2kW Directional Coupler for LDMOS Amlifiers

this is a special development for my LDMOS amp. It does not need any metal case because the PCB planes are designed for 50 ohms impedance which makes it easy to build. It works from 0,1 to 52 (70) MHz and more than 2kW. Schematics and other documents are available on www.dj0abr.de

[@marklowe7431]

Hi, I just wanted to pass on my thanks to you for sharing so much of your work. Sharing this information on your web site in such a complete form is extremely helpful in the learning process. Thank you!

[@Factory400]

This is a slick design. Nice.

[@pritygupta1798]

Hello Sir very good video made by you. Have you tested this coupler for High Power RF which can handle more than 1.5KW CW up to 30MHz. Which PCB material used for this design,

[@Paul_VK3HN]

Excellent explanation!

[@wilbertvillenagonzales2854]

Great video!. It is quite easy to follow and understand. By the way, what do you mean when you say that the "PCB planes are designed fro 50 ohms impedance"?. Is this the width of the tracks?

[@harry4516]

thank you Wilbert. Yes, it is the width of the tracks, but its not that easy. There are many parameters influencing the impedance, so most of the layout was done by measurement and try and error, until the frequency range was flat from 0,5 to 50 MHz.

[@Officinadoradio]

Hi. For me to have a full TX at 2.420Kilohertz with 2Kw, could you help me?

[@sogosogo834]

Sir, what is directivity in dB? Is this SWR in dB?

[@wesleymatthews137]

I don’t see the schematic on the English version of your website. Did I miss it?

[@sivaapparao2978]

sir how to know core value and winding turns for a particular frequency plz tell me sir

[@harry4516]

Siva, Amidon 43 material is perfect for 1.8 to 30 MHz and useable for 500kc to 50 MHz. For lower bands you can use Amidon 73. Winding turns depend a lot on circuit and layout and must be tested by try and error. vy 73.

[@ua9lhu1]

Hello, are the capacitors c1,c2,c5,c6 10uF or 10nF ?

[@ssmbssmbssmb]

Hello, is your pcb pattern free to download, if so where to download please ? I just want the directional coupler pattern. Thanks

[@AbdulMalik-in3cl]

ITS very good desind Can I get this PCB and how much will it cost if plus components de yb2bam

[@harry4516]

you can get this board from [e-mail] , please contact him

[@mehmetrasidogunc260]

Excellent video Tnx for understand setep by step. I like your videos so much. What is your Solder machine name model ? its very tiny 73' de ta4au

[@harry4516]

Thank you Mehmet ! This is the complete kit: www.helitron.de/shop/product_info.php?products_id=105 All SMD soldered, just the coils have to be wound and mounted.

[@harry4516]

is is Model: C.I.F FT-02

[@TheSKYNET83]

This device automatically switches the antenna from the transceiver (receiving) to the amplifier (transmitting)?

[@TheErilaz]

NO.

[@falsedragon33]

You are looking for a sequencer.

[@TheErilaz]

Can you construct a ATU with these values: the capacitor range should be 15pF - 8000pF, in good enough increments. The inductors should be 0.2 to 20 uH. A high pass "Tee" network is fine for 160m up to and including 10 meters. For 6m a low pass"Pi" network with the capacitor range of 20 to 400 pF, and inductor values from 0.05 to 1uH gives the best range. I think that the ATU will be able to handle up to 1:20 SWR mismatch with those values, that's a bit insane. A more reasonable value is 1:5. At 1500W RF power a 1:10 mismatch, the current and voltages will be 1225Volts, the maximum Irms will be 17.3 Amps. At a 1:20 mismatch and the same power, the voltage will be 1700 volts, and maximum Irms 24.5 Ampere. It should use a heuristic algorithm called neighbor searching algorithm,for really fast tuning.

[@harry4516]

Erilen, this may be a future extension of my current ATU. I am running a 120m long horizontal loop, fed by a symmetrical remote controlled 1,5kW tuner. It comes very close to your values, and will be upgraded this summer. There is no english translation, but you can use google translator to view this page: dj0abr.de/german/technik/tuner/tuner.htm My plans for this year are to extend this tuner with a lower C and L network and to make an auto tuning software (currently its manually). I am also experimenting with a stepper motor controlled C in the range of 5 to 50pF for the very low values, so switching higher values by relais and then fine tuning with the motor. If there are some news I will do a separate video.

[@TheErilaz]

@@harry4516 Super!

[@rogeronslow1498]

Why do you need the log amps?

[@harry4516]

Hi Roger, the output signal of the AD8307 follows the dBm value of the input. This makes calibration very easy and give a wide operating range.

[@lynwoodwilson6274]

Are you selling any pallets?

[@harry4516]

no sorry, but all my project are totally free. If somebody wants to use it for own products, feel free to do it, under GPL V.3

[@JamesCutlervk2tim]

Whats an "Amlifier"?

[@mehmetrasidogunc260]

www.helitron.de/shop/product_info.php?products_id=104&MODsid=tikqeaajccbsgu2b46o2sma06pgt1s5jc9oma73n5j6dartad4s0 This kit is not mounted board but inside all parts or only board price ?

[@harry4516]

the kits is SMD mounted, all other parts are inside the kit.