'Noble' TRF radio (Portadyne Princess 'lookalike'). Any info please?

[Yorkie]

Hi David,
I do like the practicality rather than the originality of the dropper. Does this throw out a lot heat in this configuration??

Regards

Rob

Arguably, they'd be better if mounted vertically Rob, but the original was horizontal. In the thread below I remarked that I'd calculated the wattage dissipated by the droppers at 23 Watts or thereabouts. I felt that by using 50-Watt metal-clad resistors mounted on a thick heat sink would be well up to the task, though since the rectifier valve is just behind the heat sink there's no room for a finned heat sink. The original droppers seem to have not been up to the task, though the Noble radio seems to have had a lot of use before became a 'fuse', judging by the fluff and grime on the chassis.

So far, I've drawn a blank on any info on the Noble, but IIRC, I think it was Joe who spotted one on e-bay some months back. Thankfully, the component count is low, so I don't think a circuit is essential, and I dare say that if I traced it out, it would be very similar to the Portadyne Princess. I don't think the Noble is 'rare' but it's certainly uncommon. (The guy at the NVCF had two on his stall).

Here's my earlier thread 'Thoughts on Droppers':

http://golbornevintageradio.org/forum/sh...p?tid=2115