NORCAL 2N2/XX Manuale utente
NORCAL 2N2/XX V1.2
Assembly Manual
Copyright 200 /2009 by
Jim Kortge, K IQY
and NORCAL
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Introduction
This is the assembly manual for the NORCAL 2N2/XX transceiver designed by im Kortge, K8IQY.
A great deal of effort has gone into the design of the rig and this manual to assure that the kit you are
about to build will work properly. This is not a beginning builders kit. It has a great many parts (over
300) and assumes the builder has some working knowledge of electronics and electronic parts. To
successfully build this transceiver, one needs to be able to understand and follow a schematic diagram,
convert resistor and molded inductor value call outs to the equivalent color code, and be able to
recognize various capacitor types. In addition, one needs to be able to read and understand this manual,
follow the instructions correctly, and work carefully.
A common assembly manual is used for all 2N2/XX rigs, therefore, no parts values are given in this
manual, only part designators. This assembly manual is used with the band specific Bill of Material
(BOM) and schematic diagram to identify the part values being installed. The schematic diagram for
each band contains the actual part value for each designator. Using this approach encourages the
builder to become familiar with the schematic diagram of the 2N2/XX transceiver being built so that
he/she is familiar with the design of the rig should any troubleshooting be necessary. However, if all of
the parts are installed in their correct locations, the rig will perform as designed and no troubleshooting
will be required!
With that thought in mind, go slowly and double check your work to avoid having to remove either an
incorrect part or a correct part installed in the wrong location on the PC board (PCB). As a
suggestion, make a 2X size copy of the schematic diagram. While you are building, check off the parts
installed in the brackets [ ] provided in this manual, while also highlighting the part on the schematic as
a cross check. When you are done building, all of the parts shown on the schematic should be
highlighted. (On 40-meters, the Receive RF Amplifier stage is not built, so those parts will not be
highlighted.)
A parts overlay page is included in the Appendix. This page will show how the various transformers
and trimmer capacitors are to be mounted. An “F” designates the “flat side” of a trimmer capacitor
(TCx designation). When mounting a wound transformer, the primary (“Pri” notation) is always the
winding with the most turns. The secondary (“Sec” notation) is the winding with the fewer or equal
number of turns, if the transformer is a bifilar type. Transformer T5 is somewhat unique, as it has two
secondaries, a 3-turn and a 1-turn. The primary is connected to the locations marked “P” as shown on
the overlay, the 3-turn secondary to “S1” on the overlay, and the 1-turn secondary to “S2” on the
overlay. All transformers having several turns for the primary and fewer turns for the secondary can be
wound with the secondary interleaved between the primary winding turns from approximately centered
on the primary winding to near the end where its leads will be soldered to the appropriate pads on the
PCB. The location is not critical. An examination of the various figures supplied will illustrate this
approach.
This manual is structured to build a section and then test it to assure it is working correctly, before
moving on. Space is also provided at the end of each test section to write down your measurements and
observations. You are encouraged to do this as it will help later on if you run into problems or need
assistance. Using this approach promotes confidence the end product will work, since all of the
previous stages worked. If you build a section and it doesn't work properly, do not continue on,
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expecting that the section will fix itself. It will not and the remainder of the build will be
compromised. Please fix any and all problems as they occur!
PCB Preparation
[ ] Assemble the four 1-inch hex screws and 1-inch hex nuts to the four corners of the PCB. The
screws go on the bottom side and the nuts on the top side. This hardware holds the PCB up off
the work surface and makes it easy to work on regardless of which side is up.
Your PCB should look like that shown in the figure.
- Figure 1 -
Power protection
[ ] Install diode D18
[ ] Install capacitor C87.
Your PCB should look like that shown in the next figure.
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- Figure 2 -
Test - Apply 12 volts to the board. With a DVM or VOM, measure that more than 11.7 volts
appears at the junction of D18 and C87.
Your Measurements/Observations - ______________________________________________
____________________________________________________________________________
Receive Active Power Decoupler
[ ] Install transistor Q21
[ ] Install resistor R96
[ ] Install capacitor C38 matching the polarity markings on the capacitor case with those on the
PCB.
Your PCB should look like that shown in the next figure.
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- Figure 3 -
Test – Apply 12 volts to the board. Measure with a DVM or VOM that 11.5 volts (or more)
appears at the left center pad where transformer T3 will be installed.
Your Measurements/Observations - ______________________________________________
____________________________________________________________________________
Receive Main Audio Amplifier
[ ] Install transformer T3; note orientation, “P” side toward the interior of the PC board. There is
no need to solder the mounting tabs; doing so makes it virtually impossible to remove the
transformer should it be mounted incorrectly.
[ ] Install transistors Q3, Q4, Q5 and Q6.
[ ] Install resistors R5, R6, R9, R10, R11, R12 and R13.
[ ] Install capacitors C4, C5, C8 and C11.
[ ] Install electrolytic capacitors C6, C9, C10 and C82 matching the polarity markings on the case
with those on the PCB.
5
[ ] Install volume control R80 (marked A10K) to the pads marked “VOLUME” using discarded
leads from previously installed components as shown in the next figure.
- Figure 4 -
[ ] Install the SPKR jack, using the rear terminals, to the pads marked “SPKR” using discarded
leads from previously installed components as was done above. Other controls will be installed
on a temporary basis similar to these two elements. Once the rig is completed and working,
these parts will be removed and rewired when the PCB and controls are installed in the case.
Your PCB should look like that shown in the next figure.
- Figure 5 -
Test – Connect a speaker or headphones to the “SPKR” jack. Apply power to the board. Rotate
the volume control fully clockwise and touch the center pad of the pad set marked “VOLUME”;
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60 Hz hum should be heard coming from the speaker or headphones.
Your Measurements/Observations - ______________________________________________
____________________________________________________________________________
Receive/Transmit Keying
[ ] Install the PN2907A PNP transistor at Q8
[ ] Install resistors R17 and R18
[ ] Install capacitors C14, C20 and C21
Your PCB should look like that shown in the next figure.
- Figure 6 -
Test – Apply 12 volts to the board. Confirm with a DVM or VOM that at least 11.5 volts (+V
Tx) appears at the collector of Q8 (left pad of R86 location) when the “KEY” pads are
connected together.
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Your Measurements/Observations - ______________________________________________
____________________________________________________________________________
Receive Mute
[ ] Install the J176 JFET at Q7
[ ] Install diodes D2, D3, and D4. Note cathode ends (bar) so they are installed correctly. The
anode of D3 and the cathode of D2 should be the non-grounded ends.
[ ] Install the two test points provided for the R14 location, then install R14. Using these test
points allows R14 to be easily removed and replaced should the audio level during transmit
not be set to your liking.
[ ] Install resistors R15 and R16.
[ ] Install capacitors C12 and C13.
Your PCB should look like that shown in the next figure.
- Figure 7 -
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Test – Connect a speaker or headphones to the “SPKR” jack. Apply power to the board.
Advance the volume control to maximum. Touch the top (ungrounded end) of diode D2; 60 Hz
hum should be heard coming from the speaker or headphones. Rotate volume control R80
counter clock wise (CCW) to verify the hum level changes. At full volume, jumper the pads
marked “KEY” and verify that the 60 Hz hum is muted.
Your Measurements/Observations - ______________________________________________
____________________________________________________________________________
Receive Audio Preamplifier
[ ] Install transistor Q10.
[ ] Install resistors R19, R20, R21, R22, R23 and R24.
[ ] Install capacitors C27 and C28.
[ ] Install tantalum (tan color, both leads on one end) capacitors C26 and C30 matching the polarity
markings on the case with those on the PCB.
[ ] Install electrolytic capacitors C23 and C29 matching the polarity markings on the case with
those on the PCB.
Your PCB should look like that shown in the next figure.
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- Figure 8 -
Test – Connect a speaker or headphones to the “SPKR” jack. Apply power to the board. Touch
the pad on the minus end of tantalum capacitor C30 or the lower pad for L10. The hum volume
should be louder than it was before this stage was added.
Your Measurements/Observations - ______________________________________________
____________________________________________________________________________
Receive Local Oscillator (RxLO)
[ ] Install inductors L4 and L7.
[ ] Install trimmer capacitor TC9. The rounded end is the grounded end.
[ ] Install transistor Q11.
[ ] Install resistors R26, R27, R28, R69, R70 and R71.
[ ] Install capacitors C15, C32, C33, C67, C68 and C69.
[ ] Install crystal X5; it will be one of two marked LO or XX. Place a spacer (made from brown
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