Vintage Bleep Bloops

A long time ago… back in the ‘before times’… I picked up this old HP wide-range frequency generator off of Craigslist. Since then, it’s been sitting on my bench as a large, heavy ornament. 

Once I cleared my queue of customer radio projects, I decided that this would be my first personal restoration. I’d ordered up the parts for it a year or two ago, but just hadn’t gotten around to repairing it.

It needed the standard stuff… mostly a re-cap, replace some out of tolerance resistors, and then do a calibration on it. Pictures 2 and 3 show the removal of the filter choke which I needed to take out to access the capacitor can solder terminals. 

Next I replaced the multi-section capacitor cans with modern electrolytics which I mounted on terminal strips. There were also 2 older paper/foil capacitors installed which I removed and replaced (new caps and resistors seen in the 7th pic). 

Lastly the mechanical parts that drove the tuning capacitor were all greasy and dirty, so I cleaned them up with some degreaser, re-lubricated the shafts and reinstalled it. Now the tuning knob (big plastic and metal knob on the left-hand side) turns nicely. 

I fired it up today and it puts out a very clean sin wave. The tuning dial isn’t 100% on frequency, so I’ll probably need to calibrate it, but at least it’s working now. Overall I’m really happy with how this turned out. It’s a cool piece of HP history and a great piece of test gear that will hopefully give me years of excellent service.

Sparton 558 sled radio designed by Walter Dorwin Teague for the Sparks-Worthington Company from Jackson, Michigan, USA in 1937.

The radio features grey mirrors on the front, top, and left sides, with a contrasting dark walnut lacquer finish.

Best product ever! The Retro Encabulator saves me hours every day.

Well… here it is folks! The epic before and after on the Philco 39-45 project.

This has been the most challenging restoration I’ve ever done, and involved touching almost every aspect of this radio. From the wiring and electrical components, to the cabinet and grill cloth… everything on this unit needed to be repaired or replaced. 

First 2 pics show the cabinet as it was when I got it back in 2017. It definitely showed its age, and the fact that it had spent much of its life in a cabin on a river. Next 2 pictures show the chassis. When I got it, all the rubber insulated wires were dried out, corroded and completely unsafe. Most of the resistors were bad, and of course all of the old wax-paper capacitors needed to be replaced.

In addition, I didn’t know at the time that the AM broadcast tuning coil in the bandswitch was also bad. Fortunately one of my friends from work was able to help me and re-wind the coil. :D

5th picture shows the electronics replaced, and the 6th pic shows the chassis cleaned up. Last few pictures show the cabinet as it looks today. Spent A LOT of time on this… sanding it down, doing a little staining, and adding some semi-gloss poly on top. The new grill cloth also turned out really well. 

Now the radio is playing nicely and will go back to its owners on Sunday.

If you want to help support my radio restoration hobby… check out my Patreon! 

https://www.patreon.com/Magicclam