Port-o-matic - The Antique IPOD of the 1930's - Repair project Part 1

Franks send us a large surprise package from the far reaches of the mid west. Where unwrapping is half the battle. Ill admit, at first I wasn't quite sure what it was. It turns out its a 'portable' AM/SW/Phonograph that is made by Port-o-matic. Its an AC/or DC (battery) unit. I have never heard of them.

Adding insult to injury, the cover is an extension of the tonearm, so you have to close the case on the record to play them.... terrible. Given the AC/DC setup we can be sure its a transformer-less deathtrap.

Lets tear it apart..... and it comes apart like a puzzle, it takes some thinking. Some pieces are worn, some broke but no horror stories, except for the fact that sever tubes are floating free in the unit. The knobs are made of real wood, probably to stop the user from dying when changing channels to adjusting the volume.

As the device is disassembled it looks ALMOST home-made, like they guessed their way through assembly. Eventually the radio is removed from the chassis. and the chassis and platter is moved off to the side.

An inspection of the underside shows the age of the unit, old school 30's components, resistor and capacitor codes, very cool. All the paper caps and electrolytics will have to go. All in all, its in good condition. Finding a schematic was however a challenge.

The most interesting component, BK-23-B identified the units schematic, a bunch of voltage dropping resistors stuffed in a tube container. This leads to tube testing time.....

This project was a crossover between the century tester and the Hickok 6000. Tube testing is done after each tube is cleaned like new. The tube/resistor thingy is ohmed out.... Weird....

Once the parts arrived I do a full cap swapout, this includes my leakdown test of the old ones and physical size comparisons and discussion of strategy.

I start with an evaluation of the paper caps to see how bad they are.... They are bad... says the IT11. I swap out each one. Once the cap job is done it is put upright, the tubes are reinstalled and most importantly, the knobs are put back on.

Power is slowly turned up on the Variac. As smoke testing begins. one light bulb is found to be burned out, but we can hear AM coming from the radio, a good sign. But the magic eye is extremely weak. There are some issues in this unit still. Shortwave works too, but neither side is very sensitive.

Видео Port-o-matic - The Antique IPOD of the 1930's - Repair project Part 1 канала Retro Tech & Electronics