BBI using eBay LDMOS Boards?

[543_Dallas]

If LDMOS worked good, everyone would jump on that bandwagon to replace the inevitable demise of the bi polar design. Why isn't this the future?

It's is the future. Almost any idiot can make a class C 2879 amplifier work. The youtube cb amp builders aren't competent enough to work with these devices. Several guys are using the ldmos on 11 meters but aren't sharing publicly. The youtube and Facebook builders will copy their work and try to make a buck.

Old News:.
.
Can you do this with the old Toshibas?

No, but if you overdrive that ldmos or don't get the bias circuit right it goes poof. The bipolar transistors were more forgiving where most operators and builders screw up.

 

[543_Dallas]

So ldmos is a potential goldmine for a smart businessman who knows how to manufacture and sell amps to CBrs.

Yes. You would see more of them for ham radio if there wasn't a law against an amplifier with more than 15db gain. Imagine an amplifier you could drive with a few watts and get a kw out. The majority of CB amp builders are still copying a design davemade NJ used decades ago. No surprise they haven't started using ldmos.

I know a few people who have built the boards from scratch but they will not share publicly. It's a very simple circuit but these people spent time and money to figure it out. It would be ashame for someone like BBi to copy it and act like they invented it.

 

[Pappas and Beer]

It makes sense to buy the pcb boards from low cost foreign producers assemble the final amp in the USA and resell them retail or wholesale. BBI has the right idea but he may not be executing correctly. If Trump taxes imports 35 percent that has to be dealt with

 

[543_Dallas]

It makes sense to buy the pcb boards from low cost foreign producers assemble the final amp in the USA and resell them retail or wholesale. BBI has the right idea but he may not be executing correctly. If Trump taxes imports 35 percent that has to be dealt with

He could build his own board much cheaper to build an 11 meter amplifier. He doesn't know how or he would. He has all the parts that he's been using for 2879 amps. He doesn't know how because he hasn't gotten a hold of one to copy.

 

[LeapFrog]

It makes sense to buy the pcb boards from low cost foreign producers assemble the final amp in the USA and resell them retail or wholesale. BBI has the right idea but he may not be executing correctly.

He needs to be forthcoming and open about the fact that he didn't design the circuit.
If he credited the guy who designed the pcb when he unveiled his ldmos box it would be different.

 

[Pappas and Beer]

What team and tools would you need? An wannabe rf electrical engineer, a former machine shop guy and of course a marketing genius. Rent a 1000 square foot bottom office floor spend 10k for the tools, and wammo another cb amp manufacturer. You have to come up with a catchy name and cute logo.

 

[Pappas and Beer]

He could build his own board much cheaper to build an 11 meter amplifier. He doesn't know how or he would. He has all the parts that he's been using for 2879 amps. He doesn't know how because he hasn't gotten a hold of one to copy.

Reverse Engineering dah da.

 

[543_Dallas]

What team and tools would you need? An wannabe rf electrical engineer, a former machine shop guy and of course a marketing genius. Rent a 1000 square foot bottom office floor spend 10k for the tools, and wammo another cb amp manufacturer. You have to come up with a catchy name and cute logo.

The hard part is getting enough CBers to buy the things to cover your overhead. Most just want cheap watts. You'd have to sell drugs at the back door to stay in business

 

[Pappas and Beer]

The hard part is getting enough CBers to buy the things to cover your overhead. Most just want cheap watts. You'd have to sell drugs at the back door to stay in business

CBrs are cheap doods for sure. You would have to corner the market somehow, not easy as there is some decent competition. Not all people in the CB manufacturing and sales are compromised. Some have day jobs.

 

[Captain Kilowatt]

Old News:.
.
Can you do this with the old Toshibas?

I was talking about typical CB operator abuse like over-volting them and driving the piss out of them.

 

[LeapFrog]

10-4, Thanks for pointing out the key differences.

 

[nomadradio]

The one thing that the lab-coat guy in the NXP video does NOT do is overdrive the transistor. If you can come up with a proper protection circuit for that hazard, the 11-meter market might be worth a risk. Otherwise, probably not. Besides, the too-much drive crowd would just disable it.

Viktor R3KR sells his boards on Ebay, and from his www.eb104.ru website. I have only used his wattmeter boards so far, but he appears to be legit. He has video posted of completed amplifiers running under load.

The surface-mount capacitors in this sort of amplifier have to be the right ones. If they aren't, the RF current fries them. The cheap capacitors have excessive losses, but they look the same as the good ones. For a while.

Baruch, 4X4RB from Israel has been selling amplifiers and boards on Ebay, but there are some negative reviews for him out there. Complaints of premature failures. Really only a "he said, she said" sort of thing unless you have reliable info about it.

I suspect that he has cheaped out on some of the SMT ceramic resistors.

Just my educated guess. Haven't tried Viktor's amp boards.

Yet.

73

 

[Tallman]

What team and tools would you need? An wannabe rf electrical engineer, a former machine shop guy and of course a marketing genius. Rent a 1000 square foot bottom office floor spend 10k for the tools, and wammo another cb amp manufacturer. You have to come up with a catchy name and cute logo.

Or just a guy who knows his way around all of the stuff mentioned above and has it in his garage.

 

[Captain Kilowatt]

The one thing that the lab-coat guy in the NXP video does NOT do is overdrive the transistor. If you can come up with a proper protection circuit for that hazard, the 11-meter market might be worth a risk. Otherwise, probably not. Besides, the too-much drive crowd would just disable it.

Viktor R3KR sells his boards on Ebay, and from his www.eb104.ru website. I have only used his wattmeter boards so far, but he appears to be legit. He has video posted of completed amplifiers running under load.

The surface-mount capacitors in this sort of amplifier have to be the right ones. If they aren't, the RF current fries them. The cheap capacitors have excessive losses, but they look the same as the good ones. For a while.

Baruch, 4X4RB from Israel has been selling amplifiers and boards on Ebay, but there are some negative reviews for him out there. Complaints of premature failures. Really only a "he said, she said" sort of thing unless you have reliable info about it.

I suspect that he has cheaped out on some of the SMT ceramic resistors.

Just my educated guess. Haven't tried Viktor's amp boards.

Yet.

73

You are correct about the over drive part. Most people would defeat any protection to get that last 50 watts out. It would be quite easy to do with a fixed attenuator on the input but how long would that take to bypass? Then there is the issue of driving it with a stock CB radio versus a dual final export radio. This means the onus is upon the operator to ensure proper drive levels and we are right back to square one with that issue again.

As for board manufacturers, you also have to watch out for the ones out of Greece as well. I forget the Ebay vendor but I know someone that has purchased some of his stuff and was NOT happy with the quality of the product nor the selection of under rated parts in a combiner section.

 

[nomadradio]

Viktor's protection circuits in action.

73