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K2 Armor

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Fernando Quinones

K2 Armor

Hello readers.

If your recall some months ago, I was looking for some leather cases
for my K2.
Unfortunately, they are a bit pricey for what I was looking for.

However, I've come across this fellow who makes great looking paddles.
In one of his pages, I spied a K1 with what he calls Armor plates.

I have since order the ones for the K2. The price is a bit more
manageable
then the leather case or the other protective plates that where
offered here
awhile back.

Have a look at the bottom of his page. < http://
www.saylorsmachine.com/ >

All disclaimers apply.

Happy Holidays to all.

Fernando N2FQ
<http://pages.sbcglobal.net/n2fq>

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N8LP

K2 dead xmtr

OK. I'm hoping someone has seen this before I start tearing into things
(and tearing my hair out).

My K2 started to lose power yesterday. Within an hour, the output
dropped to close to zero (1mW on 160m, 40mW on 10m). There are no signs
of distress or burning odors.

I checked the ALC... pinned at 5v. Everything looks good in terms of
levels/frequencies thru the XMIT mixer and filters, except the rf levels
are higher than indicated in the manual. I suspect this is due to the
ALC being wide open.

The dc levels for Q5, Q6, and Q7-8 bases are normal, and the resistance
checks on Q7-8 are OK. 8T looks fine. But the rf levels are all
considerably high, and look pretty ratty except on 10m. The rig draws
about 600ma in xmit.

Anyone seen this before?

Larry N8LP
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Don Wilhelm-3

RE: K2 dead xmtr

Larry,

Exactly where are the RF levels higher than normal? Obviously not at the
output of the Low Pass filter or you would have power output (unless you
have the tuner and have set it to ANT2 instead of ANT1 or something like
that).

With the requested power set at 5 watts, send us the RF Voltage levels at
the W6 jumper, Q5 collector (case), Q6 collector (tab), Q7,Q8 base, and the
RF Output jack. With that info, we should be able to home in on the problem
area.

73,
Don W3FPR

> -----Original Message-----
>
> OK. I'm hoping someone has seen this before I start tearing into things
> (and tearing my hair out).
>
> My K2 started to lose power yesterday. Within an hour, the output
> dropped to close to zero (1mW on 160m, 40mW on 10m). There are no signs
> of distress or burning odors.
>
> I checked the ALC... pinned at 5v. Everything looks good in terms of
> levels/frequencies thru the XMIT mixer and filters, except the rf levels
> are higher than indicated in the manual. I suspect this is due to the
> ALC being wide open.
>
> The dc levels for Q5, Q6, and Q7-8 bases are normal, and the resistance
> checks on Q7-8 are OK. 8T looks fine. But the rf levels are all
> considerably high, and look pretty ratty except on 10m. The rig draws
> about 600ma in xmit.
>
> Anyone seen this before?
>
> Larry N8LP
>

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N8LP

Re: K2 dead xmtr

Hi Don. The levels are high everywhere in the chain up through the bases
of Q7-8. Requested power is immaterial in this case, since the ALC sees
zero detected power, and therefore is pegged at 5v all the time.

I measured the levels with a scope, and divided the p-p values by 2.82
to compare with the voltage probe reference levels in the manual. BTW, I
removed the KAT2 and KSB2 to simplify access and minimize the number of
possible fault zones.

W6 - .28 Vrms
Q5 case- 1.4 Vrms
Q6 tab- 3.5 Vrms
Q7,8 base- 1.4 Vrms
RF out- .55 Vrms

Note: These waveforms are pretty dirty looking except on 10m, where I
made these measurements.

Larry N8LP

Don Wilhelm wrote:

>Larry,
>
>With the requested power set at 5 watts, send us the RF Voltage levels at
>the W6 jumper, Q5 collector (case), Q6 collector (tab), Q7,Q8 base, and the
>RF Output jack. With that info, we should be able to home in on the problem
>area.
>
>73,
>Don W3FPR
>
>
>
>>-----Original Message-----
>>
>>OK. I'm hoping someone has seen this before I start tearing into things
>>(and tearing my hair out).
>>
>>My K2 started to lose power yesterday. Within an hour, the output
>>dropped to close to zero (1mW on 160m, 40mW on 10m). There are no signs
>>of distress or burning odors.
>>
>>I checked the ALC... pinned at 5v. Everything looks good in terms of
>>levels/frequencies thru the XMIT mixer and filters, except the rf levels
>>are higher than indicated in the manual. I suspect this is due to the
>>ALC being wide open.
>>
>>The dc levels for Q5, Q6, and Q7-8 bases are normal, and the resistance
>>checks on Q7-8 are OK. 8T looks fine. But the rf levels are all
>>considerably high, and look pretty ratty except on 10m. The rig draws
>>about 600ma in xmit.
>>
>>Anyone seen this before?
>>
>>Larry N8LP
>>
>>
>>
>
>
>
>
>
>

