There's an AM oldies station I like to tune in to when I'm working in my shop. Unfortunately, there's also a mountain between me and the station. The only radios in my stable that can pull it in are the 6 tube Stromberg Carlsons and the Stromberg Carlson 1500, which has 5 tubes and a selenium (now a silicon) diode.
I want my Crosley E-15 5 tuber to be stronger on reception so I can play it more. Tell me quick if this is a waste of time.
If I replace the 35W4 rectifier with a SS diode, I can use the socket for a 12BA7. I would add a dropping resistor to the filament string. I can copy the Stromberg C 1500 schematic for my first RF amp stage.
Could I use capacitor coupling for this stage? The SC's have an extra IF trans, I believe.
Will that first stage be too close to the 50C5? Those sockets are about an inch apart on the Crosley chassis, but a shield could be added. Has anyone tried this? Of course they have, but did it work out?

Did you forget about a 3 section tuner and an RF coil ?
If you really want to hod rod an AA5 check this out and have fun.

http://www.wa2ise.com/radios/12ba7.html

Or perhaps use R/C coupling between the plate of the RF tube and the mixer tube input grid. Say maybe a 4.7k or so plate resistor for the RF tube and a 100K resistor between the mixer tube grid and AVC or ground with perhaps a 250pf coupling cap. Let the RF section of the tuning cap tune the RF tube control grid and loop/Ant transformer.

Clifton

:Did you forget about a 3 section tuner and an RF coil ?
:If you really want to hod rod an AA5 check this out and have fun.
:
:http://www.wa2ise.com/radios/12ba7.html
:
:
:

Thanks Warren, I saw that site and will copy a few ideas. There's no need to invent anything anymore, just find it with Google.

Clifton, have you actually done what you suggest, or is this something that theoretically might work? I don't want to build an uncontrollable Frankenstein, although that could be fun, too.

:Or perhaps use R/C coupling between the plate of the RF tube and the mixer tube input grid. Say maybe a 4.7k or so plate resistor for the RF tube and a 100K resistor between the mixer tube grid and AVC or ground with perhaps a 250pf coupling cap. Let the RF section of the tuning cap tune the RF tube control grid and loop/Ant transformer.
:
:Clifton
:
:
::Did you forget about a 3 section tuner and an RF coil ?
::If you really want to hod rod an AA5 check this out and have fun.
::
::http://www.wa2ise.com/radios/12ba7.html
::
::
::
:
:

John,

Years ago took a radio course and one of the projects was building an AM radio. It used a 6BA6 mini tube as an RF amplifier and used R/C coupling between the RF amp and mixer tube. I don't know if I still have the schematic, but I do the radio and probably could trace out the circuit for you. The radio also used a mini adjustable loopstick antenna. I later replaced the loopstick with a regular loop antenna unit.

Clifton

:Thanks Warren, I saw that site and will copy a few ideas. There's no need to invent anything anymore, just find it with Google.
:
:Clifton, have you actually done what you suggest, or is this something that theoretically might work? I don't want to build an uncontrollable Frankenstein, although that could be fun, too.
:
:
::Or perhaps use R/C coupling between the plate of the RF tube and the mixer tube input grid. Say maybe a 4.7k or so plate resistor for the RF tube and a 100K resistor between the mixer tube grid and AVC or ground with perhaps a 250pf coupling cap. Let the RF section of the tuning cap tune the RF tube control grid and loop/Ant transformer.
::
::Clifton
::
::
:::Did you forget about a 3 section tuner and an RF coil ?
:::If you really want to hod rod an AA5 check this out and have fun.
:::
:::http://www.wa2ise.com/radios/12ba7.html
:::
:::
:::
::
::
:
:

I think I shall leave the rectifier as is for now and just add a 7-pin socket on a little temporary stand on top of the chassis, near the 12BE6. Then swap that with a 6BE6, with a 6BA6 for my RF amp. Thanks for the suggested R values.

:John,
:
:Years ago took a radio course and one of the projects was building an AM radio. It used a 6BA6 mini tube as an RF amplifier and used R/C coupling between the RF amp and mixer tube. I don't know if I still have the schematic, but I do the radio and probably could trace out the circuit for you. The radio also used a mini adjustable loopstick antenna. I later replaced the loopstick with a regular loop antenna unit.
:
:Clifton
:
:
::Thanks Warren, I saw that site and will copy a few ideas. There's no need to invent anything anymore, just find it with Google.
::
::Clifton, have you actually done what you suggest, or is this something that theoretically might work? I don't want to build an uncontrollable Frankenstein, although that could be fun, too.
::
::
:::Or perhaps use R/C coupling between the plate of the RF tube and the mixer tube input grid. Say maybe a 4.7k or so plate resistor for the RF tube and a 100K resistor between the mixer tube grid and AVC or ground with perhaps a 250pf coupling cap. Let the RF section of the tuning cap tune the RF tube control grid and loop/Ant transformer.
:::
:::Clifton
:::
:::
::::Did you forget about a 3 section tuner and an RF coil ?
::::If you really want to hod rod an AA5 check this out and have fun.
::::
::::http://www.wa2ise.com/radios/12ba7.html
::::
::::
::::
:::
:::
::
::
:
:

