RF Man Demos LDMOS RF Amp
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- čas přidán 30. 07. 2024
- RF Man Demo's New Dual 3000w PEP LDMOS RF Amplifier. If you are interested in purchasing one of these amplifiers, you may contact me at 770-500-5945 or checkout my website at RFlinear-amplifiers.com
Well done and more importantly.... well described. I have built a few and the results are incredible. I have never built one with the drains shorted in PPP. Nice no combiner (+ 1:2 step up) needed. Nice job man.... good luck
Thanks for your comments and feedback.
Always wanted one of your amps, this duck stamps are short.
In the future I would like to have one that has 16-18 "new style pills".
Without using a spectrum analyzer this means nothing. I am a retired hobbyist and after my scope I got a spectrum analyzer. It really is an essential tool.
3000 watt 2 pill love it man!!!!
Im gonna build me a few of these for sure!!!
This is the future of RF hillbillly pill box amps,love the LDMOS technology!!!!
Hey RF MAN, I really Appreciate this and the idea. Of doing this that way, Thankyou
BEAUTIFUL!
Thank unso much for this informative video! I have a couple of questions i really hope u answer them, how can we know the output and input impedence if the ldmos at a certain frequency? do we need to add a 1:1 balun after the combiner stage? doesn’t using two ldmos together halves the impedence so i higher transformer ratio would be needed? Thanks
What does the output look like on a spectrum analyzer? need to see that it's not splattering all over the place an meats the -54dBc requirements for ham use!
Awesome Build, Awesome Explanation On This Build. Do You Sale Your Builds??
Do you build a 4 transistor amplifier?
How about to show output RF signal on Spectrum analyzer?
m.czcams.com/video/acX2Bie5fEU/video.html
Cause then you will know 50% of that power is in harmonics
Yes, without specan outputs and analysis I wouldn’t use the amp :)
Great videos u explain it well TY
I have one i am assembling and yes im a ham so we can legally operate 1.5kw
Id like to know your take on rf protection circuits like swr like putting a attenuator on this ldmos and the use of a low pass filter unit as your striker unit is 10 meter as well? Also do you sell this assembled? $? Lastly where did you find a 50V 40+amp power supply for this unit?
you are a master thanks for the video
So what are you seeing pep modulating that 1500 carrier?
Great video
What do you recommend for a power supply RF man? Is it a good idea to use those switch mode Blade server rack mounted power supplies you see on eBay for a couple of hundred dollars, or should I build something linear? Nice website by the way. Simple snappy and clear.
Man I would love to learn more about this 440 said that.
So this amp comes as is tuned to 50 ohm impedance input and output only for one band ? For operation on other bands we must build a selection of different wideband transformers? Is the matching networks enough to keep spurious emissions below acceptable levels? I would think that some passband filtering might be prudent too?
Ok so if purchased I would need to provide my own 50v 75amp dc powersupply and a heatsink along with a case. This would allow me operation of 3k out with 4 watts in on 11 meters only? Not interested in 11 meter but interested on 20 and 40
The amplifier is board band and will provide acceptable SWR's and power output from 1.8 to 54 Mhz. For FCC compliance, you will need to add a Low Pass Filter for each of the bands you transmit on.
Can this amp work with 53V? I want to use a flatpack 2 HE power supply because these are really high quality and much cheaper than meanwell. Does the bias have to adjust down if I want to use it with 53V? Nice work! Do you offer a low pass filter module/kit? I can't find many and none for this power level. I just need one cutoff frequency no fancy ham relays. I haven't bought yet, but once I get an antenna that I know will work, I'll go for it.
One more question: Does it work at 100% duty cycle or does the matching get too hot? Hehe.
Yes it will work justr fine with the HP power supply. Duty cycle should not exceed 75%.
but where can you find atleast a 1 ldmos amp?and how much $$you lookin at to get a 1 pill moreless..??
I'm looking at a PS that is 48 VDC at 41 amps. Would that power the BLF188XR's pair on this amplifier even if at slightly lower output power?
BBI has a video fixing one of these things with a new transformer as it sits it has massive spurs 100+mhz up.
Nice. I have a couple of questions, I would like to run 700 to 800 watts RTTY can I do it with 1 LDMOS or should I go for the 2. Secondly I don't think I have a radio that goes below 5 watts out. Is there some sort of input attenuation available with 10 - 12 db of attenuation
The single LDMOS amplifier can provide 750 watts RMS, so I think it will work for your application. You have 2 options on the input power. You can turn down the output power of your transceiver by using the internal adjustments or you can add an attenuator. There are 2 types, an in-line type or an attenuator pad. Please feel free to call me and I can send you the information via email. 678-646-8986
Folks you need a Chebyshev Filter for each band. Something that you did not see in this video. The problem with solid state is , that there's no tank circuit like in a tube amp so if you do not have a Chebyshev on the output it will have Spurs everywhere and not just on the harmonic frequencies , and all your power will be spread all over the place meaning less power out on the frequency that you're actually trying to put it out on.
