Elecraft

KX-1 assembly question

Classic

List

Threaded

8 messages Options

Doug Person

KX-1 assembly question

Hi Folks,

I'm building a KX-1. I just completed Assembly Part II. Unfortunately,
I can't perform Alignment and Test - Part II because my kit was short
the two little 5-20 pf trimmers. While I'm waiting for these parts to
arrive, does anyone think there would be any issues with completing the
remaining assembly steps and coming back to Alignment and Test - Part II
later?

Thanks,

Doug -- K0DXV
_______________________________________________
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

RE: KX-1 assembly question

Doug,

The real answer depends on your confidence level that you have already made
no errors in the assembly.
It really will not hurt anything, but it complicates matters for debugging
if you had made an assembly error.

If you ordered the trimmers already, it should take no longer than 4-5 days
for them to arrive at your mailbox.

73,
Don W3FPR

> -----Original Message-----
>
> I'm building a KX-1. I just completed Assembly Part II. Unfortunately,
> I can't perform Alignment and Test - Part II because my kit was short
> the two little 5-20 pf trimmers. While I'm waiting for these parts to
> arrive, does anyone think there would be any issues with completing the
> remaining assembly steps and coming back to Alignment and Test - Part II
> later?
>
> Thanks,
>
> Doug -- K0DXV
>

_______________________________________________
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

johnny-52

KAT2 power calibration

HI Don and the Group

I have recently got Larry’s LP100 digital wattmeter (factory calibrated).
I therefore used it to re-do the power calibration of KAT2 with K2. I did
it according to the manual by adjusting R1 to get a matched reading between
K2 and LP100. The K2 was set at 7100khz.

However, I noted the following:

For 17, 15, 12, 10m �C the power output reading in K2 is higher than that
of LP100;
For 80, 160m �C the power output reading in K2 is lower than that of LP100

Is this a normal observation ????

I also take this chance to realign the output power of my K2 especially the
10m band. Gary’s advice in the email resource page does really work. I
got higher output on 10m by expanding or / and compressing L21 & L22 and
T2. I also did the same for T1 and got slightly power after the previous
step.

TNX & 73

Johnny Siu VR2XMC

_________________________________________________________________
与联机的朋友进行交流，请使用 Live Messenger;
http://get.live.com/messenger/overview

_______________________________________________
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

Doug Person

Re: KX-1 assembly question

In reply to this post by Don Wilhelm-3

Hi Don,

Thanks for your input. I guess I'm pretty confident. I built K2 #1920
with all the accessories as well as a K1. I've learned to be extremely
careful. I was just wondering if any of the tests and alignment
procedures were depending on the remaining parts not being installed yet.

I'm very impressed with the design of the KX-1. Can't wait to pound out
my first CQ...

Doug -- KØDXV

Don Wilhelm wrote:
> Doug,
>
>

> The real answer depends on your confidence level that you have already made
> no errors in the assembly.
> It really will not hurt anything, but it complicates matters for debugging
> if you had made an assembly error.
>
> If you ordered the trimmers already, it should take no longer than 4-5 days
> for them to arrive at your mailbox.
>
> 73,
> Don W3FPR
>
>
>> -----Original Message-----
>>
>> I'm building a KX-1. I just completed Assembly Part II. Unfortunately,
>> I can't perform Alignment and Test - Part II because my kit was short
>> the two little 5-20 pf trimmers. While I'm waiting for these parts to
>> arrive, does anyone think there would be any issues with completing the
>> remaining assembly steps and coming back to Alignment and Test - Part II
>> later?
>>
>> Thanks,
>>
>> Doug -- K0DXV
>>
>>
>
> _______________________________________________
> 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

RE: KAT2 power calibration

In reply to this post by johnny-52

Johnny,

Things are not always perfect, so you can expect some variation.
The 1N5711s in the KAT2 are not entirely frequency independent, and the
detector in the LP100 is similarly frequency dependent. The exact results
will vary with the particular 1N5711 diode that is in your KAT2 and the
particular diode detector in your LP100.