Don Wilhelm-3

RE: K2 dead xmtr

Larry,

With those RF voltage measurements, I would say that the final output
transistors have likely failed - that goes along with your earlier report
that the power out decreased rapidly to zip.

There is only one other possibility that I can think of, and that would be
the transmit signal being shorted somewhere - so before blaming the finals
themselves, check that Q2 is operating properly - the juction of D3 and D4
in the TR switch should be at a low voltage during receive and go up
somewhere close to 8 volts during transmit.

If the receiver is still functioning properly, a short in the Low Pass
Filter is quite unlikly because that kind of fault would drag the receiver
way down too.

73,
Don W3FPR

> -----Original Message-----
> From: Larry Phipps [mailto:[hidden email]]
> Sent: Sunday, December 11, 2005 10:46 PM
> To: [hidden email]
> Cc: [hidden email]
> Subject: Re: [Elecraft] K2 dead xmtr
>
>
>
> Hi Don. The levels are high everywhere in the chain up through the bases
> of Q7-8. Requested power is immaterial in this case, since the ALC sees
> zero detected power, and therefore is pegged at 5v all the time.
>
> I measured the levels with a scope, and divided the p-p values by 2.82
> to compare with the voltage probe reference levels in the manual. BTW, I
> removed the KAT2 and KSB2 to simplify access and minimize the number of
> possible fault zones.
>
> W6 - .28 Vrms
> Q5 case- 1.4 Vrms
> Q6 tab- 3.5 Vrms
> Q7,8 base- 1.4 Vrms
> RF out- .55 Vrms
>
> Note: These waveforms are pretty dirty looking except on 10m, where I
> made these measurements.
>
> Larry N8LP
>
>
>
> Don Wilhelm wrote:
>
> >Larry,
> >
> >With the requested power set at 5 watts, send us the RF Voltage levels at
> >the W6 jumper, Q5 collector (case), Q6 collector (tab), Q7,Q8
> base, and the
> >RF Output jack. With that info, we should be able to home in on
> the problem
> >area.
> >
> >73,
> >Don W3FPR
> >
> >
> >
> >>-----Original Message-----
> >>
> >>OK. I'm hoping someone has seen this before I start tearing into things
> >>(and tearing my hair out).
> >>
> >>My K2 started to lose power yesterday. Within an hour, the output
> >>dropped to close to zero (1mW on 160m, 40mW on 10m). There are no signs
> >>of distress or burning odors.
> >>
> >>I checked the ALC... pinned at 5v. Everything looks good in terms of
> >>levels/frequencies thru the XMIT mixer and filters, except the rf levels
> >>are higher than indicated in the manual. I suspect this is due to the
> >>ALC being wide open.
> >>
> >>The dc levels for Q5, Q6, and Q7-8 bases are normal, and the resistance
> >>checks on Q7-8 are OK. 8T looks fine. But the rf levels are all
> >>considerably high, and look pretty ratty except on 10m. The rig draws
> >>about 600ma in xmit.
> >>
> >>Anyone seen this before?
> >>
> >>Larry N8LP
> >>
> >>
> >>
> >
> >
> >
> >
> >
> >
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.371 / Virus Database: 267.13.13/198 - Release Date:
> 12/12/2005
>
>

N8LP

Re: K2 dead xmtr

I think I checked the T/R switch already, but I'll double-check. The
thing that's weird is that the DC voltages and resistance checks on the
finals are OK. I never got a Hi-Cur warning at any time before the
failure (or since). The rig draws about 600ma during xmit.

Thanks for the feedback.

