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[K2] Ooof.. Update

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bdenley

[K2] Ooof.. Update

I am beginning to think I may have wacked or damaged the PIN diode for the
T/R switch while adding the resistor for the KNB2. That might explain no
receive or transmit that I am getting now. Does that make sense?
Brian
KB1VBF
http://home.comcast.net/~b.denley/index.html

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Don Wilhelm-4

Re: [K2] Ooof.. Update

Brian,

Actually, that does not make a lot of sense. The T/R switch is too far
removed from the KNB2 for that to be a problem (unless you were really
wild with the soldering iron :-) ).

Try jumpering (with a piece of bent wire) between pins 1 and 6 of the
J12 header. If receive comes back to life, you have a problem on the
KNB2 board.

Let us know the results.

73,
Don W3FPR

On 1/18/2011 10:26 PM, Brian Denley wrote:

> I am beginning to think I may have wacked or damaged the PIN diode for the
> T/R switch while adding the resistor for the KNB2. That might explain no
> receive or transmit that I am getting now. Does that make sense?
> Brian
> KB1VBF
> http://home.comcast.net/~b.denley/index.html
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

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bdenley

Re: [K2] Ooof.. Update

Don was right! I had taken the SSB adaptor out and that (without jumpers)
rendered the K2 non-functional. Putting the KSB2 back in and adding the
pin1 to pin 6 jumper at J12 (as Don suggested) brought my K2 back to life!
Now I still have to figure out what is wrong with my KNB2...
Thanks again Don!
Brian
KB1VBF
http://home.comcast.net/~b.denley/index.html

----- Original Message -----
From: "Don Wilhelm" <[hidden email]>
To: "Brian Denley" <[hidden email]>
Cc: "Elecraft Reflector" <[hidden email]>
Sent: Tuesday, January 18, 2011 10:43 PM
Subject: Re: [Elecraft] [K2] Ooof.. Update

> Brian,
>
> Actually, that does not make a lot of sense. The T/R switch is too far
> removed from the KNB2 for that to be a problem (unless you were really
> wild with the soldering iron :-) ).
>
> Try jumpering (with a piece of bent wire) between pins 1 and 6 of the J12
> header. If receive comes back to life, you have a problem on the KNB2
> board.
>
> Let us know the results.
>
> 73,
> Don W3FPR
>
>
> On 1/18/2011 10:26 PM, Brian Denley wrote:
>> I am beginning to think I may have wacked or damaged the PIN diode for
>> the
>> T/R switch while adding the resistor for the KNB2. That might explain no
>> receive or transmit that I am getting now. Does that make sense?
>> Brian
>> KB1VBF
>> http://home.comcast.net/~b.denley/index.html
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>

L Kendall

Re: [K2] Ooof.. Update

In reply to this post by Don Wilhelm-4

I'm having a similar problem after installing the KNB2.

So, I triple checked component location and applicable polarity and all
solder joints for bad joints or bridged/shorted solder pads; removed,
checked and re-installed the 2 bandpass toroid chokes, checked the ID
number on the caps.

Checked the K2 RF board J12, and checked the mods to R88, R89 & R90.

...and the K2 is still nearly deaf as a post.

Next, I jumpered 1 & 6 on J12 and could then hear stations all over 40
meters.

Checked WWV @ 10 MHz and I thought it was going to blow the speaker
before I could turn down the AF gain.

So it looks like I did not screw up the K2 itself. That is a relief.

I'm guessing the next thing to do is check U2 for correct voltage
output, and if that's OK see what I can measure on the RF amp. It's an
SMD and mounted on one of those SMD piggy back things for PCBs made for
the old school DIP ICs.

Kinda frustrating, but it happens.

Larry
K5END

On Tue, 2011-01-18 at 22:43 -0500, Don Wilhelm wrote:

>
> Try jumpering (with a piece of bent wire) between pins 1 and 6 of the
> J12 header. If receive comes back to life, you have a problem on the
> KNB2 board.
>
> Let us know the results.
>
> 73,
> Don W3FPR
>
>
> On 1/18/2011 10:26 PM, Brian Denley wrote:
> > I am beginning to think I may have wacked or damaged the PIN diode for the
> > T/R switch while adding the resistor for the KNB2. That might explain no
> > receive or transmit that I am getting now. Does that make sense?
> > Brian
> > KB1VBF

Don Wilhelm-4

Re: [K2] Ooof.. Update

Larry,

You are trying to analyze too much in the KNB2 without looking at the
schematic. The signal always passes through the Bandpass Filter. It
only goes to the amplifier to detect noise.
So check the toroids L1 and L2, C3, C4, C6, C7, R8 and R8.
The RX signal should pass through the KNB2 with only those components in
place and working.
Also check the soldering of P1 and its mating header on the K2 RF Board
= make certain pin 1 has been soldered on both.

