• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

Galaxy 99V Bad sounding SSB

Low_Boy

Sr. Member
Jan 21, 2010
1,931
1,193
173
Rochester N.Y.
Side band is just not right on this radio.
I tuned the radio and rechecked everything. All settings are right on. The radio puts out full power all modes. Sounds perfect on AM and FM. All limiters in tact. Side band does not sound right. LSB has no carrier. USB is a bit strange. There is a carrier too low to see on a watt meter but it shows on a spectrum analyzer and about 11 MHz on a frequency counter. It also shows a bit on the scope.
Mode switch checks good. shows same voltages on both USB and switched to LSB.
I see no leakage in voltage from AM. or FM.
balanced modulator is good. BUT still shows a carrier in USB when the balanced modulator is removed. and microphone keyed.
IC 4 dual op amp good.
Most everything before the balanced modulator checks good. Seeing how there is a carrier with the balanced modulator removed I am thinking the problem is after the balanced modulator.
TR 30 Carrier oscillator. checks good. TR 52 SSB Audio switch good, TR 46 TX RX Amp good, TR 31 AM FM Shorting good.
Anyone have any ideas what I am missing. I think if I can get rid of the carrier in USB that will solve the problem.
Thank You
 

Side band is just not right on this radio.
I tuned the radio and rechecked everything. All settings are right on. The radio puts out full power all modes. Sounds perfect on AM and FM. All limiters in tact. Side band does not sound right. LSB has no carrier. USB is a bit strange. There is a carrier too low to see on a watt meter but it shows on a spectrum analyzer and about 11 MHz on a frequency counter. It also shows a bit on the scope.
Mode switch checks good. shows same voltages on both USB and switched to LSB.
I see no leakage in voltage from AM. or FM.
balanced modulator is good. BUT still shows a carrier in USB when the balanced modulator is removed. and microphone keyed.
IC 4 dual op amp good.
Most everything before the balanced modulator checks good. Seeing how there is a carrier with the balanced modulator removed I am thinking the problem is after the balanced modulator.
TR 30 Carrier oscillator. checks good. TR 52 SSB Audio switch good, TR 46 TX RX Amp good, TR 31 AM FM Shorting good.


I'm assuming although you didn't specifically mention it that you adjusted the carrier balance I think it's vr7 if memory serves me? you didn't say you did so I was just wondering. It's not necessarily a big problem that it would have such a slight carrier and also not necessarily something that would cause or be the cause for SSB to sound bad. these are hard to troubleshoot over the text.. What does SSB sound can you describe it?

OldTech03
 
I did adjustment carrier balance that's about as low as I could get it. I think it sounds kind of like underwater almost I'm told over the air that it sounds garbally. Of course my testing was done on a radio in the same room so it's really hard to tell from that.
Old Tech nice to see you around again.
 
If you are running the radio on a known good power supply with good amperage to the radio, with a proper power cord, I would replace TR51 (labeled B754) with a TIP36C. This will help fix the warble issue in most cases. As far as the carrier balance is concerned, if one sideband has a small amount of carrier emission (ie. barely noticeable), I wouldn't get too upset over it. Some radios simply won't tune out all of the carrier. I've seen radios new out of the box that won't tune out all of the carrier on one of the sidebands before.

Give that a try and let us know how you get on.


~Cheers~
 
  • Like
Reactions: tba02
Xit13, isn't TR51 only used on AM?

am i missing something?

Low Boy, how is the frequency stability on the IF (10.695) coils?

do you notice the freq bouncing around in one mode more than the other?

if you do notice one mode that seems less stable than the other, you might try switching the AM and the USB IF coils since they are the same type, and see if the problem follows the coil.

I only say that because i have had this problem with Galaxy radios before, and this was the cause twice that i can remember.

also make sure the mode switch is clean, or try jumpering past it to eliminate it as a culprit.

good luck
LC
 
So long as you're confident that all three carrier-frequency settings are correct for each mode, this suggests that your sideband filter has gone wockerjaw.

If you have a vector network analyzer, you can unsolder it and check to see that the passband is not shaped properly, letting carrier leak out on one sideband, but not the other.

Of course, if the carrier-frequency trimmer coils L23, L24 and L25 are set wrong, this can produce the same sort of symptom.

Quickest check for a bad SSB crystal filter starts with unplugging the antenna. Turn up the volume, and switch from USB to LSB and back. The, uh, "musical" pitch of the receiver noise will change. You'll almost never hear a Galaxy SSB radio that sounds identical when you switch back and forth. But if you hear an extreme difference, with the pitch more like a low-pitched "roar" on one sideband and a tinny "hiss" on the other, your sideband crystal filter is shot.

Don't see it all that often, but it's a possibility.

73
 
  • Like
Reactions: Tech5 and NZ8N
LC,

In the case of the Galaxy radios, TR51 is also used in SSB. They do it that way because the mode selector switch cannot withstand the extra current draw from running dual finals, so the board was designed to redirect the current flow through TR51 instead of the mode switch.

Nomad brings up another potential culprit with the TX offset cans, L23/L24/L25.

Provided those have NOT been touched, and the radio has been "peaked and tuned" to any degree, TR51 can be an issue. The stock 2SB754 doesn't take the increased current draw very well during SSB use and can cause a warble issue, almost like the radio is "starved" for power.

~Cheers~
 
I will try answering all in one post.
Astron 35 Amp power supply I do not think power supply is the problem.

TR 51. I did not know that had anything to do with SSB. I do have 2SB817 transistors but no TIP36's here. I will have to git some.

I think Nomad is talking L23, L24 and L25 offsets Also TX offset VR 21. All checked and double checked.

I tried switching Fr. USB to LSB with radio turned up full. Not much difference. LSB may sound a touch deeper in tone but no extreme.

Way in the beginning I removed X4 to make sure it was making good contact and all legs were still attached. Other than what Nomad said I have no way to check it.

TR41 shows correct voltages.

LC. I have not changed coiled or moved coils but everything is stable. I can not stand problems like this. I have no more hair to pull out LOL. Possibly changing TR51? At one time TR32 was out of this radio I was also wondering if that may have weekend a component? Thank You guys I am sticking with it and if I missed something let me know. I will try TR51 next.
 
Last edited:
I will try answering all in one post.
Astron 35 Amp power supply I do not think power supply is the problem.

TR 51. I did not know that had anything to do with SSB. I do have 2SB817 transistors but no TIP36's here. I will have to git some.

I think Nomad is talking L23, L24 and L25 offsets Also TX offset VR 21. All checked and double checked.

I tried switching Fr. USB to LSB with radio turned up full. Not much difference. LSB may sound a touch deeper in tone but no extreme.

Way in the beginning I removed X4 to make sure it was making good contact and all legs were still attached. Other than what Nomad said I have no way to check it.

TR41 shows correct voltages.

LC. I have not changed coiled or moved coils but everything is stable. I can not stand problems like this. I have no more hair to pull out LOL. Possibly changing TR51? At one time TR32 was out of this radio I was also wondering if that may have weekend a component? Thank You guys I am sticking with it and if I missed something let me know. I will try TR51 next.

The 2SB817transistors are just fine and will do a good job.
A better upgrade would be the newer Palomar Max Mod transistors.
 
At this point if quality SSB is a must have I would get the Galaxy 99 set as good as you can get it and move it down the road. They were always a strong AM talker with echo and talkback, pretty much a sailboat on SSB. They bring strong money on E-Bay if it's a clean radio. Then get a processor controlled radio which will be rock solid on SSB.
 
At this point if quality SSB is a must have I would get the Galaxy 99 set as good as you can get it and move it down the road. They were always a strong AM talker with echo and talkback, pretty much a sailboat on SSB. They bring strong money on E-Bay if it's a clean radio. Then get a processor controlled radio which will be rock solid on SSB.
My Thoughts exactly. This thing takes about 45 mi. to 1 HR. to heat up and stabilize. I sure would like to get it to sound better before I do anything with it. I think there is also a upgrade for TR50.
 
LC,

In the case of the Galaxy radios, TR51 is also used in SSB. They do it that way because the mode selector switch cannot withstand the extra current draw from running dual finals, so the board was designed to redirect the current flow through TR51 instead of the mode switch.

Nomad brings up another potential culprit with the TX offset cans, L23/L24/L25.

Provided those have NOT been touched, and the radio has been "peaked and tuned" to any degree, TR51 can be an issue. The stock 2SB754 doesn't take the increased current draw very well during SSB use and can cause a warble issue, almost like the radio is "starved" for power.

~Cheers~

wow what a bonehead i am LOL. it's easy to see when you look at the schematics. I should really start checking myself before i go spouting off.
TR52 turns TR51 into a switch allowing the B+ to be delivered to the finals.

I'm sure i used to know this LOL. I just never think about its role in supplying the collectors of the driver and finals in SSB.

Thanks for the insight.
LC
 
  • Like
Reactions: NZ8N
On a side note, these radios can be made to over-modulate too easily. Case in point, is the 4558 mic audio amp mods; in particular the resistors that control the amount of amping that IC chip will put out. IIRC the OE 10k biasing resistors may have been swapped out for 1k resistors. Don't exactly recall; seen it one of the radios I've worked on and put it back to OEM specs. Dunno why anyone would bother to do that, since this radio can easily over-modulate w/o that kind of mod.
Just a thought . . .
 

dxChat
Help Users
  • No one is chatting at the moment.