A 600W broadband HF/6m amplifier using affordable LDMOS devices

A 600W broadband HF/6m amplifier using affordable LDMOS devices - 2x MRF300 @ 48V

Рет қаралды 67,320

4 жыл бұрын

600W HF/6m linear amplifier using rugged MRF300 transistors - NXP Homebrew RF Design Challenge entry.
Home page for the project: qrpblog.com/a6...
A few performance figures for the A600:
- coverage from 1.8MHz to 54MHz and more
- P1dB output power between 580W and 750W depending on band
- over 20dB large signal gain, flatness around 1dB
- high efficiency (min 57%, max 73% at P1dB depending on band)
- stable clean bias with thermal tracking
- power supply: 48V, 18A typical, 20A max
- advanced thermal design using a liquid metal alloy and copper heat spreader
- multiple onboard sensors accesibile via the diagnostic header provide measurements for PA supply voltage, PA instantaneous current draw, heatsink temperature, output power and output mismatch
- bias voltage can be disabled via a control line, to save power when not transmitting
- onboard connectors for separate low pass filter bank
- compact size 190x100x80mm (including heatsink but excluding fans)
PCBs were manufactured by PCBway. Have a look, as they offer excellent service: www.pcbway.com/

Пікірлер: 94

@uprogc Жыл бұрын

The PA IMD must be measured with two tone (clean) signal, not with one tone.

@machinetoolswarehouse 11 ай бұрын

Nice work!. I have used PCBway in the past as well. I was very happy with their service.

@g0fvt Жыл бұрын

Very nice project, well done, the MRF300 is a very inexpensive way to make that level of RF.

@brentcrier8570 4 жыл бұрын

Very nice project. Looking forward to the kit.

@africanelectron751 4 жыл бұрын

In the name of all that is good tell me I can buy this as a kit.....

@mx1209 5 ай бұрын

Yes, ebay

@marklowe7431 3 жыл бұрын

Absolutely talented.

@alsanderson4917 Жыл бұрын

Beautiful amp.

@RickGreenPhoto 4 жыл бұрын

Please sell this a s a kit! It looks like fun to build, Great work.

@JamesCutlervk2tim 3 жыл бұрын

Arnold Schwarenegger making linear amplifiers.....awesome!

@chronobot2001 Жыл бұрын

Nice amp. You are obviously a master of engineering. I aspire to a higher level of skill, but I am no where near your level. Bravo.

@kevinkang4308 4 жыл бұрын

Nice looking PA, hope you can provide PCB or kit

@aga5897 7 ай бұрын

Nice ! Looks a lot like the outstanding Motorola EB104 from 1993 by Helge O Granberg ;)

@k1zmt 4 жыл бұрын

I am surprised that SMA connectors are capable to withstand 600W load. The PA is really cool! Very neat design!

@johnc3403 4 жыл бұрын

Me too, but i found this spec online for a high quality SMA connector: Max 150W CW @ 27GHz @ 160deg ...now, If that's the case, It could probably handle 600W at HF relatively comfortably. It's surprised me tbh. I wouldn't have guessed any higher than 50-60W max myself ..but we live and learn.

@reedreamer9518 2 жыл бұрын

I like it!

@bloguetronica 4 жыл бұрын

Great design!

@YO2MSB 4 жыл бұрын

Excelent proiect Razvane, daca te apuci sa "produci" asa ceva sunt si eu interesat. Este exact tipul de amplificator LDMOS care lipseste de pe piata, toti producatorii se orienteaza spre puteri crocodilistice de minim 800-1000W. Eu zic ca sunt multi cei pentru care 4-600W sunt arhisuficienti si optiunile sunt extrem de putine, practic ne limitam la RM Italy. Succes cu acest proiect! 73 es GL de YO2MSB Bizzu

@Qrpblog 4 жыл бұрын

Multumesc Sorin ! Te tin la curent cu evolutia ;)

@BD4CB Жыл бұрын

GOOD JOB

@de_w8tam 4 жыл бұрын

What a great looking project! Will you be offering kits or more details for others to build it? Thanks! 73 de w8tam

@YO2DA 4 жыл бұрын

Foarte frumos si interesant.Felicitari!

