QRZ! Ham Radio 7/QRZ Ham Radio Callsign Database - Volume 7.iso/mac/files/q_review/ark40.kit

Internet Message Format | 1994-11-26 | 21KB

Date: Mon, 4 Oct 93 13:11:37 -0400
From: [e-mail] (James R. Johns)
Message-Id: <[e-mail]>
Posted-From: The MITRE Corporation, Bedford, MA
To: [e-mail]
Subject: ARK 40 QRP Rig


I thought the QRP group might be interested in my opinions on the
ARK 40 QRP rig from S&S Engineering.  While I bought the kit at the
1993 Dayton Hamvention, business and personal activities made it
impossible to finish the rig as fast as I would have liked to.
I fully agree with the review in the latest issue of 73 magazine.
The rig consists of very high quality components, a great assembly
manual and the little rig works great!  While not a kit for a beginner,
anyone who has put a few kits together and who takes their time will
have no problems with this kit.  I tend to be extra careful when
assembling a kit and check out all the components on a bridge before
soldering them into the kit.  For that reason the problem pointed out in
the 73 piece about the brown vs violet resistor markings wasn't really
a problem for me.  The rig tunes up easily and I was able to work from
Boston to Philly using my 20 Meter dipole (attic mounted) and an ATU.
(Remember this is a 40 Meter Xcvr into a 20 Meter dipole at 7 PM local time)
The rig keys cleanly and the waveform looks good on a scope.  Now when
the NEN meets on Saturday morning I'll know exactly where 7.040 is :-)
If anyone has any questions about the kit I'd be happy to provide any
info I can.  73 & 72

Jim Johns  KA0IQT
[e-mail]


Note:  I have no association with S&S Engineering other than as a
satisfied customer.


======================================================================

Date: Tue, 5 Oct 93 08:31:23 -0400
From: [e-mail] (James R. Johns)
Message-Id: <[e-mail]>
Posted-From: The MITRE Corporation, Bedford, MA
To: [e-mail] (Wayne Burdick)
Subject: Re: ARK 40 QRP Rig
Cc: [e-mail]

I haven't had a problem with the thumbwheel switches and tuning the ARK 40.
As I indicated on an earlier post, it probably wouldn't be too hard to
come up with an optical encoder to replace the RIT control and slip a
display in place of the thumbwheels and convert the rig to a more
conventional method of tuning.  Or I suppose one could control the
tuning from a computer and have all kinds of fancy scanning and memory
for operation.  Once you get used to switching the ARK 40's thumbwheels
when you need to carry or decrement a higher switch position, tuning
hasn't been a problem.  One thing I forgot to mention in the review of
the rig is the large prototyping area that is left available on the
transceiver PCB.  Lots of room for add on or modification hardware.
  73 & 72

Jim Johns  KA0IQT
[e-mail]

The opinions expressed are mine and not my employer's.

======================================================================

Date: Wed, 27 Oct 1993 08:42:16 -0500 (CDT)
From: "JEFF M. GOLD" <[e-mail]>
Subject: QRK 40 review
To: [e-mail]
Message-Id: <[e-mail]>
X-Vms-To: IN%"[e-mail]"
X-Vms-Cc: JMG
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; CHARSET=US-ASCII
Content-Transfer-Encoding: 7BIT

Ok,

As promised..just got it on the road and here is my views:


Please do not reprint this without permission (Yet).



