[Hammarlund] OB2 factoid and JAN tubes

[Craig Roberts]

As my arduous education continues, I've learned another curious fact about
the OB2 gas discharge voltage regulator tube.

The "straight" OB2 glows a mellow purple (just like I was told).

The military version OB2WA (or at least mine) glows bright orange.  This can
be scary if you're expecting soft violet.

This is another of the bits of circumstantial evidence that led me to
wrongly assume my HQ-170's power supply was wired incorrectly.

On the topic of military tubes: the "WA" versions of tubes are not always
interchangeable with their civilian counterparts.  Anybody who's re-tubed a
Collins S-Line with JAN tubes has learned this the hard way (especially if
he enthusiastically but unwisely swapped all the tubes at once -- and then
tried to find the one that didn't work). That's why the "NOS tube kits" sold
on eBay are not always the convenient bargains they seem to be. Many of
these kits are stocked with readily available, but not always compatible,
JAN tubes.

Has anyone found any military tubes that don't work correctly in Hammarlund
sets?

73,
Craig
W3CRR