Galaxy Saturn no Tx
Galaxy Saturn no Tx
I have a galaxy saturn main board #ept360012b that someone has done the ekl 2030 mod. and it has no tx power or modulation but the receive is fine. I have replaced tr44,tr56,tr43,tr45,tr50,tr51 and rechecked all the changes for this conversion and i still have no tx power or modulation. When i key the mic the tx light comes on as it should. I also checked volts at ic8 and all are good here are some of the other voltages that i have checked gate volts on tr44,tr56,tr43 are3.42 volts in tx mode. The voltage on the drain in rx mode for tr44,tr56,tr43 is3.8volts on all three and in tx mode the drain volts are7.64 volts on all three. I also checked volts on tr 45 b 1.13,c 8.5,e .45 in tx mode tr50 b 13.0,c 7.6,e 13.0 in tx mode. tr 51 b 13.0,c 7.6, e 13.0 in tx mode. i have also checked all connections going to the antenna jack and all connections are good. Anyone have any idea on what could be wrong with this radio.Thanks for any information and help on this.
Rick thanks for helping me when they done the erf-2030 mod. it looks like the bias controls were taken out of circuit like on the galaxy 99v mod. they installed the ekl companion parts on tr 44 is en-369dr and tr 43 is en-369fn. I can send you a copy of the mod. sheet they went by if you need it. Thanks
Last edited by smokinjoe on Thursday 6th Mar 2008, 6:37, edited 1 time in total.
Re: Galaxy Saturn no TX.
I am a bit confused. As in your message you say b, c, e and not g, s, d if MOSFET.
Are you using 2030 Mosfets for driver and final?
If yes then what is the Gate voltage of the driver? and the finals?
What is the voltage on the Collector of TR51? on AM key-up and can you adjust the voltage with VR13?
Are you using 2030 Mosfets for driver and final?
If yes then what is the Gate voltage of the driver? and the finals?
What is the voltage on the Collector of TR51? on AM key-up and can you adjust the voltage with VR13?
Rick.
Rick sorry about the confusion. Yes the radio has three 2030 mosfets installed. The collector voltage on TR51 is 7.6 volts keyed and 3.6 volts unkeyed and i can adjust it up or down with vr13. The gate volts on all three 2030 mosfets is 3.42 volts with radio keyed and 0 volts unkeyed. The drain volts on all three 2030 mosfets are 7.64 volts with radio keyed and 3.8 volts unkeyed. Thanks.
Re: Galaxy Saturn no TX.
I think I ask you once before if you had a scope or an RF probe.
I maybe an idea to temporally put the driver back to 2SC2166 as this should aid you in finding the fault.
You could send to a copy of the mod sheet to my email address, as I may find some think you have over look.
I maybe an idea to temporally put the driver back to 2SC2166 as this should aid you in finding the fault.
You could send to a copy of the mod sheet to my email address, as I may find some think you have over look.
Rick.
Rick thanks again for your help i don't have the original finals but i may have a new set of 1969 finals and a 2166 driver. Let me get back to you over the weekend i may try and put the radio back to stock and see if the problem is still ocurring. I guess this is the best way to see if someone has done something wrong. Also i will look into building a rf probe. Thanks
Re: Galaxy Saturn no TX.
All test to be carried out with the RF Probe.
Check the inputs to the TX mixer IC9 with the radio set to AM and in TX mode.
Check R231 this is the 15 to 17 MHz input to the TX mixer.
Check R232 this is the 10.695 MHz input to the TX mixer.
If both signals are presented check, the output of the TX mixer IC at pins 2 and 3 if all signals is presented check the Base of TR46.
Let us know how you get on.
Check the inputs to the TX mixer IC9 with the radio set to AM and in TX mode.
Check R231 this is the 15 to 17 MHz input to the TX mixer.
Check R232 this is the 10.695 MHz input to the TX mixer.
If both signals are presented check, the output of the TX mixer IC at pins 2 and 3 if all signals is presented check the Base of TR46.
Let us know how you get on.
Rick.
Re: Galaxy Saturn no TX.
The inputs to the TX mixer are the 2 resistors number I gave you in my last message.
From what you have told, me the 10.695 MHz Oscillator is not working.
Check for cold solder joint around X4 and TR30.
With the radio in AM TX mode connect RF probe go to the Emitter of TR30 to see what signal you have?
If you have no signal, try-replacing crystal X4, which is 10.6975 MHz or it, could be the transistor TR30 also make sure the Collector has volts in TX or the Oscillator will not work.
From what you have told, me the 10.695 MHz Oscillator is not working.
Check for cold solder joint around X4 and TR30.
With the radio in AM TX mode connect RF probe go to the Emitter of TR30 to see what signal you have?
If you have no signal, try-replacing crystal X4, which is 10.6975 MHz or it, could be the transistor TR30 also make sure the Collector has volts in TX or the Oscillator will not work.
Rick.
Re: Galaxy Saturn no TX.
Check the the copper track from the emitter of TR30 to R232. It looks like it is O/S
Rick.
Rick i would like to thank you for your help on this radio because it has a few things wrong with it and i was trying to take care of one problem at a time . I now have rf power radio keys 2 watts and swings to 30 with modulation now i need to find out why i have a high carrier on usb and lsb anyone have any ideas as to what would cause this? Thanks for your help.