OTOH, you have to believe something. Take into consideration the potential
errors of everything in the calibration chain:
My previous emails with Larry have revealed that he uses an HP836A for his
reference - consider that the HP836A is good to 2% (that is optimistic) -
then, your LP100 may be good to 5% of the actual reading, and the KAT2 may
also be good to 5% of the actual reading, the total window for error is
12% - you said only that the KAT2 reading is higher than that of the LP100,
but you failed to say by how much. I would expect that it should be well
within my optimistic error of 12% (1.2 watts at a 10 watt level).

This is a lesson in calibration practices - every potential error in the
calibration system must be accounted for. If you want to obtain labratory
standard practice, the standard should be 10 times more accurate than the
device being calibrated. I doubt you will find that level acceptable in any
wattmeters available today. You may just have to be satisfied with some
reasonable discrepancy. Alas, it is not a perfect world, especially not in
the wattmeter arena.

All in all, I have found that the KAT2 agrees with my 100 MHz 'scope (and
150 MHz probes) and and along woth my precision dummy loads I can achieve a
KAT2 calibration within 5% across all bands. I believe the LP100 is rated
at 5% too. So if you are no more than 10% different between the two, you
are doing pretty good. That is a whole lot better than the 'run of mill'
amateur grade wattmeter which is speced at 20% of full scale.

Your output power 'tweaking' is not related to the power output reported by
the KAT2, but I am glad that you achieved good results by using Gary's
advice. If you have an antenna analyzer, you can 'tweak' the LPF for the
best SWR across the bands and obtain even better results than those obtained
by 'tweaking' for maximun power output. If you attempt that, be certain
that you terminate the LPF in 50 ohms - which means removing the W1 jumper
and inserting a 50 ohm load (this can be done easily at the K160RX header if
you have that option installed).

73,
Don W3FPR

> -----Original Message-----
>
> I have recently got Larry’s LP100 digital wattmeter (factory
> calibrated).
> I therefore used it to re-do the power calibration of KAT2 with
> K2. I did
> it according to the manual by adjusting R1 to get a matched
> reading between
> K2 and LP100. The K2 was set at 7100khz.
>
> However, I noted the following:
>
> For 17, 15, 12, 10m �C the power output reading in K2 is higher than that
> of LP100;
> For 80, 160m �C the power output reading in K2 is lower than that of LP100
>
> Is this a normal observation ????
>
> I also take this chance to realign the output power of my K2
> especially the
> 10m band. Gary’s advice in the email resource page does really work. I
> got higher output on 10m by expanding or / and compressing L21 & L22 and
> T2. I also did the same for T1 and got slightly power after the previous
> step.
>
> TNX & 73
>
> Johnny Siu VR2XMC
>
> _________________________________________________________________
> 与联机的朋友进行交流，请使用 Live Messenger;
> http://get.live.com/messenger/overview
>
> _______________________________________________
> 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: 7.1.409 / Virus Database: 268.13.28/518 - Release Date: 11/4/2006
>
>

johnny-52

Adjustment for more output power for K2

Hi Don,

Thanks a million. You have just hit the nail on its head. Yes, correct,
the difference in power output readings between K2 and LP100 is within 10%.
It is wonderful to have you in this reflector. Bearing in mind, I am not a
radio man by profession and can easily head to the wrong direction.

Could please advise how I can use antenna analyser to achieve better power
output with the LPF? Do you mean feeding the output of the antenna
analyser to the antenna jack with W1 terminated with 50 ohm load?

Thanks a lot indeed. Playing with K2 is really another kind of fun which
cannot be obtained from factory made transceivers. Regrettably, there are
not many hams in Hong Kong exploring this area.

TNX & 73,

Johnny Siu VR2XMC

From: "Don Wilhelm" <[hidden email]>
Reply-To: <[hidden email]>
To: "Siu Johnny" <[hidden email]>,<[hidden email]>
Subject: RE: [Elecraft] KAT2 power calibration
Date: Tue, 7 Nov 2006 00:09:59 -0500

Johnny,

Things are not always perfect, so you can expect some variation.
The 1N5711s in the KAT2 are not entirely frequency independent, and the
detector in the LP100 is similarly frequency dependent. The exact results
will vary with the particular 1N5711 diode that is in your KAT2 and the
particular diode detector in your LP100.

