Uniden AX144 (PC 833 AF) SSB Power Issues

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Posts: 1
Joined: Thursday 23rd Oct 2014, 19:27
First Name: Brett
Location: Auckland

Uniden AX144 (PC 833 AF) SSB Power Issues

Post by Glassman »

Firstly, NO issues on receive.
AM seems to function fine, both TX & RX.
USB seems OK TX & RX but minimal contacts made to be sure of this.
Apart from the odd one, reports back from contacts made on LSB into Australia say that I have some sort of power problem and that I sound like I'm talking under water with a background humming sound as well so its hard for them to understand what I'm saying.
Have tried a new mic with no change and also changed power supply to my Yaesu (25 amps) with no change although it did improve the meter light that was dimming on TX.
I have:
Connected frequency counter to TP3, CH 19, checked and adjusted AM to 16.490 with L16. LSB to 16.4875, L18 and USB 16.4925 with L17. Slight adjustment to VR3 during TX on AM. ALL GOOD

Connected frequency counter to TP5, CH 19, AM TX at 27.185 with no issues.
CAN NOT get LSB and USB to lock on to 10.6925 & 10.6975. Both fluctuate all over the place.Have spent hours on this. Notice frequency drops slightly when I move away from the bench or touch the power supply or disconnect other items on the bench from power supply.
Connected freq counter to antenna. AM on TX hits the right frequency every time. CAN NOT get LSB and USB up to there correct frequencies trying to use L20 & L21. Highest frequency on TX is anywhere from 20.000 to 22.000 but no higher. Around here I get a humming sound and the watt meter fluctuates particularly on USB and can not adjust the L20 any further down.

I have gone further i.e. adjustments to VR8, VR9 via TP's 6,7 and 8. VR's 4, 7, and 10 as well as L's 13, 14 and 15 but am stopping here as nothing seems to work.
Appreciate any advice on this.
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