73,
Don W3FPR

On 3/21/2011 1:21 AM, L Kendall wrote:

> I'm having a similar problem after installing the KNB2.
>
> So, I triple checked component location and applicable polarity and all
> solder joints for bad joints or bridged/shorted solder pads; removed,
> checked and re-installed the 2 bandpass toroid chokes, checked the ID
> number on the caps.
>
> Checked the K2 RF board J12, and checked the mods to R88, R89& R90.
>
> ...and the K2 is still nearly deaf as a post.
>
> Next, I jumpered 1& 6 on J12 and could then hear stations all over 40
> meters.
>
> Checked WWV @ 10 MHz and I thought it was going to blow the speaker
> before I could turn down the AF gain.
>
> So it looks like I did not screw up the K2 itself. That is a relief.
>
> I'm guessing the next thing to do is check U2 for correct voltage
> output, and if that's OK see what I can measure on the RF amp. It's an
> SMD and mounted on one of those SMD piggy back things for PCBs made for
> the old school DIP ICs.
>
> Kinda frustrating, but it happens.
>
> Larry
> K5END
>
>
>
>
>
>
>
>
>
> On Tue, 2011-01-18 at 22:43 -0500, Don Wilhelm wrote:
>
>
>> Try jumpering (with a piece of bent wire) between pins 1 and 6 of the
>> J12 header. If receive comes back to life, you have a problem on the
>> KNB2 board.
>>
>> Let us know the results.
>>
>> 73,
>> Don W3FPR
>>
>>
>> On 1/18/2011 10:26 PM, Brian Denley wrote:
>>> I am beginning to think I may have wacked or damaged the PIN diode for the
>>> T/R switch while adding the resistor for the KNB2. That might explain no
>>> receive or transmit that I am getting now. Does that make sense?
>>> Brian
>>> KB1VBF
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Don Wilhelm-4

Re: [K2] Ooof.. Update

That last R should have been R9, sorry for the typo (it is still
morning - need more tea)

73,
Don W3FPR

On 3/21/2011 8:59 AM, Don Wilhelm wrote:

> Larry,
>
> You are trying to analyze too much in the KNB2 without looking at the
> schematic. The signal always passes through the Bandpass Filter. It
> only goes to the amplifier to detect noise.
> So check the toroids L1 and L2, C3, C4, C6, C7, R8 and R8.
> The RX signal should pass through the KNB2 with only those components in
> place and working.
> Also check the soldering of P1 and its mating header on the K2 RF Board
> = make certain pin 1 has been soldered on both.
>
> 73,
> Don W3FPR
>
> On 3/21/2011 1:21 AM, L Kendall wrote:
>> I'm having a similar problem after installing the KNB2.
>>
>> So, I triple checked component location and applicable polarity and all
>> solder joints for bad joints or bridged/shorted solder pads; removed,
>> checked and re-installed the 2 bandpass toroid chokes, checked the ID
>> number on the caps.
>>
>> Checked the K2 RF board J12, and checked the mods to R88, R89& R90.
>>
>> ...and the K2 is still nearly deaf as a post.
>>
>> Next, I jumpered 1& 6 on J12 and could then hear stations all over 40
>> meters.
>>
>> Checked WWV @ 10 MHz and I thought it was going to blow the speaker
>> before I could turn down the AF gain.
>>
>> So it looks like I did not screw up the K2 itself. That is a relief.
>>
>> I'm guessing the next thing to do is check U2 for correct voltage
>> output, and if that's OK see what I can measure on the RF amp. It's an
>> SMD and mounted on one of those SMD piggy back things for PCBs made for
>> the old school DIP ICs.
>>
>> Kinda frustrating, but it happens.
>>
>> Larry
>> K5END
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> On Tue, 2011-01-18 at 22:43 -0500, Don Wilhelm wrote:
>>
>>
>>> Try jumpering (with a piece of bent wire) between pins 1 and 6 of the
>>> J12 header. If receive comes back to life, you have a problem on the
>>> KNB2 board.
>>>
>>> Let us know the results.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>>
>>> On 1/18/2011 10:26 PM, Brian Denley wrote:
>>>> I am beginning to think I may have wacked or damaged the PIN diode for the
>>>> T/R switch while adding the resistor for the KNB2. That might explain no
>>>> receive or transmit that I am getting now. Does that make sense?
>>>> Brian
>>>> KB1VBF
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

L Kendall

Re: [K2] Ooof.. Update

In reply to this post by bdenley

Don, thanks.

I understand about the band pass LC section and that is what perplexed me.

Late last night I found and corrected a tiny solder short hidden under the connector on the KNB2 board. Of course it had to be pins 1 & 2 and you know what that would do.

Had to call it a night at that point per the whole work/job/employment thing for this morning and will reinstall into the K2 & test it tonight.

If this turns out to be the "only" problem I'll be a happy Ham.

Thanks & 73.

LK
-----Original Message-----
From: "Don Wilhelm" <[hidden email]>
To: "Elecraft Reflector" <[hidden email]>
Cc: "L Kendall" <[hidden email]>
Sent: 3/21/2011 8:06 AM
Subject: Re: [Elecraft] [K2] Ooof.. Update

That last R should have been R9, sorry for the typo (it is still
morning - need more tea)

73,
Don W3FPR

On 3/21/2011 8:59 AM, Don Wilhelm wrote: