Toggle sidebar Toggle sidebar
  • 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.
  • A Winner has been selected for the 2025 Radioddity Cyber Monday giveaway! Click Here to see who won!

DX2517 EDP690010Z Low RF Power First Time Posting. Really need some HELP,INPUT

6

66gto#2

New Member
Oct 18, 2025
26
15
3
79
Have a friends Galaxy DX2517 with low power problem. Has EDP690010Z board. When i received it he told me it Quit Transmitting. Receives perfect the P.A. works fine. I have some meters to check Transistors and Capacitors i have 2 peak Atlases. DCA55&LCR45 they are some what accurate. I replaced these with all new 2 finals 2sc2312 Q47,48.1 Driver 2SC2166 Q49,Pre driver Q51 2SC2538 they were all burnt out.Also replaced 3 Diodes, at the base of the driver and finals.D90,91,92. Also replaced AF Power 2SB25754 Q54. Also replaced 19 Electrlitic capacitors.Checked all when removed, all were good. Put in New ones,checked all new ones before reinstall.Thought i had it fixed. Not so Lucky. Got it to key up but only puts out 1 1/2 Watt A.M. Went back and Removed more Transistors Q50,53,55,56,57. All checked Good. I reinstalled them all. When i went in to set Bios on Driver and Finals, Milla Amps the Driver should be set 50-75 M.A.( VR12 is the small pot) The most i can get set to is 17. It won't go Any Higher ( This is the Big Issue.) If i could get it it to respond to50-75 M.A. the unit would work properly. I can't figure out WHY??? I went through the transmitter Alignment and everything is fine until i get toSSB ALC can't get past 13.3 watts should go to 28 Watts.( I guess it's all about the Bios Milla Amp setting i can't get to work.) I always check my solded work and make sure i don't have any solder bridges and clean all flux away. I have a great Hako FR-301 desoldering gun. also have a FLIR Gun to check for any hot spots on pc board. Couldn't find any. I really need some Help= Input with this problem. ANY HELP APPRECIATED.. I'M Stumped, don't know what to do. Have a nice Day.
 
Last edited:

Are you in SSB (with mic gain minimum) while trying to set the bias current, or AM?

New transistors, new diodes, responsive pot, makes me think the collector voltage is low. AM will put less than half the supply voltage on the collectors which might explain the low current. Make sure you are doing this in SSB!

If you were in SSB, double check the bias pot.
 
Last edited:
66gto#2 said:
Have a friends Galaxy DX2517 with low power problem. Has EDP690010Z board. When i received it he told me it Quit Transmitting. Receives perfect the P.A. works fine. I have some meters to check Transistors and Capacitors i have 2 peak Atlases. DCA55&LCR45 they are some what accurate. I replaced these with all new 2 finals 2sc2312 Q47,48.1 Driver 2SC2166 Q49,Pre driver Q51 2SC2538 they were all burnt out.Also replaced 3 Diodes, at the base of the driver and finals.D90,91,92. Also replaced AF Power 2SB25754 Q54. Also replaced 19 Electrlitic capacitors.Checked all when removed, all were good. Put in New ones,checked all new ones before reinstall.Thought i had it fixed. Not so Lucky. Got it to key up but only puts out 1 1/2 Watt A.M. Went back and Removed more Transistors Q50,53,55,56,57. All checked Good. I reinstalled them all. When i went in to set Bios on Driver and Finals, Milla Amps the Driver should be set 50-75 M.A.( VR12 is the small pot) The most i can get set to is 17. It won't go Any Higher ( This is the Big Issue.) If i could get it it to respond to50-75 M.A. the unit would work properly. I can't figure out WHY??? I went through the transmitter Alignment and everything is fine until i get toSSB ALC can't get past 13.3 watts should go to 28 Watts.( I guess it's all about the Bios Milla Amp setting i can't get to work.) I always check my solded work and make sure i don't have any solder bridges and clean all flux away. I have a great Hako FR-301 desoldering gun. also have a FLIR Gun to check for any hot spots on pc board. Couldn't find any. I really need some Help= Input with this problem. ANY HELP APPRECIATED.. I'M Stumped, don't know what to do. Have a nice Day.
Click to expand...
Where did you get the final and drivers from
 
  • Like
Reactions: BC Coyote
woaa! you replaced all that!

but can you adjust VR10/11 for the bias there? the finals?

as brandon said, "in SSB (with mic gain minimum)"

key up.

check the 8V that supplies the bias R243/R245 junction to ground.

check the voltage at base of Q47/48/49 for around .65
the voltage at the collectors at around 12.5

but if the conducting voltage at D92 is lower than normal, then
that will be a problem to adjust Q49 bias.

I have had this same problem as you, so I take out them
diodes in the bias circuit and change it up.

I do something like this-

new bias circuit.jpg
 
just checked the posting here,

and SuperLid just asked a great question

"Where did you get the final and drivers from"



I recently had good results using the HQ made transistors
from that Fat Boy guy in New Jersey.
 
I check Bios usb with no mike gain. Purchased parts from RF Parts in California
I also check anything I replace with my( 2 meters Peak Atlas )to make sure they are working. Also removed the Driver 1K Pot and it is O.K.
 
66gto#2 said:
I check Bios usb with no mike gain. Purchased parts from RF Parts in California
I also check anything I replace with my( 2 meters Peak Atlas )to make sure they are working. Also removed the Driver 1K Pot and it is O.K.
Click to expand...
What is the RF PO in FM? What are you measuring power with? Also, peak Atlas will not tell you a device is a fake. I generally trust RF Parts, but I don't know what they are selling these days, so I just checked. The do NOT have 2SC2312, but are subbing MRF475, which does not have the same Po as the 2312. When did you acquire these devices? Can you post a photo of the 2312, 2166?
 
Last edited:

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


      Top Bottom