• 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 73v modulating dog!

Cityboy

Active Member
Dec 25, 2008
123
1
26
I have tuned the radio up and can not get the modulation up on this radio. I have cranked VR 14 all the way up and it is a dog. Is the limiter that I can cut that will raise the modulation and will it effect the radio at all. Thanks for any help.
 

that radio should give you all the audio you would need without clipping anything. What is your set up ? antenna ? mic ? That radio should have some pretty big audio on it to begin with. What's really going on ? Do you run a amp with it ? How high do you have this thing tuned up ? If your boring it out on the watts , this could be your problem ? Tell us more.
 
Last edited:
It is going through my dosy 4002 psw and into my 1.5kw palstar dummy load. So no mistakes there; it just wont swing and the guy that owns it has owned it since it was new and never seemed to have the big audio it should. He had me put it on my meters and it will dk 10.5w and only swing to 20-21w with the little modulation it has. Maybe it is the driver or final that is weak. What do you think modulation is set 95% and swings to 100%. Only a 5% swing is why it sounds like a cobra 29 right out of the factory. Let me know what you think and what I should do. Thanks.
 
I tested it with my astatic 636l and my ranger sra-158 so it is not a stock mic being used. Like I said no mistakes as far as testing it; VR14 is turned all the way up and it only swings from a set point of 95% and swings to 100%. A 5% swing explains why my friend never was impressed with this radio. Please help my friend out; I could change out the driver and final but figured I would pick your collective brains before I start throwing parts at it. Thanks.
 
158 is a stock mic /636 are NC mic's (baiscally a stock mic ) 10.5 watt DK on that radio sounds like a bit much . Drop it down to 6 and IM sure the audio will grow from there. No need to clip anything.

After you drop the watts down it should bring the audio up. Not that much diff from 6 to 10 anyway other then the audio your looking for. That radio has a echo board in it ? those tend to work like audio amps in there own way ,

Although I don't like power mic's in vehicles , and I think those mic's mentioned or the radios own stock mic should be more then enough , you could still try a good power mic on it after you drop the watts down if need be.
 
Hey CBoy,

I will agree with what was mentioned earlier. There is a part getting weak/going bad. Take it to a shop for a repair. It won't be any big deal to locate and replace one bad transistor or something.

Good luck

interview.gif
 
SRA-158 is a ceramic element and will give you the most modulation you can possibly get from a radio, it is a stock mic for the RCI products but is probably the most sensitive one on the market and will make any radio swing full modulation with little effort because of the mic element. As far a the radio being turned up a little your correct; but it was at 8 1/2 and still a total dog; in fact it will swing to 100% and when checking the set point it was 100%. There is definitely something very wrong with this radio. I have the 1969 final and the 2166 driver for this radio and have no problems installing it; but I didn't want to just throw parts at it if I am wrong. Please help!
 
It is going through my dosy 4002 psw and into my 1.5kw palstar dummy load. So no mistakes there; it just wont swing and the guy that owns it has owned it since it was new and never seemed to have the big audio it should. He had me put it on my meters and it will dk 10.5w and only swing to 20-21w with the little modulation it has. Maybe it is the driver or final that is weak. What do you think modulation is set 95% and swings to 100%. Only a 5% swing is why it sounds like a cobra 29 right out of the factory. Let me know what you think and what I should do. Thanks.

Try turning the key down to 4 or 5 watts and see if that's enough audio for you. I have always had good results using this ( your peak power..21 watts divided 4= 5.25 watt dead key) which should put you around 100% modulation. You can lower the key more than that if you want but be sure that it does not get to choppy and over modulated.
 
I will try and lower the dk to around 4-5w and see if will let the dog swing its tail; but I really doubt it. I think there is something going on from the factory, it has been a dog all its life. It should easily go to dk of 8-11w and show at least at 40% swing in modulation. So I should be able to set at say 60% set point and go to 100%. This thing as it sits now is only swinging 5%, that is pretty bad for this radio. And as far as pep watts it should easily hit in the 24-28w range with the 1969 final and right now it only around 18,19-20w range. Thanks for the suggestion I will try it out and post back my results.
 
I tried lowering the dk and found the best result around 6 1/2w; but the modulation set point was only 70-75% and swings to 100%. It is an improvement but not what this radio should do. This radio should be set around at least 60% and swings to 100% and a dk between 8 and 10w and should hit a pep of 25-29w. This radio is still a dog; please help.
 
City boy, does this Galaxy have dual finals and ssb? And if it has ssb what is the ssb output watts?
 
City Boy -

Check the settings on VR16 and VR13. With the front panel RF POWER control set to max, adjust these two pots for max RF output. Do this with the Echo and Voice Control turned OFF. Also check the value of R237. Should be 100 ohms. Check the solder joints on this resistor also.

- 399
 
To answer purenrg it is a AM/FM radio and is a single final radio with a 2sc2166 for a driver and a 2sc1969 for the final transistor. Unit_399 I will check the resistor at this location and report back in just a little while. The factory specs for the VR16 which is the low power setting says to set at 1w not to max it out so one could use an amplifier if one chooses to. Are you saying max it out anyways? And VR13 the high power setting will max out at 12-13w and will not help the modulation. I will check the resistor and its solder joints. Thanks.
 
I checked out R237 and it is 100ohms; but the interesting thing I noticed is where R212 should be there are two prongs from a potentiometer on the solder side of the board. Do you think if I adjust it will it make the modulation go up?
 

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