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ldmos.....BBI


They really are amazing devices. Why would an entrepreneur like yourself wait so long to utilize technology that's been out for years? I thought builders would jump on this way back when the guy in Israel started selling boards on ebay.
 
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I was looking them myself. They use Sparky to demo the device at trade shows. You can buy almost everything premade from Russia off Ebay. Those guys build some neat components, All you need is copper plate and heatsink.
 
As I understand it is comes down to what voltage and amperage you feel safe driving around with. I was into serious car audio in addition to home audiophile. Two completely different worlds I know but.....Do you really want a 50V high amperage device in your car? I have seen 12V high amperage devices cause some serious burns and fires. Sure fusing at the battery and again externally even better internally is always good. The problem comes in car accidents. I can not count how many times I have seen OEM wiring and equipment short out after a car accident and cause an electrical fire under the hood. If the fuel pump keeps running I have seen huge under hood fires from both battery going up and fuel being sprayed under hood etc....No lets just imagine this 50V high current device has some issues in the accident 50V at the amount of current these devices will use can be serious for you health.

If you reduce the voltage and power output the durability is insane but the gain drops to really low levels.

For base station use I would say in a hurry "Sign Me Up". My dream amp in High School was the JRC-2000 look that girl up! If I recall properly it was 1000 watts continuous 24 hours on 220 and 750 continuous at 110/120. That was LDMOS and that was back inthe 1990's I wanted one of those.

I think what really kills me though is that the people wanting to go to these have been churning out outdated simple but not at all efficient or durable designs with bipolars for years! If they are not building a bipolar amp with perfect transformer coupling, swr protection, continuous reverse polarity protection, true temp. tracking AB bias why should we trust them to build a good LDMOS amplifier. If they cannot build a durable, clean, efficient, fully protected amp with bipolars than moving to LDMOS at 50V is just going to be more of the same dirty crap. I do not expect auto tuning and a continuous 24 hour carrier output of 1000 watts liek you could get in the 1990's but I do expect more than I have seen lately!!

It is bad enough that we have people blowing through bipolars like a fat kid eating cup cakes but do we really want them burning through LDMOS's like that? Right now at 12-19v idiots are not getting killed or injured badly enough to need public assistance but at 50V on up we might see a pandemic! I can just see all the golden screwdriver home brew electroconvulsive shock therapy now!!! If you think channel 6 is bad now and all this guys with 32 adn 64 2SC2879's in the back of a 1980's big block GM Suburban is bad wait until they have 12-20 LDMOS devices and start to exceed 50V at higher freq. then start trying to drop it down....I am not ready for that level of stupidity and voltage!!! I can just picture some idiot with an Aircraft Aux. Pwr Unit aka APU in a Suburban.
 
Many of the CBers with those suburbans found out long ago that tubes give you more bang for your buck. 50 volts is much safer than some of the old suburbans with 7 to 10kv (regulated by engine rpm) feeding ceramic tubes.
 
As I understand it is comes down to what voltage and amperage you feel safe driving around with. I was into serious car audio in addition to home audiophile. Two completely different worlds I know but.....Do you really want a 50V high amperage device in your car? I have seen 12V high amperage devices cause some serious burns and fires. Sure fusing at the battery and again externally even better internally is always good. The problem comes in car accidents. I can not count how many times I have seen OEM wiring and equipment short out after a car accident and cause an electrical fire under the hood. If the fuel pump keeps running I have seen huge under hood fires from both battery going up and fuel being sprayed under hood etc....No lets just imagine this 50V high current device has some issues in the accident 50V at the amount of current these devices will use can be serious for you health.

If you reduce the voltage and power output the durability is insane but the gain drops to really low levels.

For base station use I would say in a hurry "Sign Me Up". My dream amp in High School was the JRC-2000 look that girl up! If I recall properly it was 1000 watts continuous 24 hours on 220 and 750 continuous at 110/120. That was LDMOS and that was back inthe 1990's I wanted one of those.

I think what really kills me though is that the people wanting to go to these have been churning out outdated simple but not at all efficient or durable designs with bipolars for years! If they are not building a bipolar amp with perfect transformer coupling, swr protection, continuous reverse polarity protection, true temp. tracking AB bias why should we trust them to build a good LDMOS amplifier. If they cannot build a durable, clean, efficient, fully protected amp with bipolars than moving to LDMOS at 50V is just going to be more of the same dirty crap. I do not expect auto tuning and a continuous 24 hour carrier output of 1000 watts liek you could get in the 1990's but I do expect more than I have seen lately!!

It is bad enough that we have people blowing through bipolars like a fat kid eating cup cakes but do we really want them burning through LDMOS's like that? Right now at 12-19v idiots are not getting killed or injured badly enough to need public assistance but at 50V on up we might see a pandemic! I can just see all the golden screwdriver home brew electroconvulsive shock therapy now!!! If you think channel 6 is bad now and all this guys with 32 adn 64 2SC2879's in the back of a 1980's big block GM Suburban is bad wait until they have 12-20 LDMOS devices and start to exceed 50V at higher freq. then start trying to drop it down....I am not ready for that level of stupidity and voltage!!! I can just picture some idiot with an Aircraft Aux. Pwr Unit aka APU in a Suburban.

I believe in Darwinism. I say go for it and let the thinning of the herd begin. :ROFLMAO:
 
7-10kv is about what I have seen in a mobile. Suburban here in Daytona. Monkey Man was his handle. He would run it at 7k most of the time, but could get it up to 10k that I know of. Scary ass stuff!! Only sat in it once. That was enough for me. Eyes watering. Like you could smell the RF cooking you LOL!!
 
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It seems like the herd has already thinned, it ain't the 90's. Fewer built keydown trucks out there. I know a few who gave up when gas hit $4 a gallon. It's not worth it unless it's a dedicated toy. 2 or 3 250's really effect your MPG. And things are always braking and wires getting loose.
Owning the same Davemade 3000 since the '98, twisting the HV regulator to the right and mashing the pedal is a blast.
 
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