Dropping Resistor?

View previous topic View next topic Go down

Dropping Resistor?

Post by nytuberadio on Sat Jun 18, 2011 2:30 pm

Looking at the schematic on the tube line up a 12BA6 could be used or a 6BJ6 as the RF amp.
In between the heater line up is a 3 watt 33 ohm resistor. With the 12BA6 in the line the ac voltages add up to a 114 volts without the drooping resistor. Do you still need the dropping resistor when the 12BA6 is used? I can see it is needed when the 6 volt tube is used because the string would only be up to 108 volts, but not with the 12BA6 is used.

nytuberadio
Member
Member

Number of posts : 19
Registration date : 2010-07-26

Back to top Go down

Re: Dropping Resistor?

Post by repairtech on Sun Jun 19, 2011 11:05 am

Assuming this is a series-connected AC/DC set, I'd leave the resistor as it should be.
It takes up excess surge voltage/current during warmup.

repairtech
Member
Member

Number of posts : 98
Registration date : 2010-04-28

Back to top Go down

Re: Dropping Resistor?

Post by zdiode on Tue Jan 03, 2012 1:19 pm

repairtech does have a point.
However, I have worked on Zenith H723 radios. These come in types with 6BJ6 and 12BA6 as the RF tube. H723's that have the 6BJ6 always have the resistor and H723 that have the 12BA6 never have the resistor.
My tendancy is to go with the Zenith engineers' design, however, repairtech does have a point. Reasonable persons can disagree on this.

All the Best,

Bill
avatar
zdiode
New Member
New Member

Number of posts : 3
Registration date : 2012-01-03

Back to top Go down

Re: Dropping Resistor?

Post by sprman on Sat Jan 07, 2012 7:55 pm

Yes leave the dropping resistor i place.They put it there to help keep voltage where they wanted it.Sprman

sprman
Member
Member

Number of posts : 374
Age : 62
Registration date : 2008-03-27

Back to top Go down

Re: Dropping Resistor?

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum