hi i have a a kolster k110 with a fried power xformer i found a comparible one in my junkbox except it had a six v. filament winding instead of 2.5 so i taped off the filament winding and put in a seperate fil. xformer at first it just hummed so i changed the electrolytics it had a 3 section in a tin box i hooked it in series with a 100 watt bulb and tried again the rectifier plates started glowing red so i unplugged it i'm just wondering could i have put the electrolytics in backwards?there is no polarity indicated on the schematic, from looking at the schmeatic it looks like the negative ends all tie together and tie in with the rectifier filament voltage and the ct on the b plus hooks to the plus end of one electrolytic and goes through a 750 ohm res. to another one i once had one where the plus ends were common and the neg. ends wre seperate but that doesn't seem right on this one.maybe when i i get over this head cold i'll be able to figure it out but right now help. thanks :butch

With the standard full wave rectification system utilizing a filamentary rectifier, it is always assumed that the filament supplies the positive high voltage. The two ends of the high voltage winding go to the plates of the rectifier, and the center tap goes either directly to the chassis/B- bus, or through resistors to the same. Always connect the positive side of electrolytics to anything going to the filament of the rectifier (field coil, resistors, or a direct connection). We always think of a cathode as being negative. It is only negative because it is supplied with negative energy. Forget all the mixed up notions about postive supply and all and just concentrate on electricity flowing from negative to positive. With the current flowing from negative to positive, it will flow into the cathode of the rectifier and out the plates. The cathode of the rectifier is then positive in relation to the rest of the radio, which is supplying it with negative energy. Confusing at first, but if you think about it at night while you're lying in bed, it'll all come together.

Anyway, the positive side of electrolytics always goes to the cathode of the rectifier or any resistors leading to the cathode of the rectifier. The negative side goes to the center tap of the transformer, or any resistors that lead to the center tap of the transformer.

Thomas

:With the standard full wave rectification system utilizing a filamentary rectifier, it is always assumed that the filament supplies the positive high voltage. The two ends of the high voltage winding go to the plates of the rectifier, and the center tap goes either directly to the chassis/B- bus, or through resistors to the same. Always connect the positive side of electrolytics to anything going to the filament of the rectifier (field coil, resistors, or a direct connection). We always think of a cathode as being negative. It is only negative because it is supplied with negative energy. Forget all the mixed up notions about postive supply and all and just concentrate on electricity flowing from negative to positive. With the current flowing from negative to positive, it will flow into the cathode of the rectifier and out the plates. The cathode of the rectifier is then positive in relation to the rest of the radio, which is supplying it with negative energy. Confusing at first, but if you think about it at night while you're lying in bed, it'll all come together.
:
:Anyway, the positive side of electrolytics always goes to the cathode of the rectifier or any resistors leading to the cathode of the rectifier. The negative side goes to the center tap of the transformer, or any resistors that lead to the center tap of the transformer.
:
:T

hi thomas and thanks it looks like i do have eletrolytics reversed as i have the center tap of the plate voltage going to the + end of the electrolytics funny i didn't smoke them.i'll try again i thought this might be the prob. but it just did'nt look right the other way.thanks again :butch

::With the standard full wave rectification system utilizing a filamentary rectifier, it is always assumed that the filament supplies the positive high voltage. The two ends of the high voltage winding go to the plates of the rectifier, and the center tap goes either directly to the chassis/B- bus, or through resistors to the same. Always connect the positive side of electrolytics to anything going to the filament of the rectifier (field coil, resistors, or a direct connection). We always think of a cathode as being negative. It is only negative because it is supplied with negative energy. Forget all the mixed up notions about postive supply and all and just concentrate on electricity flowing from negative to positive. With the current flowing from negative to positive, it will flow into the cathode of the rectifier and out the plates. The cathode of the rectifier is then positive in relation to the rest of the radio, which is supplying it with negative energy. Confusing at first, but if you think about it at night while you're lying in bed, it'll all come together.
::
::Anyway, the positive side of electrolytics always goes to the cathode of the rectifier or any resistors leading to the cathode of the rectifier. The negative side goes to the center tap of the transformer, or any resistors that lead to the center tap of the transformer.
::
::T
:
:
:hi thomas and thanks it looks like i do have eletrolytics reversed as i have the center tap of the plate voltage going to the + end of the electrolytics funny i didn't smoke them.i'll try again i thought this might be the prob. but it just did'nt look right the other way.thanks again :butch

hi again set is up and running changing cap. polarity worked now the only problem is low volume i know the seperate filament xformer i'm using is to small it's only 4 amp i need a eight or ten amp unless i could use the six volt tap on the replacement xformer but i can't see how i better just order one from aes thanks for all your help .butch

Low volume? Well, unless your filaments aren't receiving full voltage, you should be looking elsewhere. If they're receiving 2.5 volts, then all is well there. Make sure that your biasing resistors are attached to the filament transformer properly. Make sure that your replacement high voltage transformer is at 330 volts per side. Make sure that your DC voltage is approximately this when the radio is on and under load (operating). Measure this voltage from the cathode of the rectifier to the center tap of the transformer. Antique Electronic Supply does sell transformers with 350 volt windings and 2.5 volt filament windings, though, so you should be good with one of their's. They used to have two transformers, one with a 325 volt winding and one 2.5 volt winding and then one with the 350 and two 2.5 volt windings--one center tapped and one not. Now all they carry is the larger version, which is alright because this will work in either situation, but in some cases it is nice to be able to purchase the less expensive version. At any rate, this transformer will work great for your radio. You may use the center tapped winding to power all the tubes, or just use it for the audio tubes, and use the non-center tapped winding for the RF tubes.

When reading your circuit diagram, zoom in on all connections that you do not clearly see. A dot means that there is a connection. If two wires cross and there is no dot, then they are not connected. The dots are really small on this particular diagram, which is why I say you should be careful.

Of course be sure that your set is aligned properly, as this may have something to do with its low volume. Be sure, too, that no condensers are leaky, even in the millions of ohms--that is, if you haven't already replaced them. .....drifted resistors, etc.

Good luck,

Thomas

Your schematic:

http://www.nostalgiaair.org/PagesByModel/842/M0009842.pdf

A note on what I said about biasing resistors for the output section: with a filamentary type tube that uses alternating current for the filament, B current must be applied carefully to the filament at a central location. This is done by using a center tap on the filament transformer. If the current was applied to one side of the winding or the other, the alternating current 2.5 volts would constantly be added to and subtracted from the B current, which would introduce hum.

T.D.

:Your schematic:
:
:http://www.nostalgiaair.org/PagesByModel/842/M0009842.pdf
:
:A note on what I said about biasing resistors for the output section: with a filamentary type tube that uses alternating current for the filament, B current must be applied carefully to the filament at a central location. This is done by using a center tap on the filament transformer. If the current was applied to one side of the winding or the other, the alternating current 2.5 volts would constantly be added to and subtracted from the B current, which would introduce hum.
:
:T.D.

hi thomas i am just starting to recap tonite and i have only checked the tolerence on a few res. but i will get this all done the plate current is fine i am using a seperate filament xformer as the power xformer i had has a six v. filament winding instead of a 2.5 v. but the filament xformer i have is only 3 amps the filaments draw over 7 amps so with this xformer you can barly see the filaments glow i ordered a 10 amp one this afternoon i don't know if this is the problem or not but i couldn't be getting much emission but i'll go through it all while i'm waiting for the parts i'm just happy its working at all its been sitting here for almost 2 years it worked good when i first had it then the power xformer blew and i am just getting around to repairing it. i had hoped a power xformer with a 2.5 v. winding would come along but they seem as scarce as hens teeth i know you can buy them but they are pretty pricey and the ones i've seen wouldn't fit this set well whereas the one i'm using bolted right in. butch

Here is the transformer I was talking about. It is not too expensive ($59.95). It is sold by www.tubesandmore.com. You would use the 3.5 amp. filament winding for the output tubes, as it has a center tap, and use the 7.5 amp. winding to power all of the other tubes. I don't know if 90 MA. for the high voltage section is enough for your radio, but that's pretty good. 350 volts is a little more than your 330, but is pretty much acceptable. You would have to be sure that your electrolytics were rated for at least 375 volts. If this transformer will fit your radio (horiz. or vert.), it's a pretty good one to buy.

