Need to fix an AOR 8200-MK3 with no reception

[dragon48]

There is functionality, as if I transmit something in the same room as the radio, it picks it up loud and clear, however, there is no other reception at all. The AOR can't even pick up the strongest local FM station that all my other radios pick up with ease in same location with the same antenna.

I'm reasonably sure I know what the problem is: I think the BNC connector lost its connection (cable?) inside the radio. The male end sticking out of the radio has a loose fit and is and easy to wiggle around. If I'm on the right path, is it easy enough to open the radio and repair the loose or severed connection?

Tagging @AOR-262 as you seem to know your way around this unit.

Edit - If I am indeed on the right path, can somebody please let me know the specific size screwdriver I need to open it, as none of mine are up to the task.

 

[AOR-262]

@dragon48

You kind of answered you own question ... "the male end sticking out of the radio has a loose fit and is and easy to wiggle around". Again, this is a 'simple' job of re-securing the locking nut at the bottom of the BNC socket. Over time with the fitting and removal of antennas the locking nut becomes loose as the adhesive wears down thus the BNC socket becomes loose or has a moveable wiggle to it. The knock on effect of this loose/wiggle is the connection between the BNC socket and the circuit board also breaks away. Again ... (for me but maybe not for you?), it's a job of unsoldering the joints and applying new solder. Once you've done this, it be a good idea to run some checks on the receiver which can be found in the service manual ... nothing wrong with your receiver, just a dodgy connection. As for the size of the screws, if I remember, they are listed in the 'parts' section of the service manual. A quick search of eBay for 'precision screwdrivers' is what you'll need. The type of screwdrivers used by watch maker/repairs. Image below as an example ...

p.s. in the image of precision screwdrivers below, the screwdriver 'NO.00' might be too big even though for real it looks tiny. There are even smaller screw drivers out there. The screws on the 8200 series are about 1.5mm in length. Make sure the driver head is a solid fit at 90 degrees - attempting to unscrew at an angle +/- 90 degrees will highly likely 'round' the screw head as over time the screw would of become hardened into the casing. Use a hair dryer to heat up the area where the screw is as this will help loosen the screw - if you know anything about mechanics and have heard of a 'hot spanner' you'll understand what the heating process does. Take your time and do not loose your patience if things get tough - you'll likely bust something in temper.

 

[dragon48]

Ty - I have rudimentary soldering skills but have never unsoldered anything. I just ordered a soldering kit which comes with a Desoldering pump and ordered some solder and flux as well. Time to have a party! I have some variant of that screwdriver set already but couldn't get anything to take the AOR screws out. I'll may just go to a local hardware store and get the right tool for the job.

I didn't just invest the money for this fix; I have a few other projects planned as well.

Looks like I tagged the right person.

I'll write back with (hopefully ) the success story.

I also love my AOR 3000a, but am dying to take the handheld outside, far, far, away for my RF dead zone community.

 

[morfis]

Ty - I have rudimentary soldering skills but have never unsoldered anything. I just ordered a soldering kit which comes with a Desoldering pump

For most work like this you will find de-soldering braid far more effective (and easier to use) than a desoldering pump.

 

[Ubbe]

There are different types of screws, phillips and pozidrive. I think the 8200 use pozidrive. I have removed my screws years ago and run the scanner without them so I can't check. The halves snap together and are tight enough without needing any screws. Get a screwdriver set that has both PH phillips and PZ pozidrive and if you would like to open up a mobile phone or other modern stuff they could use T torx. Better get a kit that have them all.

/Ubbe

 

[dragon48]

For most work like this you will find de-soldering braid far more effective (and easier to use) than a desoldering pump.

Ty - If I get something like this - https://www.amazon.com/dp/B093ZYF99G/ - what width should I purchase?

 

[morfis]

The 2mm should be adequate but for flexability in your toolkit you could get wider and then taper cut the end for small stuff.

From memory the screws used were PH0 not pozidrive. Sets of microdrivers covering all manner of head types are cheap enough for hobby use (though quality professional versions aren't so cheap as you'd expect!). As mentioned earlier, ensure the head is in the screw firmly and at 90 degrees with no 'play'. Turn them slowly but firmly. They are not installed tightly enough to require heating or any more than gentle hand pressure. Screws this size have very little 'meat' and are easily damaged. When re-installing them (which might not be necessary but if you were ever to sell the unit I imagine buyers would rather they were present) do not over tighten.

 

[dragon48]

The 2mm should be adequate but for flexability in your toolkit you could get wider and then taper cut the end for small stuff.

From memory the screws used were PH0 not pozidrive. Sets of microdrivers covering all manner of head types are cheap enough for hobby use (though quality professional versions aren't so cheap as you'd expect!). As mentioned earlier, ensure the head is in the screw firmly and at 90 degrees with no 'play'. Turn them slowly but firmly. They are not installed tightly enough to require heating or any more than gentle hand pressure. Screws this size have very little 'meat' and are easily damaged. When re-installing them (which might not be necessary but if you were ever to sell the unit I imagine buyers would rather they were present) do not over tighten.

Thanks - No intent of ever selling the unit, but I'd be comfortable with the screws in - will not over tighten.

 

[dragon48]

@AOR-262

I got five screws out without problems, but I can't figure out how to get the case off because the sides don't split well at the bottom. If I pull it hard from the top, I'm afraid just going to rip a section of the plastic completely off. I ended up taking off a side panel, but it should get right back in.

