DRAKE TR7 Service Manual download pdf (Page 3)

restored later if you choose. The following photo shows the small metal wire piece that can be pulled

out easily with needle nosed pliers after pulling the spring back slightly. Once that wire is removed, the

buttons will no longer latch. If you use the FIXED switches, you'll need to remove all the currently

connected wires and make sure to tie together those that would normally be connected via the normally

closed switches.

Figure 2: The two switches in the middle are the FIXED XMIT and FIXED RCV switches. Note the vertical

wire in the lower center of the two end switches. The wire was removed from the two switches in the

middle by pulling back the spring and lifting the wire out with pliers. That converts them from latching to

momentary switches.

The STORE switch is also a good candidate for use here, but I had previously used that switch to turn

on/off the DF4DW preamp I have installed.

Most of the pushbutton switches on the TR7 have the contacts/terminals mounted in a thin plastic.

Those are easily identified as they're white as shown above. When unsoldering/soldering those

terminals, you must use some sort of heat sink to prevent melting the plastic. If you do accidentally

pull out one of the terminals, it can be reinserted and pushed into place. A dab of epoxy will hold it in

place after soldering is complete.

Dial Details

The TR7 dial is replaced by the LED panel described below and the tuning knob drives the new

encoder directly. The encoder mounts in a standard 3/8” hole and so you have to somehow reduce the

available opening and AD3G came up with the perfect solution for that. Copying his approach, I used a

piece of copper sheet (about .020 inches thick) from a roll of copper tape meant for grounding. As you

can see in the photo, you drill a hole in the copper for mounting the encoder, along with three addition

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DRAKE TR7 Service Manual Page 3