Again, a warm "Welcome!"

     A first idea became a plan and later a first concept:  A 1 KW HF Solid State PA based on two KSG 1300 Modules (bipolar transistors),

       fully completed in a single box with all necessary add-on circuits, Power-Supplies, Low-Pass-Filters and Cooling. These 4xBLW95 based

       modules are sometimes available on flee-markets - the principals of how combining them and how to secure them can be easily converted to

       similar other projects & concepts. Later newer concepts followed - nowadays all MOS FET based...


                                             QTH of  DL6EAT with OB9-5 on 70-foot tower near Hamburg: 


                       "Takeoff Direction North"... Picture shows Crank-Up-Tower "fully down", height is just 35 foot now: 



       So far so good - Here are some of my different concepts of the last couple years:


                   Step #1 The first Sample has been completed back in 2006/7. This Hagenuk Module based Amp. was

                   performing well but produced only 500W of RF.                 Status: Project completed   PA #1

                In May 2009 this amplifier got renewed - it got modified by a newly designed front panel. Also an

                   integrated Icom TRX-Interface for auto-band-switching and new final transistors were implemented.

                   Have a look: The update was worth it...                               Status: Project completed   After Mods!


                   Step #2 The second device has been completed in July 2008. This 1KW Amp. was running very well

                   over months intensively testing with no problems.               Status: Project completed   PA #2


                   Step #3 Some words about the KSG 1300 Amplifier Modules. They are a bit unusual - at least when

                   looking to In- and Output Values as well as to Gain vs. frequency. Its worth doing pre-measurements to

                   avoid surprises later´.                                                         Status: Project completed    KSG Modules


                   Step #4 Here are some picture about a set of two KSG1300s. Each one can run alone and independent

                   or both in parallel. Very reliable since I'm using professional "EATON" Power Supplies...       

                                                                                                             Status: Project completed    KSG 1300  

                   Original parts of the KSG 1300 - before modification as a pure amateur amplifier:       Parts of KSG


                   Step #5 And here (even when this is a different concept) is the legendary LV 6 (my last tube based Amp.)

                   This amplifier uses 3 tubes (2 drivers in parallel) and one final (GU43b) and offers sweet 50dB gain!

                   (16 mWin -> 1,6 KWout)                                                    Status: Project completed    LV 6


                   Step #6 Now with built-in 1KW tuner. This one is as simple to operate as even possible - including

                   Icom Auto Mode. It offers a symmetrical output to feed ladder lines directly. The basic technology

                   is based on BLW95-Bipolars.         (Part 1 - Mechanics)                                                 Customized 1

                                                                             (Part 2 - Electronics)     Status: Project completed    Customized 2


                   Step #7 - also with built-in LDG High Power Tuner (Pro Version 1KW). This project is on the way -

                   to get this completed may take a little while... As always in life: The second should be always better!

                   This PA will be based on MOS FETs (MRF154s) ... described in Step #9                   

                                                                                             Status: Project pending    My new one...


                Step #8 - This next Power MOS FET Project is based on 2 modules á 4 x MRF150 = 8 in total - all based

                   on "Helge Granberg's" Motorola-Evaluation "EB-104". The plan is to move from bipolar to MOS FETs.

                   EB104-sets can be ordered from Com.Concepts:

                   This very compact 1200W-design uses 50V @ 45A+, has 2400W total dissipation, offers much higher gain

                   and better IM3 & IM5. The concept shown here is also using the latest & newest MOS FET driver design

                   of QRPproject, Berlin. (30 dB gain, 10mWin, 10Wout) Info available here:

                   The completed amplifier will have 3 stages and boosts 10mWin to solid 1200Wout! (50dB gain!)

                                                                                                Status: Project completed   MOS FET PA 1   


! This one got updated last! 

                Step #9 - The enemy of "good" is simply "better": Motorola's AR347 is a MOS FET Amplifier based on

                   just 2 powerful MRF 154s (or MRF157s). These semiconductors are pretty expensive, but there's no need

                   to combine modules, no need for 8 matched MRF´150s. Output is a solid 1200W of RF...Of course not

                   cheap but probably "Simply the best":  Including 50 MHz, gain is up to 20dB+.   

                                                                   Why using the MRF154 and MRF157?                          The Decision

                                                                                                              Status: Project completed   MOS FET PA 2

                                                                                                                    Status: Under R&D   "The Project!"

                   Step #105Here are some pictures of a 100W / 200W-dummy with -40dB Output of "Funkamateur".

                   This useful toy can be ordered for 67,- €...                         Status: Project completed   200W Dummy


                   Step #115Another valued tool of "Funkamateur" (Box73) : The Network-Tester! This is available from

                   just 199,- €. This offers 2 input channels, 160 MHz Bandwidth, 400MHz clock and has an USB-Port!

                   This is a clear "must" for any serious developing. There is another good and cheap tool: The Spectrum   

                   Analyzer with an additional programmable stepping attenuator and a second reflexion head. The whole

                   tool is available for around 700,- Euro - all in a nice new alu-enclosure. BTW, the whole kit is controlled

                   by your PC (via USB-Port).  Click here and see more: 

                                                                                                          Status:   Project completed     NW-Tester

                                                                                                                                                     Project completed      Spec-Analyz. 

                                                                                                                                                    Project completed      NWT "Plus" 


   Step #125Another little tool of "Box73" is a portable battery-powered L/C-Analyzer - here are

                   some pictures ...                                                                  Status: Project completed  L/C-Tester 


                   Step #135Another little tool is this 2-tone-Generator - ideal for IM tests of transceivers and amplifiers.

                   Tones are 866Hz and 1080Hz...level is adjustable.               Status: Project completed  2 Tone Gen.


                Step #14 - All of these solid-state PA-designs need to have Low Pass Filter Units in order cutting off

                   Harmonics. In this step you find some help/pictures about the design of a LP-Filters. Its planned to

                   create a 2KW-unit. If necessary two or more High Power PAs can be combined right after their LPFs.

                   Of course you would need to have more filters instead of just one. The main reason is the limited

                   availability of high power RF parts (mainly capacitors).    

                                                                                                                Status: Under R&D          LP Filters


                   Step #15 - The Titanex Logarithmic Periodic Beam at Michael's (DL3HCC) location in Neuhaus, Oste.

                   This was quite an experience! It took us 4 full days to get it completed and up on the tower - but it is

                   running and performing like perfect. This is a very sweet design...                                Log Periodic


                        Step #16 - Our new Electronic R&D Lab - just finished and ready to use...                   New R&D Lab


                       Step #17 - According some very good ideas of "Andreas, DL5CN"  I started to do some R&D on S570-

                   based synthesizers. The plan is building a fully programmable 2-tone exciter for power amplifier tests

                   with at least 10W RF from 3,5 MHz to 160 MHz with >=45dBc IM3 and no modulator. How is that

                   possible? Have a closer look:                                           Status: under development    USB-Synth. 1

                                                                                                                                                                     tbc soon ...    USB-Synth. 2                  


        And again - any input is highly appreciated! Just drop me an Email:                                                                                                        

         Andreas, DL6EAT  


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