A very high power solid state linear amplifier board
3 ++ kw OUTPUT
This board is designed for four LDMOS-FET's BLF188XR operating in a push-pull circuit.
also the MRF6VP12k and the new MRF15k50
These boards are the result of a long R&D and many experiments into
LDMOS FET high power linear amplifiers.and using 4 devices was not a simple design task.
each node in the PP circuit uses 2 devices so
having 4 devices with 1200-1400 output each makes this board loaf at 2.5-3 kw out! without real strain on devices
I have revised my design many times (with failures too) to improve matching and IMD figures.
The board features a high power transmission line transformer wound on stacked ferrite toroids.
For lower IMD, lower saturation ( see ON9CVD research
[link removed by eBay] ) .
and higher power output
in a push-pull circuit.
The dual sided . PCB is plated. and is 14 cm x 27 cm in size.
All critical RF capacitors are ATC and silver tabs rf caps from Murata for best rf performance.
Efficient feedback circuitry ensures stable clean broadband operation.
Operating voltage: 42--50V
Imax up to 125A \
Bias is regulated on-board and thermally compensated. Thermal tracking of bias is also provided on board.
This is a populated board but without the active LDMOS devices. "you install your own". The board is supplied ready for your devices to be “dropped in”.
All instructions and schematics are supplied and to answer your questions I will be standing-by with e-mail and Skype support.
These are very high power boards !!!!
The board has enough "headroom" to cover up most minor operating mistakes.
The LDMOS devices with the "XR" are Extremely rugged devices!!!
The amplifiers have very good IMD since the devices are designed to “loaf along” at the designed power level. They are not pushed to the limit or to saturation!
I was asked a few questions by members so here is my added reply
Amps are made for 160-10 and 6m
Slight trade off to et the right balance in power/bandwidth so there is
about 20% drop on 6
As for duty cycle If the boards are mounted as needed on
a proper heat sink with a good sized copper heat spreader with 10mm thickness
and air is directed on fins as well on top of board to cool the magnetics I
was able to run the amps for a long time
Cores are large and many thus an
average rise of core temperature is also controlled As a result I have not
seen core failure or saturation and far away from curie point
Also the use
of many cores gives better IMD and far better results than using A single
very large tube or core Also as seen in ON9CVD study on Magnetics
I also
tested the 3 ++kw board with 4x BLF188XRS on a full copper heat sink with
clamping the devices and not just using 4-40 screws at the tabs Results are
very good and when ran at 2000w out F2 and F3 were way down and very known
10-11 MHz distortion of LDMOS (known physical property probably to the way the device is made)
was down too.see bird power meter picture on 2kw outwith about 4 w drive!!
over all a very stable and powerful board.
look at input VSWR curve I have added
all below 1:1.5
The items shipped to you, are NEW, UNUSED, TESTED and WORKING modules.
The transistors, mosfets, ldmos or RF semiconductors installed in this Module Board are NOT Covered by Warranty.
For repair, buyer pays both shipping cost to seller and return shipping cost for item repaired.
Before returning a module for repair, please contact your seller to coordinate and for a cost estimate.
SHIPPING
Shipping WORLDWIDE!!! The shipping costs to all countries are the same.
Shipping cost include handling and shipping.
Handling time: 1-15 days
Shipping time: 5-20 days
We ship by registered parcel post with a tracking number.
International Orders: The buyer is responsible for any applicable import duties and local taxes. Please check customs in your country before making your purchase.
Please verify your address during checkout. We are not responsible for any wrong or undeliverable addresses.
Items will be checked carefully before sent out.
please contact me at 4z4rb11 at gmail.com for all details
or on Skype: baruch4z4rb
Thank you and 73's
This Amp is intended for use by suitably Licensed Amateur Radio Operators Only and is not intended for CB or any other radio services where regulations prohibit its use.