[Elecraft] K3 key-out jack - configuration needed?

[Don Wilhelm]

  Olli,

The Key Out and the ACC connector Keyout-LP are developed from the same 
internal signal, but the driving transistors are different for each.
The Key Out jack is driven by Q5 and Q3 on the RF Board, and you will 
find your problem associated with one of those transistors.  See the 
schematic for the RF board at the top left of sheet 1.  Check R4 as well 
- the gate of Q3 should go to a high level during transmit (use TX test).

73,
Don W3FPR

On 10/10/2010 10:31 AM, Oliver "Olli" Dröse wrote:
> Hi guys,
>
> preparing for the autumn contest season I thought to do some cable work today.
> Made up a cable to key the amplifier and wanted to use the key-out jack therefor
> (only need to sink 13,8 V / 60 mA so should work perfectly well). But the amp
> isn't keying. So I measured the RCA jack and unkeyed I can measure infinite
> resistance as it should be the case but if I ptt the radio no change on the RCA
> jack?! Should be around zero then so no keying there.
>
> Checked the manual but couldn't find anything related to configuration of that
> jack, seems it should be always working, right? Any ideas why it is not?
>
> Checked the LP key-out on the ACC connector and that is working properly (but
> not enough for the amp, ofcourse, only measured there for verification the radio
> is really keying out, hi).
>
> Can anybody help?
>
> TIA&  73, Olli - DH8BQA
>
>
>
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