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
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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
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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
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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
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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...
Original parts of the KSG 1300 - before modification as a pure amateur amplifier:
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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
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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)
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(Part 2 - Electronics)
Status:
Project completed ![]()
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
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: http://www.communication-concepts.com/default.htm
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: http://www.qrpproject.de
The completed amplifier will have 3 stages and boosts 10mWin to solid 1200Wout! (50dB gain!)
! 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? ![]()
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
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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:
Step #125Another little tool of "Box73" is a portable battery-powered L/C-Analyzer - here are
some pictures ...
Status:
Project completed
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 ![]()
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).
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...
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Step #16
- Our new Electronic R&D Lab - just finished and ready to use...
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
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tbc soon ...
And again - any
input is highly appreciated! Just drop me an Email:
Andreas, DL6EAT