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K2 head phone jack

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N5SM

K2 head phone jack

Hello
I plan to wire my AEA PK-232MBX to use with my K2. The K2 has the stero
headphone jack and
my PK-232 has a mono sound input jack. If I use a mono plug in the K2
headphone jack is that
going to damage the K2 sound system? If I use two wires, one on each side
of the stero jack
to the single contact on the plug at the PK-232 would it be nescessary to
install diodes in the lines
to keep the two line from causing a short circuit across both side of the
stero jack on the K2?
Guess I'm a little gun shy after smoking all the digital ic's in it with a
solder bridge when buillt it!
Sure don't want to do something that would let the smoke out of it again!
Thanks
Scott N5SM

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Don Wilhelm-3

Re: K2 head phone jack

Scott,

Have no fear, a mono plug will not damage the K2 - there are resistors
in each side of the headphone circuit for exactly that reason - BUT, you
will lose half of the full audio output.

It is better to use a stereo jack and tie both the tip and ring together.

As another alternative, use the external speaker jack in the back - it
is a mono jack.

73,
Don W3FPR

Scott McDowell wrote:
> Hello
> I plan to wire my AEA PK-232MBX to use with my K2. The K2 has the stero
> headphone jack and
> my PK-232 has a mono sound input jack. If I use a mono plug in the K2
> headphone jack is that
> going to damage the K2 sound system? If I use two wires, one on each
> side of the stero jack
> to the single contact on the plug at the PK-232 would it be nescessary
> to install diodes in the lines
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KJ3D-2

KPA-100 Problem

Good evening Group,

I seem to be having some trouble with my KPA-100. (K2 serial 4991),
Perhaps one of you could shine a light where mine don't reach.

Assembly and initial checks went OK.

At the end of the assembly, I ran into the problem.

Checks on page 46:

Junction of C77 and R11 says 90 to 150 V, I get 11.6 V

U4 pin 8 says -5 to -25 V, I get 2.8 mV

I have rechecked T3 and all looks well. I was careful with D1 - D8 as I
knew they would be hard to check after assembly.

Any suggestions before I take the rear panel and heat sink off? (shudder).

FWIW: Since the smoke wasn't getting out, I went ahead with the checks on
page 46 and the first one on page 47 and all went well, but that's probably
inconsequential. I'm sure the problem must be in the bias supply.

Thanks,

Tom, kj3d

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n0so

RE: KPA-100 Problem

Tom,

I hate to admit this, but I had a similar problem when I built my KPA100.

The reason I hate to admit it is after troubleshooting, I found that I had
installed Q6, Q7 (the two odd shaped FETs) backwards. To make matters
worse, I broke a lead on one removing it to turn it around and ended up
ordering replacements from Elecraft, which delayed the completion of the amp
by several days.

Hope this helps!

73 de Mike, N0SO
K2 #4757

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of KJ3D
Sent: Friday, May 25, 2007 5:10 PM
To: [hidden email]
Subject: [Elecraft] KPA-100 Problem

Good evening Group,

I seem to be having some trouble with my KPA-100. (K2 serial 4991), Perhaps
one of you could shine a light where mine don't reach.

Assembly and initial checks went OK.

At the end of the assembly, I ran into the problem.

Checks on page 46:

Junction of C77 and R11 says 90 to 150 V, I get 11.6 V

U4 pin 8 says -5 to -25 V, I get 2.8 mV

I have rechecked T3 and all looks well. I was careful with D1 - D8 as I
knew they would be hard to check after assembly.

Any suggestions before I take the rear panel and heat sink off? (shudder).

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KJ3D-2

RE: KPA-100 Problem

Hi Mike,

Thanks for the reply.

I rechecked all the transistors and FETs, and they are all installed
inaccordance with their outlines. Also rechecked diodes D1 - D8 and all
check OK (unless I installed ALL of them backwards).

Should I have to remove the heatsink - as you did, I guess, it looks like
just removing the 3 screws holding the back plate on, the 7 standoffs and
the 4 screws that hold Q1, Q2, Q3 and Q4 should do it. I guess I won't have
to remove the back plate - I REALLY didn't want to do that.

I hope someone can suggest a fix before I have to do even that.

73,

Tom

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Mike Heitmann
Sent: Friday, May 25, 2007 6:35 PM
To: 'KJ3D'; [hidden email]
Subject: RE: [Elecraft] KPA-100 Problem

Tom,

I hate to admit this, but I had a similar problem when I built my KPA100.

The reason I hate to admit it is after troubleshooting, I found that I had
installed Q6, Q7 (the two odd shaped FETs) backwards. To make matters
worse, I broke a lead on one removing it to turn it around and ended up
ordering replacements from Elecraft, which delayed the completion of the amp
by several days.

Hope this helps!

73 de Mike, N0SO
K2 #4757

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of KJ3D
Sent: Friday, May 25, 2007 5:10 PM
To: [hidden email]
Subject: [Elecraft] KPA-100 Problem

Good evening Group,

I seem to be having some trouble with my KPA-100. (K2 serial 4991), Perhaps
one of you could shine a light where mine don't reach.

Assembly and initial checks went OK.

At the end of the assembly, I ran into the problem.

Checks on page 46:

Junction of C77 and R11 says 90 to 150 V, I get 11.6 V

U4 pin 8 says -5 to -25 V, I get 2.8 mV

I have rechecked T3 and all looks well. I was careful with D1 - D8 as I
knew they would be hard to check after assembly.

Any suggestions before I take the rear panel and heat sink off? (shudder).

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