A question about amperage

[teevee]

Not rocket surgery.. 201 has a 5V 1A filament, 201A is 5V .25A. So, (assuming a standard 5 tube radio) you'd need 5A capable supply form running 201's, or 1.25A capable supply to run the 201A's. You might try swapping the tubes to different positions and check performance. We used to put the weakest tube in the "detector" position.

[decojoe67]

Originally Posted by teevee

Not rocket surgery.. 201 has a 5V 1A filament, 201A is 5V .25A. So, (assuming a standard 5 tube radio) you'd need 5A capable supply form running 201's, or 1.25A capable supply to run the 201A's. You might try swapping the tubes to different positions and check performance. We used to put the weakest tube in the "detector" position.

Thanks for your input. Yes, I have a good understanding of the situation now. The Westinghouse RC has 3 tubes. I have the non-A UV-200 in the det. and 201's in the amps as the original manual states. The original ads from the period instructs the use of a 6V battery for these sets and well over 3 amps is necessary. I used a 6V lead-acid battery with 4 amps with no audio out of the Vocarola speaker. Surprisingly a 12amp battery provides a borderline acceptable audio. I actually tinkered with the set today and got decent results. I have a 20amp multi-purpose battery on order and I'm expecting this to be optimum. At minimal it should provide plenty of operating time.

***UPDATE***I received the 6V 20amp battery and, lo and behold, the set plays great. It proves that these sets with these early tubes needed plenty of kick from their batteries!
In conclusion as to what was needed to run my RC with the non-A UV tubes:
1 UV-200 tube (det.)
2 UV-201 tubes (amp)
1 6V/20amp multi-purpose lead-acid battery (A supply)
1 ARBE III battery eliminator (B supply det-22, amp-45)
#12 gauge wire

Here's a pic of the non-A's blazing away. It's quite a sight and so cool to see the set playing the way it did in '22!

[Kevin Kuehn]

Those puppies are really bright! And I'm sure folks took advantage of that light source back in the day.

One very important point missing from the previous discussions is that all batteries have an equivalent internal series resistance. It's roughly based on the chemistry and the physical size of the plates. But in general a lower AH capacity battery would have more internal resistance than a larger one of the same construction. It's this internal resistance that is the real reason your voltage was pulling down more so when you tried the smaller AH capacity batteries. Based on ohms law(V/I=R) if your battery voltage was being pulled down 1.5 volts under load, you'd divide 1.5 volts by 3 amps, which gives an equivalent internal series resistance of .5 ohms. If you pull even more amps through that same .5 ohms then you'll have a proportionally larger internal voltage drop. Hope that all makes sense.

[decojoe67]

Originally Posted by Kevin Kuehn

Those puppies are really bright! And I'm sure folks took advantage of that light source back in the day.

One very important point missing from the previous discussions is that all batteries have an equivalent internal series resistance. It's roughly based on the chemistry and the physical size of the plates. But in general a lower AH capacity battery would have more internal resistance than a larger one of the same construction. It's this internal resistance that is the real reason your voltage was pulling down more so when you tried the smaller AH capacity batteries. Based on ohms law(V/I=R) if your battery voltage was being pulled down 1.5 volts under load, you'd divide 1.5 volts by 3 amps, which gives an equivalent internal series resistance of .5 ohms. If you pull even more amps through that same .5 ohms then you'll have a proportionally larger internal voltage drop. Hope that all makes sense.

I get the gist of what you're saying Kevin. If you look back years ago at the battery set-up for these very early sets, they were hefty looking batteries. The set just jumped to life with the large 6V/20amp battery.

[Electronic M]

Some of the early (IIRC wet cell) 'A' batteries were basically car batteries of the time marketed as radio batteries...There were stores that had charging stations for them.

Ever wonder why 6.3V and 12.6 became common heater voltages?....Well they did it so common automotive batteries could power the power hungry filaments/heaters of early tubes.

[jr_tech]

Those filaments look very bright... I hope that you are not exceeding the 5 volt specification by turning the rehostats up too far with the new battery, which will severely shorten tube life. Can you measure the filament voltage?

jr

[decojoe67]

Originally Posted by Electronic M

Some of the early (IIRC wet cell) 'A' batteries were basically car batteries of the time marketed as radio batteries...There were stores that had charging stations for them.

Ever wonder why 6.3V and 12.6 became common heater voltages?....Well they did it so common automotive batteries could power the power hungry filaments/heaters of early tubes.

I heard many would swap the battery back and forth from their Model-T with their radio at the time!

[teevee]

Additional info, using higher B+ and bias battery for more output.

[old_coot88]

Originally Posted by jr_tech

Those filaments look very bright... I hope that you are not exceeding the 5 volt specification by turning the rehostats up too far with the new battery, which will severely shorten tube life. Can you measure the filament voltage?

jr

The non-A tubes' filaments were non-thoriated and ran that bright by design. The 'A' tubes' thoriated filaments could run much cooler at 1/4 the amperage

[decojoe67]

Originally Posted by teevee

Additional info, using higher B+ and bias battery for more output.

Very interesting. Thank you. As a collectible the set just has so much more charm viewing the bright tubes through the sets peep-hole. I got so much volume I actually had the amp rheo turned down. I also noticed an improvement dropping the B+ amp from 90 to 45. Another member had recommended that to me and he was right.