Stryker SR-497HPC what a mess!

[Cable Guy]

Not a question, more sharing and documenting what needs documented. So, a guy who I do repair work for, actually a few guys all recommended me to this one guy, they gave my info to their friend who has this radio. He called me out of the blue and asked if I repair radios. I asked who he was and how he got my info, as I don't want to be put out there and get overwhelmed, telling everyone that I do repair work for, not to advertise me directly and if they have a friend who needs something done, they must be a buffer, a middle man if you will. No, I don't run a shop, I enjoy a hobby. Back to the story...

He asks if I work on radios and I hesitantly answered him. He says he used to do all his own radio work but a medical condition has overcome his abilities and he needs a hand. He said he replaced the regulator but his shakiness caused him to burn a trace. I said I would take a peek. He meets me and hands me this radio. I popped the covers and LOOK at what I found...















I'm not one to run away from anything but the devil, but this radio is a hot mess. There are a few swollen caps near the front also, I really don't know where to begin. I know, my innards are screaming that I should button it back up and hand it back, but I haven't had a good challenge in a while. All I can think is I hope he didn't plug it up and try to use it.

 

[danmcclain]

Not a question, more sharing and documenting what needs documented. So, a guy who I do repair work for, actually a few guys all recommended me to this one guy, they gave my info to their friend who has this radio. He called me out of the blue and asked if I repair radios. I asked who he was and how he got my info, as I don't want to be put out there and get overwhelmed, telling everyone that I do repair work for, not to advertise me directly and if they have a friend who needs something done, they must be a buffer, a middle man if you will. No, I don't run a shop, I enjoy a hobby. Back to the story...

He asks if I work on radios and I hesitantly answered him. He says he used to do all his own radio work but a medical condition has overcome his abilities and he needs a hand. He said he replaced the regulator but his shakiness caused him to burn a trace. I said I would take a peek. He meets me and hands me this radio. I popped the covers and LOOK at what I found...

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I'm not one to run away from anything but the devil, but this radio is a hot mess. There are a few swollen caps near the front also, I really don't know where to begin. I know, my innards are screaming that I should button it back up and hand it back, but I haven't had a good challenge in a while. All I can think is I hope he didn't plug it up and try to use it.

I would say that radio deserves the "Golden Screwdriver Award". Sorry to say it looks like a challenge to me. Good luck with it, you'll need it... Dan

 

[Cable Guy]

Update, I finally got some time to look at it, and this PA board is rough. I'm not sure if the guy used a soldering iron or a branding iron.





I can't find this PA board on cbtricks, they show the single 2290, not the quad 520's. I would like to see a schematic, I think there are some missing components.

I did get the power straightened out and the 8v regulator was shot. Replaced it, now the radio does rx. I also replaced a failed 'lytic that was about to burst.

I have since installed the toroid after cleaning it up, some shrink wrap and uv resin over the melted insulation. I would rather have rewound it but didn't have any 16 ga solid wire handy.


I will tackle the PA board next.

 

[Cable Guy]

It looks like they removed 3 capacitors and left 1. Also, added some resistance across the output of the input transformer that goes to the bases (gates) of the finals. All I can find is an old listing as a Stryker replacement board, no pic or specs. Someone removed the original transistors and installed the irf-520's. I don't know if that is what this board took or if the evident modifications of this board were to accommodate the new transistors.

Oh well, I will figure it out. I had hoped to find at least a schematic but it's not the end of the world, I have done more with less.

 

[brandon7861]

What is the PCBX-# on the PA board. There is a sticker covering it in your picture.

 

[Cable Guy]

It's the pcbx-1026r1 as listed above in the screenshot from strykers page.

 

[brandon7861]

I wasn't sure if that was it or a potential compromise replacement. I cannot find anything on it either, but I will look more while at work. Some states have right to repair laws now, maybe they will provide you with the schematic.

 

[Cable Guy]

I wasn't sure if that was it or a potential compromise replacement. I cannot find anything on it either, but I will look more while at work. Some states have right to repair laws now, maybe they will provide you with the schematic.

I have never received any response from a company when trying to get info like that, I guess it just goes to file 13, but I will try. Thanks.

 

[brandon7861]

I know here in Minnesota we have a fairly broad right to repair law, although I have never attempted to use it.

 

[Cable Guy]

I talked to the guy, he said there was a smd "diode" on the regulator trace that came off and burned up on his iron tip. I see a place marked for a capacitor, c339 that is missing. Maybe that's what he means. I can't find it on the schematic so have no idea it's value. I circled the location I believe it lived. If anyone has one that can take a pic to verify, I would be grateful.

 

[Cable Guy]

I had to repair some burned traces on the PA board and 1 of the 520's in the final spot was toast. I also had to repair a few traces on the main board. Back together and I see ~105 peak watts on AM, that's good enough to call it. No overheating and a quick alignment, she's back in business. I would still like to see a schematic and all of the replacement PA board but maybe we can get one within 60 days ; ).. wink. The added resistors on the PA board seem to reduce the final stage gain, and given all the additional shielding everywhere on this chassis, it was probably to keep self oscillations down. Still haven't figured out the cap (or diode) near the regulator, but neglecting it doesn't seem to be detrimental. If it comes back to me, I will know where I left off.

 

[brandon7861]

Is there a C212 on the other side of the board?

 

[danmcclain]

View attachment 73713
It looks like they removed 3 capacitors and left 1. Also, added some resistance across the output of the input transformer that goes to the bases (gates) of the finals. All I can find is an old listing as a Stryker replacement board, no pic or specs. Someone removed the original transistors and installed the irf-520's. I don't know if that is what this board took or if the evident modifications of this board were to accommodate the new transistors.
View attachment 73714
Oh well, I will figure it out. I had hoped to find at least a schematic but it's not the end of the world, I have done more with less.

If you're still looking for a schematic here's one... Dan

 

[Cable Guy]

Is there a C212 on the other side of the board?

Yes, a large green mylar, can't see the value tho.

 

[Cable Guy]

If you're still looking for a schematic here's one... Dan

Thanks Dan, I found that on cbtricks. I'm looking for the schematic for the IRF520 PA board, it's a replacement board for the obsolete 2290 PA board. The 2290 board schematic is listed on cbtricks also.