[Elecraft] [K2] Sensitivity on 17m

[Bill W4ZV]

Joe Subich, W4TV-4 wrote
> Bill,
> 
> Is the K2 ATU like the ATU in the K3 in that it simply selects values
> for 50:50 Ohm rather than physically bypassing?  If so, something has
> undoubtedly overwritten the 50 Ohm values.

I just did ATU TUNE into a 50 ohm load and the ATU made no changes so I
believe you're correct...and ATU INIT restored the correct 50 ohm values. 
The strange thing to me about the original problem was that the ATU tuned
antennas correctly for transmit yet there was RX sensitivity loss on some
bands.  Oh well...

73,  Bill



On 6/18/2013 9:21 AM, Bill W4ZV wrote:
> ATU INIT appears to have restored the sensitivity loss on affected bands.
> Anyone have any ideas what might have caused this problem?  Hopefully ATU
> INIT didn't create other problems!
>
> 73,  Bill
>
>
> Bill W4ZV wrote
>> Mike K8CN and I both came to the same conclusion overnight.  Check the
>> ATU
>> in bypass mode!  Using both RX ANT and forcing bypass via CAL_P, the
>> sensitivity is back on 17m.  I also notice smaller but still noticeable
>> loss on 15m.
>>
>> I didn't build this KAT2 myself but it seems to tune OK for TX on all
>> bands.  I guess it's time for some ATU troubleshooting but other ideas
>> are
>> appreciated.
>>
>> 73,  Bill  W4ZV
>> Bill W4ZV wrote
>>> During a SOTA activation Saturday I used 17m quite a bit as well as 15
>>> and 20.  Sensitivity on 17m seemed weaker than on adjacent bands and I
>>> thought it could be my antenna (44' doublet up 25' with 450 ohm ladder
>>> linie through a BL1 4:1 and KAT2).
>>>
>>> Tonight I decided to check it with my XG3 and indeed the 1uV setting is
>>> noticeably weaker than on 15 and 20.  I first redid RX alignment of L10
>>> and L11 on 15m and then C32 and C34 for 17m with no improvement.  The
>>> S-meter reads the same for all 3 XG3 levels but 1uV sounds weaker on 17.
>>> Anyone have any ideas?
>>>
>>> 73,  Bill  W4ZV
>
>
>
>
>
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