K3 / MH2 - No TX Audio

[VaibhaV Sharma]

Hello,
Here is my story -

Bought a 4 month old K3/10 off ebay (yes) from another radio operator in
Texas. Unit arrived in excellent physical condition except that it won't
transmit any audio using the MH2 hand mic.

The radio has -
* K3/10
* KAT3
* 2.7 kHz 5 pole filter (standard)
* 5ppm oscillator

I have searched through the tubes and done the following -
* Enabled mic bias
* Enabled L./h. for front mic port
* Adjusted mic gain / CMP / moni levels
* Reset the unit to factory defaults and repeated the above
* Upgraded the unit to latest firmware and repeated the above

No amount of coaxing or loving is helping. The mic key-up works (TX lit)
but no audio is transmitted. SWR / PO meters don't move at all.

The radio "does transmit" when -
* ATU cycle is kicked in
* Rear mic port is used with a headset
* CW paddle is used

I sent a stinker to the ebay seller (awaiting response) but after hours of
debugging, wanted to find out if this is just a dead MH2 hand-mic or could
be an issue with the radio? Is there a way to test the MH2 electret element
separately?

The problem might just be between the MH2 and my chair and I am here to
learn.

Thanks in advance,

--
VaibhaV Sharma
W7VAI
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[VaibhaV Sharma]

Update on this -

* Worked with the seller to figure out what could be wrong. He had never
used this K3 for SSB/voice. Always CW.
* The nice folks at Ham Radio Sunnyvale let me try a few kenwood mics to
test. None of them worked.
* Spoke with Howard (Elecraft Support) and he gave a few pointers on what
could be wrong

After discussing with the seller, decided to open the unit and found that
on the DSP board attached behind the front panel, a 5/6 pin connector, just
between the AF/SQL nobs was completely off its mating black connector. Not
a single pin on that connector was in place. Static mat spread, and
re-aligned the board. Front mic transmit now works just fine! I was
surprised nothing else was wrong with the radio with that entire connector
off its alignment.

Next problem:
After going to factory defaults and all calibration with a dummy load, the
radio is not transmitting well on 20 meters. With 12W set, it barely does 5
watts out. Elecraft (Howard) suggests I go through the calibration process
again with the filter offset etc. Will try again this evening.

I also got a bunch of offline responses on this problem.

Thank you all for the support.

--
VaibhaV Sharma
W7VAI



On Tue, Sep 10, 2013 at 12:18 AM, VaibhaV Sharma
<[hidden email]>wrote:

> Hello,
> Here is my story -
>
> Bought a 4 month old K3/10 off ebay (yes) from another radio operator in
> Texas. Unit arrived in excellent physical condition except that it won't
> transmit any audio using the MH2 hand mic.
>
> The radio has -
> * K3/10
> * KAT3
> * 2.7 kHz 5 pole filter (standard)
> * 5ppm oscillator
>
> I have searched through the tubes and done the following -
> * Enabled mic bias
> * Enabled L./h. for front mic port
> * Adjusted mic gain / CMP / moni levels
> * Reset the unit to factory defaults and repeated the above
> * Upgraded the unit to latest firmware and repeated the above
>
> No amount of coaxing or loving is helping. The mic key-up works (TX lit)
> but no audio is transmitted. SWR / PO meters don't move at all.
>
> The radio "does transmit" when -
> * ATU cycle is kicked in
> * Rear mic port is used with a headset
> * CW paddle is used
>
> I sent a stinker to the ebay seller (awaiting response) but after hours of
> debugging, wanted to find out if this is just a dead MH2 hand-mic or could
> be an issue with the radio? Is there a way to test the MH2 electret element
> separately?
>
> The problem might just be between the MH2 and my chair and I am here to
> learn.
>
> Thanks in advance,
>
> --
> VaibhaV Sharma
> W7VAI
>
>

______________________________________________________________
Elecraft mailing list
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Please help support this email list: http://www.qsl.net/donate.html