Larry N8LP

Don Wilhelm wrote:

>Larry,
>
>With those RF voltage measurements, I would say that the final output
>transistors have likely failed - that goes along with your earlier report
>that the power out decreased rapidly to zip.
>
>There is only one other possibility that I can think of, and that would be
>the transmit signal being shorted somewhere - so before blaming the finals
>themselves, check that Q2 is operating properly - the juction of D3 and D4
>in the TR switch should be at a low voltage during receive and go up
>somewhere close to 8 volts during transmit.
>
>If the receiver is still functioning properly, a short in the Low Pass
>Filter is quite unlikly because that kind of fault would drag the receiver
>way down too.
>
>73,
>Don W3FPR
>
>
>
>
>
>>-----Original Message-----
>>From: Larry Phipps [mailto:[hidden email]]
>>Sent: Sunday, December 11, 2005 10:46 PM
>>To: [hidden email]
>>Cc: [hidden email]
>>Subject: Re: [Elecraft] K2 dead xmtr
>>
>>
>>
>>Hi Don. The levels are high everywhere in the chain up through the bases
>>of Q7-8. Requested power is immaterial in this case, since the ALC sees
>>zero detected power, and therefore is pegged at 5v all the time.
>>
>>I measured the levels with a scope, and divided the p-p values by 2.82
>>to compare with the voltage probe reference levels in the manual. BTW, I
>>removed the KAT2 and KSB2 to simplify access and minimize the number of
>>possible fault zones.
>>
>>W6 - .28 Vrms
>>Q5 case- 1.4 Vrms
>>Q6 tab- 3.5 Vrms
>>Q7,8 base- 1.4 Vrms
>>RF out- .55 Vrms
>>
>>Note: These waveforms are pretty dirty looking except on 10m, where I
>>made these measurements.
>>
>>Larry N8LP
>>
>>
>>
>>Don Wilhelm wrote:
>>
>>
>>
>>>Larry,
>>>
>>>With the requested power set at 5 watts, send us the RF Voltage levels at
>>>the W6 jumper, Q5 collector (case), Q6 collector (tab), Q7,Q8
>>>
>>>
>>base, and the
>>
>>
>>>RF Output jack. With that info, we should be able to home in on
>>>
>>>
>>the problem
>>
>>
>>>area.
>>>
>>>73,
>>>Don W3FPR
>>>
>>>
>>>
>>>
>>>
>>>>-----Original Message-----
>>>>
>>>>OK. I'm hoping someone has seen this before I start tearing into things
>>>>(and tearing my hair out).
>>>>
>>>>My K2 started to lose power yesterday. Within an hour, the output
>>>>dropped to close to zero (1mW on 160m, 40mW on 10m). There are no signs
>>>>of distress or burning odors.
>>>>
>>>>I checked the ALC... pinned at 5v. Everything looks good in terms of
>>>>levels/frequencies thru the XMIT mixer and filters, except the rf levels
>>>>are higher than indicated in the manual. I suspect this is due to the
>>>>ALC being wide open.
>>>>
>>>>The dc levels for Q5, Q6, and Q7-8 bases are normal, and the resistance
>>>>checks on Q7-8 are OK. 8T looks fine. But the rf levels are all
>>>>considerably high, and look pretty ratty except on 10m. The rig draws
>>>>about 600ma in xmit.
>>>>
>>>>Anyone seen this before?
>>>>
>>>>Larry N8LP
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>--
>>No virus found in this incoming message.
>>Checked by AVG Free Edition.
>>Version: 7.1.371 / Virus Database: 267.13.13/198 - Release Date:
>>12/12/2005
>>
>>
>>
>>
>
>
>
>
>
>

Jack Brindle

Re: K2 dead xmtr

Larry;

I suggest you call Elecraft customer support on this. Something tells
me they will want you to check out the KSB2 module to find the problem.

Good luck!

On Dec 12, 2005, at 7:52 AM, Larry Phipps wrote:

