Thanks, John
Are you sure the wire insulation is plastic, and not rubber? Rubber insulated wire was used at that time, and may have been a repair true to the period- if not factory. Rubber of that vintage- if not stored correctly- will also be very brittle. It will not be shiny like PVC, but will be a dull sheen at best.
Early Brunswicks used Radiola Chassis, and the 18 chassis was used in a number of Brunswick models.
:Hello, a fellow at work brought in a beautiful Brunswick model 3KR0 "Panatrope with Radiola" (radio/phono combo) he bought at a yard sale cheap. After it sat in our maintenance shop a few days he finally asked me if I could look it over and try to make it work. After some online investigation, I found the chassis is actually an RCA Radiola 18 that was supplied to Brunswick (not 100% sure, the RCA label inside the cabinet is tore off at the very top). The chassis appears to be exactly the same as the Radiola 18 pictures I've seen on the web. My question is this-- There is an antenna terminal board mounted at the right rear of the chassis. On it there is a spring loaded terminal marked "A", for antenna I suppose, right below it there is an adjustment knob mounted to some sort of capacitor with round plates that sandwich in and out as the knob is turned. The cap is in series with the antenna lead and is connected to the left two big round chokes on the chassis underside as viewed from the rear. This doesn't appear on any schematics I have for the Brunswick or for the Radiola 18. The schematics have the antenna going straight to the volume knob. Is this cap arrangement original or was it added on? The leads are plastic covered so I'm suspicious. Would it behoove me to remove it and rewire as to original if it is an add-on?
:
:Thanks, John
John
:Hi,
:Sounds like you may be describing a "Wave Trap".
:
:Are you sure the wire insulation is plastic, and not rubber? Rubber insulated wire was used at that time, and may have been a repair true to the period- if not factory. Rubber of that vintage- if not stored correctly- will also be very brittle. It will not be shiny like PVC, but will be a dull sheen at best.
:
:Early Brunswicks used Radiola Chassis, and the 18 chassis was used in a number of Brunswick models.
:
:
:
::Hello, a fellow at work brought in a beautiful Brunswick model 3KR0 "Panatrope with Radiola" (radio/phono combo) he bought at a yard sale cheap. After it sat in our maintenance shop a few days he finally asked me if I could look it over and try to make it work. After some online investigation, I found the chassis is actually an RCA Radiola 18 that was supplied to Brunswick (not 100% sure, the RCA label inside the cabinet is tore off at the very top). The chassis appears to be exactly the same as the Radiola 18 pictures I've seen on the web. My question is this-- There is an antenna terminal board mounted at the right rear of the chassis. On it there is a spring loaded terminal marked "A", for antenna I suppose, right below it there is an adjustment knob mounted to some sort of capacitor with round plates that sandwich in and out as the knob is turned. The cap is in series with the antenna lead and is connected to the left two big round chokes on the chassis underside as viewed from the rear. This doesn't appear on any schematics I have for the Brunswick or for the Radiola 18. The schematics have the antenna going straight to the volume knob. Is this cap arrangement original or was it added on? The leads are plastic covered so I'm suspicious. Would it behoove me to remove it and rewire as to original if it is an add-on?
::
::Thanks, John
Sooo, you caould leave it in place, if the cap looks old enough to pass, and then wire that up as a wave trap, or remove it entirely and either way you go on that choice, address the original problem that supposed "fix" was to remedy.
:Thanks for the reply,
:The wires are older but not brittle, somewhat shiny and flimsy. However, they have had some work done with them. Yellow wire is spliced directly into the original black fabric covered wire (can't tell what color tracer), which goes into the transformer between the first and second RF stages. Red wire is tied into the bare wires between the second stage tube and the transformer in between that and the next stage. Doesn't look original. Maybe this provided some extra selectivity.
:
:John
:
:
::Hi,
::Sounds like you may be describing a "Wave Trap".
::
::Are you sure the wire insulation is plastic, and not rubber? Rubber insulated wire was used at that time, and may have been a repair true to the period- if not factory. Rubber of that vintage- if not stored correctly- will also be very brittle. It will not be shiny like PVC, but will be a dull sheen at best.
::
::Early Brunswicks used Radiola Chassis, and the 18 chassis was used in a number of Brunswick models.
::
::
::
:::Hello, a fellow at work brought in a beautiful Brunswick model 3KR0 "Panatrope with Radiola" (radio/phono combo) he bought at a yard sale cheap. After it sat in our maintenance shop a few days he finally asked me if I could look it over and try to make it work. After some online investigation, I found the chassis is actually an RCA Radiola 18 that was supplied to Brunswick (not 100% sure, the RCA label inside the cabinet is tore off at the very top). The chassis appears to be exactly the same as the Radiola 18 pictures I've seen on the web. My question is this-- There is an antenna terminal board mounted at the right rear of the chassis. On it there is a spring loaded terminal marked "A", for antenna I suppose, right below it there is an adjustment knob mounted to some sort of capacitor with round plates that sandwich in and out as the knob is turned. The cap is in series with the antenna lead and is connected to the left two big round chokes on the chassis underside as viewed from the rear. This doesn't appear on any schematics I have for the Brunswick or for the Radiola 18. The schematics have the antenna going straight to the volume knob. Is this cap arrangement original or was it added on? The leads are plastic covered so I'm suspicious. Would it behoove me to remove it and rewire as to original if it is an add-on?
:::
:::Thanks, John
:Hi,
:I would check to make sure there were no open windings in the two transformers "bypassed". I think they were trying to make a sort of "wave trap", but didn't do a good job of it. Either that, or they were trying to set up a trimmer of a sort, to get better tuning (no one told them they could bend the blades on the tuning condensor to achieve that), or as you suggest- better selectivity, but changing the value of the grid leak resistor to a higher value will do that.
:
:Sooo, you caould leave it in place, if the cap looks old enough to pass, and then wire that up as a wave trap, or remove it entirely and either way you go on that choice, address the original problem that supposed "fix" was to remedy.
:
::Thanks for the reply,
::The wires are older but not brittle, somewhat shiny and flimsy. However, they have had some work done with them. Yellow wire is spliced directly into the original black fabric covered wire (can't tell what color tracer), which goes into the transformer between the first and second RF stages. Red wire is tied into the bare wires between the second stage tube and the transformer in between that and the next stage. Doesn't look original. Maybe this provided some extra selectivity.
::
::John
::
::
:::Hi,
:::Sounds like you may be describing a "Wave Trap".
:::
:::Are you sure the wire insulation is plastic, and not rubber? Rubber insulated wire was used at that time, and may have been a repair true to the period- if not factory. Rubber of that vintage- if not stored correctly- will also be very brittle. It will not be shiny like PVC, but will be a dull sheen at best.
:::
:::Early Brunswicks used Radiola Chassis, and the 18 chassis was used in a number of Brunswick models.
:::
:::
:::
::::Hello, a fellow at work brought in a beautiful Brunswick model 3KR0 "Panatrope with Radiola" (radio/phono combo) he bought at a yard sale cheap. After it sat in our maintenance shop a few days he finally asked me if I could look it over and try to make it work. After some online investigation, I found the chassis is actually an RCA Radiola 18 that was supplied to Brunswick (not 100% sure, the RCA label inside the cabinet is tore off at the very top). The chassis appears to be exactly the same as the Radiola 18 pictures I've seen on the web. My question is this-- There is an antenna terminal board mounted at the right rear of the chassis. On it there is a spring loaded terminal marked "A", for antenna I suppose, right below it there is an adjustment knob mounted to some sort of capacitor with round plates that sandwich in and out as the knob is turned. The cap is in series with the antenna lead and is connected to the left two big round chokes on the chassis underside as viewed from the rear. This doesn't appear on any schematics I have for the Brunswick or for the Radiola 18. The schematics have the antenna going straight to the volume knob. Is this cap arrangement original or was it added on? The leads are plastic covered so I'm suspicious. Would it behoove me to remove it and rewire as to original if it is an add-on?
