Hello All,
This chassis is supposed to have two 5Z4s in it. However someone changed one of the sockets so it can accept a 5Z3. The other socket (5Z4) doesn't seem to have the filament connected. Will this provide enough current for the two 6L6 tubes? Was this a revision? I will be working on this set in the near future.

Thanks,

Dave

I think someone may have changed the setup to save some power draw and heat. Have a look at this link.

http://www.nj7p.org/Tube4.php?tube=5z3

Then look at a 5Z4. I think you should see what some other person was thinking. Should work too.

Warren,
Yes, I know what they did but... Does the one 5Z3 provide the same amount of B+ current as two 5Z4s in parallel? That is the question. It sounds ok as it is but, maybe it could use a little more current. I replaced all 24 capacitors. It was pretty straight forward. Nothing unusual except that someone connected one end of the input transformer to the chassis. It didn't work too well that way, Fortunately this ground connection to the plate of the driver tube was through a capacitor. So it didn't hurt anything. You can't hear anything when the sound is going into the chassis but it wasn't a big problem. I disconnected the other end of the capacitor and the end of the input transformer from the chassis, and "like magic" there was sound coming through the speakers. This radio has two speakers.

I could see where someone had given up on this radio and wrote B+ in red and marked every place in Red where B+ went but couldn't figure out why there was no sound. B+ was working fine. There were no problems with the power supply.

Lafayette also put their name on this radio (Model B97-98). I wonder who made these Chromed chassis sets with the "movie" dial? This radio was made or sold in 1936. It "resembles" a Scott. But it's nowhere near as elaborate as a Scott, as far as I can tell. It;s like a "mini" Scott. It does have both an RF amplifier stage and a second IF stage. In addition it has a Broad-Sharp selectivity control. Then add in the 20 Watt amplifier and WOW! All these features make it a very good radio. That's why I bought it. One of my friends had it locally. He doesn't know how to electronically restore them and didn't want to pay anyone to do the work. My other friend had a vehicle it would fit in and he brought it over.
Now I need to find an 1129 lamp (not sure that this is the correct bulb) for the Movie tuning, so I can see the dial scale. The movie drum needs a dial cord too. The main dial cord is fine.

Dave

:I think someone may have changed the setup to save some power draw and heat. Have a look at this link.
:
:http://www.nj7p.org/Tube4.php?tube=5z3
:
:Then look at a 5Z4. I think you should see what some other person was thinking. Should work too.
:

To be certain about current draw, measure the rectifiers output current draw with the radio playing at moderate volume. If it's within specs of the tubes listing, then I would think it's fine. I would add a fuse though to protect the set. Those department store radios were made by different manufactures. Some were high end, some low end. Depending on what the customer would spend. It sounds like you have a high end one. Nice set too. I would restring both dial cords. Old cords will give up after some use. Since you already have it apart, do that so you won't have to later. Here is the specs for that 1129 bulb.

http://www.bulbtown.com/1129_MINIATURE_BULB_BA15S_BASE_p/1129.htm

Warren,
I have already checked the tube data and found that the 5Z3 is very much like a 5U4. But at the time whoever replaced the socket replaced it, the 5U4 was either very new or didn't exist yet. But the tube data indicates that they are very close, if not the same.
As for the bulb, I was asking if the 1129 was the same as the original bulb that was in the radio. This is probably a replacement bulb. I know what an 1129 is.

Thanks,

Dave
:To be certain about current draw, measure the rectifiers output current draw with the radio playing at moderate volume. If it's within specs of the tubes listing, then I would think it's fine. I would add a fuse though to protect the set. Those department store radios were made by different manufactures. Some were high end, some low end. Depending on what the customer would spend. It sounds like you have a high end one. Nice set too. I would restring both dial cords. Old cords will give up after some use. Since you already have it apart, do that so you won't have to later. Here is the specs for that 1129 bulb.
:
:http://www.bulbtown.com/1129_MINIATURE_BULB_BA15S_BASE_p/1129.htm
:

Hello All,
5Z3 is capable of 250 mA at for B+. The 5Z4 is capable of 125 mA, for B+ so it's a match. Two 5Z4s in parallel are the same as one 5Z3.
A 5U4 wouldn't work because it's only capable of 225 mA. However in some tube data it mentions a 5Z3 being 225mA. So I think a 5Z3 and 5U4 are close. Maybe I should make a new thread for this topic.

Thanks,

Dave

:Warren,
: Yes, I know what they did but... Does the one 5Z3 provide the same amount of B+ current as two 5Z4s in parallel? That is the question. It sounds ok as it is but, maybe it could use a little more current. I replaced all 24 capacitors. It was pretty straight forward. Nothing unusual except that someone connected one end of the input transformer to the chassis. It didn't work too well that way, Fortunately this ground connection to the plate of the driver tube was through a capacitor. So it didn't hurt anything. You can't hear anything when the sound is going into the chassis but it wasn't a big problem. I disconnected the other end of the capacitor and the end of the input transformer from the chassis, and "like magic" there was sound coming through the speakers. This radio has two speakers.
:
: I could see where someone had given up on this radio and wrote B+ in red and marked every place in Red where B+ went but couldn't figure out why there was no sound. B+ was working fine. There were no problems with the power supply.
:
: Lafayette also put their name on this radio (Model B97-98). I wonder who made these Chromed chassis sets with the "movie" dial? This radio was made or sold in 1936. It "resembles" a Scott. But it's nowhere near as elaborate as a Scott, as far as I can tell. It;s like a "mini" Scott. It does have both an RF amplifier stage and a second IF stage. In addition it has a Broad-Sharp selectivity control. Then add in the 20 Watt amplifier and WOW! All these features make it a very good radio. That's why I bought it. One of my friends had it locally. He doesn't know how to electronically restore them and didn't want to pay anyone to do the work. My other friend had a vehicle it would fit in and he brought it over.
: Now I need to find an 1129 lamp (not sure that this is the correct bulb) for the Movie tuning, so I can see the dial scale. The movie drum needs a dial cord too. The main dial cord is fine.
:
:
:Dave
:
:
::I think someone may have changed the setup to save some power draw and heat. Have a look at this link.
::
::http://www.nj7p.org/Tube4.php?tube=5z3
::
::Then look at a 5Z4. I think you should see what some other person was thinking. Should work too.
::
:

Hi

5Z3 and 5U4 are the same except for basing regasrdless of what is in tube manuals. There is a 5U4GB rated higher. Some list output as 300 ma but I've seen it shown as high as 350 ma for 5U4GB.

Another difference between 2 - 5Z4's and a 5Z3. 5Z4 is a cathode type tube. Elements are closer spaced so voltage output is higher. Voltage drop for a 5Z4 is around 20 volts. A 5U4 or 5Z3 around 58 volts.

B+ will be higher using 5Z4 but with todays line voltage usually extra B+ isn't needed.

Norm

:Hello All,
: 5Z3 is capable of 250 mA at for B+. The 5Z4 is capable of 125 mA, for B+ so it's a match. Two 5Z4s in parallel are the same as one 5Z3.
:A 5U4 wouldn't work because it's only capable of 225 mA. However in some tube data it mentions a 5Z3 being 225mA. So I think a 5Z3 and 5U4 are close. Maybe I should make a new thread for this topic.
:
:Thanks,
:
:Dave
:
::Warren,
:: Yes, I know what they did but... Does the one 5Z3 provide the same amount of B+ current as two 5Z4s in parallel? That is the question. It sounds ok as it is but, maybe it could use a little more current. I replaced all 24 capacitors. It was pretty straight forward. Nothing unusual except that someone connected one end of the input transformer to the chassis. It didn't work too well that way, Fortunately this ground connection to the plate of the driver tube was through a capacitor. So it didn't hurt anything. You can't hear anything when the sound is going into the chassis but it wasn't a big problem. I disconnected the other end of the capacitor and the end of the input transformer from the chassis, and "like magic" there was sound coming through the speakers. This radio has two speakers.
::
:: I could see where someone had given up on this radio and wrote B+ in red and marked every place in Red where B+ went but couldn't figure out why there was no sound. B+ was working fine. There were no problems with the power supply.
::
:: Lafayette also put their name on this radio (Model B97-98). I wonder who made these Chromed chassis sets with the "movie" dial? This radio was made or sold in 1936. It "resembles" a Scott. But it's nowhere near as elaborate as a Scott, as far as I can tell. It;s like a "mini" Scott. It does have both an RF amplifier stage and a second IF stage. In addition it has a Broad-Sharp selectivity control. Then add in the 20 Watt amplifier and WOW! All these features make it a very good radio. That's why I bought it. One of my friends had it locally. He doesn't know how to electronically restore them and didn't want to pay anyone to do the work. My other friend had a vehicle it would fit in and he brought it over.
:: Now I need to find an 1129 lamp (not sure that this is the correct bulb) for the Movie tuning, so I can see the dial scale. The movie drum needs a dial cord too. The main dial cord is fine.
::
::
::Dave
::
::
:::I think someone may have changed the setup to save some power draw and heat. Have a look at this link.
:::
:::http://www.nj7p.org/Tube4.php?tube=5z3
:::
:::Then look at a 5Z4. I think you should see what some other person was thinking. Should work too.
:::
::
:

