EPT360014B Galaxy DX 11B frequency issue

[Hawkeye351]

Had to jump on another one while waiting on parts to arrive for the emperor.

What we have here is a Galaxy DX 11B (the 2517 took the place of the 11b's). This radio was given to me as trade for some radio work I did for a friend. He told me he was listening to it last week and all of a sudden he lost the 11m band and 10m band. I have read other issues pertaining to the same symptoms this one, and I tried the quick power on trick but it never works. This radio does have some odd mods I've never seen before. I've attached some photos in hopes someone can help me get this one to at least get the 11m and 10m back up. Then I can look into removing all the mods I know about. Everything worked great until a week ago, then no cb or 10m and no xmit. It all went at the same time. I've checked the vco, and yes someone has been dicking around with it, the vco is actually bottomed out and if you bring it back up then it just drops below 25mhz on the display. I've heard about ic6 and ic7, and I'm hoping it's not those. If it is, then I need to know where I can get some replacements or a known working substitute.








Frequency display on counter according to band selected. Yes, the frequency does change when you change the channel, and the course tune does affect slide. Note, all below pics are with the channel selector set on channel 1, all I did was switch bands and snapped a pic for every band so you all can see what freq it jumps to according to which band you select.










These other pics are some pics of sloppy work.



I have more photos but I couldn't upload but 10 at a time.

Again, this is my personal radio which was recently given to me. I worked great up until last week. I have heard this radio on air several times and it does sound pretty good. But now it's sick and needs some help. Any help is greatly appreciated.

 

[Hawkeye351]

Here are some more pics:












Sloppy work, left legs sticking up, 2 diodes tied together with both banded ends soldered together.

 

[nomadradio]

I would first make sure the 10.24 MHz crystal is running, and feeding into pin 3 of the 145106 chip.

If you have a 'scope, you should see a 5.12 MHz square wave of about 8 Volts peak-to-peak coming out of pin 4. This is the one way to know that the drive level to pin 3 is sufficient to make the chip function.

Might have a different cause, but that's what this symptom sounds like.

73

 

[Hawkeye351]

Thank you nomad for the response. That's exactly what I was planning on doing is checking the 10.240, but again I have to put my personal radio aside for a customer. But I will check into this as soon as I get back on this radio.

Now on my desk is a Galaxy DX 99v. The customer stated he could talk on it fine for about 15 to 20 minutes and then everyone would say it gets muffled. I told him it sounded like bias was offset, regulator getting hot or crap mods.

Got it home, popped the cover off and OMG is all I could say. Looks like 3 different swing kits, 1 is a swing module and the other 2 are the typical diode resistor tied together and a diode across the rails from the regulator on the trace side. Also the AMC and alc was removed.

I'll upload some pics for enjoyment purposes later, lol... Why do people do these radios like this? You can only get so much out of these finals, regulators and such, it's ridiculous. No wonder he sounded muffled after 15 minutes, he's overworking and stressing the circuits out, of course they're gonna start breaking down. Jesus Christ...

 

[nomadradio]

Another case of worship the wattmeter and who cares how it sounds.

Sounds like the real miracle is that it didn't blow the plastic face off of a transistor.

73

 

[Handy Andy]

Just to point out a few things...

This is a disaster...
Never even clipped off the leads - sigh...
This region has to be "rebuilt";
as in carefully remove these wires - even replace the transistor...
I have seen this work and they are in spots that control audio "gain" Envelope and speaker
Hopefully removing them is all you need to do. I see open holes so you may need to grab
a similar EPT360014 board and use it as a template...​

This is a "Frankenstein" - a lab experiment...

The other area I'd look at - at least unsolder the shields and leave them open to see if there are soldering blobs covering or shorting spots under these foil sheets.

These protect your VCO section - those IC's are your 4008 adders and PLL
​

 

[Hawkeye351]

Ok, just pulled this one back out. Still waiting on 4008 ic's. I decided I would just look it over and fiddle to see if it's a loose solder connection or wire.

