Hello forum. I found a non-working Crosley 11-106U that I have spent most of the weekend working on and I need a suggestion from someone to get me back on track. The radio is a fairly standard All American 5 design except the 12AV6 tube is replaced with a 12SQ7. The schematic is on page 21-22 in Riders.

I replaced the electroytics and tested the tubes and replaced every capacitor in the radio. I now get a slight hum. The B+ DC voltage is only 90 V coming out of the 35W4 about 20 V low. It really shows up on pin 6 of the 12sQ7 which should be 52V but is only about 25 V. All the tubes have tested fine, but I have went through individual substitution but there is no change. Any thoughts would be appreciated.

Brad.

:Hi Brad

I think your problem may be that a 12SQ7 is not a replacement for a 12AV6. To use a 12SQ7 you would need to make some changes to the wiring.

More suitable, direct replacements for a 12AV6 are; 12AT6, 12AT6A, 12BK6 & 12BT6.

Gary

:Hello forum. I found a non-working Crosley 11-106U that I have spent most of the weekend working on and I need a suggestion from someone to get me back on track. The radio is a fairly standard All American 5 design except the 12AV6 tube is replaced with a 12SQ7. The schematic is on page 21-22 in Riders.
:
:I replaced the electroytics and tested the tubes and replaced every capacitor in the radio. I now get a slight hum. The B+ DC voltage is only 90 V coming out of the 35W4 about 20 V low. It really shows up on pin 6 of the 12sQ7 which should be 52V but is only about 25 V. All the tubes have tested fine, but I have went through individual substitution but there is no change. Any thoughts would be appreciated.
:
:Brad.

In this case Gary, the 12SQ7 is factory installed in some sets. The problem first sounds like you need to check the power supply resistors. As I have seen, there's been an increase in resistance. Check those resistors Brad.

::Hi Brad
:
:I think your problem may be that a 12SQ7 is not a replacement for a 12AV6. To use a 12SQ7 you would need to make some changes to the wiring.
:
:More suitable, direct replacements for a 12AV6 are; 12AT6, 12AT6A, 12BK6 & 12BT6.
:
:Gary
:
::Hello forum. I found a non-working Crosley 11-106U that I have spent most of the weekend working on and I need a suggestion from someone to get me back on track. The radio is a fairly standard All American 5 design except the 12AV6 tube is replaced with a 12SQ7. The schematic is on page 21-22 in Riders.
::
::I replaced the electroytics and tested the tubes and replaced every capacitor in the radio. I now get a slight hum. The B+ DC voltage is only 90 V coming out of the 35W4 about 20 V low. It really shows up on pin 6 of the 12sQ7 which should be 52V but is only about 25 V. All the tubes have tested fine, but I have went through individual substitution but there is no change. Any thoughts would be appreciated.
::
::Brad.

Hi Brad:

I wans't aware of this fact. The schematic for this chassis (11-106U) shows the 12AV6.

I agree, resistors R12, R13 and R14 are suspect.

Gary

:In this case Gary, the 12SQ7 is factory installed in some sets. The problem first sounds like you need to check the power supply resistors. As I have seen, there's been an increase in resistance. Check those resistors Brad.
:
:
:
:
:::Hi Brad
::
::I think your problem may be that a 12SQ7 is not a replacement for a 12AV6. To use a 12SQ7 you would need to make some changes to the wiring.
::
::More suitable, direct replacements for a 12AV6 are; 12AT6, 12AT6A, 12BK6 & 12BT6.
::
::Gary
::
:::Hello forum. I found a non-working Crosley 11-106U that I have spent most of the weekend working on and I need a suggestion from someone to get me back on track. The radio is a fairly standard All American 5 design except the 12AV6 tube is replaced with a 12SQ7. The schematic is on page 21-22 in Riders.
:::
:::I replaced the electroytics and tested the tubes and replaced every capacitor in the radio. I now get a slight hum. The B+ DC voltage is only 90 V coming out of the 35W4 about 20 V low. It really shows up on pin 6 of the 12sQ7 which should be 52V but is only about 25 V. All the tubes have tested fine, but I have went through individual substitution but there is no change. Any thoughts would be appreciated.
:::
:::Brad.

Sorry, I meant Hi Bill:

I wans't aware of this fact. The schematic for this chassis (11-106U) shows the 12AV6.

I agree, resistors R12, R13 and R14 are suspect.

Gary

:In this case Gary, the 12SQ7 is factory installed in some sets. The problem first sounds like you need to check the power supply resistors. As I have seen, there's been an increase in resistance. Check those resistors Brad.
:
:
:
:
:::Hi Brad
::
::I think your problem may be that a 12SQ7 is not a replacement for a 12AV6. To use a 12SQ7 you would need to make some changes to the wiring.
::
::More suitable, direct replacements for a 12AV6 are; 12AT6, 12AT6A, 12BK6 & 12BT6.
::
::Gary
::
:::Hello forum. I found a non-working Crosley 11-106U that I have spent most of the weekend working on and I need a suggestion from someone to get me back on track. The radio is a fairly standard All American 5 design except the 12AV6 tube is replaced with a 12SQ7. The schematic is on page 21-22 in Riders.
:::
:::I replaced the electroytics and tested the tubes and replaced every capacitor in the radio. I now get a slight hum. The B+ DC voltage is only 90 V coming out of the 35W4 about 20 V low. It really shows up on pin 6 of the 12sQ7 which should be 52V but is only about 25 V. All the tubes have tested fine, but I have went through individual substitution but there is no change. Any thoughts would be appreciated.
:::
:::Brad.