    If you are looking for something different in a QRP
transceiver kit S & S Engineering may have just the kit for
you.    Their new ARK is a synthesized QRP single band
transceiver. It uses a super heterodyne receiver that covers
from 7.000 to 7.1999 MHz and the transmitter puts out 5
clean watts. The rig offers full break-in (QSK) keying.
What makes this rig different than the other QRP rigs out is
that it uses two phase-locked loops to synthesize the
frequencies.  Tuning is done with thumb wheel push button
switches. When you are on a frequency you know exactly
what it is. If someone asks you to QSY up 5 you know you
will be exactly on that frequency. The rig also comes with
RIT, AGC for easier listening, crystal filters and an narrow
(200Hz) audio filter. There is plenty of audio to drive the
included speaker.
    When I first looked at the $269.95 price tag I was a
little taken back. The finished transceiver has more features
than most (such as the narrow audio filter), but this is the
highest priced mono-band QRP transceiver that I am aware
of. As I finished building and testing the rig the reasons for
the price tag became more apparent.
    S & S offers a guarantee that the rig will work as
advertised or you can send it back and they will fix it. They
have a company policy that they will do everything in their
power to get the rig fixed and out the door within 24 hours
of receiving it. If the problem is found to be caused by a
faulty part or fault of the companies it will be fixed for free.
If you have put a part in the wrong place or done something
wrong they will fix it for under $25.
    I have built kits of all levels and all levels of
instructions. Some kit suppliers basically give you a bag of
parts and a schematic. Heath use to be on the other end of
the spectrum and tell you in minute step-by-step detail how
to assemble the rig.  The S &  S instruction manual is a
work of art. It was professionally written with excellent
quality type, good schematics and excellent photos. The
instructions are step-by-step, but not in the Heath approach.
One step will say put in all the resistors. There is a master
list of parts that has complete descriptions of each parts.
There is then a separate parts list with a two checkoff boxes
so that you can use this to build the boards with. The parts
list is in the back of the manual. At first I wasn't sure I liked
this approach. I went to the step that said to solder the
resistors and then went to the back of the manual to use the
parts check off list.  While building the boards, I found this
worked fine. The parts list has complete descriptions of
each parts including things like the color code on the
resistors. This make part placement a lot surer. One of the
biggest problems builder experience is incorrectly
identifying parts and putting them in the wrong place on
the board. The assembly instructions for each of the boards
is separate and then the final assembly process and
alignment are each separate. The manual also has very nice
sections explaining the theory of operation of the rig and a
trouble shooting section. This was by far the most complete
and well done manual I have come across since building
my Heath HW9.
    The next area I was really impressed by was the kit
itself. There are two main printed circuit boards and one
small board. There are over 1000 solder connections in all.
They clearly state that this is not a beginner's kit. I found
that with a little help a beginner should easily be able to
build this rig. It is in fact much easier to build than many of
the other QRP kits on the market. There are a lot more parts
in this kit, but the way the kit is packaged makes it a
different type of kit. The two main boards and their
corresponding parts are each packaged separately. Within
each board packaging parts are packaged separately.  If
there are a lot of the same resistors or capacitor, they are
put in separate packages. If there is any chance of a part
being identified incorrectly it is in a separate wrap and
clearly labeled. The coils are all pre-wound. In one case
there are tiny surface mount capacitors and they give you
an extra in case you mess it up. It turned out that this was
the only part I had trouble with. I used some surgical
forceps that lock and managed to crunch one. It was no
problem, I just used a different tool and used the spare
capacitor.
    My approach to building a kit is to take all the parts
out of the box and check them off and separate them. I
usually take a big piece of paper for the resistors and
capacitors. I label the number of the components (ex: R1,
C34),  and put the leads through the paper. I find that when
I build I am much less likely to make a mistake using this
method. I also know ahead of time if I am missing a piece
and can call and get one sent before I need it. This is
usually my least favorite part of building the kit. I found
that the parts were so well prepared with the ARK 40 I
built that I didn't need to do this. I took a number of small
plastic bins and just dumped each of the pre-prepared
packages into each one. There were no missing parts with
this kit. With the resistors many had been sorted and I only
needed to sort out a small number of them. The same was
true for the capacitors. The S & S Engineering approach to
preparing their kits made the building process a lot more
enjoyable.
    When examining the boards I found them to be clearly
silk screened and the best quality  I have come across. A lot
of time went into numbering components so that they are
