I have a galaxy 73v that transmits on oe channel recieves on another

sounds like a repair for a tech to me.

you may have a broken transmit wire in your mic get a mic tester and check it out. If its not the mic then its an internal problem

make sure the mic is wired correctly for this radio--lots of different 4 pin connections are possible or have it tested by a shop

You may have a dead meter.
Modulation is audio's affect on swing wattage or pep. Notice that needle moving more with your voice.
Dead key or carrier wattage is without your voice enhancing the power only with mic keyed.
I can only assume that the chipset you are referring to is an ic chip audio or pll which must be working if you are receiving audio.
Check your mic cord................ transmit and modulation and even your receive volume can be affected by the cord/mic plug solder joints or broken wires here.
http://www.cbtricks.com/radios/galaxy/dx33hp2/graphics/dx_33hp2_sch.pdf this is a similar radio the General Lee, Connex 3300hp and Galaxy hp2 share boards i believe dont hold me to that thou.

Do you have receive?

mike has wiring problems. Check for breaks in cord and where the plug goes into the unit. If not original mike then has incorrect wiring for the radio and will need to be changed for config

To add 10Khz to your transmit frequency:

FIXED/OFF/+10KHz SWITCH: The left position puts the radio on
one of the three fixed channels that is selected by the channel switch
(6,19, or 21). This over-rides the channel selected by the 40 channel
knob. The right position adds 10KHz to whatever frequency you are ON.
In the middle, both features are OFF.

Otherwise, a radio tech would be able to retune the frequency inside the radio.

After adding 10KHz to your frequency, use the SWR control to check the SWR of your antenna.
Here's how:
SWR CAL CONTROL: Normally this switch is set to “PO”. Then,
during transmission, the meter indicates output power. To read SWR,
rotate this knob during transmission until the needle moves to the “SET”
point on the SWR scale. Then, while still transmitting, set the R.B./SWR
switch to SWR.

Ideal SWR is 1 but you'll want to be as near one as possible. An SWR of 1.6 or greater will make ineffective use of your antenna.
If in doubt, a radio tech has the required meters and tools to adjust the SWR/Tuning of your antenna.

Check the wiring on the mic plug sounds like you have a loose wire or one thats about to break off.Good luck.....Dan

Hello Darren, Yes it sounds like the mic is wired bass ackwards,,! A cobra 25 mic wiring is
PIN #1- Shield or ground wire
PIN#2- Audio or Transmit modulation
PIN #3- Transmit or Dead Key
PIN #4- Receive Audio.
When your keying the mic, the RX wires are being connected to make the RX work,,,
*** Let me know how you get along with it. Either buy a new mic wired for your radio or you or someone comfortable with soldering needs to resolder the correct wires back on the mic plug,,,Like I said, let me know and have a great day,, Mechanic is back quiet!

as far as the transmit frequency changing while you have the mic keyed this is normal, the transmit frequency is a little different than the receive, as far as the lost channels go you need to check the galaxy website and check to see if thier is any fixes listed. if none is listed then you can send the tech's a e-mail and tell them your problem and they will advise you on what to do.