OTOH, you have to believe something. Take into consideration the potential
errors of everything in the calibration chain:
My previous emails with Larry have revealed that he uses an HP836A for his
reference - consider that the HP836A is good to 2% (that is optimistic) -
then, your LP100 may be good to 5% of the actual reading, and the KAT2 may
also be good to 5% of the actual reading, the total window for error is
12% - you said only that the KAT2 reading is higher than that of the LP100,
but you failed to say by how much. I would expect that it should be well
within my optimistic error of 12% (1.2 watts at a 10 watt level).

This is a lesson in calibration practices - every potential error in the
calibration system must be accounted for. If you want to obtain labratory
standard practice, the standard should be 10 times more accurate than the
device being calibrated. I doubt you will find that level acceptable in
any
wattmeters available today. You may just have to be satisfied with some
reasonable discrepancy. Alas, it is not a perfect world, especially not in
the wattmeter arena.

All in all, I have found that the KAT2 agrees with my 100 MHz 'scope (and
150 MHz probes) and and along woth my precision dummy loads I can achieve a
KAT2 calibration within 5% across all bands. I believe the LP100 is rated
at 5% too. So if you are no more than 10% different between the two, you
are doing pretty good. That is a whole lot better than the 'run of mill'
amateur grade wattmeter which is speced at 20% of full scale.

Your output power 'tweaking' is not related to the power output reported by
the KAT2, but I am glad that you achieved good results by using Gary's
advice. If you have an antenna analyzer, you can 'tweak' the LPF for the
best SWR across the bands and obtain even better results than those
obtained
by 'tweaking' for maximun power output. If you attempt that, be certain
that you terminate the LPF in 50 ohms - which means removing the W1 jumper
and inserting a 50 ohm load (this can be done easily at the K160RX header
if
you have that option installed).

73,
Don W3FPR

_________________________________________________________________
与联机的朋友进行交流，请使用 Live Messenger;
http://get.live.com/messenger/overview

_______________________________________________
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

RE: Sweeping the LPF in the base K2.

Johnny,

To sweep the LPF in the K2 with an antenna analyzer, you must terminate the
LPF with a 50 ohm resistor (51 ohms is a close enough standard value).
Terminating the LPF is easy if you have the K160RX header installed - simply
put the resistor leads between pins 7 and 2 of the K160RX header.
If the K160RX is not installed, W1 must be removed and the resistor
connected between the right end of W1 and ground.

To accomplish the sweep, select the band of interest and power off the K2 -
connect the analyzer to the antenna jack and sweep across the band. You
will not likely see a perfect SWR=1, but you will definitely see a low SWR
and be able to observe the SWR climb as you approach the cutoff frequency.
It is an easy and interesting exercise in observing filter behavior with
frequency if you have never swept a filter before. For those filters with
capacitors in parallel with the inductors (eliptical filters), you can see
the very sharp increaase in SWR as you approach the resonance points.

73,
Don W3FPR

> -----Original Message-----
>
> Could please advise how I can use antenna analyser to achieve
> better power
> output with the LPF? Do you mean feeding the output of the antenna
> analyser to the antenna jack with W1 terminated with 50 ohm load?
>
>
> Johnny Siu VR2XMC
>
>

N8LP

Re: Adjustment for more output power for K2

In reply to this post by johnny-52

Measuring power is not as easy as one might think. The lab where I had
my HP-436A calibrated told me they thought it would be safe to advertise
an LP-100 calibrated against it at 0.1 dB accuracy. That works out to
~2.3%. If I recall correctly, their reference had a certificate that
said something between 0.01 and 0.02 dB compared to an NIST primary
reference. They have their equipment re-certified once a year, but at
those levels, even temperature and humidity can make a difference.

I don't feel comfortable claiming a 2% accuracy and so rate the LP-100
at 5%, but several owners with access to NIST traceable lab
instrumentation have verified a 2-3% accuracy.