@HB9GZE 2 жыл бұрын

Very nice project! Congrats. I am using the smaller brother of your LDMOS FETs the MRF101 and I would like to simulate my circuit in LTSpice. Do you have a Spice Model for your MRFs? Any idea where I could find one? I asked NXP and they do not provide one they said (have their own simulation tools).

@GBHoyt 4 жыл бұрын

Since you're only -45dB at the 3rd, do you have plans for a switchable band specific LPF? Thanks for posting!

@k2icc 3 жыл бұрын

Any literature and part numbers to build one? 73

@Raj72544 4 жыл бұрын

Congrats Razvan, great work and video! - vu2zap

@TheArtofEngineering Ай бұрын

Well done, a lot of work and looks like it was well worth it! 73 de VK2AOE

@pa3vos 4 жыл бұрын

Nice project. Do you have the Gerber-files available so I can order the PCB?

@liaowei1234 3 жыл бұрын

You promised to send back my two A600 boards in January, where are they now?

@sreekumarg Жыл бұрын

Hi ... Can I get the Gerber file ? Regads

@massimages 4 жыл бұрын

Great project Razvan! 73 de Bob AB2NE/G3ZFJ

@youtubeaccount931 3 ай бұрын

Nice!

@doceave 3 жыл бұрын

Hi there Razvan --- I have built your V2 kit and it has all worked well until I upgraded my cooling and reassembled. When I increase the DC supply to the A600 above 12V a 150-160MHz waveform can be seen at the input and output. Perhaps I damaged a component / got thermal compound residue on the PCB in a critical place? Would you kindly give me a clue as to where to begin troubleshooting this? Thanks.

@petrsuchomel9639 2 жыл бұрын

Probably parasitic oscillation. Check the feedback. I had similar problem with MRF300's (my own brew)

@Isochest 10 ай бұрын

@@petrsuchomel9639It sounds like parasitic oscillation.

@nbookie Жыл бұрын

This is what Arnold does in retirement?

@abbyck 10 ай бұрын

Lol

@nicolaebostan7971 4 жыл бұрын

Razvan buna. Sunt incintat fii amabil da-mi te rog un mod de contact er1zz. Bravo, mersi.

@vne2328 3 жыл бұрын

Amazing voice and nice amp!

@johncundiss9098 2 жыл бұрын

Question. What heat sink compound did you use? did you solder the transistors to the heat spreader?

@yuraws 4 жыл бұрын

Where can I find PCB layout? 73!

@a.v.stechs9398 Жыл бұрын

Can I use with hand hold walkie talkie

@vu3mes 2 жыл бұрын

Are you making these AMPS commercially?

@JohnUsp 2 жыл бұрын

Just the MRF300AN & MRF300BN transistors cost more than $120!!!

@mrtechie6810 8 ай бұрын

@@JohnUsp So? That is an ok price for this level of power. I would like to build a 250 watt version.

@tvnteleviziuneaneamt6409 4 жыл бұрын

Buna Razvan. Sunt incantat sa vad ca in RO se mai gasesc pasionati de Ham Radio Construct!!! Ma intereseaza si pe mine un amplificator asemanator celui prezentat de tine. Un pret estimativ te rog. Zi faina

@sanli5561 4 жыл бұрын

Razvan +++ молодец, Вам надо отдать 1 место! не то что занявший 1 место, с рисованным мультфильмом американец.

@mrtechie6810 8 ай бұрын

Would love a 300 watt version!

@ramsin. 8 ай бұрын

Lower your input?

@aga5897 7 ай бұрын

@@ramsin. Doesn't work that way from 0 to Max. Those output transformers are calculated to match the transistors' Drain impedance up to 50 Ohms. At half power, the drain impedance is way off so the transformers don't work properly.

@ramsin. 7 ай бұрын

Interesting, good to know. So basically the amp *has* to be pushed to 600w...

@aga5897 7 ай бұрын

@@ramsin. You can reduce/increase a small amount, e.g. 450W, but it will be less efficient, so the transistors will heat up too much.

@wisehomo 7 ай бұрын

@@aga5897 I don't believe what you are saying. Impedance is unaffected by power input!!! It is only affected by frequency and it's an intrinsic characteristic of the transistor that is only dependent on frequency and very little to temperature! So reducing input power will absolutely make the transistor even last longer as they are barely pushed to their limits. Please stop telling people things you don't understand!

@Aleziss 3 жыл бұрын

so no low pass filter board is needed ?? do you happend to have the controler board also ?

@MrTalaue 2 жыл бұрын

Why do you think that?

@Aleziss 2 жыл бұрын

@@MrTalaue uhm... because I did not heard him talk about low pass filters... that's why...

@MrTalaue 2 жыл бұрын

@@Aleziss He did not talk about a T/R switch or a cabinet either.

@Aleziss 2 жыл бұрын

So... As he did not talk about any of those things either... Does it need a low pass filter?

@MrTalaue 2 жыл бұрын

@@AlezissDepends on the regulations in your country. In Germany -40dB are required and that linear is 5dB better.

@nicolalamotta9554 3 жыл бұрын

hi can you tell me where i can find the arduino codes for the lcd sreen?

@garyheald4704 2 ай бұрын

I know that your comment was a few years ago but I was about to ask the same question (and what the board is). I’m currently building a 300W 144 MHz PA and would like to display various info!

@shopcubebikeparis3417 2 жыл бұрын

FB do you have the version with 4 MRF300 1KW? BEST 73

@simonkirby5724 Жыл бұрын

What is the 12v bias amp needed?

@letitrotfuckit 4 жыл бұрын

where can i buy it?

@HighlanderMcLeod Жыл бұрын

Hello! UB3AXZ is here :) 73!

@prizeking1647 4 жыл бұрын

Is the power 300 watts on fm ?

@mrtechie6810 8 ай бұрын

I happen to have a 48V power supply (UPS / battery - 45-58V). How would I change the design to produce 250 watts out?

@BarsMonster 8 ай бұрын

Reduce input power?

@mrtechie6810 8 ай бұрын

@@BarsMonsterok, but would a 300 watt design be cheaper to build and more efficient to run? Perhaps using one MRF300?

@aga5897 7 ай бұрын

@@mrtechie6810 If it's for One band only, e.g. for CB use, check out the MRF300 data sheet. It has several one-band designs using 1 transistor, giving 300W output. One is for 27MHz. The board is 2" x 3" in size. Really cool.

@wisehomo 7 ай бұрын

@@mrtechie6810 Yes one transistor is sufficient but it is not going to be broad band! so it will work only for a small range of frequency. not what he is sharing in his video. in his case he is using transformers to balance spread the input to matched transistors so that the input signal is split and the power in two signals of same power (half the input) and opposite in phase. since both transistors are active in opposite phase this results in both transistors active simultaneously and in phase producing twice power of each 300watts approximately. my guess you can keep his exact same design and just eliminate one of the transistors. you'll get half the power but you are basically using only half the input power as the input transformers are dividing the power by half at each gate of the transistors.

@jameshansen3984 2 ай бұрын

@@mrtechie6810 You could use two MRF150 devices, but you will have to redo the output transformer for proper impedance matching.

@Davidsmith218 2 жыл бұрын

Has anyone tried a irf250 or have any information about a amp using this transistor I see some videos but not a lot of info

@aga5897 7 ай бұрын

IRFP250N works OK on 40m (7MHz) but cannot hack it on higher frequencies. It's a high-power switch, not designed for RF. Best i found is the IRF510. Lower power but gets up to 24MHz (just)