>
> I think I checked the T/R switch already, but I'll double-check.
> The thing that's weird is that the DC voltages and resistance
> checks on the finals are OK. I never got a Hi-Cur warning at any
> time before the failure (or since). The rig draws about 600ma
> during xmit.
>
> Thanks for the feedback.
>
> Larry N8LP
>
>
>
> Don Wilhelm wrote:
>
>> Larry,
>>
>> With those RF voltage measurements, I would say that the final output
>> transistors have likely failed - that goes along with your earlier
>> report
>> that the power out decreased rapidly to zip.
>>
>> There is only one other possibility that I can think of, and that
>> would be
>> the transmit signal being shorted somewhere - so before blaming
>> the finals
>> themselves, check that Q2 is operating properly - the juction of
>> D3 and D4
>> in the TR switch should be at a low voltage during receive and go up
>> somewhere close to 8 volts during transmit.
>>
>> If the receiver is still functioning properly, a short in the Low
>> Pass
>> Filter is quite unlikly because that kind of fault would drag the
>> receiver
>> way down too.
>>
>> 73,
>> Don W3FPR
>>
>>
>>
>>
>>> -----Original Message-----
>>> From: Larry Phipps [mailto:[hidden email]]
>>> Sent: Sunday, December 11, 2005 10:46 PM
>>> To: [hidden email]
>>> Cc: [hidden email]
>>> Subject: Re: [Elecraft] K2 dead xmtr
>>>
>>>
>>>
>>> Hi Don. The levels are high everywhere in the chain up through
>>> the bases
>>> of Q7-8. Requested power is immaterial in this case, since the
>>> ALC sees
>>> zero detected power, and therefore is pegged at 5v all the time.
>>>
>>> I measured the levels with a scope, and divided the p-p values by
>>> 2.82
>>> to compare with the voltage probe reference levels in the manual.
>>> BTW, I
>>> removed the KAT2 and KSB2 to simplify access and minimize the
>>> number of
>>> possible fault zones.
>>>
>>> W6 - .28 Vrms
>>> Q5 case- 1.4 Vrms
>>> Q6 tab- 3.5 Vrms
>>> Q7,8 base- 1.4 Vrms
>>> RF out- .55 Vrms
>>>
>>> Note: These waveforms are pretty dirty looking except on 10m,
>>> where I
>>> made these measurements.
>>>
>>> Larry N8LP
>>>
>>>
>>>
>>> Don Wilhelm wrote:
>>>
>>>
>>>> Larry,
>>>>
>>>> With the requested power set at 5 watts, send us the RF Voltage
>>>> levels at
>>>> the W6 jumper, Q5 collector (case), Q6 collector (tab), Q7,Q8
>>>>
>>> base, and the
>>>
>>>> RF Output jack. With that info, we should be able to home in on
>>>>
>>> the problem
>>>
>>>> area.
>>>>
>>>> 73,
>>>> Don W3FPR
>>>>
>>>>
>>>>
>>>>
>>>>> -----Original Message-----
>>>>>
>>>>> OK. I'm hoping someone has seen this before I start tearing
>>>>> into things
>>>>> (and tearing my hair out).
>>>>>
>>>>> My K2 started to lose power yesterday. Within an hour, the output
>>>>> dropped to close to zero (1mW on 160m, 40mW on 10m). There are
>>>>> no signs
>>>>> of distress or burning odors.
>>>>>
>>>>> I checked the ALC... pinned at 5v. Everything looks good in
>>>>> terms of
>>>>> levels/frequencies thru the XMIT mixer and filters, except the
>>>>> rf levels
>>>>> are higher than indicated in the manual. I suspect this is due
>>>>> to the
>>>>> ALC being wide open.
>>>>>
>>>>> The dc levels for Q5, Q6, and Q7-8 bases are normal, and the
>>>>> resistance
>>>>> checks on Q7-8 are OK. 8T looks fine. But the rf levels are all
>>>>> considerably high, and look pretty ratty except on 10m. The rig
>>>>> draws
>>>>> about 600ma in xmit.
>>>>>
>>>>> Anyone seen this before?
>>>>>
>>>>> Larry N8LP
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>> --
>>> No virus found in this incoming message.
>>> Checked by AVG Free Edition.
>>> Version: 7.1.371 / Virus Database: 267.13.13/198 - Release Date:
>>> 12/12/2005
>>>
>>>
>>>
>>
>>
>>
>>
>>
> _______________________________________________
> 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

-Jack Brindle, W6FB
=======================================================================

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N8LP

Re: K2 dead xmtr

Thanks Jack,

I'll call them, but I removed the KSB2 module and I still have the
problem. There appears to be plenty of drive either way. I ordered a PA
replacement kit just to have it on hand. I can get the xstrs locally,
but not all the mounting stuff.

