[AMRadio] WTB/WTS and a question


Edward B Richards zuu6k at juno.com
Fri Dec 30 13:18:46 EST 2005


Thanks, I am now better educated.

EBR

On Fri, 30 Dec 2005 12:37:19 -0500 KB2WIG at twcny.rr.com writes:
> from the'63 RCA Tub Man....2A3 power triode,plate 200v,3.5W  mue 60,  
> 
> 2A5,twin diode/high mue triode,, 2A7 Pentagrid converter---- more 
> stuff, diodes, etc... then there are the 3V stuff.....  the Manuel 
> is 
> gud reading on long winter nights......   klc
> ----- Original Message -----
> From: Edward B Richards <zuu6k at juno.com>
> Date: Friday, December 30, 2005 12:09 pm
> Subject: Re: [AMRadio] WTB/WTS and a question
> 
> > Hi Brian;
> > 
> > In my ignorance, I have never heard of 2 volt tubes. What are 
> their
> > numbers? Thanks and HNY.
> > 
> > 73, Ed Richards K6UUZ
> > Simi Valley, Ca 93065
> > Home of the Air Force 1 pavilion
> > 
> > On Fri, 30 Dec 2005 10:21:15 -0600 Brian K Harris
> > <brian.k.harris at philips.com> writes:
> > > Good Morning,
> > > 
> > > 1.  I would like to buy or swap for two solid state plug-in 
> > > replacements 
> > > for the 872A mercury vapor rectifiers for my KW-1.  Enuf said.
> > > 
> > > 2.  I am restoring a broadcast/shortwave radio set for my 
> > brother.  
> > > It is 
> > > an RCA 8BT, battery operated 'farm set' from the 30's.  In 
> > addition 
> > > to 
> > > using three 45V batteries in series for the 135V B+, it used 
> > four 
> > > small 
> > > 1.5V cells for biasing the 1st detector and the 1st and 2nd 
> > IF's, 
> > > and a 
> > > multi-tapped battery to get 3V bias for the 2nd detector and 
> > 7.5V 
> > > bias for 
> > > the audio driver.  As my brother doesn't live on an electricity 
> 
> > > deprived 
> > > farm, I am building a solid state AC supply to meet those 
> needs.
> > > 
> > > The tubes all have 2V filaments.  The radio has two inputs for a 
> 
> > > filament 
> > > supply, 2V or 2.5V (the 2.5V input merely inserts a series 
> > > resistor).  My 
> > > question is....why did anyone manufacture 2V filament tubes and 
> 
> > what 
> > > kind 
> > > of battery put out 2V or 2.5V?  I am building a solid state 
> > supply 
> > > for the 
> > > 2V requirement as well so the question is merely to satisfy my 
> > > curiosity.
> > > 
> > > By the way, this set uses a pair of push-pull 49's for the audio 
> 
> > > output 
> > > stage.  These are zero bias tubes in Class B with 3.5W 
> > capability.  
> > > Very 
> > > cool.
> > > 
> > > Thanks for reading,
> > > 
> > > Brian WA5UEK
> > > 
> > > ______________________________________________________________
> > > AMRadio mailing list
> > > Home: http://mailman.qth.net/mailman/listinfo/amradio
> > > Help: http://mailman.qth.net/mmfaq.html
> > > Post: mailto:AMRadio at mailman.qth.net
> > > AMfone Website: http://www.amfone.net
> > > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
> > > 
> > > 
> > ______________________________________________________________
> > AMRadio mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/amradio
> > Help: http://mailman.qth.net/mmfaq.html
> > Post: mailto:AMRadio at mailman.qth.net
> > AMfone Website: http://www.amfone.net
> > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
> > 
> ______________________________________________________________
> AMRadio mailing list
> Home: http://mailman.qth.net/mailman/listinfo/amradio
> Help: http://mailman.qth.net/mmfaq.html
> Post: mailto:AMRadio at mailman.qth.net
> AMfone Website: http://www.amfone.net
> AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
> 
> 



More information about the AMRadio mailing list

This page last updated 14 Dec 2017.