Looking ahead to the days when Darth is actually on the road, I was eyeballing the empty hole in the dashboard where a radio once lived, especially now that I’ve got a good power source. As mentioned before I think I threw out the old radio that was with the truck, but I’ve still got a period correct radio from the green Travelall. At first, I thought it was a Ford or Chevy unit based on some very quick research but doing deeper digging led me to a very thorough website with actual pictures and I was actually able to identify it as a Motorola 7SMI, which was standard for Internationals of that year.
This particular unit only had three wires coming out of the back: a black wire ending at one side of a fusible link and two green wires that ended in a terminal connector labeled 22. It stands to reason the black wire was power and I guessed the green wires were for speakers. Much like everything else in the truck, I assumed the whole thing was grounded by the chassis, but none of the service manual diagrams I have for any year showed wiring for a radio at all.
These units were developed at a turning point for car electronics, when things were moving from tubes to transistors and circuit boards, so they are a mixture of the old and the new. This one is filled with old capacitors and sported a phenolic-based circuit board, which was the industry’s first material of choice before they realized it wasn’t resistant to wild swings in temperature and switched to silicon. The 60-year-old capacitors were almost surely fried at this point. On top of all that, it’s only an AM radio.
So the question was: what do I do with this thing? Should I spend hours poring over electrical diagrams, a hundred dollars for fiddly electronic parts, and even more time attempting to desolder and resolder scores of capacitors just to succeed and have a scratchy AM radio that only pulled in rambling religious sermons from Alabama? I think you might know the answer already.
I stumbled upon a YouTube video where a guy gutted an old AM radio and installed a $15 Bluetooth amplifier board on one side, using the knob to act as a stealth controller. This meant disassembling the unit, of course, which bothered the traditionalist in me, but I decided I had nothing to lose.
The electronics on the left side came out relatively easily once I’d cut a bunch of the wires, and I kept all of the stuff I pulled out. Assembling the bluetooth receiver, I bench-tested it and found it paired with my phone almost immediately. So I used some of the leftover metal bracing to bend a new cage for the receiver, widened a hole for the stalk, and mounted it back on the chassis in the empty spot, lined up with the stalk hole. Then I pulled the old stalk pot apart to get the brass rod itself, and machined one side down with a Dremel to fit into the slot on the receiver stalk. With that extra length, the knobs mounted on the front as they did from the factory. Cleaning the whole thing up with some 409 and 0000 steel wool, I made the chrome shine again. Finally, I ganged the power lead to the receiver up with the dial bulb so that the dial will light up when the receiver is turned on.
The only drawback I see is that it’s not very powerful. I’ve spent enough time in 60-year-old trucks to know that you need volume to overcome the road noise, and this unit won’t cut it. So if I want to use it, I’ll have to find an amp of some kind to go between the receiver and the speakers.
The one issue I’ve got is that the faceplate that came on the truck doesn’t fit this radio. The knobs are spaced a little too widely for the existing holes. I could use the faceplate from the green truck but that had a Deluxe dashboard and was covered in black vinyl from the factory. So I could remove that, clean up the faceplate and use it instead. And of course I can find other faceplates at Nationals this year as a longer-term solution.
Update: here are some photos of the cage I build from leftover parts. I widened out one of the existing holes with a Christmas tree bit to accept the stalk of the bluetooth receiver.
William Miller says:
Hi Bill, I’m taking on the task of duplicating your radio conversion to bluetooth. I’m using the same model radio and bluetooth receiver you listed on your post. So far, I’ve removed the internals from the radio and have to figure out the best way to mount the bluetooth receiver…many options to consider but I’m trying to find the most convenient/less labor intensive method to mount it securely. I noticed you left some of the internals inside the radio, not sure why…likely not worth the effort? Regardless, I’m following your lead and hope to have it completed ideally sometime this week (although, I’m easily distracted these days). I obviously didn’t pay much attention to your comment about the switches not perfectly lining up with the radio…my bad. Have you solved this? I’ve searched online for a chrome faceplate for my 68 Travelette but, so far no joy. Regarding your comment “I can find other faceplates at Nationals” I would be most interested in what you find, I’m in southeast Alaska so unable to attend the Nationals (but it is now on my bucket list). Thank you Sir for your help with everything you never fail to impress!! If you know anyone that might be willing to help a disabled veteran with a chrome faceplate it would most appreciated. I’m not seeking a handout, absolutely expect to pay.
bill says:
Hi William, Yeah, I did leave a bunch of the internals in place—basically the entire tuning side. There seemed to be no reason to pull them out, and with the main power lead to the radio cut they’ll never work anyway.
For the wireless unit, I re-used the cage that went around the back of the volume/tone knobs that I had to remove to get to the control pots. I put it in a vise and flattened the original bends, then re-bent it to fit around the back of the wireless box. I fastened it with two shallow metal screws and ran the leads out underneath. If you strip the dial bulb wire out, you can add that to the power lead and it’ll look like the radio is on. It’s pouring here right now, but I’ll pull the unit out of the dash tomorrow and post another picture so you can see what I’m talking about.
One other thing—we’re going to need some kind of an integrated amp to boost the power in between the wireless unit and the speakers. At max volume it’s still pretty low—and any International, as you already know, makes a ton of noise on the road.
If I can find a plain gray faceplate that works for my truck at Nats, I’ll send you the fancy one I’ve got here—it’s chrome with a black vinyl trim over top, which I’m sure could be easily removed. Stay tuned.
William J. Miller says:
Hi Bill,
I have a faceplate which appears to be OEM with the studs on the back. Its been painted black but could easily be repainted to match your dash. If you were inclined to trade I’d be more than happy to send you pictures of the one I have. I suspect enlarging the holes for the stalk controls would easily be hidden by the radio knobs, even if a flat washer was used. I like what you have done, as always good job!
bill says:
Hi William, That would be great if the stalk holes are 5 3/8″ wide on center (the gray plate that came with the truck was cut for a modern radio with holes that are wider apart). I think this plate I have would clean up very well with some 0000 steel wool once the vinyl is removed. I’ve added more pictures of the cage I made above so you can see how I assembled it. I’m happy to trade—I can send address info via email.
William J. Miller says:
Sounds like a plan Bill, address via email works and I’ll send you a few pictures to let you know what it looks like as well as where I’m at with the radio conversion.