Sidebar 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.

receive issues? 959

9

9Lives

Active Member
Oct 3, 2012
182
6
28
40
When I got the radio it was extremely quiet. I figured the transistor was over driven by local linears. I replaced the transistor with a 2sc1674 from an old radio. Now there its good receive on ssb and even weaker signals. But when a loud signal comes thru it sounds like "honking" or "gatey" nasauly. I've tried retuning the coils but I don't know how to do this.

Also they're is no moment on the s meter on receive. All other functions on the radio are excellent. And meter works on other functions.
Clarifier has been unlocked correctly, regulator swapped out. That's all.
 

The gain knob works. I'm wondering if there is a transistor driving the meter? Or if anyone else knows thus symptom
 
Is the meter not working on AM either, or is the meter not working just on SSB only? Usually there will be a transistor that is in the metering circuits, usually one for AM, one for SSB. The transistors are usually located right by the adjustment pots, VR1 and VR2. It's possible that one or both might have gone fault.

There could possibly be an alignment issue with the SSB TX offset cans that can cause your receive to sound a bit "nasally". They can also cause your TX to sound that way too. You will need a decent frequency counter to realign these cans. Can't confirm that this is the issue, but I have seen the TX offsets poorly aligned from the factory before, especially on refurbs.

Hope this info helps. :)

~Cheers~
 
  • Like
Reactions: 1 person
I have no meter movement in either modes. The nasally sound of actually on am. The component before meter driver s maybe?
 
Alright...could be an outside chance that both of the transistors in the metering circuit let go... but that's unlikely. As far as the nasally sound goes... is the sound like that on ssb at all? Or just AM? If it sounds like that in all modes, I'd almost suspect a bad capacitor in the audio circuit. The nasally RX audio is a unique problem.. can't say I've ran into that before... lol


~Cheers~
 
Are you sure that you don't have the meter switch in the wrong position?
See pages 7-8 and read #8/'FRONT PANEL METER' AND #11/'SWR/MOD/POWER SWITCH' in the Owners Manual:
http://www.cbtricks.com/radios/galaxy/dx959/graphics/om_dx959.pdf

Messing with the receive coils in this radio is also very risky business. The first three coils L5, 6, & 7 should NOT be messed with unless you understand their functions in the receive circuit. Even then, using a high grade signal generator and a SINAD meter is required to get the ultra critical L5 adjustment correct!
 
Last edited:
From the DEFPOM page:
"Super Ears" Modification - D9

Here?s one that many folks ask me about and I was hesitant to include it here. This modification significantly lowers the effectiveness of diode D9 and greatly increases the injected received signal to the radio. This was very popular when the Galaxy 10-meter radios first hit the market (D7 on the Galaxy DX-series 10-meter chassis). The modification requires that you remove the banded end of diode D9 and add a 1/4W, 1.5K resistor in-line with the banded end and the now vacated board location. This actually works very well for any distant station giving you an S-1 to an S-5 signal. A typical example is a station giving you an S-3 will increase to an S-9 (relative) without any increase in background noise (as is the case with most preamps). The downside is that anyone in your immediate vicinity keying up will tremendously overdrive the front end of your radio, possible causing damage to the receive portion of the board. Because of this, I ALWAYS perform this modification with a SPDT sub-miniature or micro-mini switch so that the modification can be turned ON and OFF as needed. The Galaxy DX959 and 949 front panels are heavily populated so your installation options are limited. I installed my switch between the Clarifier and Talkback controls.

DISCLAIMER: Although this modification works great, I can not stress enough the care that must be taken when using it. Careless use of this modification can lead to radio damage. Engage this circuit modification only when copying distant stations. I take no responsibility for any damage incurred as a result of this modification.
Click to expand...
The Defpom EPT06960Z Galaxy 949 / 959 modifications

Look for D9. If you find a 1.5k ohm resistor in series with it (should look like it was modded); the take out that resistor and just hook the diode back up as it was originally put in that spot.
 
Nah dude, switch is in the right place. It almost seems to me that what ever drives those transistors might be down. Meter move ment works in all positions except receive (in all modes) the nasal sound could be all modes but generally ssb coming from distant. It's power ful signals sound gated.

There's a trim pot that connects to rf gain labeled fine tune, what's this for?
 
If the cores start to crumble can I just use one from a different radio? Or are they different material? Where can I buy galaxy parts?
 
9Lives said:
If the cores start to crumble can I just use one from a different radio? Or are they different material? Where can I buy galaxy parts?
Click to expand...

The only way they would crumble is if:

1) The ferrite core is too tight inside the coil. Poor quality control when mfd. Think it would be OK to put a small drop of light oil/kerosine into the threads.

2) You used a jewelers screwdriver to adjust them. NEVER use a jewelers screwdriver! Ever. Ferrite is very brittle. The proper tool is a nylon or ceramic tool designed to adjust coils. I use nylon alignment tools.

You can use another ferrite so long as it is the same length, thread pitch/count, and the ferrite is made of the same material. Ferrite material is not all the same. Some are made with different mix formulas to be more/less permeable to the electromagnetic field of the coil. That should be OK to try what you have if you understand this first.
 
Last edited:
Ok cool that might be what's wrong w a different radio of mine. I used a different core in the output chain. It's complete square wave with straight line carrier
 
9Lives said:
Ok cool that might be what's wrong w a different radio of mine. I used a different core in the output chain. It's complete square wave with straight line carrier
Click to expand...

Ummm . . . maybe/maybe not . . . just means that the coil will either be not as effective or too effective or even work like it is supposed to.

IMO - that isn't the problem.

Can you still put the other radio back to stock? Then wait until you get a bigger and better grip on what happened. Did you try turning down the mic gain/modulation and bring it back up slowly and watch it on the scope?
 
Last edited:
Yes, but I'm not as worried about that one. I really wanna figure out what's up with this galaxy first..
 
Problem solved. I don't understand why.. but when I changed q17 to 2sc1674 the problem arose..the schematic calls for that transistor but it's a different one. Maybe different pin? Meter works, receive sounds great
 

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


      Top Bottom
      Back