***UPDATE TO THIS VIDEO*** This sutuation was resolved long ago simply by placing the pallet in an appropriately sized trash receptacle. Long story short, this pallet has so many issues and shortcomings it is worth nothing more than the 2 transistors attached to it. Since this video I've come a VERY long way in designing and engineering my own amplifers from the ground up. Take a look at my more recent videos to see what a WORKING LDMOS pallet can do!
sorry to be so offtopic but does any of you know of a trick to log back into an Instagram account?? I was stupid forgot my password. I would love any tricks you can give me!
@Emerson Konnor thanks for your reply. I found the site through google and I'm trying it out atm. I see it takes quite some time so I will get back to you later with my results.
My friend, these LDMOS transistors are only rated to 700 watts at 50 Volts. In the NXP lab we routinely ran them at 1000 watt on a cold plate but not more. Your friend has a defective meter - it is not possible to get 3 KW out with those devices. 73's, Alex W5YB
In his video to you he said "53v @ 30a = 1590w input power. So @ 75% eff. which would be good that would be 1590w in 1192w out AM carrier. For the1800w AM carrier he claimed @ 75% eff. you would need 2400w input power or 53v @ 45+ amps. I have the single pallet from him and with the neg. feedback removed & bypassing the gate stoppers + 2amps bias total results were okay on just 10m. 53v @ 24a gave me approx. 1k+ pep out. I didn't put it on the scope. I boxed it up and put it on the shelf and moved on I wanted full hf coverage and this wasn't going to do it for me. Thanks for the video!
Hello there, I had simillar problem with my amplifier. The problem is in the feedback circuit. You need to modify it. Remove the old feedback and put 10ohm resistor in series with 1000pF N0P capacitor from gates to source This helped me to get rated power from amplifier, 9A3SMS
If you have a peak kit that is properly calibrated .. you could also have a deffective slug ... what slug are you using in your meter? And have you tried a different bird meter??
Make sure those ldmos es are not 65 v instead of 50v. Also put a fast oscilloscope on power supply rail to see if voltage not dropping on keying. If all good pull out ldmoses and put a vna instead to measure impedance and reactance seen by transistors, make sure 50v rail ils not on.
MudDuckSharky, I have struggled with this exact same situation. Assuming you have correct bias, and plenty of drive voltage on your gates (-4 to 10V swing is desirable), the simple answer is you have no impedance matching network between the output transformer, and your coax to your load. This will never work without a matching network. (believe me I know) My guess is you need a series capacitor of somewhere between 100 to 1000pF (use a high quality RF capacitor) Your guy may just be very lucky with the length of his coax on how he is getting good impedance match.
@@rfmanchannel6915 so your saying this in the comments did u tell Sharkey that you pallet is not properly tuned and requires exactly 1/4 wave to operate? Cause most people are going to have 50'+ not +/- 12' to get to antenna.....I do my best to land on a half or full wave so my coax is completely invisible to the amp. Because I trust the amp isn't relying on my coax to tune the amp just saying
Has the oputput stage been optimised for 10m. Try a transmission line transformer instead of broadband ferrites. I had the same issue with the EB104 PA. TLT solved it. What power do you get on say 14mhz as an example.
Another problem you could be having is that your voltage in your house it's actually having what they call voltage sag, very common in homes. and if you're having voltage sag obviously you're not feeding the correct ac voltage into the power supply thus the power supply will not produce the correct output. I had that happened in my house with a tube amplifier where when I took it to the shop it had 3,200 volts to the plate and then when I brought it home it only had 2,600 volts to the plate well I went back and forth with the technician he told me calling the electrician and check the voltage in your house well guess what my friend it was the voltage in my house it was sagging and I had what they call brownouts around my house so my voltage was not being fed correctly into the amplifier so the amplifier was not producing the correct plate voltage for the correct amount of output power
In the whole video you talked about everything, tuning circuits, bypass capacitors, power supplies and so on but so far didn't eve aproach the most important parameteres when it comes about amplifiers, and those are: - Max power that your power supply is capable of deliver. - Minimum DC power required by the amplifier module to reach desired output. - Maximum RF power that your transceiver/source is capable - MInimum RF power needed to achieve the desired output - Maximum input RF power to not destroy the module. - Total gain of the amplifier module (it helps on calculating/verifying the input required) Did you check that the amplifier was clipping (getting saturated)? Did you check the two amplifier stages transistors specs to check if they're capable of that configuration? For me it looks very much that you where not feeding enough power to the module (you won't get 3KW for free). And that's why you were alwas hitting the brick wall. Usually say an aplifier like the ACOM needs at least 100W to reach 2KW so, what I saw on the video is that the amplifier was performing so well for the amount of power that your transciever is capable of. Looking at the video, it seems you where looking for the problem where it wasn't. Also the seller didn't specify those parameteres, so of course you'll be lost if you're not expert.
It would be good to know the power supply output voltage and current to determine if the DC power input to the amp is correct. You said you paralleled two DC power supplies. If that is correct, then I would check the line voltage going to the power supply/supplies. The bottom line is the amp has to be using 60 plus amps at 50 VDC to get 3KW out. And with 89% efficiency, it would take closer to 67 amps. Just a thought.
I tested that board. I used 2 agilent signal generators, weinschel combiner then minicircuit amplifier that makes easy 2W with IMD better than 40dB. Output connected to bird 4391A and bird 5kw load. Sniffer placed inline for IMD output measurement feed into Agilent spectrum analyser. Power supply 50V with 60amp capable. The board flat tops at 1.1kW IMD at 1KW 18dB from tone or 24db pep. This board looks funny as I am building one 1.5kw and it requires much more ferrite material. Not sure what are theysugesting in corresponding E mail as they said my watter cooling is an issue and need fan for ferrite. Yes ferrite gets hot but 2 sec key should be ok for good performance without fan. This board is a piece of crap. Not worth spending any time on it.
Чтобы раскачать твой новый усилитель на его выходе до 2000W нужно ПОПРОБОВАТЬ на его вход подать более мощный высокочастотный сигнал из твоего фирменного трансивера с выходной мощностью от 100 до 200W и с более мощным антеннюатором на входе твоего нового усилителя с сопротивлением 50 Ом (что бы он не сгорел) ....
BBI was having the same problem until BBI did some mods on the tuning and cleaning it up to get rid of all the harmonics that it had and then it started working right. Here it is: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-acX2Bie5fEU.html
Okay well first off let me explain something to you that design of a board is 85% efficient, and each of those LDMOS devices are rated at 1200 watts at full power obviously of carrier due to the manufacturer it's one watt drive of carrier to yield 1200 watts of output power on the carrier so two of them should produce anywhere between $2,400 w of carrier with a two-watt drive. But having this type of board design which is 85% efficient you might get a couple hundred Watts less not much. And also you have to supply it with 50 volts and no minimum than 30 amp. And if you think that a bird want meter does not have to be calibrated you sir a sadly mistaken this is what I cannot stand about CBers they think that the bird want meter is a God actually it can go out of calibration with the minimal misuse.
By the way anything over about 2-volt excuse me 2 Watts is way too much power to drive that amplifier to watch will drive it way past its maximum power you might have even burned up the transistor
Sorry to hear that. The seller is absolutely conning people. I think I found the solution... it's a bit complicated. I'll make a video once I have it running solid.
It looks like there was little or only the 12v bias (GROUND WIRE)....... Where is the main GROUND? There is that big 50v VCC cable but I could not see it's other half there? GROUND wire was probably too small to pull that 3k and was maxing out at it's potential to ground..... Or did I miss something in the video? Also keeping in mind it's illegal here to use that much power for HAM radio and absolutely illegal for 11 meters. Non the less the amp should have worked...
Those blue caps are ceramic disc caps and aren't the cheapest China caps your thinking about lol I know the ones your thinking about lol lol....the ones you will see on the output of 4 pill circuits and such. Those Blue caps are actually very high quality but the problem is for some reason China picked the color blue for some of there cheap crap which sucks because that is my favorite color lol. Errrrrggggghhhhh china!!!
That is a 1:4 output transformer; with 50V supply and that transformation ratio, the theoretical limit is about 1.5kW into 50 ohm. It is absolutely impossible to achieve 3kW with that setup. Also, it looks like you are using the HP ESP120 PSU to power it; its output power is limited to 2950W. You need at least two of those to get 3kW output. Please don't use these on the air. Besides the obvious legality issue of using this level of power, it looks like 1. there is no output filtering present and 2 .(without trying to offend) you need a much deeper understanding of the circuit before radiating its signal for everyone to receive.
I think possible your 50 volt supply is not enough current if you look closely at his videos he uses two of those computer power supplies one for each transistor just thinking I have several of those boards they all have seemed to work well
The other guy's Bird slug is probably defective. How many different Watt meters did he try the amplifier boards on? I bet money the answer is "just the 1." Have him show you the 'scope voltage across his dummy load. BTW, why were you repeating the same information over and over, but not telling us how many amps the amplifier was drawing? Power is Volts times Amps, not just Volts. A good 50 Volt supply reads 50 Volts whether the amplifier is turned on or not. It's the Amps being delivered that tell you what power output to expect, some less (roughly 30 to 40% or so less,) than the DC input 'Volts * Amps'. And finally, the most fundamental and obvious question, what are the transistors rated for with that RF drive level at the frequency of interest? What's the manufacturer's specified 1 dB compression point power output? Did you bring up the drive level slowly and look for the 1 dB compression point? These are the simplest and most fundamental questions, and there was no mention of their answers.
it sounds like you are runing 10/11 meters which is fine i do not care but do you nder stand the difference the amp amp sees on 10 meters versus 40-80 or 160 its easier to make power down there period....next ok at 1500 watts you will be able to eat any thing attached to the coax pretty damn fast and it only get s worse the farther up you go my last amp was a henry 5k classic it had 2 3cx1200a7 tubes in it and would make 26-2700 watts with a hundred watts input and the amp was designed for 200 wats input but even at 1500 watts i was frying coax connectors coax swr meters hell it would even burn the wire in 2 if it brushed up against a branch on the tree when it was wet out and up on 10 you can look forward to melting gama matches and anthing else you have in the line of fire and 3000 watts aint just twice as bad its 15-20 times more prone to failures
If the AMP is for real 3KW output then I think you are having problems on output side don`t connect output with dummy can load which is normally filed with oil try connecting out to real antenna which exactly match with your operating frequency and with some thicker coax...dude its 3KW the coax wire seems to be very thin in my opinion the RF energy have not a proper path to exit Don't rely on SWR reading what ever it says try adjusting Antenna and output cable.If you are using Bird meter to check output power then connect output side of bird meter with real antenna with thicker coax.and as you know frequency must match your antenna.
RF man lives 5 miles from me and are loco Ducks try to buy one .they ask me to look in to it . 1st red flag Why don't you sell it ready to go then a kit . I will stay with terry aka bull-it amps
I purchase RF Man's amplifier baords on a regular basis. I have purchased more that 10 of his HF boards (dual and Single) and several of his VHF boards. They all work fine and as advertized. I think you should learn what you are doing before providing false information about his boards.
Camera phone to make videos????? Get a decent real camera. What's the output xfmr turns ratio???? The reason your amp doesn't work is that you don't seem to know much about RF amp engineering. You assume the source knows what they are doing. You assume the boards you are buying are plug and play. You assume the boards are designed correctly. You assume the seller is honest. Good luck. Again, what is the turns radio in the output xfmr???
Please do us all a favor and not use the language of the world while explaining the problems of the circuitry, PLEASE~!~ cursing is not going to solve anything but maybe chase off someone who might have the answer your needing. We are not all heathens as the world around us are. I would say find out why the other guys testing center gave a different reading than yours is doing. Well I know who does know what is wrong with it and can help you with it and that is Anthony Ray (Skull Cracker) and BBI, Luke. They can help you figure it out but it sounds to me that the input impedance resistance is too high for the device holding the input wattage too to low of attenuation in order to drive the device maybe? I hear LDMOS like more inductance than capacitance, just shooting ideas out there have no clue that is why I am watching you experiment on this stuff. You have a ton more equipment that I do to figure this stuff out. That's why I am here to learn this new technology to me. Just because your mad at something doesn't give you the right to put your anger out here into the public with terms used in a truck stop or Lumber mill. Tired of it. If it continues I will leave and I am sure I am not the only subscriber you will lose in the process.
