#Solder splash #qcx+ #solder


Larry Acklin
 

Check the board before populating...
40M QSX+ build...
I had the following symptoms- BPF jumping but kind of sort of peaked, I/Q balance never found minimum, CCW fully was lowest, I/Q hi and lo no min.  Rewound T1 no change.Re-soldered all over, no change. Found by using the troubleshooting document and scoping that “I” was ok, “Q” was not there (DC only) at the test points at the output of the Tayloe detector. Replaced FSD QSD, no change. Pulled out IC6, no change. Finally used a strong magnifier and good light, saw that SI5351 clk0 and clk1 were shorted on the SI5351 pins- a solder bridge. It was a big deal to clear, because the option TCXO was installed which made access quite difficult. Finally used rosin flux and solder wick to clean up the SI5351 pins, replaced IC 6, and now everything peaks and nulls correctly.  Whew!  Nice sharp BPF peak, nulled I/Q low and high, on air I can’t hear the opposite sideband. 

So long story short, check workmanship/solder job on the FST and SI chips pre installed first, it’s way easier to clean up before the board is loaded with parts. 


73
Larry
KB3CUF


UPNORTHOF48 :
 

When you hear the opposite ssb, does it sound like wind blowing under water?


Larry Acklin
 

this is a CW radio , so I hear the same station. Tune through zero beat, and there he is again. (classic Direct Conversation with out unwanted sideband suppression (Heathkit HW-8). Using other radios-and tuning SSB signals , being on the wrong sideband does sound like an alien language. 

Larry

On Thu, Dec 31, 2020 at 9:42 AM UPNORTHOF48 : <trevorogden66@...> wrote:
When you hear the opposite ssb, does it sound like wind blowing under water?


Larry Acklin
 

All cleaned up and now with the signal chain all working, alignment was a breeze. sharp BPF peaks, nulls, a s9+++ station can not be detected on the suppressed sideband.  

On Thu, Dec 31, 2020 at 9:57 AM Larry Acklin via groups.io <acklin=gmail.com@groups.io> wrote:
this is a CW radio , so I hear the same station. Tune through zero beat, and there he is again. (classic Direct Conversation with out unwanted sideband suppression (Heathkit HW-8). Using other radios-and tuning SSB signals , being on the wrong sideband does sound like an alien language. 

Larry

On Thu, Dec 31, 2020 at 9:42 AM UPNORTHOF48 : <trevorogden66@...> wrote:
When you hear the opposite ssb, does it sound like wind blowing under water?


Zdenek OK2BQN
 

Hi Larry,
Right at the beginning I had the same problem with SI5351.
And rosin also helped.
73
Zdenek