[Elecraft] Q21

Sat Dec 21 21:34:00 2002

Hi Ira,

The MPS5179 will probably work okay if your 2N5109 was the problem.

You can find a drawing showing the pinout here:
http://psas.pdx.edu/psas/Resources/DataSheets/Communications/MPS5179.pdf

The 2N5109 data sheet is here:
http://www.oselectronics.com/downloads/2n5109.pdf

If that doesn't fix it, write down all the DC voltages in the Q21 circuit
(that is, all the components between C141 and C143) and email the data to
me.

73/ Bob - AG5Q

----- Original Message -----
From: "Ira Saber" <[email protected]>
To: <[email protected]>
Sent: Saturday, December 21, 2002 7:36 PM
Subject: [Elecraft] Q21

> To: Any and all who wish to read/answer this e-mail
>
> Because I am having difficulty with the proper functioning of the preamp
> in my new K2 (3076); and because I have exhausted just about everything
> that I could do; save replace Q21 in the attempt to get the preamp to
> amplify rather than to attenuate;  Scott @ Elecraft and I decided that
> replacing Q21 would be the last step in the cycle of fixes.
>
> So, today I received from FedEx my new Q21.  Surprise!!  The replacement
> part does not look nor does its product number match the Part No:
> E5800013 in the K2 Manual.  The original Q21 is a metal jacketed
> transistor labeled 2N5109.  My replacement part is a standard appearing
> (D-Shaped, black body) transistor with the code MPS 5179 3030 stamped on
> the flattened surface.
>
> Now, since Elecraft will be closed for their week long Christmas break
> (God knows they deserve it), I will not be able to call Scott and
> determine if the replacement transistor is in fact a true replacement
> that can be substituted for the original Q21.
>
> I would welcome a response by anyone with more information than I .
>
> Warmest regards and all the best for the Holidays and New Year to all of
> those out there who read/respond to this e-mail.
>
> 73's         Ira, N2IS
>
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