[Milsurplus] HRO

[Hubert Miller]

The HRO was certainly in service before the SX-28 but I think the -M version was late WW2. I have some literature on the history of the
-M and -5 and maybe I'll look that up. The SP-200s followed the HRO shortly and were in direct competition. The variable selectivity 
feature of the Super Pro was certainly more advanced than anything National had at the time. I suggest as an intercept receiver it was
way superior to the HRO. My feeling is that the HRO was kind of a "good, and good enough for the job" item. I suppose the hassle of 
coil storage - imagine the coil storage for a solid wall of HROs - plus the hassle of dealing with a not very detailed look-up chart to set
the dial, and you can see why for some uses the HRO was out.

This said, I think all the HROs from first to last and from all countries are an interesting history and not well documented.
( I had no intention of collecting HRO-types, but I have German ( KST ), Japanese ( Chi-Ichi ), Australian ( AMR-101 ), and a Northern
Radio ( Seattle ) labeled HRO as "S-20", and an HRO-60 and HRO-5.  The last 2, at least, are going to have to go. )   The Northern is a 
Jr. model and the logging sheet/ scale is marked with Alaska cannery stations. 
-Hue