::::
::::Thanks, John
:After scratching my head alot, doing continuity checks and looking at the schematic, this device appears to be the "regeneration capacitor". I'm not very knowlegeable of TRF radios but if I remember correctly this is a feature unique to them. Whatever original unit that was in the chassis must have failed and was replaced with this trimmer-looking thing on the back. I guess the antenna connection that came with this add-on was not to be used as such.
:Another goofy thing... The schematic shows the wiper arm of the reostat going straight into the cathode of the first RF tube. However on this radio the wiper is attached to a loose lead that I guess was for the antenna. The resistor leads on it are attached to ground (correct) and the cathode (incorrect). The rheostat looks just like the original unit I've seen in pictures, however it only measures to be exactly 70 ohms, and is continuosly and smoothly variable at the wiper down to 0. The schematic and the write-ups I've seen call for a 2k ohm rheostat. I don't see this resistor as being partially shorted, but maybe I'll try a standard 2k ohm pot wired correctly and see what happens.
:
:
::Hi,
::I would check to make sure there were no open windings in the two transformers "bypassed". I think they were trying to make a sort of "wave trap", but didn't do a good job of it. Either that, or they were trying to set up a trimmer of a sort, to get better tuning (no one told them they could bend the blades on the tuning condensor to achieve that), or as you suggest- better selectivity, but changing the value of the grid leak resistor to a higher value will do that.
::
::Sooo, you caould leave it in place, if the cap looks old enough to pass, and then wire that up as a wave trap, or remove it entirely and either way you go on that choice, address the original problem that supposed "fix" was to remedy.
::
:::Thanks for the reply,
:::The wires are older but not brittle, somewhat shiny and flimsy. However, they have had some work done with them. Yellow wire is spliced directly into the original black fabric covered wire (can't tell what color tracer), which goes into the transformer between the first and second RF stages. Red wire is tied into the bare wires between the second stage tube and the transformer in between that and the next stage. Doesn't look original. Maybe this provided some extra selectivity.
:::
:::John
:::
:::
::::Hi,
::::Sounds like you may be describing a "Wave Trap".
::::
::::Are you sure the wire insulation is plastic, and not rubber? Rubber insulated wire was used at that time, and may have been a repair true to the period- if not factory. Rubber of that vintage- if not stored correctly- will also be very brittle. It will not be shiny like PVC, but will be a dull sheen at best.
::::
::::Early Brunswicks used Radiola Chassis, and the 18 chassis was used in a number of Brunswick models.
::::
::::
::::
:::::Hello, a fellow at work brought in a beautiful Brunswick model 3KR0 "Panatrope with Radiola" (radio/phono combo) he bought at a yard sale cheap. After it sat in our maintenance shop a few days he finally asked me if I could look it over and try to make it work. After some online investigation, I found the chassis is actually an RCA Radiola 18 that was supplied to Brunswick (not 100% sure, the RCA label inside the cabinet is tore off at the very top). The chassis appears to be exactly the same as the Radiola 18 pictures I've seen on the web. My question is this-- There is an antenna terminal board mounted at the right rear of the chassis. On it there is a spring loaded terminal marked "A", for antenna I suppose, right below it there is an adjustment knob mounted to some sort of capacitor with round plates that sandwich in and out as the knob is turned. The cap is in series with the antenna lead and is connected to the left two big round chokes on the chassis underside as viewed from the rear. This doesn't appear on any schematics I have for the Brunswick or for the Radiola 18. The schematics have the antenna going straight to the volume knob. Is this cap arrangement original or was it added on? The leads are plastic covered so I'm suspicious. Would it behoove me to remove it and rewire as to original if it is an add-on?
:::::
:::::Thanks, John
It has a 0-10 mmfd variable capacitor used as a volume control.
Ed.
:I figured out what the deal is with the volume control. Someone had the bright idea to relocate the record player's volume control to the radio when the one on the radio broke. They straight-wired the phono and covered the empty hole by the turntable with the metal Panotone model number decal. They did manage to make it inconspicous. So I'm going to try to get it back halfway original and buy a pot to put on the radio. Thanks for the help and ideas.
