How feasible would it be.....

[144inBama]

With the ever developing mosfets such as the SD2933, VRF2933, SD4933 and SD2943 and LDMOS BLF188XR/XRS BLF188 transistors, and the increasing wattage of power inverters, how feasible would it be to build an A/C setup for mobile use? The SD4933 is a 300W pill at the current cost of an original Toshiba 2879 (roughly)....$136.00 and the complete boards, less pills, can be had for 1-250 dollars.....just doing some late night figuring, opinions?

 

[Cody Dixson]

I've had the same question. @kopcicle more than likely knows the answer

 

[144inBama]

I personally don't see why it wouldn't work, providing you use a quality inverter with good filtering. About the only prohibitive factor I can see is space, which depending on your situation, may not be an issue at all i.e SUV/crew cab truck, no kids, you'll have plenty of room. It's just something I'd like to tinker with.

 

[kopcicle]

https://www.rfmw.com/products/detail/mrf300an-nxp/618411/
https://qrpblog.com/2019/12/a600-v2-0-amplifier-module-changes-and-improvements/
https://www.ebay.com/itm/224009060107?ul_noapp=true

or


$25.77 / 300 watts
$51.54 / 600 watts
$103.08 / 1200 watts

plus board, passive components, heatsink, and ferrite of course.

so..

https://www.mouser.com/datasheet/2/389/sd4933-1849917.pdf
or
https://www.nxp.com/docs/en/data-sheet/MRF300AN.pdf

It's hard to point to a clear advantage for one over the other. Then you look at the price.
SD4933 $136
MRF300 $27

got what ya need @Cody Dixson ?

 

[144inBama]

https://www.rfmw.com/products/detail/mrf300an-nxp/618411/
https://qrpblog.com/2019/12/a600-v2-0-amplifier-module-changes-and-improvements/
https://www.ebay.com/itm/224009060107?ul_noapp=true

or

View attachment 37644
$25.77 / 300 watts
$51.54 / 600 watts
$103.08 / 1200 watts

plus board, passive components, heatsink, and ferrite of course.

so..

https://www.mouser.com/datasheet/2/389/sd4933-1849917.pdf
or
https://www.nxp.com/docs/en/data-sheet/MRF300AN.pdf

It's hard to point to a clear advantage for one over the other. Then you look at the price.
SD4933 $136
MRF300 $27

got what ya need @Cody Dixson ?

Waaay better options. Thank you.

 

[2NC995]

Waaay better options. Thank you.

But now you need 50V.

 

[144inBama]

But now you need 50V.

Working in a steel mill.... I can get all kinda cool stuff..

 

[2NC995]

Working in a steel mill.... I can get all kinda cool stuff..

Im just pointing out that it’s additional expense with 50v devices.

 

[kopcicle]

But now you need 50V.

...and your point?

So much is made of the 50v requirement. I don't get it .
There is no such thing as an available, in quantity, cost effective, bi-polar junction transistor @ 12v . Getting a 12v device to cover 1-30MHz with reasonable efficiency, linearity, minimal IMD, and a reasonable cost? The decision has been made for you.

Boost converters, super-caps, LiFePo batteries, just work it out .
Creating a 50v source for mobile or base use just isn't a big deal.
Again , 50V? So what?!

 

[2NC995]

...and your point?

So much is made of the 50v requirement. I don't get it .
There is no such thing as an available, in quantity, cost effective, bi-polar junction transistor @ 12v . Getting a 12v device to cover 1-30MHz with reasonable efficiency, linearity, minimal IMD, and a reasonable cost? The decision has been made for you.

Boost converters, super-caps, LiFePo batteries, just work it out .
Creating a 50v source for mobile or base use just isn't a big deal.
Again , 50V? So what?!

I don’t think I’ve made a big deal out of anything, just noting that it was an additional requirement. Lol.

 

[kopcicle]

I don’t think I’ve made a big deal out of anything, just noting that it was an additional requirement. Lol.

True enough
There just isn't a 12v (13.8?) option anymore

 

[2NC995]

True enough
There just isn't a 12v (13.8?) option anymore

Only a Chinese gamble...

 

[2NC995]

Funny enough, I’ve seen some exceptionally strange electrical systems even for 12v devices in the CB world.

Like a guy around here that used a 6v battery in series with his existent batteries, along with an inverter and battery charger to keep - er, ummm chase - the proper charge.

Strange way to get to 20V when you already have a second alternator installed.

Would have been far cheaper in the long run to build a new regulator for the alternator.

 

[Tallman]

The short hand answer to the question, Yes very feasible!
Only two ways to make power. Shitloads of amps at low voltage, or High volts with low amps. They make static inverters that take 13.8 vdc and turn it into 120Vac.
The low voltage dc to dc converters can't boost that much from 13.8 vdc. However would make good regulators for 60 vdc to 50 vdc.

 

[144inBama]

https://www.rfmw.com/products/detail/mrf300an-nxp/618411/
https://qrpblog.com/2019/12/a600-v2-0-amplifier-module-changes-and-improvements/
https://www.ebay.com/itm/224009060107?ul_noapp=true

or

View attachment 37644
$25.77 / 300 watts
$51.54 / 600 watts
$103.08 / 1200 watts

plus board, passive components, heatsink, and ferrite of course.

so..

https://www.mouser.com/datasheet/2/389/sd4933-1849917.pdf
or
https://www.nxp.com/docs/en/data-sheet/MRF300AN.pdf

It's hard to point to a clear advantage for one over the other. Then you look at the price.
SD4933 $136
MRF300 $27

got what ya need @Cody Dixson ?

Do MOSFETS have the same characteristics as the old "pills" do? By which I mean the ungodly interference to everything in a 20 mile radius or are they cleaner? I know the radio tune has practically everything to do with that as well but from my experience, the pills were just dirty on their own. I would LOVE to have 700 W that was so clean that unless you were right beside me, you'd never get any bleeding one channel up or down.