One thing to remember about the LP-100 is that I calibrate the meter at
the center of each band to within 0.1% of my HP-436A, and of course the
correction values for each band are saved and recalled based on the
reading of the internal frequency counter in the meter. Because of this,
the relative band-to-band error of the LP-100 should be very close to
that of the HP-436A.

73,
Larry N8LP

Siu Johnny wrote:

> Hi Don,
>
> Thanks a million. You have just hit the nail on its head. Yes,
> correct, the difference in power output readings between K2 and LP100
> is within 10%. It is wonderful to have you in this reflector. Bearing
> in mind, I am not a radio man by profession and can easily head to the
> wrong direction.
>
> Could please advise how I can use antenna analyser to achieve better
> power output with the LPF? Do you mean feeding the output of the
> antenna analyser to the antenna jack with W1 terminated with 50 ohm load?
>
> Thanks a lot indeed. Playing with K2 is really another kind of fun
> which cannot be obtained from factory made transceivers. Regrettably,
> there are not many hams in Hong Kong exploring this area.
>
> TNX & 73,
>
> Johnny Siu VR2XMC
>
>
>
> From: "Don Wilhelm" <[hidden email]>
> Reply-To: <[hidden email]>
> To: "Siu Johnny" <[hidden email]>,<[hidden email]>
> Subject: RE: [Elecraft] KAT2 power calibration
> Date: Tue, 7 Nov 2006 00:09:59 -0500
>
> Johnny,
>
> Things are not always perfect, so you can expect some variation.
> The 1N5711s in the KAT2 are not entirely frequency independent, and the
> detector in the LP100 is similarly frequency dependent. The exact results
> will vary with the particular 1N5711 diode that is in your KAT2 and the
> particular diode detector in your LP100.
>
> OTOH, you have to believe something. Take into consideration the
> potential
> errors of everything in the calibration chain:
> My previous emails with Larry have revealed that he uses an HP836A for
> his
> reference - consider that the HP836A is good to 2% (that is optimistic) -
> then, your LP100 may be good to 5% of the actual reading, and the KAT2
> may
> also be good to 5% of the actual reading, the total window for error is
> 12% - you said only that the KAT2 reading is higher than that of the
> LP100,
> but you failed to say by how much. I would expect that it should be well
> within my optimistic error of 12% (1.2 watts at a 10 watt level).
>
> This is a lesson in calibration practices - every potential error in the
> calibration system must be accounted for. If you want to obtain
> labratory
> standard practice, the standard should be 10 times more accurate than the
> device being calibrated. I doubt you will find that level acceptable
> in any
> wattmeters available today. You may just have to be satisfied with some
> reasonable discrepancy. Alas, it is not a perfect world, especially
> not in
> the wattmeter arena.
>
> All in all, I have found that the KAT2 agrees with my 100 MHz 'scope (and
> 150 MHz probes) and and along woth my precision dummy loads I can
> achieve a
> KAT2 calibration within 5% across all bands. I believe the LP100 is
> rated
> at 5% too. So if you are no more than 10% different between the two, you
> are doing pretty good. That is a whole lot better than the 'run of mill'
> amateur grade wattmeter which is speced at 20% of full scale.
>
> Your output power 'tweaking' is not related to the power output
> reported by
> the KAT2, but I am glad that you achieved good results by using Gary's
> advice. If you have an antenna analyzer, you can 'tweak' the LPF for the
> best SWR across the bands and obtain even better results than those
> obtained
> by 'tweaking' for maximun power output. If you attempt that, be certain
> that you terminate the LPF in 50 ohms - which means removing the W1
> jumper
> and inserting a 50 ohm load (this can be done easily at the K160RX
> header if
> you have that option installed).
>
> 73,
> Don W3FPR
>
> _________________________________________________________________
> ÓëÁª»úµÄÅóÓÑ½øÐÐ½»Á÷£¬ÇëÊ¹ÓÃ Live Messenger;
> http://get.live.com/messenger/overview
> _______________________________________________
> 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
>
>
>