Galaxy dx99v LSB freq problem

[jef]

I acquired a Galaxy 99v off an online site and it is working great in every mode and does work on lsb with proper power output and is on freq on center slot,but the problem is on lsb only you can be on channel 38 on the channel indicator but the freq counter says you are on 27.405 and that is where it is on 40 .The radio has almost no slide on lsb with the clarifier so it seems on lsb it is maxed on the unlocked clarifier but in every other mode am and usb everthing is spot on and it slides aright and displays right..Lsb work with proper power but I would like to get it right please ,give me some area to look at to fix the lsb (slide) (channel) issue.Thank you in advance Jef

 

[Handy Andy]

Go here, see if this site can help you...

http://www.cbtricks.com/radios/galaxy/dx99v/index.htm

You may have a wire that fell off or header issues - like broken wire or bad soldering joints...

Here's the clue, it deals with your "source voltage" - you can switch to "mode USB or AM" and you have clarifier - but if you go to LSB you lost it. You say you have LSB "works" but shows a frequency 2 channels away.

Indicates either failed wiring - no LSB Clarifier [quick check see if voltage on the clarifier in that mode - one should show 8 volts on 1 terminal ONLY] - or Diode failure - but I'm not going to send you on a wild goose chase trying to find the diode that failed.

Check the link and see if its something you can use.

Read it - digest it - ruminate over it - then act accordingly.

:+> Andy <+:

 

[nomadradio]

Sounds to me as if L21 could be shorted.

First time I ran into this was a radio that had some 'bad soldering' repairs done to it.

But with the power still applied. He shut it off the first time he drew a tiny spark to the tip of the soldering iron.

Oops. He was resoldering the circuit board near the three trimmer coils that set the clarifier for each mode. But before turning off the radio. He was honest enough to mention that the radio was on frequency before he 'fixed' it. It was way, way off when he turned it back on.

He shorted some things to ground while the radio was powered up. It caused damage to some of the switch diodes that turn only one of the three coils on at a time. Also overheated the winding inside two of the three coils. Caused them to short from one turn of the coil to the next inside. A continuity test can't reveal this.

If turning the slug of L21 makes little or no difference, that coil may be bad.

73

 

[jef]

L21 has very little difference so am going to change the coil now. Which diodes should I be checking that could be suspect to lsb?

 

[jef]

changed L21 out of parts radio didn't effect it ,ordered a new one its on its way.Could one of diodes d34 35 36 be the culprit?

 

[nomadradio]

Whups, I may have screwed up here. Tracing the schematic makes L20 the USB trimmer coil, not L21.

Not sure every radio is wired that way, but L21 appears to be the LSB clarifier-set adjustment, NOT the USB trimmer.

There is only one diode feeding into L20, and that's D35. And if the factory moved something around in production, that detail of the schematic could be wrong.

Could be. And if L21 does indeed function when you turn the slug in LSB mode, that would be the reason it doesn't do much in USB mode.



Sorry about getting L20 and L21 switched the first time.

73

 

[Handy Andy]

Lets take a look.

Ok, one of the symptoms is, the radio won't slide...

Ok, let's stop there for a moment and look into VOLTAGES in and around L21

Let's get a snapshot of that area ...
Go to this link...
http://www.cbtricks.com/radios/galaxy/dx99v/index.htm

There's a lot of information there, but it's your starting point - so click and look around on those links...See if there is something you can use to help you - I'll do my best here - if you need me to slow down - I can - just trying to move along here...

Locate your Frequency Counter PCB - its wiring harness - theres a specific color code - like RED and Orange - when you switch between modes like AM/USB/LSB - these wires will show a voltage - can you tell me what they are?

Why?

Verifying your MODE SWOTCH is ok, and not fried...it may explain some things.

Let me know - will be right back!
:+> Andy <+:

 

[jef]

Nomad L21 is for lsb and doesn't seem to work, but L20 is for Usb and adjusts freq properly on Usb. Lsb frequency is high 2 channels on freq counter vs channel number display but is on freq just 2 channels high and clairifier doesn't seem to clairify on Lsb all other modes work great.Lsb transmits with full power and is on freq just 2 channels high from channel display and clarifier won't adjust on Lsb or I should sa barely adjusts.Andy I have been talking on Lsb and contacs say it sounds great but id like it to be right.I believe the mode switch must be switching because I have transmit and receive in Lsb mode

 

[Handy Andy]

I'm currently working on a graphic to help sort all this out.

But, while you're here...

If you can "probe" the D34 / D35 / D36 section - from the component side, look to see if you have voltages on all three modes of AM / USB and LSB - each diode will have a voltage on the BANDED side (or should) - but you also need to check the UNBANDED side - which is why I'm working on a graphic, so you and those others still interested - can find the DIODE locations and probe for voltage's and understand the readings they get.

This gets tougher when there are TWO poles of the MODE switch, one side can place full voltage on the rails - the other only 8 volts and is constant. There is also the issue of TX and RX toggling using a set of diodes to route power accordingly to the sections that need it. All these DIODES serve a purpose to steer power to the correct locations and not short out to other sections.

I'll stop here - check back for updates...

WHY did I have you check the "Freq counter" harness for voltage - because it uses the MODE switch to select the proper offset.

:+> Andy <+:

 

[Handy Andy]

I will b busy for the next few days if not a week or more-so what I have done so far someone else may have to pick up this ball and run with it...



The problem here is failed MODE.

But if radio has RX does it have PROPERLY operating RX - 2 channels away?

Reasoning.

IF MODE failed but other modes operate normally it usually is a power feed problem - usually a diode or an assembly issue - pretty straightforward.

But if it doesn't have any RX but shows frequency tuning 2 channels away - may indicate a power feed failure but BOTH the PLL - Clarifier as well as the Audio AN612 sides need to be checked for failure.

:+> Andy <+:

 

[jef]

Thanks Andy! I will check this out,The radio does receive normally just 2 channels high on Lsb.,Have been talking on Lsb just have to have channel indicator say 36 to be on 38 with very little clarifier control.Usb and Am work properly on channel and plenty of slide Just Lsb is messed up but works if that makes sense.

 

[jef]

Mode selector switch has 8 volts on lsb to yellow wire which goes topin 36 on plug j103 on board and has 8 volts there, am and usb all have 8 volts at mode switch so far I have changed l21 can for new one,d34 tests fine still have no adjustment L21 can claifier barely slides on Lsb ,also forgot to mention the clarifier is unlocked on this radio if that help with diagnosis. still searching.

 

[jef]

Thank yurou so much Andy for your help I reflowed solder on d35 d36 the end toward ic10 and that fixed it right on.Your help and patience is greatly appreciated .And Than you Nomad for your ideas it all helped in this journey.It is right now hurray!Thanks again guys for the help Jef

 

[nomadradio]

Rock and roooooolllll!

Glad to hear it worked out.

Gotta love it when a plan comes together. Congratulations for sticking with it.

73