Looks great! Nice work!

A textbook perfect example demonstrating the performance of this incredibly high quality of RF engineering. Congratulations on a job well done.

Very cool videos. What an awesome piece of equipment.

Very nice job! Congrats , Z31MA 73

A very nice job sir. Well done!

real cool and perfect work i wish to do so........congratulation !

Excellent work

I'm impressed, an amplifier without stupid noise of that FAN. You have nice equipment my friend and the part you solder the transistors on the board with your cooking plate is very funny.

@harry4516

5 жыл бұрын

thank you so much for your compliments !

It's a very beautiful job. Respect from RUSSIA.RA3ASA. 73!!!

It was easier for me to buy an LDMOS 1kW amp! Good work! Very interesting video!

Hi, nice job! What probe did you use to measure the almost 700 vpp?

Like how you used your oscilloscope. Do you have a video showing how you did your measurements? Thank you in advance. 73s

Nice

Hello! Which value of external attenuator you are using? Onboard attenuator is 4dB.

what a great work!!! congratulations. Grüsse aus Brasilien. 73 de Eger PY2EX

How much do the 50v HP computer power supplys go fir?

put water supply under the PC board just in case you have water leakage it will not damage the board.

Any kits supply in the market?

What is the insertion loss of the LPF??

top d++++ maravilha esse seu projetor como faço para ter uma dessa aqui?

I am impress with his amplifier. I tried simulation test of your amplifier. I got impressive results. Are you from MIT? Very nice amplifier

@harry4516

5 жыл бұрын

thank you ! I'm a radio amateur from Germany doing all these things just for fun.

Tolles Video! Sag mir, kann ich ein Netzteil mit einer Spannung von 53,7 Volt verwenden?

@harry4516

6 жыл бұрын

ja, das kannst du, wenn du die neuen 65V LDMOS Transistoren verwendest. Mit den BLF188XR gehen max 50V.

@fnordist

5 жыл бұрын

2x50 Ampere Dioden in Serie.

Nice work! You have really great attention to details. I like your work. How much did it cost you to buy all the equipment for smd placement machine and soldering? Friend from Tunisia.

@unclequack5445

2 жыл бұрын

I promise you that placement machine was not cheap like he says he has some nice equipment.

Please tell me your offering these for sale I am upgrading to my General class next month and this would be just the ticket for my shack but between my poor eyesight and lack of skill building this is probably way above my abilities.

@harry4516

6 жыл бұрын

this should not be your first project. It's not too complicated, but runs a lot of power which could do bad things if something goes wrong. Maybe OMs in your local club can help.

@OG_Gamers_Live

6 жыл бұрын

not around here, back in the 11 meter days I worked on a lot of simpler amps even a few tube types but this is way beyond my abilities. I'll probably end up buying an Ameritron AL-80 in the next year or so

how much does it cost to make all of these things?

Wasserkühlung ist schon super, aber was nützt das, wenn das 50V Netzteil einen Lüfter hat.

Hi a little question what is the current of rest for a blf 188 xr for optimum operation with a power supply of 50 v I know you mounted several of these transistor I thought between 1.5 amperes has 2 amperes but I'm not very sure See you soon 73

@harry4516

6 жыл бұрын

2 amps is ok, but it is not critical. Works with 1.5 as well.

@darknessninja13

6 жыл бұрын

many thanks vy 73 F5MAG facebook.com/groups/f5mag/?ref=bookmarks

Ich bin sehr an Ihrem Brennstoff interessiert, Wie können Sie kontaktiert werden?

Very nice job! But I was wondering about the output transistors replacement, in your next project they would be attached to the heatsink using screws, not soldered directly to the copper block. Bets regards!

@harry4516

6 жыл бұрын

Hi Claudio, thank you. I always solder the transistors to the heat sink. Transferring a kilowatt need the best possible thermal contact. I don't know if that would work with screws and thermal paste. Has anybody tried this already ?

@normanweiz2646

3 жыл бұрын

@@harry4516 My preferred way is to solder the transistors to the heat sink but I have six commercial Nautel FM 30KW and one 50KW transmitter with 4 PA to one RF Module and none of the transistors are soldered. They are screwed done. I was surprised when I replaced a PA because of lightning. So I think you can screw them down like the commercial transmitters made here in Canada have them all screwed down and no copper spreaders. If you interested I will send you pictures the next time I work on the PA's again. Also just to mention. I have noticed that everyone makes their board in two pieces. I have always wondered why two. The Nautel PA board is just one board with a rectangular hole made for the LDMOS. Anyway excellent work on your Amp. You have set a great example to follow. Keep up the good work. I have seen so many on the internet and if I were to build one, yours would be the one to follow. Cheers...

@normanweiz2646

3 жыл бұрын

@@harry4516 I forgot to mention that each of the PA's were 1.25KW and used thermal paste. Cheers...

Hello Harry, I this a kit you sell? Thanks!

@harry4516

6 жыл бұрын

the PCBs are available at www.helitron.de

Cool enclosure, where did you get that?

@harry4516

6 жыл бұрын

this is a 4HE rack mount enclosure from Schroff

@ManofCulture

6 жыл бұрын

Harry May Ohhh, thanks :D

Das sieht wirklich sehr professionell aus. Was ist das für ein Gehäuse? 73 Till

@harry4516

6 жыл бұрын

Danke Till, das ist ein 4HE Gehäuse von Schroff, gekauft bei rs-online. Ist nicht ganz billig. Inzwischen haben wir selbst eines gebaut aus Edelstahl, zu sehen im letzten Drittel dieses Videos: kzread.info/dash/bejne/fGuVqqSzXduphc4.html . DL1EV baut diese Gehäuse, im Moment nur für unseren OV U02, mal sehen ob er Lust hat auch mehr davon zu machen.

@tillreckers8047

6 жыл бұрын

Hallo Harry, ich habe mir schon gedacht das es von Schroff ist. Die Verarbeitung von deren Gehäusen ist aber auch wirklich sehr gut, das kostet halt ein wenig. Habe das Edelstahl-Gehäuse aus Deinem anderen Video schon bewundert. Ist wirklich sehr gut gelungen. Hab gleich mal ein Abo da gelassen ;)

Ausgezeichnet.

For my vhf 2meter band

what is the total cost of this unit????

@harry4516

6 жыл бұрын

the cost of the prototype (just material) was about 1000 €

@mohammedbuti8707

6 жыл бұрын

Harry May nice are still making them and selling them ?

Why are you only able to get 1kw with two blf188xr pallets!! Other guys are able to get 2400watts easily without overdriving the transistors! Is there a reason why you made it so low compared to what you can get?

@harry4516

6 жыл бұрын

yes, hi, there is a reason. The other guys doing wrong measurements. The power is not a matter of the number of transistors. The power comes from the transformation ratio of the output transformers and the supply voltage. So, if you use two instead of one transistor, the power will increase a little bit because of lower losses. But the ohms law allows the 1kW, not much more. What other guys are doing, they measure the power without any filtering, so measure i.e. the massiv 3rd harmonics. This will corrupt almost every measurement instrument. A better method of power measurement is to connect a 50 ohm dummy load and use an oscilloscope to measure the voltage on 50 ohms.

@peakaboozen

5 жыл бұрын

Clean is mean! People go crazy for more watts. The correct way to get more output power is to have more amplifier.

PSE send me your email thanks