[Elecraft] K3 Sub no signal

[Jim Rhodes]

That was the only thing I could think of after reading your post.  I am
away from home and my K3 right now, So I can't dig it out and mess with it
to see what messes it up.

On Wed, Nov 5, 2025 at 8:30 AM Curt Nixon <radio.ku8l at gmail.com> wrote:

> Hi Jim
> If you mean in config, then yes I did.  I get no errors or other
> indication that something is wrong.  Rx noise similar to main rx that
> responds like I expect with the rf gain and volume.
>
> Thanks.
> Curt
> KU8L
>
> On Wed, Nov 5, 2025, 9:31 AM Jim Rhodes <jimk0xu at gmail.com> wrote:
>
>> You did turn the sub on in the menu, right?
>>
>> Jim K0XU
>> jim at rhodesend.net
>>
>> On Tue, Nov 4, 2025, 10:32 Curt KU8L via Elecraft <
>> elecraft at mailman.qth.net> wrote:
>>
>>> Good Morning Folks
>>> I have finally added a couple of K3 to the contest station lineup here
>>> and just coming up to speed on how to use them.  Had a K2 for a while
>>> but big difference!
>>>
>>> K3  100W, KAT3, 2m Module, Kiob, ser 00872  MCU vers 5.62  Has original
>>> Synths and Sub rcvr .
>>>
>>> Problem is no signal thru SUB.   It appears to be working because I hear
>>> normal background noise which comes up with RF gain and audio prperly
>>> splits to right and left headset channels.
>>>
>>> I went thru getting my head around the options for SUB antenna sources
>>> and after deciding  I definitely wanted to use the MAIN shared option I
>>> opened the unit to check how the SUB aux antenna was connected.  Removed
>>> the TMP jumper to the KAT3.
>>>
>>> Set config to ANT=BNC, pwr cycled, and selected BSET RX ANT is set to
>>> MAIN.  My understanding is this should share the main ANT1 or ANT2
>>> selection of the main rx with the SUB.
>>>
>>> All else looks to be in order inside but still no Signal from SUB.
>>>
>>> Before I remove the 2mtr unit and lift the SUB out to be sure the SUBIN
>>> connections are OK looking for any other things to check. This was a kit
>>> build but had sat unused for a couple years after owner went SK.  Clean
>>> and looks good inside but no idea if it ever worked
>>>
>>> Final thought was to try replacing the TMP connect to SUB Aux and KAT3
>>> and reconfig for using the non tx ant to verify the SUB operation and
>>> perhaps narrow the field to looking at the SUBIN connect and the Jumper
>>> W4 situation.
>>>
>>> Any ideas on where to go next with this?
>>>
>>> Thank you in advance for any advice.
>>>
>>> Curt
>>> KU8L
>>>
>>>
>>>
>>> --
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>>

-- 
Jim K0XU
jim at rhodesend.net