easier to locate on the printed circuit board while building.
The boards are double sided and plated through. This
makes the soldering a lot easier and solder connections
come out better with less chance of cold soldering joints.
The down side to this type of board is that if you put a part
in the wrong place it is a lot harder to remove it from the
board. The parts in the kit were also all top quality. The
case is fantastic and should stand up to about any type of
use.
    This isn't a kit you would want to throughout together
quickly. Building is a type of therapy for me. After a tough
day of work I love to come home, lock myself in my ham
shack and work on building something. The nature of the
kit determines in many cases how much enjoyment I get out
of building. I found that due to the careful attention to
detail and quality of all components that this was one of the
most enjoyable projects I have ever done. I was able to
come home and work on the kit for 10 minutes or 2 hours
and enjoy every moment of it. I found that the manual was
complete enough so that I didn't get frustrated and was
written in a way so that it didn't insult my intelligence.
    After you complete each board you are given some
simple resistance checks to perform with an ohmmeter.
You can tune this rig up without any special equipment by
using a receiver with a digital readout. If you have use of a
frequency counter, it is a lot easier. A scope is always
preferable for tuning up the transmitter, but you can do a
good job without one using a power meter capable of
reading QRP levels  The alignment procedures are very
clear and detailed. They even give you a good plastic
alignment tool for the coils.  If you run into problems with
the alignment the trouble shooting section should help
point you in the right direction to localize the problem. If
you need to take advantage of the service, you will find the
people at S & S Engineering knowledgeable and helpful .
    I still get real nervous when I first power up a rig,
especially one that has so many parts in it. The more parts
the more likely I have made some dumb mistake. No matter
How careful I am, I always seem to put something in the
wrong place. I anxiously turn on the power while at the
same time looking and smelling for smoke. When I flipped
the switch on this rig, the power came on and no smoke
billowed out of the rig. Boy was I happy. I feel if I get this
far, nothing too bad can be wrong.
    I started aligning the transceiver using my digital
frequency counter as directed by the instructions. I used a
small digital multimeter to check the voltage at one of the
ICs. The voltage was a little off. You change the voltage by
either spreading or compressing the coil windings of one of
the coils. It isn't very hard to do. I would suggest that after
the rig is completely operational and checked out you
might want to put a little glue on the windings to make sure
they stay in place. Most of the alignment procedures are
very typical of QRP transceivers. There are two coils and a
couple of variable caps to adjust the receiver section and
two transformers for the power output of the transmitter. I
didn't have a scope at home and used my QRP watt meter
to adjust for maximum output. The transmitter was putting
out better than 6 watts, so I adjusted it to about 4.5 watts. I
went to a hamfest the day after I aligned the rig and came
across a good deal on a scope. I went home and checked
the wave form of the transmitter out with the scope. I found
the wave to be very nicely shaped. I found that when I
played with the two transformers and adjusted the power
level down that the wave form was still very good. I believe
you can easily align the entire rig using another rig that has
a digital readout, a voltmeter and a power meter that reads
QRP levels.
    Building the rig is half the fun. Putting a rig I just
have built always is an exciting experience for me. This
was no exception. I was impressed with the quality of parts
and had a really good time building the kit. I was very
anxious to see if the rig performed as good as it looks. I
usually find that I like to align a rig, put it on the air and
then take it apart and fine tune it. I usually go through this
procedure a few times before I am satisfied with the way a
rig operates. No matter what the frequency counter and
other test instruments tell me, I like to tune a rig till it feels
right for the way I operate.
    I plugged in the antenna and key and turned on the
power. The 40 meter band was not in very good condition.
I tuned around a little and heard someone calling CQ. I
answered and he came back with a QRZ? This was a good
sign as far as I was concerned. I answered back with my
call twice and turned it over.  Ralph,N3QF in Washington
DC,  came right back to me. We had a nice forty minute rag
chew. The radio received an excellent signal report. The
other person was very impressed that my 4.5 watts was
getting through all the atmospheric noise. He said my
signal had a very nice sound to it. I listened on my
Kenwood 850 to the keying and it sure sounds sweet.
    At first I had serious reservations about the use of
push buttons to tune around the band. I found that after a
few minutes I didn't mind this method at all.  The rig
sounds great, is very sensitive, has great full break-in
keying, and is extremely rugged. The size is about right for
backpacking or portable operation. I am impressed with
this little rig. It is a fun to build and operate rig.

