galaxy dx 949 low am modulation

[doc919]

I have the galaxy dx 949 (mosfet version) I have very low modulation on AM but seems to work well on ssb swinging up to 18w. On AM deadkeying 1won low power swinging 1.5w .on showing about 4% modulation on 949 meter & also checked the same with an inline to verify. Thank you for any help or suggestions. I have already checked the oltage regulato just in case. All is ok there

 

[dave457]

Sounds like a stock galaxy to me

Sent from my SGH-T599N using Tapatalk

 

[GnG8d]

What meters are being used?

 

[doc919]

Is pretty much stock except radio has already been tuned to match my box.i haven't done any major mods or limiter clipping cause I want a clean sounding radio over the airwaves.

 

[doc919]

Using (dosy) for test Eq. All I can afford at the moment

 

[Z-MAN 369]

I didnt understand what you typed on the AM numbers.

 

[Lil'Yeshua]

Check your high power pot setting. That's my guess. I have my 959's low deadkey set at 1.5 watts and the high deadkey set at 6 watts.

Further note:with the deadkey set low my 959's modulation meter doesn't swing full scale even with a Road Devil mic.


Galaxy Radios DX949 Service Manual



Note: I changed the pic and posted the link instead for 949 adjustments.

 

[doc919]

Before it messing up on low power deadkey 1 swinging to 8. High deakey at 4 swinging to about the same.. Now deadkey reading 1 watt swinging to 1.5 watts. High deadkey at 4 with no swing on the am

 

[Lil'Yeshua]

You didn't touch VR16? How to you sound on talkback?
If the modulation meter is set right 100% modulation will show around 80% by saying a loud audio into the stock Galaxy mic and 100% whistling into it with the rf power turned up on the front of the radio.
What mic are you using?
The SSB alc could be turned up high or maybe SSB power. It should only swing to 12 watts(legal watts)on SSB if everything else is set right.

 

[Lil'Yeshua]

Note: that's my observations on my DTB tuned 959 with it set at a legal 4 watts high dead key/1 watt low deadkey,100% modulation,12 watts legal SSB power.

 

[doc919]

Double checked vr 16 making sure its set to max. Still low deadkey at 1 watt swinging to 1.5... High deadkey set to 4 watts with no swing enough to move needle

 

[Z-MAN 369]

Sounds like either a bad solder joint or poor AM reg. Push on the board with an eraser end of a pencil.

 

[Lil'Yeshua]

Sounds like either a bad solder joint or poor AM reg. Push on the board with an eraser end of a pencil.

Hmmmmmm! Interesting! I'd love to find out how the am regulator works.
http://www.cbtricks.com/radios/galaxy/dx949/graphics/dx949_ser_manual.pdf

 

[Robb]

Typically, when the AM Regulator is at fault, the symptom is a high carrier (~16 watts) output and no modulation.
But I'd agree there is a problem with the AM modulation circuit somewhere.

 

[binrat]

Just a thought. If it was me having this problem I would crank VR16 the othr way to see if it made a difference at all.