:
:
::After scratching my head alot, doing continuity checks and looking at the schematic, this device appears to be the "regeneration capacitor". I'm not very knowlegeable of TRF radios but if I remember correctly this is a feature unique to them. Whatever original unit that was in the chassis must have failed and was replaced with this trimmer-looking thing on the back. I guess the antenna connection that came with this add-on was not to be used as such.
::Another goofy thing... The schematic shows the wiper arm of the reostat going straight into the cathode of the first RF tube. However on this radio the wiper is attached to a loose lead that I guess was for the antenna. The resistor leads on it are attached to ground (correct) and the cathode (incorrect). The rheostat looks just like the original unit I've seen in pictures, however it only measures to be exactly 70 ohms, and is continuosly and smoothly variable at the wiper down to 0. The schematic and the write-ups I've seen call for a 2k ohm rheostat. I don't see this resistor as being partially shorted, but maybe I'll try a standard 2k ohm pot wired correctly and see what happens.
::
::
:::Hi,
:::I would check to make sure there were no open windings in the two transformers "bypassed". I think they were trying to make a sort of "wave trap", but didn't do a good job of it. Either that, or they were trying to set up a trimmer of a sort, to get better tuning (no one told them they could bend the blades on the tuning condensor to achieve that), or as you suggest- better selectivity, but changing the value of the grid leak resistor to a higher value will do that.
:::
:::Sooo, you caould leave it in place, if the cap looks old enough to pass, and then wire that up as a wave trap, or remove it entirely and either way you go on that choice, address the original problem that supposed "fix" was to remedy.
:::
::::Thanks for the reply,
::::The wires are older but not brittle, somewhat shiny and flimsy. However, they have had some work done with them. Yellow wire is spliced directly into the original black fabric covered wire (can't tell what color tracer), which goes into the transformer between the first and second RF stages. Red wire is tied into the bare wires between the second stage tube and the transformer in between that and the next stage. Doesn't look original. Maybe this provided some extra selectivity.
::::
::::John
::::
::::
:::::Hi,
:::::Sounds like you may be describing a "Wave Trap".
:::::
:::::Are you sure the wire insulation is plastic, and not rubber? Rubber insulated wire was used at that time, and may have been a repair true to the period- if not factory. Rubber of that vintage- if not stored correctly- will also be very brittle. It will not be shiny like PVC, but will be a dull sheen at best.
:::::
:::::Early Brunswicks used Radiola Chassis, and the 18 chassis was used in a number of Brunswick models.
:::::
:::::
:::::
::::::Hello, a fellow at work brought in a beautiful Brunswick model 3KR0 "Panatrope with Radiola" (radio/phono combo) he bought at a yard sale cheap. After it sat in our maintenance shop a few days he finally asked me if I could look it over and try to make it work. After some online investigation, I found the chassis is actually an RCA Radiola 18 that was supplied to Brunswick (not 100% sure, the RCA label inside the cabinet is tore off at the very top). The chassis appears to be exactly the same as the Radiola 18 pictures I've seen on the web. My question is this-- There is an antenna terminal board mounted at the right rear of the chassis. On it there is a spring loaded terminal marked "A", for antenna I suppose, right below it there is an adjustment knob mounted to some sort of capacitor with round plates that sandwich in and out as the knob is turned. The cap is in series with the antenna lead and is connected to the left two big round chokes on the chassis underside as viewed from the rear. This doesn't appear on any schematics I have for the Brunswick or for the Radiola 18. The schematics have the antenna going straight to the volume knob. Is this cap arrangement original or was it added on? The leads are plastic covered so I'm suspicious. Would it behoove me to remove it and rewire as to original if it is an add-on?
::::::
::::::Thanks, John
:I do not know what model of Brunswick you have but I am looking at a schematic for a model 15-22, 1930-31.
:
:It has a 0-10 mmfd variable capacitor used as a volume control.
:
:Ed.