Jeff M. Gold, AC4HF        S&S ARK 40 Review  1


======================================================================

From: [e-mail] (Mike Czuhajewski)
To: [e-mail]
Subject: More ARK4 comments
Date: Thu, 09 Jun 94 06:50:17 EST5EDT

Some more comments on the new ARK4 from S&S Engineering--

Severn, MD, 8 June 1994--Someone recently asked about performance of
the new ARK4 from S&S Engineering. I sent him some brief comments but
The System didn't like the address I used (even though it was
identical to the one on his message--that happens sometimes) so
instead of remailing it I decided to flesh it out a bit and "go
public."

I got a loaner from Dick, KA3ZOW, a couple weeks ago at a local
hamfest, for review.  I played with it a bit, mostly off the air,
then loaned it to a friend whose antenna is in the air (unlike mine,
which is mostly on the ground at the moment).  I didn't do any
sensitivity or stability tests yet (the latter seems a bit pointless
in a synthesized rig, which is based on the stability of crystal
oscillators).  I did notice some things I didn't like in the RX audio
chain, but this is an early iteration of the design and Dick will, I
hope, fix them when brought to his attention.

First, in all fairness, I should point out that the ARK4 I have now
is a prototype, and the ARK40 last year was either a prototype or
very, very early production model.  (I received both already
assembled.)  In both the loaner ARK40  this ARK4 there is a constant
whine or tone in the audio chain, even with volume control all the
way down.  Dick told me the ARK40 problem was the LM386 oscillating a
bit.  In the ARK4, which will NOT drive a speaker and is not intended
to, there is a much higher tone, about 10Khz (confirmed with an audio
oscillator), with volume at min.  That shows it's in the audio chain,
not the main rig.  The ARK40 tone was about 2K, as I recall.

Both were low level, probably not easily noticed with volume cranked
up to usable levels, but the point is they should NOT be there in the
first place.   Second ARK4 audio bug is the constant low level
sidetone freq heard at all times, even with vol at min.  He runs the
sidetone osc constantly and gates the output on and off. It's
probably not easily noticed with vol at working levels.   It's gated
on and off by shorting the oscillator output to ground with a 47 uF
capacitor and transistor (2N3904?).  At first I thought the
collector/emitter voltage drop of the conducting transistor was
keeping the cap from shorting the signal completely, but later
disproved that.  I also thought that the problems might be caused by
the inches-long PCB trace from the volume control to the audio amp
picking up stray signals along the way; I disproved that one, too.

The audio IS distorted as someone recently said of an ARK4 he saw at
Dayton.  It finally clears up fairly well at about 12 o'clock on the
vol, but at lower levels it is distinctly distorted and harsh and
annoying.  By the way, this one had the optional audio filter.
Here's the audio chain--sidetone and product detector feed a single
op amp section which goes to the phone jack.  If the filter is
installed, that op amp section  instead goes into another op amp,
where it is attenuated, filtered and passed on to the jack.  I
disabled and removed that filter IC, jumped the signal straight over
to the output line, running the audio chain in its "stock",
nonfiltered mode; all problems were still there so can't blame the
filter.  (Part of that IC in the filter is used for the audio whether
the filter is turned on or not; switching the filter in or out is
accomplished with +12V, not by use of a DPDT switch as in some rigs.)


Transmitter output signal on good quality HP spectrum analyzer--all
spurs and harmonics down WELL over the required 30 dB.  Interestingly
it has a spur on the TX signal at the IF freq of 3579, not too
surprising, I suppose, and perhaps to be expected...and it IS about
40 dB down.  There is a second spur just below that, at 34-something,
and that second spur moves when you change freq, moving 100 KHz if
you change the rig by 100 KHz (a one to one change).  That, too, is
waaaaay down.  (I didn't check the ARK40 on the analyzer when I had
it, but would assume harmonics are down similarly.)

One final experiment, which I've always wanted to do on something,
anything, was to look at the output signal on a sweep from 0.1 to 36
MHz, seeing up through the 5th harmonic, both with and without the pi
net filter in place.  I'd always heard that harmonics were pretty
strong in a class C amp, and here was the perfect chance to do it.
"Dramatic" is the best way to compare the two different sweeps.  I
took pictures of both with a scope camera, and will have them in the
Idea Exchange in the QRP Quarterly in the future.  (This is certainly
not an indictment of the ARK4, of course, but a simple fact of
electronics, and will happen with ANY class C amp--and that's why
everything we build has a filter on it!)


73 de [e-mail] packet and [e-mail] (which
works just as well as the longer Internet address with my name in it)
--
Mike Czuhajewski, user of the UniBoard System @ wb3ffv.ampr.org
E-Mail: [e-mail]
The WB3FFV Amateur Radio BBS - Located in Baltimore, Maryland USA
Supporting the Amateur Radio Hobby, and TCP/IP InterNetworking