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K2 Alignment and Verification of Specifications

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AC6JA

K2 Alignment and Verification of Specifications

Does Elecraft offer an alignment and verification of specifications service?
I'm sure many people would like to have their K2's aligned to "factory"
specifications and have those performance numbers documented, kind of like having
an oscilloscope calibrated and verified with a sticker.
It would be nice to see what your own individual K2 performance numbers are
against an expensive spectrum analyzer that most of us don't have.
I, for one, would be willing to pay for that service, within reason of
course.
Hopefully there are others that would too that would make this a service
Elecraft could offer?
Any input would be appreciated.
Thanks!

Mike AC6JA
K2 #028
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Bekir Kemal Ataman

K2 Alignment and Verification of Specifications

I second that.

73!
de TA2RX

Mike AC6JAWrote:

>Does Elecraft offer an alignment and verification of specifications service?
>I'm sure many people would like to have their K2's aligned to "factory"
>specifications and have those performance numbers documented, kind of like
>having
>an oscilloscope calibrated and verified with a sticker.
>It would be nice to see what your own individual K2 performance numbers are
>against an expensive spectrum analyzer that most of us don't have.
>I, for one, would be willing to pay for that service, within reason of
>course.
>Hopefully there are others that would too that would make this a service
>Elecraft could offer?

----------------------------------
Bekir Kemal Ataman
ArchiMac BBS Sysop & Webmaster <http://www.archimac.org/>

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Don Wilhelm-3

RE: K2 Alignment and Verification of Specifications

In reply to this post by AC6JA

Mike,

Several 'builders for hire' will offer that service for you if you would
like it done for a fee.

The "Facts of The Case" are that you can Do It Yourself. Follow the
instructions in the K2 manual for peaking the K2 bandpass filters (in
transmit), and set the IF filters using Spectrogram, and you will heve most
all of the critical alignment done. Expensive and exotic lab instruments
are not required.

The 'critical tool' is Spectrogram. You can download the last freeware
version form Tom Hammond's website www.n0ss.net, and use the instructions at
Tom's website, the Elecraft website, or the one that I like best, my website
http://w3fpr.qrpradio.com. All you need to know about aligning the filters
and setting the K2 for accurate dial calibration may be found in my article
on K2 Dial Calibration. It is not hard to do at all, and when you are done,
you can not only say "I built it", but also say "I aligned it to
perfection".

As I said, there is no 'magic', and there are no exotic tools required. You
can 'DIY' with a DMM, and the free Spectrogram program running on your
computer - a wideband noise generator is nice to have, but not essential
(see my website article).

Honest folks, that is all there is to aligning the K2 - try it and see,
nothing exotic, just follow the instructions in the manual and use
Spectrogram as a visual aid for the precision filter alignment.

73,
Don W3FPR

> -----Original Message-----
>
> Does Elecraft offer an alignment and verification of
> specifications service?
> I'm sure many people would like to have their K2's aligned to "factory"
> specifications and have those performance numbers documented,
> kind of like having
> an oscilloscope calibrated and verified with a sticker.
> It would be nice to see what your own individual K2 performance
> numbers are
> against an expensive spectrum analyzer that most of us don't have.
> I, for one, would be willing to pay for that service, within reason of
> course.
> Hopefully there are others that would too that would make this a service
> Elecraft could offer?
> Any input would be appreciated.
> Thanks!
>
> Mike AC6JA
> K2 #028
>

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8:22 AM

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ni0c

RE: K2 Alignment and Verification of Specifications

In reply to this post by AC6JA

As Don, W3FPR has already pointed out, alignment of the K2 is straightforward and requires no test equipment. By following the instructions in the manual, as well as the frequency calibration info provided on Don's website, my dial calibration is now accurate within about 20 Hz, using WWV as a reference. I calibrated my BFO frequencies by ear, using on the air signals. When I have an opportunity to check them using Spectrogram, I expect this will only serve to verify the settings I have.

The most difficult part of the alignment involved the peaking of the various inductors-- only because it was an iterative process. My K2 is receiving at least as good as, and on some bands, better than my Omni 6, Option 1. Pardon my owner's pride, but I really don't see how a factory alignment by Elecraft could improve my K2.