Norm,
This radio sounds really really good in the HiFi position but looses volume when I try to use the tone control. So something is probably still not right there. This is a very good radio even with the 5Z3.

Thanks,

Dave

:Hi
:
: 5Z3 and 5U4 are the same except for basing regasrdless of what is in tube manuals. There is a 5U4GB rated higher. Some list output as 300 ma but I've seen it shown as high as 350 ma for 5U4GB.
:
: Another difference between 2 - 5Z4's and a 5Z3. 5Z4 is a cathode type tube. Elements are closer spaced so voltage output is higher. Voltage drop for a 5Z4 is around 20 volts. A 5U4 or 5Z3 around 58 volts.
:
: B+ will be higher using 5Z4 but with todays line voltage usually extra B+ isn't needed.
:
:Norm
:
:
:
::Hello All,
:: 5Z3 is capable of 250 mA at for B+. The 5Z4 is capable of 125 mA, for B+ so it's a match. Two 5Z4s in parallel are the same as one 5Z3.
::A 5U4 wouldn't work because it's only capable of 225 mA. However in some tube data it mentions a 5Z3 being 225mA. So I think a 5Z3 and 5U4 are close. Maybe I should make a new thread for this topic.
::
::Thanks,
::
::Dave
::
:::Warren,
::: Yes, I know what they did but... Does the one 5Z3 provide the same amount of B+ current as two 5Z4s in parallel? That is the question. It sounds ok as it is but, maybe it could use a little more current. I replaced all 24 capacitors. It was pretty straight forward. Nothing unusual except that someone connected one end of the input transformer to the chassis. It didn't work too well that way, Fortunately this ground connection to the plate of the driver tube was through a capacitor. So it didn't hurt anything. You can't hear anything when the sound is going into the chassis but it wasn't a big problem. I disconnected the other end of the capacitor and the end of the input transformer from the chassis, and "like magic" there was sound coming through the speakers. This radio has two speakers.
:::
::: I could see where someone had given up on this radio and wrote B+ in red and marked every place in Red where B+ went but couldn't figure out why there was no sound. B+ was working fine. There were no problems with the power supply.
:::
::: Lafayette also put their name on this radio (Model B97-98). I wonder who made these Chromed chassis sets with the "movie" dial? This radio was made or sold in 1936. It "resembles" a Scott. But it's nowhere near as elaborate as a Scott, as far as I can tell. It;s like a "mini" Scott. It does have both an RF amplifier stage and a second IF stage. In addition it has a Broad-Sharp selectivity control. Then add in the 20 Watt amplifier and WOW! All these features make it a very good radio. That's why I bought it. One of my friends had it locally. He doesn't know how to electronically restore them and didn't want to pay anyone to do the work. My other friend had a vehicle it would fit in and he brought it over.
::: Now I need to find an 1129 lamp (not sure that this is the correct bulb) for the Movie tuning, so I can see the dial scale. The movie drum needs a dial cord too. The main dial cord is fine.
:::
:::
:::Dave
:::
:::
::::I think someone may have changed the setup to save some power draw and heat. Have a look at this link.
::::
::::http://www.nj7p.org/Tube4.php?tube=5z3
::::
::::Then look at a 5Z4. I think you should see what some other person was thinking. Should work too.
::::
:::
::
: