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

[@machinetoolswarehouse]

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

[@brentcrier8570]

Very nice project. Looking forward to the kit.

[@uprogc]

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

[@africanelectron751]

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

[@mx1209]

Yes, ebay

[@g0fvt]

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

[@marklowe7431]

Absolutely talented.

[@alsanderson4917]

Beautiful amp.

[@kevinkang4308]

Nice looking PA, hope you can provide PCB or kit

[@k2icc]

Any literature and part numbers to build one? 73

[@de_w8tam]

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

[@sreekumarg]

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

[@chronobot2001]

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.

[@JamesCutlervk2tim]

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

[@HB9GZE]

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).

[@reedreamer9518]

I like it!

[@SHTFchef]

I'm wonder about the sma connector. Does that truly handle 600 watts?

[@fredwester5705]

radiall version....450watts @ 1 Ghz...

[@soerkrampf]

Hello, is the Arduino control ready? I can't find it. Can an Arduino be connected directly to the B1500 RF AMPLIFIER BACKPANEL UNIT KIT? vy73

[@GBHoyt]

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

[@doceave]

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]

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

[@Isochest]

​@@petrsuchomel9639It sounds like parasitic oscillation.

[@k1zmt]

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

[@johnc3403]

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.

[@pa3vos]

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

[@liaowei1234]

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

[@BD4CB]

GOOD JOB

[@HamRomania]

Foarte frumos si interesant.Felicitari!

[@bloguetronica]

Great design!

[@YO2MSB]

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]

Multumesc Sorin ! Te tin la curent cu evolutia ;)

[@a.v.stechs9398]

Can I use with hand hold walkie talkie

[@Aleziss]

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

[@MrTalaue]

Why do you think that?

[@Aleziss]

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

[@MrTalaue]

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

[@Aleziss]

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

[@MrTalaue]

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

[@nicolalamotta9554]

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

[@garyheald4704]

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!

[@yuraws]

Where can I find PCB layout? 73!

[@Raj72544]

Congrats Razvan, great work and video! - vu2zap

[@aga5897]

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

[@mrtechie6810]

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

[@BarsMonster]

Reduce input power?

[@mrtechie6810]

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

[@aga5897]

@@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]

@@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]

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

[@Davidsmith218]

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]

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)

[@simonkirby5724]

What is the 12v bias amp needed?

[@johncundiss9098]

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

[@tvnteleviziuneaneamt6409]

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

[@shopcubebikeparis3417]

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

[@prizeking1647]

Is the power 300 watts on fm ?

[@vu3mes]

Are you making these AMPS commercially?

[@JohnUsp]

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

[@mrtechie6810]

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

[@nbookie]

This is what Arnold does in retirement?

[@abbyck]

Lol

[@youtubeaccount931]

Nice!

[@nicolaebostan7971]

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

[@mrtechie6810]

Would love a 300 watt version!

[@ramsin.]

Lower your input?

[@aga5897]

@@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.]

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

[@aga5897]

@@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]

@@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!

[@Mark-PY2NA]

where to buy toroids?

[@CharlesJackson-w5w]

Schowalter Avenue

[@mohamedlanjri]

Is the output of the amplifier an SMA connector?🤭

[@mrtechie6810]

No, the output is RF energy. 😊

[@aga5897]

@@mrtechie6810 Hahaha.

[@TheArtofEngineering]

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

[@vne2328]

Amazing voice and nice amp!

[@RichardAugle-x3y]

Johnston Avenue

[@massimages]

Great project Razvan! 73 de Bob AB2NE/G3ZFJ

[@NoelRock-f4y]

Bertrand Light

[@EddieNelly-x1v]

McLaughlin Hollow

[@FelixZoe-y8t]

Kerluke Stravenue

[@RobertWinston-y1e]

Alfred Shores

[@JonahCornell-g2w]

Romaguera Canyon

[@GabrielEvan-q3n]

Pink Lock

[@DollyNicholas-x6n]

Johnston Mission

[@TelstarElectronics]

How many devices did you lose in your development?

[@johnc3403]

He lost a whole lot less than I would that's for sure.

[@ChristyVivian-i9f]

Ulices Glens

[@JillWeldon-e7i]

O'Keefe Fields

[@ClementBorcher-c9p]

Norene Falls

[@JenniferMcIver-k5f]

Cordelia Crossroad

[@NellHugo-m3c]

Dickinson Cliff

[@DeweyVenus-e2p]

Leland Isle

[@Q-RULZ]

Dumb newbie here - I don't see a control head. Ow do we control this and do I need a separate antenna tuner or is that built in?

[@RichardTiggs-f4o]

Jonathon Circle

[@NeedhamYetta-f1g]

Sister Mission

[@FwzfrsfBtcbyrdh-b4h]

Rodriguez Circles

[@LarkinAurora-h9i]

Kennith Tunnel

[@NewmanMona-v4t]

Duncan Fork

[@LonTrevizo-g6t]

Ankunding Forges

[@NicoleKelly-q7k]

Tillman Wall

[@ConnieTweden-g6t]

Emmerich Tunnel

[@CarolineLouise-i2o]

Farrell Village

[@KarenLopez-g6s]

Juana Harbor

[@RebekahRosenfeld-x6q]

Florine Road

[@JimLawson-j8f]

Tomasa Canyon

[@LawAttlee-v1b]

Schiller Rest

[@Yuri7287]

Yuri Mudryk UT5UMQ

[@StewartHusni-k4f]

Sid Grove

[@JoanneGiguere-r9w]

Mable Mountains

[@DeborahWashington-n6u]

Fidel Springs

[@GreshamAddison-x4n]

Myrtle Roads

[@BarneyPrudence-s6d]

Predovic Valley

[@BloorJessica-m3j]

Olson Track

[@SmithNorman-l6e]

Shanahan Mountain

[@sanli5561]

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

[@LonnyCouley-d2p]

Skiles Crossing

[@KarenMehta-k8o]

Levi Port

[@SpencerLena-p9q]

Arne Village

[@JerryNelson-i1x]

Gerhold Pike

[@CorazonMinton-e9o]

Kiara Extension

[@FrederickRussell-q8z]

Narciso Summit

[@MaryNorman-u7p]

Rowe Hills

[@HighlanderMcLeod]

Hello! UB3AXZ is here :) 73!

[@JacekSiemer-l1w]

Pfannerstill Lodge

[@EvelineSabedra-e4c]

Walsh Expressway

[@KevserCandan-c1t]

Damaris Mission

[@SteinbeckGuy-p1j]

Sammy Tunnel