[TenTec] SB220-Tubes and QSK

[k9mi at sbcglobal.net]

I have a friend that is a broadcast engineer for a company with both AM and 
FM stations. I asked him not too long ago about what massive tubes it must 
take to run a broadcast station. His reply was, they had not used tubes for 
years. He is an inactive ham now, but will surprise us every so often and 
appear on UHF or VHF. I'm thinking some of these were 50 kw transmitters.

73, Mike K9MI


----- Original Message ----- 
From: "Gary Hoffman" <ghoffman at spacetech.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Thursday, November 01, 2007 02:15
Subject: Re: [TenTec] SB220-Tubes and QSK


> Don't forget WHAM....clear channel 50k watts for many many years....and 
> they
> ran water cooled tubes....I've been there and seen em  :)
>
> ----- Original Message ----- 
> From: "Rob Atkinson" <ranchorobbo at gmail.com>
> To: <tentec at contesting.com>
> Sent: Wednesday, October 31, 2007 12:57 PM
> Subject: Re: [TenTec] SB220-Tubes and QSK
>
>
>> 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>>>
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>
>
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