I think my experience demonstrates just how well designed the K2 and its supporting documentation are. People told me how good the K2 was, and everything they told me was true!

73,
Chuck NI0C
K2 s/n 5853
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Jurgen ON5MF

Re: K2 Alignment and Verification of Specifications

Mmm, not really sure about that any more... as stated a few days ago I
have seen the signals transmitted by my K2 (SN 5549) and I'm not really
happy with them (especially on 10-12 and 30m).

Anyhow, in a few days a friend of mine with (semi-) professional will
try to tweak the filters to see if we can improve on that.

Am I one of the only ones who is also interested in the purity of the
transmitted signal and not only in the quality of the receiver?

Chuck Guenther wrote:

> As Don, W3FPR has already pointed out, alignment of the K2 is straightforward and requires no test equipment. By following the instructions in the manual, as well as the frequency calibration info provided on Don's website, my dial calibration is now accurate within about 20 Hz, using WWV as a reference. I calibrated my BFO frequencies by ear, using on the air signals. When I have an opportunity to check them using Spectrogram, I expect this will only serve to verify the settings I have.
>
> The most difficult part of the alignment involved the peaking of the various inductors-- only because it was an iterative process. My K2 is receiving at least as good as, and on some bands, better than my Omni 6, Option 1. Pardon my owner's pride, but I really don't see how a factory alignment by Elecraft could improve my K2.
>
> I think my experience demonstrates just how well designed the K2 and its supporting documentation are. People told me how good the K2 was, and everything they told me was true!
>
> 73,
> Chuck NI0C
> K2 s/n 5853
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>
>
>

Jack Smith-6

Re: K2 Alignment and Verification of Specifications

Jurgen ON5MF wrote:

> Mmm, not really sure about that any more... as stated a few days ago I
> have seen the signals transmitted by my K2 (SN 5549) and I'm not
> really happy with them (especially on 10-12 and 30m).
>
> Anyhow, in a few days a friend of mine with (semi-) professional will
> try to tweak the filters to see if we can improve on that.
>
> Am I one of the only ones who is also interested in the purity of the
> transmitted signal and not only in the quality of the receiver?
>

Jurgen:

I've made some simple receiver sensitivity measurements and posted my
results, along with those made by W5EWA, at
http://www.cliftonlaboratories.com/k2_rx_sensitivity.htm. I also plan to
make some spurious output measurements today and will post those as
well. I've done earlier measurements on my K2 with an HP8558B spectrum
analyzer, but now have a much better Advantek R3463 spectrum analyzer
with an easier way of getting data into the PC.

Do you have specific test frequencies that are of concern to you?

Jack K8ZOA
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Don Wilhelm-3

RE: K2 Alignment and Verification of Specifications

In reply to this post by Jurgen ON5MF

Jurgen,

You will probably find that even with better filter alignment, your spurs
will not be reduced.
I would tend to believe that you have an oscillator in the K2 that is not
behaving properly. You should check both the BFO and VCO for signal purity
with the Spectrum Analyzer and work on the one that is causing your spur
problems - that is not normal.

73,
Don W3FPR

> -----Original Message-----
>
> Mmm, not really sure about that any more... as stated a few days ago I
> have seen the signals transmitted by my K2 (SN 5549) and I'm not really
> happy with them (especially on 10-12 and 30m).
>
> Anyhow, in a few days a friend of mine with (semi-) professional will
> try to tweak the filters to see if we can improve on that.
>
> Am I one of the only ones who is also interested in the purity of the
> transmitted signal and not only in the quality of the receiver?
>

David A. Belsley

Re: K2 Alignment and Verification of Specifications

In reply to this post by AC6JA

Boy, I don't get this one at all. The whole essence of Elecraft,
IMHO, is doing it yourself and getting something really great for the
effort. That's a conjunction: doing it oneself AND getting a great
product. If all you want is the latter, there are plenty of other
sources. And if you want the former, then do the former. It's good
to have self doubts, but they work best when they lead you to do
what's necessary to remove them -- yourself. Don, W3FPR, is a nice
guy and provides a nice answer, but Mike, I hope you don't try to
avail yourself of someone else to tweak your K2. The K2 is really an
amazingly simple rig to align properly, and the necessary
instructions are well stated in the manual or on the Elecraft site.
This is a job you can do for yourself -- just perfectly.

