[Jayce]

Groundhog74's thread with his Gloritone 27 led me to dig out my Mantola 27 and fire it up today. My mom actually bought this radio for me as a birthday present several years back and it still really stands out in my collection. Also the only radio I have that the tubes hang upside-down in!

   

[morzh]

Well, that was an old design trick.
Hanging the tubes upside down makes electrons go with gravity and not against it, so the tube's gain is a little higher and it gave the Mantola a little edge.

[TA Forbes]

The Gloritone 27 like the one pictured in the other thread also had the "upside-down" chassis arrangement.

There are two copper electrolytics inside the chassis that are very easy to replace.

[Jayce]

All I know is that this radio was love at first sight when I saw it at a local antique shop I used to frequent before it shut down. I loved the way the dial and volume knob were on one side of the cabinet and those tubes being upside down all screamed 'early tombstone radio' to me at the time. There was supposedly a person interested in the radio, but he had not put cash down and I was broke. So, my mom slapped down the payment right there and then as she loved the radio as well!

[Eliot Ness]

Nice radio Jay. I'd venture to say it has the same U.S. Radio chassis as the Gloritone model 27. That chassis was used in a variety of sets and interestingly the chassis was inverted right side up on some sets like my funky little Radiotrope:

[Image: http://img.photobucket.com/albums/v348/j...rope27.jpg]

Notice how with the chassis flipped the dial is on the other side (left) and the volume control is underneath it? There were a few other sets like this but their names escape me at the moment.

I'm glad your mom saved that neat set for you.

[codefox1]

Nice bit of history. Wish I knew more about "upside down" tube layout, as lots of sets like workhorse amps have been chugging along for decades this way.

Seems like the tubes do not care one way or another, but beware of horizontal or angled alignment for types prone to sagging filaments, and so forth.

[Jayce]

That Radiotrope 27 is a neat looking critter! Almost makes me want to try and find one, but I'll bet it's super rare!

[Eliot Ness]

Well, it's the only one I've seen to date, but that doesn't mean a half dozen of them won't suddenly show up somewhere. They were made in Marion, IN so if you found that Mantola in your neck of the woods you might run into a Radiotrope one day.