[HBR] Octals and such

[Bill Cromwell]

Hi,

There are a lot of things that factor into this. I just happen to have a 
lot of octal and loctal tubes here. I'm a "forty meter ham" so a little 
less horsepower isn't going to make much difference. I worked the 
microwaves at ten meters once in the past 15 years and that was to fill 
a sked with a Swedish ham who wanted my card for the county hunters. The 
TX has a double barrel 6146 final and cranked it up all the way to make 
the QSO. That tube is an octal. Those old tubes still work their magic. 
And they look kewl.

73,

Bill  KU8H


On 11/23/2014 07:28 PM, Ron Barlow via HBR wrote:
>   Here is $.02 on the octal vs miniature tube discussion, FWIW.
>   When I was a young guy (looooooong ago), I shunned octal type tubes (and to even a greater degree, their 4, 5, 6 & 7 pin predecessors), like the plague! Newer was better, in my "brainwashed" mind!
>   So, most of my homebrew projects used (salvaged) miniatures.
>   My interest in electronics led to my employment as a radio/tv service guy, for a number of years. After a while, I began to notice that the miniatures with their unplated base pins (with a few exceptions, such as the Realistic brand) seemed to be much more susceptible to base contact issues, and internal shorts (due to closer element spacing, I suspected), compared to the older bottles.
>   In addition, I realized that some of those old bottles had some rather impressive performance numbers. The 6SG7 has a slightly higher gm than the 6BA6 (4700 vs 4300), & the 6AC7 has a gm of 9000.
>   Yes, the octals that I mentioned are semi remote, and sharp cutoff, respectfully. No issue for me, as I do not use AGC.
>   Long and short, I developed some new found respect for some of the older tube types. YMMV!
>                  73 de Ron
>