best wishes,

dave belsley, w1euy (getting to be, according to the wife -- among
other people --, an ol' curmudgeon)

On Dec 29, 2006, at 7:56 PM, [hidden email] wrote:

> Does Elecraft offer an alignment and verification of
> specifications service?
> I'm sure many people would like to have their K2's aligned to
> "factory"
> specifications and have those performance numbers documented, kind
> of like having
> an oscilloscope calibrated and verified with a sticker.
> It would be nice to see what your own individual K2 performance
> numbers are
> against an expensive spectrum analyzer that most of us don't have.
> I, for one, would be willing to pay for that service, within reason of
> course.
> Hopefully there are others that would too that would make this a
> service
> Elecraft could offer?
> Any input would be appreciated.
> Thanks!
>
> Mike AC6JA
> K2 #028
> _______________________________________________
> 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

--------------------------------------------
david a belsley
professor of economics
boston college

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Craig Rairdin

RE: K2 Alignment and Verification of Specifications

> Boy, I don't get this one at all. The whole essence of Elecraft,
> IMHO, is doing it yourself and getting something really great for
> the effort.

To each his own. Some people don't have the confidence to do the alignment.
Send me your K2 and $100 (I accept PayPal) and I'll align it to factory
specs. :-)

Craig
NZ0R

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dave-281

Re: K2 Alignment and Verification of Specifications

In reply to this post by David A. Belsley

Seems to me that a few might be missing the main point here. While
assembling a K2 there are a few hundred parts to be stuffed into holes.
It is not all that difficult to stuff the wrong part into a pair of
holes. Seems that I remember a firm (Sherwood Engineering I believe was
the name, but not positive) who loudly and longly claimed that the K2
did not meet its published specs nor those of the ARRL tests. Seems
that the fellow was testing just such a K2 as I'm describing. The
testing firm was not the builder and the builder had made errors. That
sample did indeed not meet spec. When he later tested a good sample the
results fell in line with expectations.

Knowing the propensity of folks to make errors, I'd say that at least
10% of the K2's out there, and maybe as high as 25%, do not meet the
published specs. Although I'm a very careful worker I'm well aware that
the one I built might not meet spec. I don't have the test equip to
fully test it so don't know for sure.

So it does not seem to me to be all that bad of an idea to have someone
who would run assembled K2's through a rigorous series of tests -
similar to those the ARRL does - to assure that a unit is in proper
working order. These would be more than the simple alignment tests
proposed so far in this thread, and would include IMD3 (at 1 or 2 kHz
spacing as well as wider spacings), IMD2, actual sensitivity, and
whatever else was needed to assure that the unit is up to speed.

I would think that anyone buying a used K2 would be interested in such a
service.

I am aware that one cannot make single errors in the assembly process -
if the wrong part is stuffed into a pair of holes then the correct part
must then be stuffed into the wrong pair, making for two errors rather
than one. This means the builder has two chances to catch their error.
But most of us have, at one time or another, bought a used kit, looked
it over carefully and found assembly errors. One small transceiver I
bought - nowhere near as complex as a K2 - had 8 such errors. (And,
yes, the builder claimed to be an expert builder.) Others have had the
far-more-common poor solder joints. This kind of stuff happens every
day. Be good to have a way of testing for it.

73 de dave
ab9ca

David A. Belsley wrote:
> Boy, I don't get this one at all. The whole essence of Elecraft,
> IMHO, is doing it yourself and getting something really great for the
> effort. That's a conjunction: doing it oneself AND getting a great
> product. If all you want is the latter, there are plenty of other
> sources. And if you want the former, then do the former. It's good
> to have self doubts, but they work best when they lead you to do
> what's necessary to remove them -- yourself. Don,
> _______________________________________________

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Bob Miller-6

KAT2 Disable?

