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Maxmod...for real?

Hello, New guy here...I have a noob type question concerning an upgrade/mod for the AT 6666 I put in my wife's car am I in the right place?

The AT 6666 is a decent radio, there is no hocus pocus mod for it. All it needs is a good shop to do the conversion, the factory alignment with a slight bump in modulation will sound great. If your antenna system is set right and you have a solid power source for the radio your good to go. You shouldn't be smoking finals unless your doing something wrong. That radio is surface mount, unless you have the proper equipment and know what your doing leave the cover on it.
 
Hi TES and welcome to the forum.

no, you don't need to replace the AM regulator with a MAXMOD or any other part.
no, you can't use it as a driver or final. simple explanation is that it's a different kind of transistor.

yes, you can use the ERF2030 to replace the driver and finals in your radio. (im not disagreeing with Ranch55's opinion on them, im just saying they will work)
HOWEVER!
it is not as simple as just de-soldering the old ones and re-soldering the new ones in.
you have to know how to set the bias on a radio when you replace a driver or final.

with the MOSFETs used these days, there is a lot of information out there telling you to set them for a certain voltage on the gate lead, but they need to be set for idle current going in to the radio in order to keep them from running away (think of a guitar amplifier feeding back and getting louder and louder until you shut it off).

this is why there were so many claims of this transistor or that transistor blowing out.
well, that, among other things...

hopefully you haven't touched any of the trimmer resistors near the driver and final yet, and if you haven't, don't!
LC
 
Hi TES and welcome to the forum.

no, you don't need to replace the AM regulator with a MAXMOD or any other part.
no, you can't use it as a driver or final. simple explanation is that it's a different kind of transistor.

yes, you can use the ERF2030 to replace the driver and finals in your radio. (im not disagreeing with Ranch55's opinion on them, im just saying they will work)
HOWEVER!
it is not as simple as just de-soldering the old ones and re-soldering the new ones in.
you have to know how to set the bias on a radio when you replace a driver or final.

with the MOSFETs used these days, there is a lot of information out there telling you to set them for a certain voltage on the gate lead, but they need to be set for idle current going in to the radio in order to keep them from running away (think of a guitar amplifier feeding back and getting louder and louder until you shut it off).

this is why there were so many claims of this transistor or that transistor blowing out.
well, that, among other things...

hopefully you haven't touched any of the trimmer resistors near the driver and final yet, and if you haven't, don't!
LC
NO! I haven't even opened the radio up and from all the information I have gathered from everybody on this forum I will leave well enough alone. 'If it ain't broke don't fix it' As I stated in my original post, I don't know #@$& about radio electronics. So thanks to everybody on this forum my wife's little radio will live another day. The only thing I plan on doing to the radio now is designing a small attachment for a 50mm fan to move some air across that so called heat sink.
 
best thing you can do for your wife's installation is to run the positive power wire to the radio directly from the battery (fused right at the battery for fire protection!) and run the negative wire to the closest big metal panel ground, or preferably something within a foot or so that bolts to the frame/unibody.

modern vehicles are computer controlled devices and trying to run two way radio equipment from a power port, or even tying in to the fuse block can increase the chances of having problems when transmitting.

one vehicle i had in the past, even with this setup, would cause the engine to stutter by messing with the cam positioning sensor when transmitting.
LC
 
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The AT-6666 is a nice rig. Mine didn't need any tweaking at all. It just gets hot quickly, especially running it full bore. Try to back off the RF power a tad. If possible, try to fit a little fan blowing towards the heat sink.

There's been a couple times I forgot about turning the fan on. That rig gets blistering hot very quickly. I have it back in the mobile now. I usually don't motor mouth when mobile. I tend to get windy on the base. I have an At-5555n in the shack now. It has little less output than the 6666, but it does run cooler. No need for a fan yet.
 
best thing you can do for your wife's installation is to run the positive power wire to the radio directly from the battery (fused right at the battery for fire protection!) and run the negative wire to the closest big metal panel ground, or preferably something within a foot or so that bolts to the frame/unibody.

modern vehicles are computer controlled devices and trying to run two way radio equipment from a power port, or even tying in to the fuse block can increase the chances of having problems when transmitting.

one vehicle i had in the past, even with this setup, would cause the engine to stutter by messing with the cam positioning sensor when transmitting.
LC
Thank you Brother...I have run a good quality 8 gauge wire direct from positive side of battery to positive lead on radio and an 8 gauge from negative side radio to engine block with several braided, silver plated copper 'ground straps' to 'bond' everything together.

The 6666 is a great little radio, better than I expected for the money and size. I have no intension of trying to get any more performance out of the radio.
I've heard so much crap about how these radios would fail so easily if driven too hard that I thought I should look into how to prevent any problems.

This is why I was asking about the 2030's, Maxmod and all that. I don't know much in the way of radio electronics and from what I could gather from all the BS online, Youtube and such it made sense to find some folks to steer me in the right direction...so, here I am and I appreciate all the input from everybody.
 
I don't do it on purpose. When I had it in the house, I'd talk a long time on it. I ran it full bore so my friend could hear me. A few times it got blistering hot before I remembered to turn fan on. I likely took some life out of it, but it still performs as new. I couldn't imagine trying to squeeze any more out of it. They need to change the heat sink. Needs to have more surface area. Just my 2 centavos
 
I don't do it on purpose. When I had it in the house, I'd talk a long time on it. I ran it full bore so my friend could hear me. A few times it got blistering hot before I remembered to turn fan on. I likely took some life out of it, but it still performs as new. I couldn't imagine trying to squeeze any more out of it. They need to change the heat sink. Needs to have more surface area. Just my 2 centavos
Yeah, that big chunk of aluminum screwed onto the back of the radio is a joke. I am looking into the fabrication of something better, something with some REAL cooling fins.
I have devised an attachment with a 50mm fan that seems to work pretty well but would rather not rely on a powered fan when a properly designed heat-sink would do the job...Thank you for the reply!
 
just face the radio straight down so the heat can rise out of the heatsink in the most efficient manner.
problem solved!
LC
 
I was thinking of trying to mill some slots in it to make fins and increase surface area.
My little fan works great but I just don't want to rely on anything mechanical. You've got the right idea...cooling fins need to be just that, FINS...long, thin 'fins' work best. That big chunk of aluminum will only soak-up and retain heat...no 'fins' to let the heat dissipate.
 
just face the radio straight down so the heat can rise out of the heatsink in the most efficient manner.
problem solved!
LC
Face the radio straight down? That great big piece of aluminum is NOT a properly designed heat-sink and will retain heat about as well as let it dissipate.
 
Needs to be like the 5555n. I run it full bore and it runs relatively cool compared to the 6666. Granted, the 6666 has more output, but not much.
 

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