Typical CB amplifiers:
Most CB amplifier builders don't even put in a low pass filter inline.. and just about all Cbers haven't a clue about them and Think just because their bleeding all over that they're putting out "lots of Power" . That's why there's so many nasty "linear" amplifiers that are not linear. And That's why the FCC comes down so hard on the CB operators with amps.
If they keep their amps clean the FCC probably wouldn't even mess with the CBers as long as they weren't interfering with other services and devices .. because in the end, that is all they REALLY care about, it's the complaints that send them to the Operator's Station and up to a $20,000 fine and confiscation of your equipment.. And the funny part is that without that easy-to-build filter your ACTUALLY loosing power on the frequency/channel you have it on... think of it like this... as if it were a 1000 watt light..... a 1000 watt light will light up a big parking lot but not much light 500 yards away... now think of that 1000watt focused like a spotlight..... you couldn't hardly even look into it 500 yards away... Demand your amp builder makes this filter and you'll stay away from the FCC and you'll talk further... and if your builder wants to charge you $100-200+ more for it....find another builder because your getting screwed... the parts don't cost squat...its just 3 small coils of wire and 2 capacitors for the CB band. .
(another hint, make sure your SWR is the 'same' with the amp on as it is with the amp off and your radio will love you for it) It's also a sign of a good builder who takes the time to tune it there.
True words here. I am not knocking the video or the author, but what is tried and true is true!
If you drive the amp with 1 watt or 1.5 watts will the amp's carrier so to speak be at 750 watts? My thought are with 100% Modulation, one would think 4 times the carrier, giving 750 X 4 = 3000 watts. If the carrier is at 1500 watts then the modulation needs to be turned down to keep from going into distortion, harmonics, signal folding back etc. On the Bay your ad states 1 to 1.5 watts, so which is it? It seems as driving the amp with 4 watts is okay during your video. I wonder how much splatter or buckshot it transmits over the band. Do you sell any band filters to keep it regulated from spatting over the other frequencies to help keep your neighbors from complaining of Bleed Over? (Seriously !) I often thought about buying one, but I have be unsure. Thanks for the video.
I am interested in an amp that can simply push 500 (driver at 35) ...for use on SSB (USB) on the 4,400. and 5,760. HF area. Specifically looking for mobile capability. any ideas?
LDMOS technology required 1 to 2 watts of drive. If you are using 35 watts you will need to add a -20dB attenuator. This amp will operate from 1.8 to 50 Mhz. For mobile used you can used a 12v to 50v boost converter. I have some videos on my channel show how this is done.Regards,RF Man
unfiltered harmonic energy, and those mosfets can be driven to almost a squarewave output, can fool a wattmeter to show much power than is actually being delivered on the desired frequency.
Would you install one in a case and sell it? Id get one if so.
Nice.
the amp function on 1.8-29 mhz with no tuning ? ?
Correct. it is a broad band amp.....
How much drive power needed for 3000w pep? How are you cooling the LDMoS? Water cooling or normal air cooling
And does it have a low pass filter?
@@Mark300win No, this is the same as many of the other AMP Pallets, it is literally JUST the AMP Pallet board...
Good review...
Please watch my video on Harmonic Distortion. There I mention numerous times the requirement to add a LPF for each band you transmitt on.
Do you make a 4 device unit?
You can used 2 dual boards with a splitter on the input and a combiner on the output. These are available from RF Parts or ICA Manufacturing. You will also need a 50 volt / 80 amp supply or two 40 amp supplies in parallel.Regards,RF Man
Why don’t you modulate so we can see what the RMS watts do??
John, I will be releasing a single LDMOS Amplifier next week if you are interested. The cost is 549 plus S&H. Regards RF Man
How much for a 2x kit like that?
Kits are 599.00
Nice design. Could it cover 6M also? I already have a 40AMP 50V psu built by ZTE China. What would be cost of a module with copper plate?
Yes, the amplifiers will work on the 6M band. I have a single LDMOS version (1500w PEP) for $499.00 plus $25 S&H and a dual LDMOS version (3000w PEP) for $699.00 plus 25 S&H. Both versions included the LDMOS Transistors and the copper heat spreader (you will need to drill and tap the HS). They are also fully assembled and tested before being shipped out. You can contact me at 678-646-8986 if you are interested. Thanks
Any pics of a completed 3kw pep version? Anyway to run one in a moible?