In reply to this post by Craig Rairdin

I need to disable the antenna tuner in my K2, while conducting a test.
I can't seem to find a menu option to accomplish this. Any ideas how
to do this?

Thanks,

Bob
wb6kwt

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Don Wilhelm-3

RE: KAT2 Disable?

Bob,

Try the menu parameter for the ATU - either CALP or CALS will bypass the LC
section of the ATU, see the KAT2 (or KAT100) manual.

73,
Don W3FPR

> -----Original Message-----
>
> I need to disable the antenna tuner in my K2, while conducting a test.
> I can't seem to find a menu option to accomplish this. Any ideas how
> to do this?
>

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pc5m, Carel

RE: K2 Alignment and Verification of Specifications

In reply to this post by Jurgen ON5MF

Just measure this:

TX: 28.400, 10W

Spurious found at 27.317 MHz approx 30-40 dB down !. This spur is coming
from (I think) 2 * VCO - 4 * IF (2 * 23.485 - 4 * 4.915)
It depends a lot on the power control setting, if you go above 10W it will
increase a lot and below 10W it will get better, but still at 1W output only
50 dB down. This spur can't be attenuated by the BPF because it can become
very close to the carrier.

Gl,

Carel.

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Jurgen ON5MF
Sent: Saturday, December 30, 2006 2:55 PM
To: [hidden email]
Subject: Re: [Elecraft] K2 Alignment and Verification of Specifications

Mmm, not really sure about that any more... as stated a few days ago I
have seen the signals transmitted by my K2 (SN 5549) and I'm not really
happy with them (especially on 10-12 and 30m).

Anyhow, in a few days a friend of mine with (semi-) professional will
try to tweak the filters to see if we can improve on that.

Am I one of the only ones who is also interested in the purity of the
transmitted signal and not only in the quality of the receiver?

Chuck Guenther wrote:
> As Don, W3FPR has already pointed out, alignment of the K2 is
straightforward and requires no test equipment. By following the
instructions in the manual, as well as the frequency calibration info
provided on Don's website, my dial calibration is now accurate within about
20 Hz, using WWV as a reference. I calibrated my BFO frequencies by ear,
using on the air signals. When I have an opportunity to check them using
Spectrogram, I expect this will only serve to verify the settings I have.
>
> The most difficult part of the alignment involved the peaking of the
various inductors-- only because it was an iterative process. My K2 is
receiving at least as good as, and on some bands, better than my Omni 6,
Option 1. Pardon my owner's pride, but I really don't see how a factory
alignment by Elecraft could improve my K2.
>
> I think my experience demonstrates just how well designed the K2 and its
supporting documentation are. People told me how good the K2 was, and
everything they told me was true!

>
> 73,
> Chuck NI0C
> K2 s/n 5853
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
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>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>
>

--

73

Jurgen Geldhof
ON5MF

[hidden email] <mailto:[hidden email]>

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

my site: www.on5mf.be <http://www.ktk.be>

our club: www.ktk.be <http://www.ktk.be>

the Belgian Amateur Radio Society: www.uba.be
<http://www.uba.be>

------------------------------------------------------------------------
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Don Wilhelm-3

RE: K2 Alignment and Verification of Specifications

In reply to this post by dave-281

Dave,

Yes, I agree. Several folks have sent me their K2 just for such a checkout
and calibration and alignment. I have the advantage of being familiar with
the K2 and its normal behavior. BUT with a little bit of ingenuity, each
builder can determine if his K2 is performing up to par without sending it
away (see below).

I do have an good array of test equipment for testing the receiver path, but
I do not (yet) have a spectrum analyzer here which limits my ability to
check the purity of the transmitter output. I can however do narrow band
spectrum analysis with a block converter to bring a portion of the spectrum
down to baseband where it can be analyzed with Spectrogram or other FFT
analyzer. That technique is good for analyzing near-in transmission
products and works well for driving with a two-tone test signal (the
Elecraft 2T-gen), but would take forever to check the entire spectrum in
that manner (Spectrogram limits the span to about 11kHz).