Well, I shook and twisted every wire in the thing, fiddled with all the connectors on the board, moved parts around, shook the entire radio, rapped the radio several times, wiggled wires on potentiometers, flexed the board, etc... No change in frequency whatsoever, not ever a flicker. Then I decided to swap out the 10.240 crystal with a known good one, same results.

I then just noted down what the channels are doing on which bands. Here are the results:

Band A - 25.615 to 26.055 in 10khz steps

Band B - 26.065 to 26.470 in 10khz steps up to ch. 37, then 37 to 40 no change.

Band C - 26.470 to 26.470 (no steps)

Band D - 25.685 to 26.125 in 10khz steps

Band E - 26.135 to 26.575 in 10khz steps

Band F - 26.585 to 27.025 in 10khz steps

Radio transmits on all bands and all modes just fine. All other features works normally, even the 10khz switch functions properly. Course clarifier tracks as it should.

Would the adders (4008's) present the same symptoms?

 

[NZ8N]

Either the 4008 Binary Adders or possibly a blown Programmable Divider input pin (or pins) could act this way, or the VCO coil (L17?) could be misaligned, too low of a lockup voltage to frequency adjustment.

 

[Hawkeye351]

Thank you NZ8N,
I have noticed that the vco has to be bottomed out to lock on to anything. Any higher on the vco and it goes haywire, won't lock on to anything.

I was given this radio. The original owner stated it worked great for about a week after pulling it off his shelf and then all of a sudden it jumped, and that's how it's been since.

I asked him if he heard any snap, crackle or pops just before this or smelt any strange smell immediately after it happened. Answer on both was no. He said he never had any issue with freqs or bands on this radio until this happened.

Like I said, this is my personal radio. Nicest looking radio I've ever owned, I'd really like to get it going. Any advice is greatly appreciated.

 

[NZ8N]

DX11B - https://web.archive.org/web/2016102...cks.com/radios/galaxy/dx11b/dx11b_pll_adj.htm

Basically, same radio as the DX99V, EPT360014B board, different case, maybe different PLL offset crystal (sets lowest channel frequency). The DX11B has a PLL Offset frequency of 14.010 MHz, the DX99V has 13.560 MHz, which adds a lower band than the DX11B.

Here is the info for the whole radio

https://web.archive.org/web/20190918043133/http://www.cbtricks.com/radios/galaxy/dx11b/index.htm

 

[NZ8N]

You said "
Band A - 25.615 to 26.055 in 10khz steps

Band B - 26.065 to 26.470 in 10khz steps up to ch. 37, then 37 to 40 no change.

Band C - 26.470 to 26.470 (no steps)

This is why I suspected L17 was out of alignment, as it was stopping at 26.470 as the highest frequency in Bands A/B/C.

Bands D/E/F have a different reaction. This is because for A/B/C, they use diode switched capacitor addons for the lower 3 bands, through C80 adding 15pf to L17 VCO coil, and C77 adding 10pf to the Collector of TR26. This lowers the frequency response to the VCO in these 2 places. When in A/B/C, they add 8v through the Band Switch, follow the wire (marked red in the below schematic), through R140 (1k) then C219 (22uf @25v) to buffer the switched voltage, then through R108 (1k) to R109 (6.8k) and R107 (10k) to turn on (hard clamp) D33 and D123 that "grounds" C80 and C77.
When in Bands D/E/F, this circuit is 0v, which unclamps D33 and D123, thereby releasing C80 and C77.
This causes the VCO to track higher frequencies, with lower VCO (TP2) input voltages.
If functioning correctly.
So, readjust L17 on the lowest band (A) on Ch.1, should see 2v on TP2. Check the rest per the PLL Adj instructions.
https://web.archive.org/web/2016102...cks.com/radios/galaxy/dx11b/dx11b_pll_adj.htm