SR(1) Disassembly Instructions

A pictorial guide, hopefully this makes all of your modification and repairs easy. Reverse the instructions to re-assemble.

1. Remove four knobs on front by prying off with small screwdriver. The SR will have bushing associated with its knobs. Remove the bushings and keep with the knobs.
   
   
   
   
2. IMPORTANT STEP – DO NOT SKIP! Turn the tuning shaft until it is positioned as shown, with the flat side facing down towards the bottom of the radio. This will help mitigate the danger of damage to the on/off switch:
   
   
   
   
3. Remove battery compartment cover and seven case screws, the short one is located in the battery compartment.
   
   
   
   
4. Push the on /off switch to the ON position. CAREFULLY separate the two halves of the clamshell case from the bottom of the unit. It is very easy to damage the on / off switch, so be careful not to apply stress to it.
   
   
5. Unsolder three wires from the speaker. Make a note of which wire goes to which terminal. It is important:
   
   
   
   

   The front of the cabinet is now free. Set it aside on a padded surface to protect it from scratches. If you are working on an original Superadio, you may want to consider replacing the speaker with a 6 1/2 inch two way speaker - used in a lot of cars. Be careful about the size of the magnet assembly, you have limited room inside the radio! Smaller is probably better in this case. I found a suitable set on sale for $40 at Frys, which would be enough to retrofit two SR's. The SR-2 already has a tweeter and doesn't need a retrofit.
   
   

   Removing Cabinet Back From Chassis

6. Pry off two slide switch knobs. Pry off the on/off switch button. Remove four chassis screws in indicated positions:
   
   
   
   
7. Unsolder the following wires:
   
   
   • 4 wires from external antenna terminals. Connections may vary. Take note of which wire goes to each terminal.
   • Wires from battery compartment. Colors may vary, so be careful to document them and where they go. Remove the positive wire from the battery compartment by sliding back the insulating sleeve and de-solder from the post on the board. Unsolder the negative wire at the battery compartment.
   
   
   
   
   

   Note that there may be glue and wax holding wires down, especially antenna and battery wires. You will have to break the wires free to disassemble. Use a hot glue gun if you want to restore the attachment points. Also note that I had accidentally knocked the dial string off of a pulley - your dial string will be more out of the way, but still - be careful not to burn the dial string with your soldering iron or you will have to re-string the radio. Not difficult, but an un-necessary hassle if you take a little care.

   The chassis is now free from the bottom half of the case. Place the bottom half of the case aside.
   
   

   Removing PC Boards From the Chassis

8. Turn the chassis assembly over. Unscrew two screws holding the transformer, and two screws holding the power cord retention fiber cover.
   
   
   
   

   The transformer and power cord can now be removed from their molded housings in the chassis. It is possible that there may be some melting. If so – I recommend NOT using the unit on AC power until the transformer and / or power cord are replaced. Carefully fold the transformer and power cord over to the left away from the chassis.
   
   

9. Unsolder the ground strap connecting the two PC boards. Remove a couple of tie wraps holding the wire bundle together:
   
   
   
   

   The SR-1 circuitry is constructed on two PC boards. You may only need to remove one of the two in order to complete service. You can skip the instructions for the board you don’t need to remove. This might even be preferable, because the front end board, in particular, is very hard to service. The instructions below are not so much removing as loosening so you can get to both sides of the board for service. The radio construction on two boards makes for a lot of interconnection wires, and it is probably better not to disconnect all of them, although you certainly may do so with the excellent diagrams in the manual. But there is little reason to do so, because you can access all the components without doing it, especially with both boards removed from the chassis.
   
   

   Removing the Main Board

   There are just a few steps remaining to loosen the main board, which is much easier to manage than the front end board. These will be shown in one picture.
   
   

10. Unscrew two small screws that hold the power switch to the chassis. There is a nut on the other side, and it is a good idea to use needlenose pliars to help remove the screws and nuts.
    
    
11. Remove the circular nut retaining the earphone jack.
    
    
12. Remove six screws holding the main board to the chassis.
    
    
    
    
13. The board may now be flipped gently to the left, free of the chassis. Remember that you have the transformer and power cord still connected. A fiber insulator preventing PC board shorts against battery terminals can now be removed as well:
    
    
    
    

    Removing the Front End Board

    NOTE: This is a bit more complex. Be prepared to re-string the dial and / or re-assemble the reducing gear assembly if you mess up. Otherwise, don’t attempt! I had to do BOTH, and I was careful! You have been warned!
    
    

14. Unsolder four wires from the AM ferrite rod to the circuit board, and unsolder the FM antenna wire. Note: There is no ceramic capacitor on the end of the antenna wire in an actual radio. This particular unit was modified to bypass the RF transistor and to change the FM ceramic filter (upper right).
    
    
    
    
15. Unscrew four screws securing the front end board to the chassis. Note that these are strain reliefed with rubber, so do not over-tighten when re-assembling.
    
    
    
    
16. Gently pry the pulley off of the tuning shaft. BEWARE, the tuning shaft will come out of the reduction fear assembly a lot easier than the pulley will come off the shaft. It is MUCH better to get the pulley loose even though the other is much easier. If you do pull the shaft out of the reduction gear assembly – like I did in this picture, the gear and stop plate WILL fall out. Restrain the pulley with a piece of duct tape as shown:
    
    
    
    

    OK, you messed up and the reduction gear assembly is apart. This close-up shows how to re-assemble the reduction gear assembly (tuning capacitor fully closed):
    
    

    
    
    

    The front end board is now loose. It can be removed (with the main board connected) from the chassis.