Hi Gary,
The schematic on this site

http://www.nostalgiaair.org/PagesByModel/199/M0003199.pdf

shows wiring for those with 12SQ7. This time period, late 40's thru perhaps first couple years of the 50's was a transitional time...I think. I've seen different mixes. I recall (hopefully correct) working on some Fada radios without schematics from that time period. The same model I get as one before and things much different. I was confused until running down the schematic. I've seen other Crosley with the 12SQ7 and a few other brands with different mix of miniature and octal. However, some did not have two versions of same model either.

Model 11-106U is also in SAMS 155-5. I don't have that folder.

:Sorry, I meant Hi Bill:
:
:I wans't aware of this fact. The schematic for this chassis (11-106U) shows the 12AV6.
:
:I agree, resistors R12, R13 and R14 are suspect.
:
:Gary
:
:
:
:
::In this case Gary, the 12SQ7 is factory installed in some sets. The problem first sounds like you need to check the power supply resistors. As I have seen, there's been an increase in resistance. Check those resistors Brad.
::
::
::
::
::::Hi Brad
:::
:::I think your problem may be that a 12SQ7 is not a replacement for a 12AV6. To use a 12SQ7 you would need to make some changes to the wiring.
:::
:::More suitable, direct replacements for a 12AV6 are; 12AT6, 12AT6A, 12BK6 & 12BT6.
:::
:::Gary
:::
::::Hello forum. I found a non-working Crosley 11-106U that I have spent most of the weekend working on and I need a suggestion from someone to get me back on track. The radio is a fairly standard All American 5 design except the 12AV6 tube is replaced with a 12SQ7. The schematic is on page 21-22 in Riders.
::::
::::I replaced the electroytics and tested the tubes and replaced every capacitor in the radio. I now get a slight hum. The B+ DC voltage is only 90 V coming out of the 35W4 about 20 V low. It really shows up on pin 6 of the 12sQ7 which should be 52V but is only about 25 V. All the tubes have tested fine, but I have went through individual substitution but there is no change. Any thoughts would be appreciated.
::::
::::Brad.

Definitely check power supply resistors. Make sure that the rectifier is not weak. Make sure that you didn't put in the new electrolytics backwards by mistake or misconnect something. If the hum isn't almost completely gone, and yet your voltages are low, electrolytics are a suspect. Make sure that they are of proper working voltage.

The 12SQ7 makes a fine substitute for the 12AV6, and will work equally well. It is by no means a direct replacement, as it has an entirely different base and pin-out, but it is essentially very much similar in design to the 12AV6. If it was installed properly (especially since it was put in at the factory), it should be no concern of your's with regard to the power supply.

T.D.

:Definitely check power supply resistors. Make sure that the rectifier is not weak. Make sure that you didn't put in the new electrolytics backwards by mistake or misconnect something. If the hum isn't almost completely gone, and yet your voltages are low, electrolytics are a suspect. Make sure that they are of proper working voltage.
:
:The 12SQ7 makes a fine substitute for the 12AV6, and will work equally well. It is by no means a direct replacement, as it has an entirely different base and pin-out, but it is essentially very much similar in design to the 12AV6. If it was installed properly (especially since it was put in at the factory), it should be no concern of your's with regard to the power supply.
:
:T.D.

Thanks for all of the help and suggestions. I've been busy at work and haven't had a chance to follow up with the radio. I will check the power resisters again, but I suspect I have wired the electroytics wrong based on Thomas's comments. I will recheck. Thanks.

BB

Keep in mind that if you *suspect* that you put the electrolytics in backwards, you shouldn't just turn them around and see what happens. If they are in backwards, they can just make the set perform poorly or they can cause a lot of damage to the radio and to themselves (and to you if one goes off like a fire cracker). Check thoroughly before reconnecting.

Thomas

Long time ago, when I was a young gay, I worked for Crosley and we use 12SQ7. If you hace this bulb in your radio is Correct, you do not need replace.

I found a non-working Crosley 11-106U that I have spent most of the weekend working on and I need a suggestion from someone to get me back on track. The radio is a fairly standard All American 5 design except the 12AV6 tube is replaced with a 12SQ7. The schematic is on page 21-22 in Riders.
:
:I replaced the electroytics and tested the tubes and replaced every capacitor in the radio. I now get a slight hum. The B+ DC voltage is only 90 V coming out of the 35W4 about 20 V low. It really shows up on pin 6 of the 12sQ7 which should be 52V but is only about 25 V. All the tubes have tested fine, but I have went through individual substitution but there is no change. Any thoughts would be appreciated.
:
:Brad.

Other than the physical size of the tube, and the pin arrangement, the characteristics are essentially the same so the components involved in that stage should be the same for the 12AV6 as is used for the the 12SQ7. The pinouts for the two tubes are avilable in the link at the top of this page to "Tubes".

Radios exported from the US often had a minor difference like that one tube just to distinguish them from domestic production.

:Long time ago, when I was a young gay, I worked for Crosley and we use 12SQ7. If you hace this bulb in your radio is Correct, you do not need replace.
:
:
:I found a non-working Crosley 11-106U that I have spent most of the weekend working on and I need a suggestion from someone to get me back on track. The radio is a fairly standard All American 5 design except the 12AV6 tube is replaced with a 12SQ7. The schematic is on page 21-22 in Riders.
::
::I replaced the electroytics and tested the tubes and replaced every capacitor in the radio. I now get a slight hum. The B+ DC voltage is only 90 V coming out of the 35W4 about 20 V low. It really shows up on pin 6 of the 12sQ7 which should be 52V but is only about 25 V. All the tubes have tested fine, but I have went through individual substitution but there is no change. Any thoughts would be appreciated.
::
::Brad.