[Elecraft] K3s Low sub receiver volume

[Thomas Doligalski]

Checked that: antenna is the same for both receivers. And, the RF signal level is the same for both: its the AF gain that has the difficulty.

73, Tom W4KX

Sent from my iPad

> On Feb 27, 2018, at 11:08 AM, brian <alsopb at comcast.net> wrote:
> 
> Tom,
> 
> Any chance you haven't directed the proper antenna to the subrx?
> Try the MAIN antenna on both RX's.  Choice is band dependent, so you have to make the right choice on all bands.  It gets a bit more complicated if you have a tuner.  The default antenna for the subrx becomes the UHF connector which is not the transmit antenna.
> 
> The above is what I recall from years ago when I first installed a sub-rx.  My memory may be faulty.
> 
> 73 de Brian/K3KO
> 
>> On 2/27/2018 15:11 PM, Thomas Doligalski wrote:
>> Also tried the front panel earphone jack, with the same results as the rear panel jack.
>> 
>> 73, Tom W4KX
>> 
>> Sent from my iPad
>> 
>>> On Feb 27, 2018, at 10:05 AM, Thomas Doligalski <w4kx at mac.com> wrote:
>>> 
>>> I use stereo earphones plugged in the rear. I get equal volume in both earphones with the same AF gain settings until I turn on the sub receiver, when I get the diminished volume in the right headphone and have to turn up the sub receiver gain.
>>> 
>>> Thanks, 73 Tom W4KX
>>> 
>>> Sent from my iPad
>>> 
>>>> On Feb 27, 2018, at 10:00 AM, brian <alsopb at comcast.net> wrote:
>>>> 
>>>> Thomas,
>>>> 
>>>> You don't say if you're using earphones or speakers.
>>>> -------------------------------------------------------------
>>>> If earphones:
>>>> 
>>>> Are your earphones plugged into the front panel or back panel?
>>>> I had the earphone jack in the back make poor contact with the earphones and low audio in one of the two channels.  To troubleshoot, I plugged earphones in the front jack and things were AOK.
>>>> 
>>>> Try plugging earphones into the "other" jack.
>>>> 
>>>> Don't overlook the earphones being the potential problem.
>>>> 
>>>> Speakers OK?
>>>> ----------------------------------------------
>>>> If speakers:
>>>> Are earphones OK?
>>>> 
>>>> 73 de Brian/K3KO
>>>> 
>>>>> On 2/27/2018 14:40 PM, Thomas Doligalski wrote:
>>>>> Larry W0LRF wrote earlier this month:
>>>>> 
>>>>>> There have been a few posts on this subject, but none had answers.
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> Both my main and sub receiver are on the same antenna.
>>>>>> 
>>>>>> The audio volume from the sub is much lower.
>>>>>> 
>>>>>> The AF for the main is…… let’s say at 9 o’clock….. to get equal volume level from the sum… Sub AF has to be at 3-4 o’clock.
>>>>>> 
>>>>>> RF on both are the same.
>>>>>> 
>>>>>> Any suggestions? Is this normal?
>>>>>> 
>>>>> 
>>>>> I have the same problem with K3 #969.
>>>>> 
>>>>> All was fine when I first installed the KRX3, right after it was released. However, when I installed the new K3SYNA boards the audio problem for the sub receiver manifested itself.
>>>>> 
>>>>> I have verified that the settings and filters for the sub receiver are the same as the main receiver. Note that the RF signal between the two receivers is identical, as shown on the K3 S-meter and the P3 display.
>>>>> 
>>>>> Recently I noted the latest KRX3 installation manual (downloaded from electraft.com) has a section entitled "Checking and Modifying Resistor R91 and DAC Input Circuits”. The manual I followed when installing my KRX3 only had a similar section entitled “Checking and Modifying Resister R91”.
>>>>> 
>>>>> The latest KRX3 installation manual states that the missing step involves cutting two traces on the main board board to the left of R91, with the justification that “This modification ensures the digital-to-analog converters (DACs) always receive the proper signal levels. It has been incorporated into all later K3s.”
>>>>> 
>>>>> Could this be the cause of my Low sub receiver volume problems? Should I cut these traces now?
>>>>> 
>>>>> Thanks and 73!
>>>>> 
>>>>> Tom W4KX
>>>>> ______________________________________________________________
>>>>> Elecraft mailing list
>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>> Post: mailto:Elecraft at mailman.qth.net
>>>>> 
>>>>> This list hosted by: http://www.qsl.net
>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>> Message delivered to alsopb at comcast.net
>>>>> 
>>>>> ---
>>>>> This email has been checked for viruses by AVG.
>>>>> http://www.avg.com
>>>>>