Please see all the attached and HELP!

 

[prcguy]

I had my 8200 apart a couple of times and it was easy, but I forget how I did it. Are there any screws at the bottom of the battery compartment?

BTW, mine was the wide open military version with voice descrambler and other features and I have a spare board that has all those features which can supposedly be swapped to a regular 8200.

 

[dragon48]

That was it - Ty!

I'm assuming I now need to bend the metal on the left so I can see what came loose from the board. No operations until this weekend, as the solder and desoldering wick haven't been delivered yet. Am I really going to have to operate through the opening in the board, or is there a safe way to remove the top board?

 

[dragon48]

Another Pic to show what's going on. If the strip on the left just needs to be attached to the board, this will not solve the problem of the loose BNC jack on the outside, so the job must require something else: Looks to me like the ability of the jack to move is what detached that piece in the first place, so I'd like to avoid a recurrence. If I push down on the top metal piece, the outside jack isn't able to move horizontally, so maybe that needs to be better affixed.

 

[prcguy]

I remember there was one or two multi-pin connectors between the boards and you just pry them apart near the connectors. Thinking about my spare board, it may have a Kapton ribbon cable where the end of the flat cable inserts into a connector and a plastic shroud clips it in place. If it has that it can be damaged easily.

 

[dragon48]

BTW, mine was the wide open military version with voice descrambler and other features and I have a spare board that has all those features which can supposedly be swapped to a regular 8200.

I have the unlocked version, but no voice descrambler and no digital. I'm not paying $350.00 for the upgrade, (AR8200MK3 Upgrade Procedures | Support | AOR U.S.A., INC. Authority On Radio Communications) as I can get ten SDR's for the same price!

 

[prcguy]

We can discuss that after you get your radio working.

I have the unlocked version, but no voice descrambler and no digital. I'm not paying $350.00 for the upgrade, (AR8200MK3 Upgrade Procedures | Support | AOR U.S.A., INC. Authority On Radio Communications) as I can get ten SDR's for the same price!

 

[dragon48]

I remember there was one or two multi-pin connectors between the boards and you just pry them apart near the connectors. Thinking about my spare board, it may have a Kapton ribbon cable where the end of the flat cable inserts into a connector and a plastic shroud clips it in place. If it has that it can be damaged easily.

I'd have to be very careful with the ribbon connectors between the sides. Unless I'm missing something, even if I were able to remove the top, higher board from the main one where the BNC problem is, I wouldn't be able to remove that board, without un-securing the connectors to the volume control and squelch knobs.

More complicated than I thought, but when I fix this, I'll feel that much better.

 

[prcguy]

I think to get the board out with the antenna connector you have to take off the knobs and nuts on the volume, squelch and antenna connector and more screws that hold the board down.

 

[dragon48]

I think to get the board out with the antenna connector you have to take off the knobs and nuts on the volume, squelch and antenna connector and more screws that hold the board down.

I'll work it out (with a little help from my friends )if I have to, but please see the below. I'm hoping there is an easier way:


I think I found the exact issue with a magnifying glass and took pictures through the glass which shows almost the complete picture. The metal strip that's connected to the inside of the BNC connector goes inside a rubber tube that's not sitting where it's supposed to. Looks to me like it's supposed to sit around a screw or ring just to the right of it. I am guessing though, that there is supposed to be metal going all the way through the tube, which then makes contact with the screw.

I'm wondering whether I can carefully reattach it to where it's supposed to sit (some kind of glue?) while carefully working in the tight space of the opening of the board? If I have to take the board off, would it make sense to remove the plastic tubing (or whatever that black thing is) and just solder the piece directly to the same spot on the board?

I'm also wondering and hoping that if I just properly secure the black piece, this will tighten the outside BNC connection as well, by having the same effect as I did when I tightened it by pushing down on the metal above.

 

[Ubbe]

would it make sense to remove the plastic tubing (or whatever that black thing is)

It's ferrite tube to stop self oscillating. It has to be there but you can bend the wire and move the ferrite higher up closer to the connector. Then it should be possible to solder the wire to the circuit board.

Better solution are to remove all solder from the BNC connector and remove the wire and straighten it out and remove the tube and then solder the wire to the circuit board. That's how it's done at the factory. Then put the tube back and solder the wire to the connector.

/Ubbe

 

[dragon48]

It's ferrite tube to stop self oscillating. It has to be there but you can bend the wire and move the ferrite higher up closer to the connector. Then it should be possible to solder the wire to the circuit board.

Better solution are to remove all solder from the BNC connector and remove the wire and straighten it out and remove the tube and then solder the wire to the circuit board. That's how it's done at the factory. Then put the tube back and solder the wire to the connector.

/Ubbe

I can't see doing this without removing the board. Please see the attached. How do I remove the volume control and squelch knobs to get the board off? If I do that, I'm assuming the board will come off, as soon as I unscrew the metal bar holding it down and lift it up. I also just removed a screw on the board that was between the squelch and volume control knobs. I don't see any other screws on that board. I then have to be very careful with placement, so as not to damage the ribbon cables connecting the board on the other side. All I can think of is to sit that board on top of the other side's board. Any other placement would stretch and place tension on both ribbon cables.


I'm not tackling this tonight but looks like I'm on the right path