Larry N8LP

Jack Brindle wrote:

> Larry;
>
> I suggest you call Elecraft customer support on this. Something tells
> me they will want you to check out the KSB2 module to find the problem.
>
> Good luck!
>
> On Dec 12, 2005, at 7:52 AM, Larry Phipps wrote:
>
>>
>> I think I checked the T/R switch already, but I'll double-check. The
>> thing that's weird is that the DC voltages and resistance checks on
>> the finals are OK. I never got a Hi-Cur warning at any time before
>> the failure (or since). The rig draws about 600ma during xmit.
>>
>> Thanks for the feedback.
>>
>> Larry N8LP
>>
>>
>>
>> Don Wilhelm wrote:
>>
>>> Larry,
>>>
>>> With those RF voltage measurements, I would say that the final output
>>> transistors have likely failed - that goes along with your earlier
>>> report
>>> that the power out decreased rapidly to zip.
>>>
>>> There is only one other possibility that I can think of, and that
>>> would be
>>> the transmit signal being shorted somewhere - so before blaming the
>>> finals
>>> themselves, check that Q2 is operating properly - the juction of D3
>>> and D4
>>> in the TR switch should be at a low voltage during receive and go up
>>> somewhere close to 8 volts during transmit.
>>>
>>> If the receiver is still functioning properly, a short in the Low Pass
>>> Filter is quite unlikly because that kind of fault would drag the
>>> receiver
>>> way down too.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>>
>>>
>>>
>>>> -----Original Message-----
>>>> From: Larry Phipps [mailto:[hidden email]]
>>>> Sent: Sunday, December 11, 2005 10:46 PM
>>>> To: [hidden email]
>>>> Cc: [hidden email]
>>>> Subject: Re: [Elecraft] K2 dead xmtr
>>>>
>>>>
>>>>
>>>> Hi Don. The levels are high everywhere in the chain up through the
>>>> bases
>>>> of Q7-8. Requested power is immaterial in this case, since the ALC
>>>> sees
>>>> zero detected power, and therefore is pegged at 5v all the time.
>>>>
>>>> I measured the levels with a scope, and divided the p-p values by
>>>> 2.82
>>>> to compare with the voltage probe reference levels in the manual.
>>>> BTW, I
>>>> removed the KAT2 and KSB2 to simplify access and minimize the
>>>> number of
>>>> possible fault zones.
>>>>
>>>> W6 - .28 Vrms
>>>> Q5 case- 1.4 Vrms
>>>> Q6 tab- 3.5 Vrms
>>>> Q7,8 base- 1.4 Vrms
>>>> RF out- .55 Vrms
>>>>
>>>> Note: These waveforms are pretty dirty looking except on 10m, where I
>>>> made these measurements.
>>>>
>>>> Larry N8LP
>>>>
>>>>
>>>>
>>>> Don Wilhelm wrote:
>>>>
>>>>
>>>>> Larry,
>>>>>
>>>>> With the requested power set at 5 watts, send us the RF Voltage
>>>>> levels at
>>>>> the W6 jumper, Q5 collector (case), Q6 collector (tab), Q7,Q8
>>>>>
>>>> base, and the
>>>>
>>>>> RF Output jack. With that info, we should be able to home in on
>>>>>
>>>> the problem
>>>>
>>>>> area.
>>>>>
>>>>> 73,
>>>>> Don W3FPR
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>> -----Original Message-----
>>>>>>
>>>>>> OK. I'm hoping someone has seen this before I start tearing into
>>>>>> things
>>>>>> (and tearing my hair out).
>>>>>>
>>>>>> My K2 started to lose power yesterday. Within an hour, the output
>>>>>> dropped to close to zero (1mW on 160m, 40mW on 10m). There are
>>>>>> no signs
>>>>>> of distress or burning odors.
>>>>>>
>>>>>> I checked the ALC... pinned at 5v. Everything looks good in
>>>>>> terms of
>>>>>> levels/frequencies thru the XMIT mixer and filters, except the
>>>>>> rf levels
>>>>>> are higher than indicated in the manual. I suspect this is due
>>>>>> to the
>>>>>> ALC being wide open.
>>>>>>
>>>>>> The dc levels for Q5, Q6, and Q7-8 bases are normal, and the
>>>>>> resistance
>>>>>> checks on Q7-8 are OK. 8T looks fine. But the rf levels are all
>>>>>> considerably high, and look pretty ratty except on 10m. The rig
>>>>>> draws
>>>>>> about 600ma in xmit.
>>>>>>
>>>>>> Anyone seen this before?
>>>>>>
>>>>>> Larry N8LP
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>> --
>>>> No virus found in this incoming message.
>>>> Checked by AVG Free Edition.
>>>> Version: 7.1.371 / Virus Database: 267.13.13/198 - Release Date:
>>>> 12/12/2005
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>
>>>
>> _______________________________________________
>> 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
>
>
>
> -Jack Brindle, W6FB
> =======================================================================
>
>
>
>
>