Does build quality affect performance?

[Darwin, Keith]

Hey guys,
 
Does a K2's performance vary depending on how well it was built?  Is
there a difference in performance between one built by a pro, one built
by a beginner who has no problems and one built by a beginner who has
lots of problems and does rework to correct them?
 
 
- Keith KD1E -
 
 
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Don Wilhelm-3]

Keith,

It all depends -- any builder, beginner or not can do a fine job of building
a K2 - it is designed so that that will happen.  I usually say that there
are 2 requirements for properly building a K2 (or any other Elecraft kit) -
first the builder must be able to do a good job of soldering and second the
builder must be able to follow well written instructions properly.  If the
beginning builder has that capability, then the K2 will be good.  I must
assume that a pro builder already has demonstrated that he has that
capability through his track record.

If the builder does a poor soldering job overall, that can cause problems
that are intermittent, and are not always easy to find, and they may not
show up for months and years afterwards.  Components may be swapped with
other values - 0.1 uf in place of 0.01 uf, 47 pf used where a 470 pf should
be (the 47 pf cap is marked 470 and the 470 pf is marked 471 - easy mistake
to make if one does not follow the instructions carefully).
So you have to judge the builder on two points - the ability to solder
properly and the ability to properly follow written instructions carefully.

The K2 may appear to work just fine with many construction faults, but it
will not display optimum performance.  Proper alignment - especially the IF
filter alignment seems to be one of the major problems with obtaining
optimum performance from the K2 - the 'standard' filter settings will work,
but they can be made much better by the use of Spectrogram or a similar
audio spectrum analyzer - all of the Elecraft builders for hire that I know
about will align your filters with some kind of tool to aid the process, but
the beginner may be satisfied with doing it 'by ear' and the manual
settings.  Of course, you can easily re-do the filter alignment and dial
calibration yourself.

The K2 has a goodly amount of design margin, so it can work with several
faults that occur during the build process, and the inexperienced builder
may not even know they are present.

73,
Don W3FPR

> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]]On Behalf Of Darwin, Keith
> Sent: Tuesday, February 28, 2006 9:18 AM
> To: Elecraft Discussion List
> Subject: [Elecraft] Does build quality affect performance?
>
>
> Hey guys,
>
> Does a K2's performance vary depending on how well it was built?  Is
> there a difference in performance between one built by a pro, one built
> by a beginner who has no problems and one built by a beginner who has
> lots of problems and does rework to correct them?
>
>
> - Keith KD1E -
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
>  http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.375 / Virus Database: 268.1.1/271 - Release Date: 2/28/2006
>
>

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Don Brown-4]

Hi

I would say that depends. If a beginner follows the directions and installs
all of the parts correctly the radio has the potential to perform the same
as a radio built by a pro. The difference is the little tricks you learn
after building several in the alignment. A beginner can get the alignment
right but in my experience it may take several tries to get optimized. Where
the pro will get it the first time. The beginner may not know when something
is not quite right and live with it because he has never had a properly
working K2 to compare it with. I see this sometimes when two owners get
together and compare K2's and notices a difference in one of the rigs. I
have build many K2's and worked on quite a few and unless there is a mistake
in the assembly they all work about the same (very good). Some are not very
pretty inside and others are beautiful but they all work about the same.
What you get from a pro (or someone that has built several) is the
experience of making the mistakes on their first radio so that won't happen
again. I try to build Elecraft products to "display" quality so if you
remove the covers the insides look as good as the outside. I clean all of
the circuit boards except the front panel (you do not want to get flux
residue in the switches or on the display). I use the proper crimp tool for
all of the connectors and cables as well as dozens of other little
techniques learned in over 40 years of electronics experience. The beginner
may not know how to do all of this or may not want to. Does it make the
radio work any better? Probably not. Its just part of being meticulous
(anal?) As to the rework , if it is done carefully it will not make any
difference to the performance although if not done carefully it can make
quite a mess. The proper tools and techniques help a lot in preventing
lifted pads and/or damaged circuit boards and again this takes a little
experience.

It really does not matter who built the radio as long as it was done
correctly. On the alignment do it a few times to get the hang of it and use
Spectrogram on the filters. You should be able to put the K2 right on
frequency and hear little or no frequency shift when you change filters and
get rated power out on all bands. If you are a beginner or a pro the
reflector is a great resource to solve any problems you may encounter.
Someone on the reflector will usually have the answer if not there is always
Gary at Elecraft. He has seen it all.

Don Brown
KD5NDB




----- Original Message -----
From: "Darwin, Keith" <[hidden email]>
To: "Elecraft Discussion List" <[hidden email]>
Sent: Tuesday, February 28, 2006 8:18 AM
Subject: [Elecraft] Does build quality affect performance?


Hey guys,

Does a K2's performance vary depending on how well it was built?  Is
there a difference in performance between one built by a pro, one built
by a beginner who has no problems and one built by a beginner who has
lots of problems and does rework to correct them?


- Keith KD1E -


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com 
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Vic K2VCO]

Darwin, Keith wrote:

> Does a K2's performance vary depending on how well it was built?  Is
> there a difference in performance between one built by a pro, one built
> by a beginner who has no problems and one built by a beginner who has
> lots of problems and does rework to correct them?

My feeling is that as long as all errors are corrected, it really
doesn't matter how skilled the builder was from a performance
standpoint.  If the instructions are followed carefully, the rig will
perform to spec.

However, since the biggest problem that beginners seem to have is poor
soldering, sometimes a beginner's rig may have poor joints that don't
cause problems immediately.
--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Craig Rairdin]

> However, since the biggest problem that beginners seem to have is
> poor soldering, sometimes a beginner's rig may have poor joints
> that don't cause problems immediately.

With that in mind, what are the most common soldering problems? Could we
head off errors by discussing them here or beefing up the material on the
Elecraft Web site on this topic?

Is it:

 * Iron too hot/cold
 * Wrong tip
 * Too much heat applied (damaging part or pad)
 * Bad technique
 * Wrong solder
 * Too much/little solder

Or something else?

Depending on what the symptoms of the problems are, this would also help new
owners choose a builder and help purchasers of used units inspect the work
before buying.

When I decided to build a K1 I spent a lot of time reading the material on
the Elecraft Web site, then I bought a suitable solder station rather than
resurrect my old Radio Shack iron. Both my K1 & K2 turned out great with no
problems in checkout, alignment, or everyday operation, but you have me
worried that I might have screwed up in ways I haven't discovered yet. :-)

Craig
NZ0R
K1 #1966
K2/100 #4941

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[W0rw]

The technical answer is that 'Reliability' is 'Quality' over 'Time'.
R=Q/T, so Quality directly affects Reliability.
Reliability is affected by soldering. Cold soldering (not enough heat or
unclean surfaces) or too much heat. Too much heat can damage components internally.
   One of the most frequent problems is the invasion of flux into variable
resistors and switches. The flux becomes an insulator after it cools and
gets hard. A contaminated part will work for a short time and then become
intermittent or open catastrophically. The soldering quality depends on
getting the flux where it is needed and keeping it out of susceptible areas.
   Parts handling can greatly affect the reliability of the equipment too.
ESD handling precautions must be taken to avoid static damage even after the
equipment is completed.
   Parts placement, bending and strain relief is important.
If a solid part like a switch or potted part is placed directly on a PCB and
soldered
down without strain relief, the temperature cycling over its life can pull the
part leads out of the solder joints.
   Board cleanliness can affect its susceptibility to dendrite growth.
After i build something, i want it to work (perform) the next time i turn it
on.
Quality is very important to the reliability of the equipment.
Paul   w0rw
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Don Brown-4]

Hi

The first problem in soldering is the iron itself. Although a K2 can be
built with a simple soldering iron the problem with most of them is they get
too hot to make up for the lack of capacity. These simple irons have
elements that must reach a reasonable temperature and hold that temperature.
With out any switching or feed back to regulate the iron they tend to be too
hot when not being used and too cold when you try to make a joint. A
soldering station on the other hand has a high capacity heater and a control
circuit or mechanical switch that can sense the tip temperature and apply
the correct amount of power to the tip to keep it at the correct
temperature. I highly recommend buying a temperature controlled soldering
station.

