[BC] getting the right tube combinations

[Miltron]

The BC-1F was on a par with the RA-1000; only one 813, but a good output network; identical audio, and no tar in the bottom.
In the BC-1J, they got by with a pairof 6146s for RF drive. The audio section really didn't get by, at all.
M

-----Original Message-----
>From: Jerry Mathis <thebeaver32 at gmail.com>
>Sent: Aug 6, 2006 12:45 AM
>To: broadcast at radiolists.net
>Subject: [BC] getting the right tube combinations
>
>On 8/5/06, Jim Tonne <<mailto:tonne at comcast.net>tonne at comcast.net> wrote:
>
>
>I think the use of the 4-400 etc was based on the thought that
>a simple driver could be used;  as I recall it was just an 807.
>The 833s, while remarkably robust and tolerant of improper
>loads etc did require a hefty driver.
>
>....Which Harris DIDN'T do either. BC-1G and similar 1 KW, RF drivers 
>are a pair of 807's. It worked, as long as the 807's were in top 
>shape. As soon as they started to weaken, you started loosing 
>positive modulation, until finally you couldn't even make full 
>carrier power. Of course, they seldon got that weak; the horizontal 
>mounting of the 807's caused the grids to sag, and they usually 
>shorted out and blew the PS fuse long before then.
>
>I know I've said this before, but the best 1KW AM transmitter I ever 
>saw was the Raytheon RA-1000. 833's driven by a PAIR of 813's on the 
>RF side, and by 845's on the audio side. You could run the 833's 
>forever in that transmitter, it seemed.
>
>--