The time to do a full lab evaluation of any transceiver similar to the ARRL
product evaluation tests would be too costly to consider IMHO. If I were to
do that type of evaluation, I figure I would have to charge something on the
order of $500 to $1000 per test because of the calibration costs and
equipment maintenance that I would have to assume and amortize it over the
number of jobs that I anticipate - I don't believe many hams would like to
spend that kind of money for such a detailed analyis of their K2 - you are
really asking for certification similar to that which would be obtained from
a calibration lab - check their prices for comparison.

Even 'off the assembly line' transceivers do not receive that level of
testing you are suggesting. They would be tested with a few simplified
tests after assembly, but for assembly level testing, the K2 already has the
instructions for the builder in the manual. If one wants a quick additional
check on performance, one can purchase the Elecraft XG1 or XG2 mini-module
and do an MDS test to see if their K2 is performing within the normal
range - cost for that is either $39 or $59, and you have a tool for other
purposes too. Add a CP1 to your toolkit as well and you can drive the input
of a fellow ham's spectrum analyzer if you want to check out the transmit
spectrum. Those mini-modules can offer a lot of test capability, and if one
wishes to learn other methods of using such tools, buy a copy of
Experimental Methods In RF Design and read the chapter on Measurements. It
is amazing how much can be done with only a few pieces of precision test
equipment - one oscilliscope whose vertical deflection has been verified
(see my website for a Voltage 'standard') can go a long way to calibrating
other measurement devices - it may not be to calibration lab standards, but
it is usually acceptable for ham use.

73,
Don W3FPR

> -----Original Message-----
>
> Seems to me that a few might be missing the main point here. While
> assembling a K2 there are a few hundred parts to be stuffed into holes.
> It is not all that difficult to stuff the wrong part into a pair of
> holes. Seems that I remember a firm (Sherwood Engineering I believe was
> the name, but not positive) who loudly and longly claimed that the K2
> did not meet its published specs nor those of the ARRL tests. Seems
> that the fellow was testing just such a K2 as I'm describing. The
> testing firm was not the builder and the builder had made errors. That
> sample did indeed not meet spec. When he later tested a good sample the
> results fell in line with expectations.
>
> Knowing the propensity of folks to make errors, I'd say that at least
> 10% of the K2's out there, and maybe as high as 25%, do not meet the
> published specs. Although I'm a very careful worker I'm well aware that
> the one I built might not meet spec. I don't have the test equip to
> fully test it so don't know for sure.
>
> So it does not seem to me to be all that bad of an idea to have someone
> who would run assembled K2's through a rigorous series of tests -
> similar to those the ARRL does - to assure that a unit is in proper
> working order. These would be more than the simple alignment tests
> proposed so far in this thread, and would include IMD3 (at 1 or 2 kHz
> spacing as well as wider spacings), IMD2, actual sensitivity, and
> whatever else was needed to assure that the unit is up to speed.
>
> I would think that anyone buying a used K2 would be interested in such a
> service.
>
> I am aware that one cannot make single errors in the assembly process -
> if the wrong part is stuffed into a pair of holes then the correct part
> must then be stuffed into the wrong pair, making for two errors rather
> than one. This means the builder has two chances to catch their error.
> But most of us have, at one time or another, bought a used kit, looked
> it over carefully and found assembly errors. One small transceiver I
> bought - nowhere near as complex as a K2 - had 8 such errors. (And,
> yes, the builder claimed to be an expert builder.) Others have had the
> far-more-common poor solder joints. This kind of stuff happens every
> day. Be good to have a way of testing for it.
>
> 73 de dave
> ab9ca
>
>
>
>
>
> David A. Belsley wrote:
> > Boy, I don't get this one at all. The whole essence of Elecraft,
> > IMHO, is doing it yourself and getting something really great for the
> > effort. That's a conjunction: doing it oneself AND getting a great
> > product. If all you want is the latter, there are plenty of other
> > sources. And if you want the former, then do the former. It's good
> > to have self doubts, but they work best when they lead you to do
> > what's necessary to remove them -- yourself. Don,
> > _______________________________________________
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
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>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
> --
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Geoffrey Mackenzie-Kennedy-2

Re: K2 Alignment and Verification of Specifications

In reply to this post by AC6JA

Mike,

If you have the time to do it, I believe that it is well worthwhile arming
yourself with test equipment to do the job yourself. Although this sounds
like a tall order, most of the test and calibration equipment required to
check the K2 can be in fact be homebrewed, which obviously takes time but
saves $$ and which can be used when building other things. The ham
literature contains some designs which could be useful including at least
one for a spectrum analyzer and several low phase noise oscillators (QEX).
If you do go down this route, a pair of honest step attenuators capable of
60db or more attenuation over the required frequency range and into VHF are
critical items, I 'rescued' my 90 db step attenuators from a German
Standards Lab for peanuts. For the more 'difficult' measurements such as
receiver Input Intercepts where two or more signals are involved (ARRL uses
only two) various items are available from Mini-Circuits such as power
splitters / combiners which can be used to set up a RF test bench without
too much difficulty or cost, using double screened coax interconnections.
BTW I do not work for them!

I believe that the saying 'practice makes perfect' is applicable here, and
doing the tests oneself is interesting and helps to prevent future build
mistakes.

73,
Geoff
GM4ESD

----- Original Message -----
From: <[hidden email]>
To: <[hidden email]>
Sent: Saturday, December 30, 2006 12:56 AM
Subject: [Elecraft] K2 Alignment and Verification of Specifications

> Does Elecraft offer an alignment and verification of specifications
> service?
> I'm sure many people would like to have their K2's aligned to "factory"
> specifications and have those performance numbers documented, kind of like
> having
> an oscilloscope calibrated and verified with a sticker.
> It would be nice to see what your own individual K2 performance numbers
> are
> against an expensive spectrum analyzer that most of us don't have.
> I, for one, would be willing to pay for that service, within reason of
> course.
> Hopefully there are others that would too that would make this a service
> Elecraft could offer?
> Any input would be appreciated.
> Thanks!
>
> Mike AC6JA
> K2 #028
>

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ni0c

Re: K2 Alignment and Verification of Specifications

In reply to this post by ni0c

Geoff, G3NAQ wrote:

> So I have installed a dummy panel in the shack on which a number of
> difficult-to-adjust trimmers and coils are mounted, all requiring
different
> trimming tools which I usually have to hunt around to find. Thus, when I
> hear that weak DX I just can't copy, and get those twiddler's withdrawl
> symptoms, I just go to this panel where I have something to 'optimise'!
>
> This doesn't help with the DX, and hasn't cured my problem, but it does
> relieve the symptoms.
>
> Geoff G3NAQ

My winter antenna is a ground-mounted vertical for the lowbands. Whenever I
get beat up in a pileup, I go out and install a couple more radials. (I
have lots of radials!)

73,
Chuck NI0C

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dave-281

Re: K2 Alignment and Verification of Specifications

In reply to this post by Don Wilhelm-3

Don,

Not sure the price for the tests required would be as steep as you
mention. I think it would be an expense that some would be willing to
pay to be assured that the rig they are using is up to speed. Remember
we are not looking for 1 dB or even 3 dB here, we expect to find
elephants. The calibration of the gear should not be terribly
critical. If someone has placed a .047 in where a 47 pf belongs (I have
found that exact problem) the effects are apt to be noticeable.

The needed test equip could be home brewed. EMRFD by Hayward, et al,
has designs for it. If I understand it all correctly the biggest
problem is getting oscillators that are strong enough and clean enough
to do the IMD and other dynamic range tests. Seems to me a couple of
crystal controlled oscillators driving clean amps should do the job.
The Elecraft mini modules are adequate for sensitivity testing. I don't
believe it would be necessary to test the K2's full IMD3 dynamic range,
which IIRC is north of 130 dB. Remember that we expect to find
elephants. Testing to 100 dB or so should be adequate. And test
equipment for that range is easier to come by.

