I did resolder the transistor legs but that didn't seem to help anything. I'm going to order a new transistor. I measured the voltage after the resolder and it was battery voltage. I shut the radio down because I didn't want the magic smoke coming out from anywhere.
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Galaxy DX 88HL HELP!!!!
- Thread starter hank
- Start date
Then, while waiting for a part to arrive...
Head off to here - it's an older site but they've got the info you're looking for...
http://cbtricks.com/radios/galaxy/dx88hl/
Head off to here - it's an older site but they've got the info you're looking for...
http://cbtricks.com/radios/galaxy/dx88hl/
Thanks. I used that site before for a Galaxy DX33HML. They have a lot of information.
I really appreciate all the help you are all giving me. I'm very new to these types of radios. I'm usually messing with uhf Motorola. I built a repeater for GMRS to use locally. That was a fun project.
Wow!
Hope you stick around , we can use someone with this type of experience at this site!
Purchased the 2SA473 and replaced it. It fixed the voltage problem. Now the frequency seems to fade away. When I turn the radio on, it slowly fades down until the frequency counter reads 888888. That is the same for any band setting. It starts at around 28.405 and fades down slowly to around 25.200. then the counter shows all 8.
First question is whether the radio has lost its grip on the channel frequency and actually drifted away from it,
--OR--
The counter display is misbehaving and the radio is still actually on frequency.
Or both the radio's PLL and the counter are misbehaving at the same time.
If this is the pre-1995 version of the radio with the enormous counter module that's 2/3 the width of the radio, this makes the "both" option look more likely.
That counter module was famous for flaky failures. Not the least of which involved their method of dropping the regulated 8 Volt supply in the counter down to 5 Volts for the chips that require the lower voltage.
They stuck a 2.6-Volt zener diode in between the regulated 8 Volts and the supply line to the 5-Volt chips.
Lame. The zener was famous for going bad. Our fix back then was to shoehorn a TO-220 7805T regulator in its place.
That was so long ago we may not have any pictures of that trick.
And if you have the post-1995 radio with the small counter module, that's a better option on the whole. The 5-Volt regulator in that counter was subject to failure, but a fixed resistor that feeds unregulated voltage to it is the more-likely culprit.
But it's a waste of time to get too specific until we know which radio you have.
Troubles in the radio's PLL will usually prove to be one of two things. For a few years those radios were built with a 10.24 MHz crystal that was failure prone. Naturally this shuts down the PLL and the radio's frequency drifts down to 25 MHz or so. This is easy to establish, if you have a 'scope or a radio that can tune in 10.24 MHz.
The other cause is what we call "Galaxy Syndrome".
Soldering defects. Most especially found underneath the metal shield covers on the solder side of the pcb under the PLL section.
Let us know which radio you have and we can take it from there.
73
--OR--
The counter display is misbehaving and the radio is still actually on frequency.
Or both the radio's PLL and the counter are misbehaving at the same time.
If this is the pre-1995 version of the radio with the enormous counter module that's 2/3 the width of the radio, this makes the "both" option look more likely.
That counter module was famous for flaky failures. Not the least of which involved their method of dropping the regulated 8 Volt supply in the counter down to 5 Volts for the chips that require the lower voltage.
They stuck a 2.6-Volt zener diode in between the regulated 8 Volts and the supply line to the 5-Volt chips.
Lame. The zener was famous for going bad. Our fix back then was to shoehorn a TO-220 7805T regulator in its place.
That was so long ago we may not have any pictures of that trick.
And if you have the post-1995 radio with the small counter module, that's a better option on the whole. The 5-Volt regulator in that counter was subject to failure, but a fixed resistor that feeds unregulated voltage to it is the more-likely culprit.
But it's a waste of time to get too specific until we know which radio you have.
Troubles in the radio's PLL will usually prove to be one of two things. For a few years those radios were built with a 10.24 MHz crystal that was failure prone. Naturally this shuts down the PLL and the radio's frequency drifts down to 25 MHz or so. This is easy to establish, if you have a 'scope or a radio that can tune in 10.24 MHz.
The other cause is what we call "Galaxy Syndrome".
Soldering defects. Most especially found underneath the metal shield covers on the solder side of the pcb under the PLL section.
Let us know which radio you have and we can take it from there.
73
Ok, to help others as for us when we need to look back on what we did and where we're going...
this should help us get you started.
One thing we do find in these radios is the Channel Selector starts to show it's age. So when pins don't line up right all the time, the PLL "stops" functioning and also uses a small switch in the "detent" to help the PLL decide the new channel selector and the pins set for it.
The thing shouldn't "die" but if we can rule out some simple hardware stuff from causing goofy problems - then we can suaully say that the problem then lies ":here".
But again, this radio is a DTD 1996 or there-about's, time for some recapping - this radio is old and so are it's components - some won't be affected by age, but some of the others on that board are - Electrolytic caps are one - and you may have to "track down" these power supply problems during your tune up to locate, and replace those bad electrolytic caps that give you these power supply headaches - the "Then it dies" condition.
So be ready to find a circuit (or two, or three or four) that seems to work ok one moment then the power feed to it drops - this is the regulator loading - there may be a lot of points on the board you'll have to replace the caps right off the bat to get it to even STAY powered up and not die off on you.
PLL Alignment
Alignment Points
(Pay particular Attention To R116 VCO section)
With the two above, ;Alignment Points
(Pay particular Attention To R116 VCO section)
this should help us get you started.
One thing we do find in these radios is the Channel Selector starts to show it's age. So when pins don't line up right all the time, the PLL "stops" functioning and also uses a small switch in the "detent" to help the PLL decide the new channel selector and the pins set for it.
The thing shouldn't "die" but if we can rule out some simple hardware stuff from causing goofy problems - then we can suaully say that the problem then lies ":here".
But again, this radio is a DTD 1996 or there-about's, time for some recapping - this radio is old and so are it's components - some won't be affected by age, but some of the others on that board are - Electrolytic caps are one - and you may have to "track down" these power supply problems during your tune up to locate, and replace those bad electrolytic caps that give you these power supply headaches - the "Then it dies" condition.
So be ready to find a circuit (or two, or three or four) that seems to work ok one moment then the power feed to it drops - this is the regulator loading - there may be a lot of points on the board you'll have to replace the caps right off the bat to get it to even STAY powered up and not die off on you.
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