deel 2
This project involves the building of a 2 meter (144Mhz) amplifier. Design is to
use a tube, much easier then using some transistors, tubes can handle a mis-match
better
and perhaps the building of the thing is cheaper as buying one,..with the same
power output.
After searching the internet I found a article from UKW-berichte from March
1977, this
is a german magazine. German amateur DK1OF made a nice design with layout and
explanation
of building this amplier, tube used is a 4CX250B and estimated power output
400Watts.
Here the PDF file of the original
article
Costs till now:
4cx250 + base + chimney | 1 | € 56,20 |
1,5mm copper for cavity | 5 | € 61,50 |
M3 x 10 brass bolts | 10 | € 0.15 p/st |
M3 brass nuts | 4 | € 0.09 p/st |
Snail-shell like fan | 1 | € 13,50 |
Axial fan (220V) | 1 | € gratis |
Elko`s 470µF/450V (105°c.) for power supply | 10 | € 24,00 |
Elko`s 330µF/450V (105°c) for power supply | 10 | € 16,00 |
Resistors, capacitors, diodes. for power supply and cavity cavity | x | € 72,00 |
High voltage trafo (600V, 800V, 1000V, 1200V, 0, 1200V,1000V 800V, 600V - 1KW) | 1x | € 105,- |
Hoogspannings elco (50µF/4000V) | 1x | € 35,- |
Silvernitrate (not all 200grams needed) | 200grams | € 80,33 |
Panelmeters (1mA/300Ω) | 3 | € 9,50 |
The copper I have is cut to size where I bought it, so I can
go ahead as soon I was home again. To draw onto the copper
I cleaned it first and put some indian ink and let it dry. This way you can put
nice drawings on the copper without damaging it.
drawings on copper
Insides of the cavity completely assembled,..all made out
of brass |
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Now the cavity is finished,..it only has to get a
nice silver finish inside,..the high power side that is, I got a luxury
problem here. The high voltage transformer has 2x4 outputs of The transformer is coming
from http://www.elektrodump.nl/
number "TRF-1602-26", here I also bought the high voltage capacitor of
50µF/4Kv. |
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Here the schematic of the transformer towards the
decked switch I now have, I didn`t put the 200-400 volts position not in
the drawing as I don`t think I need these for the amplifier, I think
below 1000volts is not needed, but it`s wasted not to use these. |
will be updated.....
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