[TenTec] SB220-Tubes and QSK

[Rob Atkinson]

Hi Chuck,

Yes, you are right--you are of course referring to Ampfet 50 no. 2;
no. 1 went to CBA in New Brunswick.  Also, when I wrote that no 50 Kw
AM in the u.s. runs a tube primary I had in mind the 1-A stations but
later I recalled that 670 in Chicago is still running a Continental
317 primary as far as I know, however I maintain that the number of
tube rigs is rapidly decreasing as the economics make solid state a
no-brainer.

73,

Rob / K5UJ


<<<I would respectfully disagree. There are lots of Tube final backups out
there and still some primaries...Smaller markets just don't get the Capital
budgets that larger ones do..Many of the large groups buy the good stuff for
the larger markets and send the junk on down the line to the tail draggers.
I spent a lot of my broadcast career installing the new and moving the junk
down the line for a couple of them... I would be afraid to make the
statement that NO US  50 KW station runs a tube PA ... you may be right, but
I would be a little leary to say it because there are a lot 50KW stations
out there..By the way I
installed the 1st 50 KW AM Broadcast transmitter in the US..1985
...KBMR --1130  Bismarck, ND..A Nautel. S/N 2
number 1 was in Canada.....We went through our share of VMOS FET's keeping
that baby putting out 50KW, but when all  the transistors were good, she
would do about 65KW!!!     22 years later it still pops some FETs now and
then, but it's still running except at only 10KW now.....Several years ago
they brought up another 50KW on 710 and due to a license foul ups they had
to drop 1130 back to 10 KW or loose it.

73's
Chuck
W6RD>>>