John,

I don't think a 6BA6 which is a 300 ma tube would light in a 150 ma series tube string. You might try a 12BA6 and maybe a 35 (35C5 ??) volt audio output tube or maybe a 6BJ6 tube.

Clifton

:I think I shall leave the rectifier as is for now and just add a 7-pin socket on a little temporary stand on top of the chassis, near the 12BE6. Then swap that with a 6BE6, with a 6BA6 for my RF amp. Thanks for the suggested R values.
:
:
::John,
::
::Years ago took a radio course and one of the projects was building an AM radio. It used a 6BA6 mini tube as an RF amplifier and used R/C coupling between the RF amp and mixer tube. I don't know if I still have the schematic, but I do the radio and probably could trace out the circuit for you. The radio also used a mini adjustable loopstick antenna. I later replaced the loopstick with a regular loop antenna unit.
::
::Clifton
::
::
:::Thanks Warren, I saw that site and will copy a few ideas. There's no need to invent anything anymore, just find it with Google.
:::
:::Clifton, have you actually done what you suggest, or is this something that theoretically might work? I don't want to build an uncontrollable Frankenstein, although that could be fun, too.
:::
:::
::::Or perhaps use R/C coupling between the plate of the RF tube and the mixer tube input grid. Say maybe a 4.7k or so plate resistor for the RF tube and a 100K resistor between the mixer tube grid and AVC or ground with perhaps a 250pf coupling cap. Let the RF section of the tuning cap tune the RF tube control grid and loop/Ant transformer.
::::
::::Clifton
::::
::::
:::::Did you forget about a 3 section tuner and an RF coil ?
:::::If you really want to hod rod an AA5 check this out and have fun.
:::::
:::::http://www.wa2ise.com/radios/12ba7.html
:::::
:::::
:::::
::::
::::
:::
:::
::
::
:
:

Hey Clifton, thanks for that. You are right, that tube won't work. I was searching for my tube manual, as I was wondering about that very same thing. I did find a reference on the net to a 6BA6 RF amp added to a Hallicrafters ham radio, so I know the principal has merit.
I have a couple of 35C5's, so can try going that route with a 12BA6 in the front end.
First step is to adapt a 7-pin socket to the chassis without drilling any new holes. There's room for it hanging off the back, and that will keep the leads short.

:John,
:
:I don't think a 6BA6 which is a 300 ma tube would light in a 150 ma series tube string. You might try a 12BA6 and maybe a 35 (35C5 ??) volt audio output tube or maybe a 6BJ6 tube.
:
:Clifton
:
:
::I think I shall leave the rectifier as is for now and just add a 7-pin socket on a little temporary stand on top of the chassis, near the 12BE6. Then swap that with a 6BE6, with a 6BA6 for my RF amp. Thanks for the suggested R values.
::
::
:::John,
:::
:::Years ago took a radio course and one of the projects was building an AM radio. It used a 6BA6 mini tube as an RF amplifier and used R/C coupling between the RF amp and mixer tube. I don't know if I still have the schematic, but I do the radio and probably could trace out the circuit for you. The radio also used a mini adjustable loopstick antenna. I later replaced the loopstick with a regular loop antenna unit.
:::
:::Clifton
:::
:::
::::Thanks Warren, I saw that site and will copy a few ideas. There's no need to invent anything anymore, just find it with Google.
::::
::::Clifton, have you actually done what you suggest, or is this something that theoretically might work? I don't want to build an uncontrollable Frankenstein, although that could be fun, too.
::::
::::
:::::Or perhaps use R/C coupling between the plate of the RF tube and the mixer tube input grid. Say maybe a 4.7k or so plate resistor for the RF tube and a 100K resistor between the mixer tube grid and AVC or ground with perhaps a 250pf coupling cap. Let the RF section of the tuning cap tune the RF tube control grid and loop/Ant transformer.
:::::
:::::Clifton
:::::
:::::
::::::Did you forget about a 3 section tuner and an RF coil ?
::::::If you really want to hod rod an AA5 check this out and have fun.
::::::
::::::http://www.wa2ise.com/radios/12ba7.html
::::::
::::::
::::::
:::::
:::::
::::
::::
:::
:::
::
::
:
: