Hoffman 706 SOLAR 1960's

[Buzzsaaw]

I ended up cutting the back of the Solar panel plastic off.. I just traced around and around with an Xacto knife until it popped off. What I found as the cause of the Solar panel not working was the wires leading from one solar "chip" to the next were either un-soldered or cold soldered. Leading me to believe that my Dads setting the radio upside down on top of a lit lamp caused the solder to melt. I re-soldered all the connections lightly and the panel came back to life!

I then changed out all the Ecaps and the radio works! After 45 years.. it's making music again!

Nice!

Buzz

[Smoky Pond]

Cool! Glad you were able to repair the array and get the radio working.

BTW, I have a solar array from a later Hoffman (709X) that puts out a lot more power with much less light. With that one connected to a 706, the radio will play full blast under the light of a 60 watt lamp more than 2 feet above it. But since it's a 6 volt array, you wouldn't want to expose it to the sun while connected to a 706.

[Buzzsaaw]

I'm glad I got the "gumption" to go ahead and tear it apart. I've had this little radio with me sense I was a kid in the 60's.

Next, after a couple of other projects here on the bench, I think I'll test some of the resistor values. The volume is a little low and that is just the solar panel, but the sensitivity is not very good. I should be able to pick up more stations than the close one in town (20 miles away)!!

So the project lives on. Oh.. I did peak the rf and If coils.. to no avail.

Still like to find a junker (black in color to match) so I could change out the back cover. (see pics above) It's warped. Front looks nice after I cleaned it up. These things are really over priced on Efray!.. Wow what a racket! Efray has really inflated all things us hobbyists like to collect. But on the other hand.. Efray allows one to cover a lot of turf by bringing many togeather for a common cause.

Buzz

[leadlike]

Glad to hear you got it working again! Never saw a Hoffman version of this set. I have seen several Zeniths from the same era with solar panels, although they put the panel in the handle, making it look pretty terrible.

[Smoky Pond]

Originally Posted by leadlike

Glad to hear you got it working again! Never saw a Hoffman version of this set. I have seen several Zeniths from the same era with solar panels, although they put the panel in the handle, making it look pretty terrible.

Yes, the Hoffman 706 series is a bit more elegant, with its solar array built into the case. It also pre-dates the Zenith Sun-Charger by 6 or 7 years.