:
::I figured out what the deal is with the volume control. Someone had the bright idea to relocate the record player's volume control to the radio when the one on the radio broke. They straight-wired the phono and covered the empty hole by the turntable with the metal Panotone model number decal. They did manage to make it inconspicous. So I'm going to try to get it back halfway original and buy a pot to put on the radio. Thanks for the help and ideas.
::
::
:::After scratching my head alot, doing continuity checks and looking at the schematic, this device appears to be the "regeneration capacitor". I'm not very knowlegeable of TRF radios but if I remember correctly this is a feature unique to them. Whatever original unit that was in the chassis must have failed and was replaced with this trimmer-looking thing on the back. I guess the antenna connection that came with this add-on was not to be used as such.
:::Another goofy thing... The schematic shows the wiper arm of the reostat going straight into the cathode of the first RF tube. However on this radio the wiper is attached to a loose lead that I guess was for the antenna. The resistor leads on it are attached to ground (correct) and the cathode (incorrect). The rheostat looks just like the original unit I've seen in pictures, however it only measures to be exactly 70 ohms, and is continuosly and smoothly variable at the wiper down to 0. The schematic and the write-ups I've seen call for a 2k ohm rheostat. I don't see this resistor as being partially shorted, but maybe I'll try a standard 2k ohm pot wired correctly and see what happens.
:::
:::
::::Hi,
::::I would check to make sure there were no open windings in the two transformers "bypassed". I think they were trying to make a sort of "wave trap", but didn't do a good job of it. Either that, or they were trying to set up a trimmer of a sort, to get better tuning (no one told them they could bend the blades on the tuning condensor to achieve that), or as you suggest- better selectivity, but changing the value of the grid leak resistor to a higher value will do that.
::::
::::Sooo, you caould leave it in place, if the cap looks old enough to pass, and then wire that up as a wave trap, or remove it entirely and either way you go on that choice, address the original problem that supposed "fix" was to remedy.
::::
:::::Thanks for the reply,
:::::The wires are older but not brittle, somewhat shiny and flimsy. However, they have had some work done with them. Yellow wire is spliced directly into the original black fabric covered wire (can't tell what color tracer), which goes into the transformer between the first and second RF stages. Red wire is tied into the bare wires between the second stage tube and the transformer in between that and the next stage. Doesn't look original. Maybe this provided some extra selectivity.
:::::
:::::John
:::::
:::::
::::::Hi,
::::::Sounds like you may be describing a "Wave Trap".
::::::
::::::Are you sure the wire insulation is plastic, and not rubber? Rubber insulated wire was used at that time, and may have been a repair true to the period- if not factory. Rubber of that vintage- if not stored correctly- will also be very brittle. It will not be shiny like PVC, but will be a dull sheen at best.
::::::
::::::Early Brunswicks used Radiola Chassis, and the 18 chassis was used in a number of Brunswick models.
::::::
::::::
::::::
:::::::Hello, a fellow at work brought in a beautiful Brunswick model 3KR0 "Panatrope with Radiola" (radio/phono combo) he bought at a yard sale cheap. After it sat in our maintenance shop a few days he finally asked me if I could look it over and try to make it work. After some online investigation, I found the chassis is actually an RCA Radiola 18 that was supplied to Brunswick (not 100% sure, the RCA label inside the cabinet is tore off at the very top). The chassis appears to be exactly the same as the Radiola 18 pictures I've seen on the web. My question is this-- There is an antenna terminal board mounted at the right rear of the chassis. On it there is a spring loaded terminal marked "A", for antenna I suppose, right below it there is an adjustment knob mounted to some sort of capacitor with round plates that sandwich in and out as the knob is turned. The cap is in series with the antenna lead and is connected to the left two big round chokes on the chassis underside as viewed from the rear. This doesn't appear on any schematics I have for the Brunswick or for the Radiola 18. The schematics have the antenna going straight to the volume knob. Is this cap arrangement original or was it added on? The leads are plastic covered so I'm suspicious. Would it behoove me to remove it and rewire as to original if it is an add-on?
:::::::
:::::::Thanks, John