Got a National HRO-50T and some other stuff today.

[Sandy G]

The National HROs were "Top Flight" sets back then. Introduced in 1935, they went thru several models, up til the HRO-60s of the early 1960s. You had to buy coil sets of what frequencies you wanted to listen to, which were matched to each individual radio. Typically, the power supply was a separate piece, too, til the HRO-50 models. If you get one, try to make sure it has the 2 coils for AM/MW work, they can be tough to find. National FINALLY "Broke Down" & introduced a radio that didn't need coilsets, the NC-173 & NC-183 series in the late forties.

[dieseljeep]

Originally Posted by Sandy G

The National HROs were "Top Flight" sets back then. Introduced in 1935, they went thru several models, up til the HRO-60s of the early 1960s. You had to buy coil sets of what frequencies you wanted to listen to, which were matched to each individual radio. Typically, the power supply was a separate piece, too, til the HRO-50 models. If you get one, try to make sure it has the 2 coils for AM/MW work, they can be tough to find. National FINALLY "Broke Down" & introduced a radio that didn't need coilsets, the NC-173 & NC-183 series in the late forties.

I have an NC-100 and a NC2-40D that technically, have individual coil sets.
It uses the sliding coil carriage assembly, that moves on a rack and pinion. Each coil position has contacts that mate with a set of fixed contacts.
James Millen, their head engineer, didn't believe in selector switches.

[dieseljeep]

Originally Posted by Sandy G

The National HROs were "Top Flight" sets back then. Introduced in 1935, they went thru several models, up til the HRO-60s of the early 1960s. You had to buy coil sets of what frequencies you wanted to listen to, which were matched to each individual radio. Typically, the power supply was a separate piece, too, til the HRO-50 models. If you get one, try to make sure it has the 2 coils for AM/MW work, they can be tough to find. National FINALLY "Broke Down" & introduced a radio that didn't need coilsets, the NC-173 & NC-183 series in the late forties.

James Millen wrote the text for same of National's adds in QST. One ad proclaimed, that when they started building sets with band selector switches, it used a higher quality switch and tuning condenser, that they made themselves.
They claimed that they wouldn't use the kind normally found in lower priced B/C receivers. I wonder, who they were referring to!