This is a reference for those who miss postings or don't want to follow the along with the class. Thank you Chuck for assembling this list and breaking the rig down into functional areas.
Part 1. Power regulator parts.
D13, C112, U2, C102, D2, and C105.
Measure voltages at C112, U3-8 (pin 8 of U3), J2-1 (pin 1
of J2). Looking at schematic are you getting the values
Part 2. VFO section.
C103, R18, D1, C8, C2, C3, R15, R16, Q2, C4, C5, C6, R17,
C9, C10, and L1. C7 is saved for later. Read NN1Gs manual,
my web page, and/or Mike's previous posting.
At this point you should have the heart of the transceiver
running. Go no further until it is generating a frequency
at pins 6 of U1 and 2 of U5. Check with O-scope, RF probe,
or GC receiver if you have one. A frequency counter would
be nice too. But for a rig for under $100 you could easily
spend almost a $1,000 for test equipment!!!
My guess is that if you are new to kit building and have gotten this
far without any problems you will have no problems with the rest.
Not at this juncture you the builder have decision to be made based
on what test equipment you may have or a receiver for the band you
are building the SWL-40+ or SWL-30+ for. If you have a receiver
or an O-scope, my personal recommendation is to go with the transmitter
section first. Just my recommendation. With that let me add the
Part 3. Get the keying circuit and transmitter mixer.
R21, R20, Q3, C111, C110, R19, D11, C109, U5, C108, C28, C29,
RFC2, and Y5.
If you have a way to monitor RF, then power up and simulate
keying by connecting (carefully) J3-3 to ground. You should
see about 7V on pin 8 of U5 and RF out of pin 4.
Part 4. BP filter.
C30, T2, C31, T3, C32, and C33.
Check for signal at base of Q4 (not installed yet) and peak
with 'key down' conditions by adjusting T2 and T3. This will
take several adjustments as there is some interplay between
the two transformers through C31.
Part 5. RF buffer section.
R23, R22, Q4, R24, and C34.
Check for signal at base of Q5 (not installed yet). Adjust
R24 to show that level can be adjusted from near zero to maximum.
If you have O-scope, note waveform at all levels.
Part 6. First RF amplifier.
R25, R26, T4, Q5, R27, R28, C114, and C35.
Again check for signal at base of Q6 (not installed yet).
Make sure that key on and off conditions do turn on and off the
See Mike Maiorana, KF4TRD, home page at http://www.qsl.net/kf4trd/ for an
excellent description by Glen Leinweber, VE3DNL, of each part in the SWL-40
and it's primary function. If you can't surf, then we'll see if Mike
or Glen have an ASCII file to ftp or email. I can do it, but they did
Now at this time comes the most dangerous part of the whole project IMHO.
This is the point where if you forget to connect a dummy load then you
can lose some parts that will need replacement. So before powering up
after the next section you need to have a dummy load with RF wattmeter
attached at all times during power on conditions.
Part 7. Final PA assembly and Chebyshev output filter.
D6, R29, Q6, L2, C113, D12, C36, C37, L3, C38, L4, and C39.
Set R26 to minimum value for output and power up. With dummy
load and wattmeter connected to antenna output you should be
able to adjust R26 to get RF out when transmitter is keyed.
You now have a transmitter up and running. Next is the receiver.
With all the testing involved you should allow yourself 3 or 4 hours
total for these steps. Take several evenings and enjoy and learn from
each step. By assembling and testing in steps you know exactly where
the problem is if things stop working.
A. Remember to always have the board on standoffs if you have them.
Otherwise have board on clean non-conducting surface away from
cuttings from assembly work, etc. Shorts do considerable damage
to parts and the PC board with high current levels possible.
Ask the people that have done it. :-) PC board traces make nice
B. As you install parts you may want to highlight them on a photocopy
of the schematic. This helps me follow the signal paths and make
sure that I don't omit something like D2 which will prevent the
VFO from oscillating if not installed. I know this cause I did
this for a minute on the beta version, but I lost no more than a
couple of minutes of time for this oversight.
Ask questions if you run into problems. It's how we all learn.