email me please as I am trying to get this sorted out for him while he is out of the country on vacation. Thanks, Jim


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## NovakTwo (Feb 8, 2006)

BEACH said:


> NovakTwo, I sent an email to the work email address. I have my hobby shop owners GTB, it is only one race old and it quit working. Can you email me please as I am trying to get this sorted out for him while he is out of the country on vacation. Thanks, Jim


Please e-mail [email protected] and he can advise you. If you need to return the GTB for service, the return forms (PDF) are liked from this page:

Service/Replacment Options


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## BEACH (Oct 13, 2002)

Thank You


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## AEman69 (Nov 21, 2007)

GTB will work on any radio i believe. I have a radio that came with a RTR b4 and i t works with that ...


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## swtour (Oct 8, 2001)

AEman,

What are you talking about? LOL this is an OLD thread...


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## AEman69 (Nov 21, 2007)

I know but there are no threads to talk in lolz.


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## hermanp (Apr 25, 2003)

*??*

I am currently not using brushless but intend to.I use a MX3 crystal radio,I am I going to have trouble with the Novak or LRP systems?Is there a correct choice,Thanks!


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