TS-2000 - CW Keying Problem Diagnosed
It's not too pretty. However, I found the problem. The key jacks are isolated from ground with a surface mount choke to keep RF out. The choke is blown. I tested the continuity between the key and all the pins on the jack and everything is good there. The connection between the jack and ground is not there.
I am posting this so you can see what I did. If you choose to get in your own radio that is your choice. I am not liable for any damage you may cause to your radio, work on it at your own risk. If you don't know what you are doing and don't feel comfortable with working on your radio then don't do it.
The board that the keyer circuit is on is in the center of the rig - so you need to dig real deep to get to it. The board is accessed through the BOTTOM of the rig. It helps to take pictures as you go so you have a visual guide when you go back to put it together. Note: some of the jacks on the following boards ARE NOT USED.
Take the bottom panel off:
Then take all the coax cables off the panel, ribbon cables, and all the wires with the white plugs - not the tan plugs. The tan plugs don't come off, the wires aren't going to other boards. Note: there are two ribbon cables with tan jacks. These are locking types. You need to pop the locking bar up, you should be able to flick it with your fingernail on each side to pop it loose. Then the cables slide right out. The ones with the black jacks are friction fit. Be VERY careful with them.
Also note that the board is mounted to a metal plate. This plate has screws up on the sides of the chassis and also four down through the circuit board holding the plate to the center of the chassis. All the screws have to be taken out to get the board out.
Once you get the top circuit board there are three smaller boards underneath. The keying circuitry is on the one in the middle. Again, make sure you note where the wires all go.
You can see the front of the board starts getting pretty confusing with the wires going to both the top board and the one here:
Note there are a LOT of screws holding this board in place. I guess they wanted to make sure the board's ground was all at the same potential HI. I think a couple screws would have held this board in place...
This is the spaghetti you are left with when the board comes out. If you don't know where everything goes it is a real mess! All the screws on the left go to this one board. Lots.
Here is the back of the board and the choke circled:
I will have to check my schematics of the rig when I get home and order the part. Unless I can find what the specifications are and find it locally. I highly doubt Universal Radio has one in stock, but it is worth a shot.
The good news - if I ground the key manually to the chassis the keying works! This is not the best way to do it as this bypasses the choke - which is designed to protect the circuitry from RF. However, it is a crutch and at least I can get on the air with it until I can make the proper repair.
Edit: If you so choose to work on your own radio (and you assume all liability in doing so) BE CAREFUL when you put it back together. Case in point: I put a coax cable in a place it didn't go and wasted a few hours of trouble-shooting time. I put the rig back together and the RX and TX were dead. I went over the pictures and the boards carefully and spotted an empty socket where I had placed a cable. In any event, the rig is back on line.
The next issue is I pulled my memory channels off and filed them on the computer (which is a good idea for anyone to do, just in case) and did a CPU reset (as one of my attempts at getting the RX and TX back before I found the misplaced cable). Now I can't get in to memory mode. So, I am not sure what is going on. The memory channels are the least of my worries right now though. I need to get the choke replaced on the RX-TX 2 board for the CW keyer to run without my rigged up ground bypass HIHI.
While I am at it I am going to run a firmware update. The last one I did was several years ago.
I am posting this so you can see what I did. If you choose to get in your own radio that is your choice. I am not liable for any damage you may cause to your radio, work on it at your own risk. If you don't know what you are doing and don't feel comfortable with working on your radio then don't do it.
The board that the keyer circuit is on is in the center of the rig - so you need to dig real deep to get to it. The board is accessed through the BOTTOM of the rig. It helps to take pictures as you go so you have a visual guide when you go back to put it together. Note: some of the jacks on the following boards ARE NOT USED.
Take the bottom panel off:
Then take all the coax cables off the panel, ribbon cables, and all the wires with the white plugs - not the tan plugs. The tan plugs don't come off, the wires aren't going to other boards. Note: there are two ribbon cables with tan jacks. These are locking types. You need to pop the locking bar up, you should be able to flick it with your fingernail on each side to pop it loose. Then the cables slide right out. The ones with the black jacks are friction fit. Be VERY careful with them.
Also note that the board is mounted to a metal plate. This plate has screws up on the sides of the chassis and also four down through the circuit board holding the plate to the center of the chassis. All the screws have to be taken out to get the board out.
Once you get the top circuit board there are three smaller boards underneath. The keying circuitry is on the one in the middle. Again, make sure you note where the wires all go.
You can see the front of the board starts getting pretty confusing with the wires going to both the top board and the one here:
Note there are a LOT of screws holding this board in place. I guess they wanted to make sure the board's ground was all at the same potential HI. I think a couple screws would have held this board in place...
This is the spaghetti you are left with when the board comes out. If you don't know where everything goes it is a real mess! All the screws on the left go to this one board. Lots.
Here is the back of the board and the choke circled:
I will have to check my schematics of the rig when I get home and order the part. Unless I can find what the specifications are and find it locally. I highly doubt Universal Radio has one in stock, but it is worth a shot.
The good news - if I ground the key manually to the chassis the keying works! This is not the best way to do it as this bypasses the choke - which is designed to protect the circuitry from RF. However, it is a crutch and at least I can get on the air with it until I can make the proper repair.
Edit: If you so choose to work on your own radio (and you assume all liability in doing so) BE CAREFUL when you put it back together. Case in point: I put a coax cable in a place it didn't go and wasted a few hours of trouble-shooting time. I put the rig back together and the RX and TX were dead. I went over the pictures and the boards carefully and spotted an empty socket where I had placed a cable. In any event, the rig is back on line.
The next issue is I pulled my memory channels off and filed them on the computer (which is a good idea for anyone to do, just in case) and did a CPU reset (as one of my attempts at getting the RX and TX back before I found the misplaced cable). Now I can't get in to memory mode. So, I am not sure what is going on. The memory channels are the least of my worries right now though. I need to get the choke replaced on the RX-TX 2 board for the CW keyer to run without my rigged up ground bypass HIHI.
While I am at it I am going to run a firmware update. The last one I did was several years ago.
posted by Steve at
10:37 PM
3 Comments