There are some pictures on eBay. Also, you can use a 12volt to 50 volt boost converter for mobile applications.
RF Man Channel awesome thank you!!! I already run a 250amp alt so I'm good on amps. It's rf man on eBay right?
Please search under LDMOS amplifier and you will see my 2 eBay listings. One is a 1500 w PEP and the other s a 3000w PEP amplifier.
So help me with the math. On Ebay you say this thing puts OUT 3000 watts PEP. Has an efficiency of 75%... meaning the input for 3000 watts PEP out is 4000 watts PEP. It also says that this thing takes 40-50 amps at 50-56 volts. So lets take the max... 56 volts times 50 amps is 2800 watts. Seems like we are about 1200 watts DC short of making 4000 watts input to get your 3000 watts PEP output. Explain. I think what you really mean is that this thing can make 2800 watts input PEP... and at 60% efficiency (more realistic), it put out 1,680 watts.
Each blf188xr are 1200 watts so two is 2400 watt so why do you say 1500 to 1600???
HOW MANY have you sold THAT are a train wreck ??
isnt the multiplier in 2x??
This is no X2 on my watt meter....
no one says a thing about padding the front end , yes talk about the protected output but watch what happens if you go over 5 watts. If your going to build something , pad the front end or its junk .
An ALC circuit and an Isolator on the output should be used also.
m.czcams.com/video/acX2Bie5fEU/video.html
Looks like Rf FRAUD
@@Ferret488 m.czcams.com/video/acX2Bie5fEU/video.html
We ran 4 LDMOS transistors in FAA approved DME's and ran WITHOUT fans. That's because we actually tuned them. You have too much inefficency and loss in the form of heat. The BLF devices are now "Not for New Design". That means they will soon be obsolete. No wonder you get them cheap.
Was all excited until conducting crude math calculations for voltage requirements of common HF mobile radio and amperage requirement equating to either the 1500 or 3000W LDMOS RF amplifier. That much amperage requirement for the latter was near frightening. Or else a U-Haul trailer to drag along 10X 6V batteries.
left the legs nice and long anything to help get the heat off
The exact opposite of almost everyone else. Long leads at RF??????????
3000w out of two 1400w LDMOS. Not quite.
Good work! I'm a student and I'm studying HF amplifiers, could you please send me the schematic?
Is this a chicken band amp?
I want one, ill put a low pass and pad the frontend no prob..... ill only use half ........ promise!
Think of how much respect you'd gain if you became friends and shared your knowledge with someone like BBI the two of you would be unstoppable even if you just apologized and made it right you would gain tons of respect maybe you'd learn something if you watch this video to where he repairs your palette
CAN YOU ADD SCHEMATIC DIAGRAM FOR ALL HAM RADIO IN THE WORLD
Can you say CB?
I can say stfu as well 😁
I don't believe those LDMOS transistors are as immune to bad operating conditions as you say. With the way it is over-driven and with no protection circuitry, law abiding radio operators can all rest assured that harmonic interference from this product will be short-lived, but hopefully long enough for the FCC to DF the source.
There's one or more videos specifically on the tests of how brutally rugged the LDMOS BLF -x series are. The engineers are also deliberately igniting sparks from the output shorting pins during the test then shortly afterwards testing to the same output power.
Would like to see you focus on Amateur bands.
You Do understand too have 1,500 Watts RMS you would have 6,000 Watts PEP and you Clam your Pallet is Making 1,500 RMS and it can only make a Max of 2,800 Watts PEP Now 1,500 Watts PEP would be only 400 Watts RMS and and 2,800 Watts PEP would only be Around 600 RMS and if your only putting 40 Amps at say 50 Volts That is only 2,000 Watts and at 80%E That's only Leaves 1,600 Watts PEP about 410 Watts RMS for the Coax and for you too have 1,500 Watts RMS you need 6,000 Watts PEP and at 80%E that 7,500 watts of Input Power and at 50 Volts you need pull 150 Amps Min. That's Simple Math a 2nd Grade can Get your Lying your head off. So your only Putting out 1,500 Watts PEP That is 400 RMS and the LDMOS you have can only make a Max of 2,800 Watts PEP or 600 Watts RMS and Since is it 80%E it can only pull a Max of 70 Amps at 50 Volts for a Total of 3,500 Watts Do the Math and Learn what your Talking About. and Everyone Says your pallet Won't make over 1,500 Watts PEP or 400 Watts RMS Not Even Close too the LDMOS Max of 2,800 Watts PEP or 600 Watts RMS.
Seems like this is setup for chicken banders. I would think these are going to blow big IMD all over the ham bands with no filtering board.
