Download Soldering and installation instructions. Assembling.

Pa0nhc Miniwip.
Soldering and installation instructions.
Ver 20160729
Please completely read this information and instructions first.
Changes :
Two versions of PCBs exist :
PCB version 20160413 :
ZD1 is not fitted.
T1 was a TO50 of SOT103 type N dual gate mosfet (BF960/982).
T2 was a TO39 type NPN VHF transistor (2N3866 / 2N4427), cooled by a
cooling star.
PCB version 20160701 :
Grounded holes now have a “thermal relief line” to make soldering easier.
The following, more easy to obtain transistors are fitted :
T1 is a N-type SMD MOSfets with high steepness :
BF998 – 24mS, SOT-143 tetrode or
BF999 – 20mS ,SOT-23 triode.
T2 is a NPN TO-126 / SOT32 type audio driver transistor (BD135/137/139)
which has a high Ft value (190MHz). It is cooled by screwing it flat onto the
PCB.
ZD1 (12V) is added as an over voltage protection for T1 in case of a higher
supply voltage than 12,6V accidentally is connected.
R2a is added for easier adjustment of the T1 drain current.
Splitter PCB
is double sided now, its layout is changed, and it has two screw holes.
Assembling.
Antenna PCB.
TOP. Solder :
a. diodes D1, D2, ZD1 (see ring positions).
b. all resistors. Please check their values with an ohmmeter before soldering !
c. C1-C4. For low IMD levels, only use the stated type.
d. elco's C5,C6. REM : the long wire is + .
e. chokes L1, L2 .
f. The BNC receptacle.
Connect a thick long wire to hole “GND”. Use tooth rings for durable contact.
It will be used to connect the antenna PCB to the grounded mast..
REM : The semi conductors are static sensitive. Before soldering, connect
your body, the soldering iron, and the packaging of the semiconductor, to the
mass surfaces of the PCB.
g. Solder T2 (BD137).
h. Solder T1 (BF998).
Splitter.
TOP. Solder :
i. R10.
j. D3 (see ring position).
k. C7,8,9. REM : for low IMD levels, only use the stated type.
l. L3,4. REM : only use the stated type regarding to high self resonance
frequencies.
m. Solder four uninsulated solid wires, length 5cm, to ANT, RX, +12V, -12V.
Splitter housing.
The splitter PCB can be screwed onto the bottom of a Hammond 1590a
aluminum die cast box. Use nuts as distance bushings, in order to prevent
ground short circuits. Use tooth rings for solid contact. The PCB then is
grounded, and the ground lugs of the BNCs can therefor be omitted.
n. Drill the holes for the connectors.
o. Install the connectors.
Only if you use a Teko 1B aluminum cabinet :
p. The ground lugs of the BNCs should direct towards the background. Bend
them 90 degr. and shorten them if necessary. Solder the BNC ground lugs
onto the mass plane of the bottom copper. REM: Do not connect the PCB
ground surfaces els were to the cabinet.
q. First temporarily put plugs into the connectors (for solder-cooling and fixing
into the correct position). Shorten the four connecting wires. Solder the wires
to the connectors.
TESTING :
r. Connect a receiver to “RX” of the splitter using a 50 Ohms coax cable.
s. Connect “ANT” to the antenna unit using a 50 Ohms coax cable.
s. Connect a 12,6Vdc (150mA), noisefree power source to “+/-12V“.
You should hear noises and radio signals.
Close the cabinet. Disconnect the antenna cable.
You should NOT hear any signal or man-made-noise.
Do not forget to install ferrite rings.
Connect the antenna unit. Measure the following voltages in the antenna
PCB. Their value can differ with different supply voltages and adjustment if T1
dian current :
C6=12,3V , C5=11,2V , R4=3,0V +-20% , R9=5,57V.
By adapting the value of R2a, the quiescent drain current of T1 can be
adjusted (20mA +-20%, measureable on R4).
The housing of the antenna PCB.
The antenna PCB fits inside a (heat reflecting) white piece of 32mm PPC
pipe, 25cm long. In the pipe, drill a 3mm hole abt. 35mm below the top. The
PCB can be hung to a M3 screw through h1 and the pipe. Close the top with
a cap.
Please use THIN (double screened) coax as definitive connection between
the splitter and the antenna unit. With thin coax more windings will fit through
a ferrite ring. Correctly loaded thin coax does still show low enough losses on
SW bands.
Drill in a second pipe cap a hole for a rubber coax bushing. The coax and the
grounding wire will be routed through it. Also drill a 2mm moisture draining
hole.
At the end of the coax to be connected to the antenna unit :
Shift the cap over the coax.
Wind the coax several times through the ferrite rings hole. Use a ferrite ring
with a BIG hole (13mm or more) and a high Ui value (5000 or more).
I suggest cheap cores with the correct material : Conrad BestNr. 534480.
Connect the BNC plug.
Now put the grounding wire through the rubber bushing.
Close the bottom of the PPC pipe with the lower cap. Waterproof ithe bottom
cap with grease or tape.
REM: by leaving the power always connected to the antenna, the warmth
generated by T2 helps as an effective anti-condensation measure.
Installing onto a mast.
PLEASE DO READ THE INSTALLAION RECOMMENDATIONS BEFORE
YOU PUT THE ANTENNA UNIT OUTSIDE..
I recommend the use of a galvanized steel pipe as a mast. Stainless steel in
contact with aluminum causes oxidation. The same is true for copper(wire)
and aluminum.
IMPORTANT : The top of the mast MUST NOT be higher than the ground
surface inside the antenna PCB. The antenna surface and its internal
connection to the electronics must be fully above the top of the mast.
Install the antenna unit on/above the top of a well grounded mast.
Shorten and connect the grounding wire, coming from the antenna unit, onto
the mast. Weatherproof the connection.
73's, Nico pa0nhc. www.pa0nhc.nl
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