When I suggest doing something similar to the ARRL tests, I'm thinking
the needed tests, but not to the level of precision that is done there.

There are other ways to go about it. One you mention - having someone
with quite a lot of experience check out the rig to see how it compares
to others. An individual with access to 2 or 3 other K2's could do this
on their own - if they could borrow the rigs long enough for an adequate
testing period. No real test equipment required. With over 5000 K2's
out there now, this one should be available to almost all builders.
Whether or not one should trust a comparison to a single K2 is an open
question.

Someone such as yourself, and a number of others, are quite capable of
sitting a rig on the bench and running some a/b type tests and knowing
whether there is a real problem.

Another approach is to do a full audit of each board to be sure each
component is in the correct location. This requires nothing except the
assembly manual and a good magnifier. But quite a few of the components
cannot be read once installed. I've not tried this and it may be easier
than I think.

The K2 is an excellent design and if the boards are populated and
soldered correctly, it will work up to spec. It is simply experience
that makes me raise a caution flag. This type of
testing/verification/comparison is something I'd think buyers of used
K2's would be interested in.

You mention that factory assembled rigs do not go through the testing I
mentioned, and this is true. But they are assembled in a very different
environment. Most are machine assembled and errors are either zero or
100%. Those are easier to find. Those factories that do hand assembly
are more likely to have problems, but about all such factories have a
few "Don's" around who know exactly the expected results from each
module or subassembly. Errors are generally spotted quickly and
corrected. This is *not* to say that factory assembled rigs come with
zero defects, but their percentage is lower, much lower, than home
assembled kits (MFJ excluded).

73 de dave
ab9ca

Don Wilhelm wrote:
> Dave,
>
> Yes, I agree. Several folks have sent me their K2 just for such a checkout
> and calibration and alignment. I have the advantage of being familiar with
> the K2 and its normal behavior. BUT with a little bit of ingenuity, each
> builder can determine if his K2 is performing up to par without sending it
> away (see below).
>
>

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Ian Stirling, G4ICV, AB2GR

Re: K2 Alignment and Verification of Specifications (do an inventory)

In reply to this post by dave-281

On Saturday 30 December 2006 11:11, dave wrote:

> I am aware that one cannot make single errors in the assembly process -
> if the wrong part is stuffed into a pair of holes then the correct part
> must then be stuffed into the wrong pair, making for two errors rather
> than one.

This leads me to the first job on opening the box of parts.
Mistakes of that kind are most likely because some parts have been
misidentified, probably as a result of digging through an unsorted
pile of parts.
I think there is an idea amongst some builders that doing a
complete inventory before getting out the soldering iron is time
taken from building.
Every part in a K2 has to be identified for its position:
whether that is done rumaging through unsorted parts or retrieving
from a sorted inventory, the time taken to find the part is just
about the same. It might take a little longer noting in the manual
just where the sorted part is, but building is much more enjoyable,
at least for me, when I can fetch a part when I need it knowing
exactly where it is.
During the inventory, some parts can be identified by elimination
and subsequent recognition of the markings on it.

I use a set of partitioned drawers. During the inventory check,
I identify and store the parts in a partition of a drawer and note
in the manual the drawer number and the partition letter.
Many parts can be mixed in the same space, such as 10 uF electrolytic
capacitors and 220 pF capacitors. Certainly a 2N7000 in the same place
could not be confused with either of the capacitors.
It takes surprisingly few drawers and partitions to sort completely
a K2's inventory so that retrieval is almost guaranteed to result
in the correct part.

Check again when taking the part from its indexed place and
check that the location it is going to is its destination.
Then pick up the soldering iron.

Ian, G4ICV, AB2GR, K2 #4962, N8LP LP-100 #278
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David Walker-8

Re: K2 Alignment and Verification of Specifications

In reply to this post by AC6JA

I asked Gary at Elecraft if he finds much variation in performance with
the radios he works on and repairs. I recall he said that if the radios
have been built correctly there is no variation between radios. I have
compared my rig to the PROII and I could not detected any difference in
relation to sensitivity. My only weakness in my station setup is my
antenna.
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