YEA along with the 5000 KW and up shit coming out of all the C.B. builders, and the F.C.C. does nothing.
Candid Sky Productions+ Buy one and throw it on your bench to test and report back!
There is more power used on CB than any other band with or without LDMOS technology,never be able to change that fact.
Actually if you're transceiver is tuned correctly to the amplifier, imd will be minimal. But you holier than thou ham fucks look down on anything that isn't ameritron and yaesu/icom
@@1903A3shooter Love the long leads on the caps. Only a chicken bander amp could make 3KW with a 50 amp power supply. Hint 50% efficiency in a real SS linear in class AB. Unbalanced load must beat the crap out of 1 of the devices. This thing should have chip caps that can handle real current. (As an owner of a homebrew 4800 watt linear)
WhatsApp??
You're a scam artist. Best case scenario , you will only get 2,100 watts out of this, BEST case scenario.. You can't say 50 x 56 = 2800 watts.. That's total dissipation, heat, harmonics, etc will consume 25% or more of the power.. You can't magically gain efficiency.
This is simple math.. you cannot get more out, than the total device consumes in power. You can't take a Honda, and state just because it's consuming as much fuel as a big block Camaro when it's floored, it's making the same horsepower as a Camaro.
I hate when people post smoke and mirrors and try to swindle people with specs. Trust me, it would have been ok to just state the true power output of this.. I'm a top level RF engineer, and design radios for a living. In fact, most of you would know who I am if I wasn't using my anonymous account... you cannot get more RF power output, than the total power you are consuming. P (power in watts) = I (Current) x E (Voltage).. Most basic electronic theory there is.. E voltage = (56 volts) I Current = (40-50 Amps) So, best best case scenario, your splatter box, is consuming between 2,000, to 2,800 total power consumption.. Even the cleanest design in the world, of a Class A/B amp , you get 65% efficiency. You claim 75%.. fine.. Even with those magical fairy dust efficiency claims, you're only producing between 1,680 to 2,100 watts total RF power output.. Seeing that there's no filters on the input or output, I'm guessing you're splattering into every harmonic there is.. I bet the 6 meter guys love you, and the FM broadcast band appreciates hearing your 3rd harmonic.. Even scarier, is the multiples of 27MHz you're producing, likely splatters into the aviation band and elsewhere.
OK, I heard it's for the HF band, that's cool enough... BUUUTTT... then I heard you say "11 meter band, channel 1 to channel 40"... ummmm... that CB radio band is not a legal band for using a linear amplifier... just in case you were not aware of that fact. shame, shame, you law-breaker - breaker one-nine.
Its a chicky band amp. This guy is a classic CBer...
@@doctorbills790 DONT BE A HATER HAMMER HEAD
@@brianneihart9721 No hate here. Its all good. Hams are just legal thats all.
Oh boy there you go talking all that b******* about being a lawbreaker listen here buddy I'm a ham radio operator myself and to be honest with you wheat hams are more lawbreakers than the CBers are.
@@doctorbills790 oh really? Like the CB operators do not use the heath kit 220 is correct? Or a Henry radio or even an adcom. Give that b******* up already dude
Boy the Ham'ers are scared to death that somebody else can put out as much power as they do. And there's just as many jerks on their frequency.
This is very, very untrue.
It seems that there are a couple of HAM operators here using vernaculars for CB operators such as "chicken banders" and looking down upon them because they are on the CB. This judgmental behavior on the part of the HAM operator is not helping advance the hobby. I believe it is keeping people out of the HAM radio hobby because the average CB operator looks at us HAM operators and thinks "those guys are uppity, judgmental jackasses".
Your NOT ALLOWED too use this on the Chicken Band!!!!!! Become a HAM operator !!!!!
News Flash: your not even allowed to use this at full power on the ham bands..1500PEP is max..
@@freezerfreezer9097 here in Canada we can... 2500 PEP is legal here.. .and this is likely much lower than the 3000 claimed... Those transistors at best are 1400each (assuming zero loss)...
The Voodoo Wizardry here is pure Smoke-N-Mirrors BS.
...phfffft.
Gain on Channel 1 or channel 40??? WTH ??? ILLEGAL CHICKEN BAND AMP?
I cannot support this kind of "advertisement" for blatant illegal CB use. Shame on you RF Man.
WHAT DO YOU CARE HAMMER HEAD
Then dont stupid
Sorry how is an amp that is good from 1.8-50mhz Illegal? Its ONLY illegal IF USED on CB Frequencies...
mickey mouse design under sized heat sink and crappy transformer design with lots of leakage inductance. Looks like a chicken bander toy to go with that chicken bander radio
Bawk bawk ham sucks and the operators as well 😁😁