For quite a while I've been looking for a suitable radio replacement for our ’55 Chevy 1st Series truck.
The online assortment ran from reasonably priced LCD display models to much more pricey original-looking analog dial units. Even finding someone local to rebuild the existing tube radio proved either fruitless, or expensive if shipped elsewhere to do it.
As I am on a shoestring budget and really didn’t need anything fancy (FM and USB connectivity), I figured there had to be a cheap and simple way of making my own. After all, in this noisy truck cab just basic tunes were all that mattered when doing short around-town hops — something to keep me company. And there are still plenty of (local) AM stations to choose from.
As the existing original tube radio was kaput because it had been brutally tampered with years ago, it could now be used as a donor.
But first what was needed was a more reliable 1960’s (transistorized) AM dial plate radio. There are still lots of inexpensive examples to choose from at the likes of Craigslist, thriftshops, garage sales, etc.
So after finding a very common but working 1964 Chevy AM basic truck radio (model 985773) in amongst our garage items, I set to work dismantling it and giving it a good cleaning.
Because the tuning and volume knobs needed spatial readjustment (to fit the dash knockouts), some metal surgery had to be performed on the ‘new’ '64 radio. That was the most complex part of the project — though not that difficult to do.
After removal of the bezel and dial assembly from the ’64 radio, some careful (Dremel) cutting of the front end was done.
I also removed the whole dial assembly from the old tuber donor radio.
It was then just a relatively straight forward process of moving the tuber’s dial assembly over and onto the front end of the ‘new’ radio.
When mounting the old dial assembly, I had to make it offset in order to accommodate the existing tuner and shaft. So that meant moving the existing volume/tone control out of the chassis. That was the bulk metal cutting.
The tuner and volume control shafts also had to be extended to accommodate the depth of the donor’s dial housing. By using some chrome tubing (an old sectional car antenna) it allowed the shafts to be easily extended.
Building a little aluminum box around the displaced volume control protected it.
Next, the donor’s dial string was rewrapped around the existing dial shaft and the donor’s pointer adjusted for proper scale tracking.
After making sure the dial assembly worked properly, I set about replacing all the e-caps, a rudimentary circuit realignment, adjusting the bias on the output transistor and trimming the unit to accept the existing truck antenna. All of which were pretty easy to do.
The radio now strongly and clearly pulls in a multitude of AM stations.
The existing 6x9 truck speaker is 8 ohm and because this ‘new’ radio chassis specs at 10 ohms impedance it was a simple matter of adding a 1 ohm, 10 watt resistor in series to the speaker.
The whole process was done at my leisure over a period of a few weeks. So it probably took maybe 10 full hours from beginning of the project to its completion. When it occurred to me I took some photos of the process, of which the link is here:
http://s525.photobucket.com/user/my_pics48/slideshow/Radio%20rebuildThe end results look just like the original radio poking out through the dash, only it is now instant-ON, picks up way more AM stations than the tuber ever did, and draws a max of only 1.25 amps — although for some unknown reason mine has a current drain of just .85 amps!
If you’d like to save yourself some moolah while also having some fun and satisfaction of building/adapting your own radio, this may be the project for you.
Please note that I am not a schooled
electronics tech, but I do enjoy a little (achievable) challenge now and then -- my interests are varied.