The next mistake is selecting too cold of a tip temperature. This goes
against what you would think as you would expect a hot tip would be more
likely to damage the board but this not the case, within reason. A 700-750
degree iron will heat the joint quicker and allow you to get on make the
joint and get off of the board faster than a 600 degree tip. It is the dwell
time on the board that is more important than the temperature when it comes
to board damage.

The recommended solder is 60/40 rosin core or better yet 63/37 rosin core
solder. Multicore or Kester 44 fit these requirements. 0.031 or preferably
0.025 diameter should be used. Silver solder is NOT recommended because it
is harder to remove in case of a mistake or rework required to install
options. If you have some experience soldering then no-clean flux will make
the board look better but it is harder to make good joints with this solder
because of the low amount of flux in the core. Of course acid core or water
soluble solders should never be used and will void the warranty.

As far as technique this takes some experience. Building one or two of the
mini kits is a good way to start. Every K2-K1-KX1 owner needs a dummy load
so build the DL1 to practice your soldering. Remember to heat the joint not
the solder. The joint should be hot enough to melt the solder when the fresh
solder is applied. Each joint should take about 2-3 seconds to make and the
iron should be removed. If it does not look good allow a few seconds to cool
and retouch the iron for 1 or 2 seconds to reflow the joint do not add more
solder.

One of the other problems is too much solder. Using 0.025 diameter solder
will help here. The pads are plated through so it is not necessary to fill
the hole so it comes through to the other side. Just a smooth fillet on the
bottom of the board is all that is needed. The solder should not be mounded
up into a ball on the pad.

The something else is tinning toroid leads. This is still the number one
problem. The wire needs to be tinned all the way up to the core so when the
wire is pulled tight you are not pulling the insulation down into the pad.
There are many ways to strip and tin the wires. Just make sure you do a good
job here and you will avoid many problems.

Don Brown
KD5NDB




----- Original Message -----
From: "Craig Rairdin" <[hidden email]>
To: <[hidden email]>
Sent: Tuesday, February 28, 2006 10:36 AM
Subject: [Elecraft] Poor soldering (was: Does build quality
affectperformance?)


> However, since the biggest problem that beginners seem to have is
> poor soldering, sometimes a beginner's rig may have poor joints
> that don't cause problems immediately.

With that in mind, what are the most common soldering problems? Could we
head off errors by discussing them here or beefing up the material on the
Elecraft Web site on this topic?

Is it:

 * Iron too hot/cold
 * Wrong tip
 * Too much heat applied (damaging part or pad)
 * Bad technique
 * Wrong solder
 * Too much/little solder

Or something else?

Depending on what the symptoms of the problems are, this would also help new
owners choose a builder and help purchasers of used units inspect the work
before buying.

When I decided to build a K1 I spent a lot of time reading the material on
the Elecraft Web site, then I bought a suitable solder station rather than
resurrect my old Radio Shack iron. Both my K1 & K2 turned out great with no
problems in checkout, alignment, or everyday operation, but you have me
worried that I might have screwed up in ways I haven't discovered yet. :-)

Craig
NZ0R
K1 #1966
K2/100 #4941
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Ron D'Eau Claire-2]

Craig NZ0R asked:

"...what are the most common soldering problems? Could we head off errors by
discussing them here or beefing up the material on the Elecraft Web site on
this topic?"

---------------------

Based on what I've seen I'd say the most common soldering error is not
soldering. Missing joints, especially in the PCB construction we use these
days. A part can sit there in a plated hole for months, sometimes years,
before the connection oxidizes enough to impact performance.

I'd guess that Gary might opine that a more immediate problem with soldering
it the dreaded PTTL (poorly-tinned toroid lead) that proves that a solder
joint can firmly hold a wire and look just perfect - shiny and bright with
solder that obviously flowed well - and still not make electrical connection
to the wire if the wire still had enamel insulation covering it! Actually,
such joints are visible if one knows what to look for. There will be a tiny
dark ring around the wire where it exits the solder. It's easy to miss and
usually requires a very strong magnifier for even the best of eyes to see.
The ring is the circle of blackened enamel on the wire that has not been
penetrated by the solder.

Ron AC7AC

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com