Tubes like the 75th and 100th sometimes had caps on the grid, the modulators in my 30k1 had caps for the grids.
I suspect they were supposed to have caps but they were 'extra' from eimac? I would have to dig in the books to find a circuit for a single ended? triode final, then look at the components power/voltage rating on the RF deck, tube base types, filament voltage, etc, to see what was likely used. Looking in the OLD handbooks, there were loads of tubes I never saw or heard of, and they were not listed in newer handbooks. Brett N2DTS > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of A.R.S. - W5AMI > Sent: Wednesday, September 13, 2006 1:16 PM > To: Discussion of AM Radio in the Amateur Service > Cc: Glowbugs > Subject: [AMRadio] Re: Need ID Help for 1930's Transmitter > > On 9/12/06, Don Merz <[EMAIL PROTECTED]> wrote: > > The final deck has a socket for a single tube with the > > large, twist-lock base and 2 plate-cap-size > > connections for plate and grid caps. Not many tubes > > fit that description, so I am thinking maybe an 810 > > goes there? The Eimac tubes are out because they used > > a pin for the grid--not a full-size plate cap. The > > final deck has a filament transformer (I haven't > > Don, > > Determine the filament voltage. Also, was the bias supply for the > final in the power supply section that's missing? If not, what does > the voltage appear to be on it? This would help narrow down a final > tube. The Eimac tubes above the 250T (450 up) used the standard .5" > grid and plate caps. The 450T had both the pin and a .5" cap on the > grid. GE also made some Eimac like triodes such as the GE806 which > was a close cousin to the 250T only it had .5" caps on the grid and > plate. Of course there are other possibilities like Taylor, etc. > > Brian / w5ami > ______________________________________________________________ > AMRadio mailing list > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > ______________________________________________________________ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