I purchased another version of this transformer many years ago when I was 15. It had a 325 volt high voltage and a smaller 2.5 volt winding with center tap. I forgot what the amperage was. This was used for powering an 80, 2A3, and a 57. It worked very well and still works very well. The only thing I did not like about this transformer is how it has always gotten quite warm. There have been transformers made in old radios, though, that get very warm, too, so I guess that's not so bad. Many radios I have, though, have transformers that do not get above 100 degrees. This transformer should work alright for what you need, though. Mine seems to have lasted a long time--10 years, at least.

P-T143
2004 Catalog
page 38

TRANSFORMER, POWER, HAMMOND, 350-0-350 V, 70-90 mA

Custom manufactured to replace most 6 and 7 tube sets of the early 1930's. Supplied with vertical mounting shells. Leads come out one side to enable horizontal mounting. Feet for vertical mounting can be cut off to enable horizontal mounting. Mounting centers in parentheses apply to horizontal mounting. Provides a seperate filament winding for audio output stages but both 2.5 volt windings can be paralleled for the combined current rating.

Specifications
Rating: 350-0-350 V, 70 or 90 mA (if 5 V winding is used with 2 A rectifier)
Windings: 5 V, 3 A; 2.5 V, 7.5 A; 2.5 VCT, 3.5 A
Mounting Centers: 2.3125" x 2.5" (2.25" x 3.125" for horizontal)
Weight: 4.6 lbs.

$59.95
Qty

:Here is the transformer I was talking about. It is not too expensive ($59.95). It is sold by www.tubesandmore.com. You would use the 3.5 amp. filament winding for the output tubes, as it has a center tap, and use the 7.5 amp. winding to power all of the other tubes. I don't know if 90 MA. for the high voltage section is enough for your radio, but that's pretty good. 350 volts is a little more than your 330, but is pretty much acceptable. You would have to be sure that your electrolytics were rated for at least 375 volts. If this transformer will fit your radio (horiz. or vert.), it's a pretty good one to buy.
:
:I purchased another version of this transformer many years ago when I was 15. It had a 325 volt high voltage and a smaller 2.5 volt winding with center tap. I forgot what the amperage was. This was used for powering an 80, 2A3, and a 57. It worked very well and still works very well. The only thing I did not like about this transformer is how it has always gotten quite warm. There have been transformers made in old radios, though, that get very warm, too, so I guess that's not so bad. Many radios I have, though, have transformers that do not get above 100 degrees. This transformer should work alright for what you need, though. Mine seems to have lasted a long time--10 years, at least.
:
:P-T143
:2004 Catalog
:page 38
:
:
: TRANSFORMER, POWER, HAMMOND, 350-0-350 V, 70-90 mA
:
:Custom manufactured to replace most 6 and 7 tube sets of the early 1930's. Supplied with vertical mounting shells. Leads come out one side to enable horizontal mounting. Feet for vertical mounting can be cut off to enable horizontal mounting. Mounting centers in parentheses apply to horizontal mounting. Provides a seperate filament winding for audio output stages but both 2.5 volt windings can be paralleled for the combined current rating.
:
:Specifications
:Rating: 350-0-350 V, 70 or 90 mA (if 5 V winding is used with 2 A rectifier)
:Windings: 5 V, 3 A; 2.5 V, 7.5 A; 2.5 VCT, 3.5 A
:Mounting Centers: 2.3125" x 2.5" (2.25" x 3.125" for horizontal)
:Weight: 4.6 lbs.
:
: $59.95
:Qty

hi thomas i saw that transformer but wasn't sure it would fit i'll try the the filament xformer first as it gives me a little more room by mounting in a different spot than the main xformer then when that doesn't work i'll buy the other one making sure i spend twice as much money as i needed to this is my usual procedure .thanks .butch

No problem. If your filaments aren't glowing properly, this is probably a large part of why your volume is low.

Good luck!

Thomas