When i power up I only get a hum from the speaker. I know the osc is working because I can wipe out my reference radio with the whistle. I went through all of the voltages and found some interesting numbers, and one voltage completely missing. Here is my findings (only listing the ones that are off, the voltages are in the schem)
35Z5GT - Pin 8 should be 128 i get 104
50L6GT - Pin 7 should be 86 i get 42, pin 6 should be 114 i get 95, pin 4 should be 87, i get 75, pin 3 should be 108, i get 90 and pin 2 should be 36, i get 18.
12SQ7 - pin 6 should be 64, i get 52
12SK7 - pin 8 should be 87, i get 75
12SA7 - (the trouble one) pin 3 should be 87, i get 0 (zero), pin 4 should be 87, i get 74 and pin 5 should be -3.5, i get -.3
As always, any help is appreciated and I hope i can pay it back as I build my knowledge.
::Well another one of my brother in laws flea market finds has made it's way to my bench. This is a Hallicrafters 5R10 (schem link: http://www.nostalgiaair.org/Resources/818/M0008818.htm) and I can't get it going. It was DOA on arrival. I did a full recapping of it, tested all the tubes etc.
::
::When i power up I only get a hum from the speaker. I know the osc is working because I can wipe out my reference radio with the whistle. I went through all of the voltages and found some interesting numbers, and one voltage completely missing. Here is my findings (only listing the ones that are off, the voltages are in the schem)
::
::35Z5GT - Pin 8 should be 128 i get 104
::
::50L6GT - Pin 7 should be 86 i get 42, pin 6 should be 114 i get 95, pin 4 should be 87, i get 75, pin 3 should be 108, i get 90 and pin 2 should be 36, i get 18.
::
::12SQ7 - pin 6 should be 64, i get 52
::
::12SK7 - pin 8 should be 87, i get 75
::
::12SA7 - (the trouble one) pin 3 should be 87, i get 0 (zero), pin 4 should be 87, i get 74 and pin 5 should be -3.5, i get -.3
::
::As always, any help is appreciated and I hope i can pay it back as I build my knowledge.
:Hi
: I'd check for a good ground on Pin 1 of the 12SA7 or and open winding in T4, to start with, and go from there.
:Mark
:
::
::Thanks for the response Mark. I will check this. Are there any other thoughts as to what could be happening???
::
::::Well another one of my brother in laws flea market finds has made it's way to my bench. This is a Hallicrafters 5R10 (schem link: http://www.nostalgiaair.org/Resources/818/M0008818.htm) and I can't get it going. It was DOA on arrival. I did a full recapping of it, tested all the tubes etc.
::::
::::When i power up I only get a hum from the speaker. I know the osc is working because I can wipe out my reference radio with the whistle. I went through all of the voltages and found some interesting numbers, and one voltage completely missing. Here is my findings (only listing the ones that are off, the voltages are in the schem)
::::
::::35Z5GT - Pin 8 should be 128 i get 104
::::
::::50L6GT - Pin 7 should be 86 i get 42, pin 6 should be 114 i get 95, pin 4 should be 87, i get 75, pin 3 should be 108, i get 90 and pin 2 should be 36, i get 18.
::::
::::12SQ7 - pin 6 should be 64, i get 52
::::
::::12SK7 - pin 8 should be 87, i get 75
::::
::::12SA7 - (the trouble one) pin 3 should be 87, i get 0 (zero), pin 4 should be 87, i get 74 and pin 5 should be -3.5, i get -.3
::::
::::As always, any help is appreciated and I hope i can pay it back as I build my knowledge.
:::Hi
::: I'd check for a good ground on Pin 1 of the 12SA7 or and open winding in T4, to start with, and go from there.
:::Mark
:Hi
: One other thought, go through and check all connections on the tube socket pins, a loose or intermittant connection on a tube socket pin can cause this too.
:Mark
:
:::
::Well another one of my brother in laws flea market finds has made it's way to my bench. This is a Hallicrafters 5R10 (schem link: http://www.nostalgiaair.org/Resources/818/M0008818.htm) and I can't get it going. It was DOA on arrival. I did a full recapping of it, tested all the tubes etc.
::
::When i power up I only get a hum from the speaker. I know the osc is working because I can wipe out my reference radio with the whistle. I went through all of the voltages and found some interesting numbers, and one voltage completely missing. Here is my findings (only listing the ones that are off, the voltages are in the schem)
::
::35Z5GT - Pin 8 should be 128 i get 104
::
::50L6GT - Pin 7 should be 86 i get 42, pin 6 should be 114 i get 95, pin 4 should be 87, i get 75, pin 3 should be 108, i get 90 and pin 2 should be 36, i get 18.
::
::12SQ7 - pin 6 should be 64, i get 52
::
::12SK7 - pin 8 should be 87, i get 75
::
::12SA7 - (the trouble one) pin 3 should be 87, i get 0 (zero), pin 4 should be 87, i get 74 and pin 5 should be -3.5, i get -.3
::
::As always, any help is appreciated and I hope i can pay it back as I build my knowledge.
:Hi
: I'd check for a good ground on Pin 1 of the 12SA7 or and open winding in T4, to start with, and go from there.
:Mark
:
I was a bonehead and connected the red wire going in to the IF to the wrong tab on the terminal strip when i replaced the .05 cap. Good thing i didn't blow anything up !!
:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
:All info didn't get in....On that missing voltage to the mixer plate check on the B+ side of the T4 transformer and track back to where it gets its B+ connection, since your 'IF' is sourced from the same B= supply point. Any change that wire was misguided during a recap pull off.
:73's de Edd
:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
:
:::Well another one of my brother in laws flea market finds has made it's way to my bench. This is a Hallicrafters 5R10 (schem link: http://www.nostalgiaair.org/Resources/818/M0008818.htm) and I can't get it going. It was DOA on arrival. I did a full recapping of it, tested all the tubes etc.
:::
:::When i power up I only get a hum from the speaker. I know the osc is working because I can wipe out my reference radio with the whistle. I went through all of the voltages and found some interesting numbers, and one voltage completely missing. Here is my findings (only listing the ones that are off, the voltages are in the schem)
:::
:::35Z5GT - Pin 8 should be 128 i get 104
:::
:::50L6GT - Pin 7 should be 86 i get 42, pin 6 should be 114 i get 95, pin 4 should be 87, i get 75, pin 3 should be 108, i get 90 and pin 2 should be 36, i get 18.
:::
:::12SQ7 - pin 6 should be 64, i get 52
:::
:::12SK7 - pin 8 should be 87, i get 75
:::
:::12SA7 - (the trouble one) pin 3 should be 87, i get 0 (zero), pin 4 should be 87, i get 74 and pin 5 should be -3.5, i get -.3
:::
:::As always, any help is appreciated and I hope i can pay it back as I build my knowledge.
::Hi
:: I'd check for a good ground on Pin 1 of the 12SA7 or and open winding in T4, to start with, and go from there.
::Mark
::
:Well another one of my brother in laws flea market finds has made it's way to my bench. This is a Hallicrafters 5R10 (schem link: http://www.nostalgiaair.org/Resources/818/M0008818.htm) and I can't get it going. It was DOA on arrival. I did a full recapping of it, tested all the tubes etc.
:
:When i power up I only get a hum from the speaker. I know the osc is working because I can wipe out my reference radio with the whistle. I went through all of the voltages and found some interesting numbers, and one voltage completely missing. Here is my findings (only listing the ones that are off, the voltages are in the schem)
:
:35Z5GT - Pin 8 should be 128 i get 104
:
:50L6GT - Pin 7 should be 86 i get 42, pin 6 should be 114 i get 95, pin 4 should be 87, i get 75, pin 3 should be 108, i get 90 and pin 2 should be 36, i get 18.
:
:12SQ7 - pin 6 should be 64, i get 52
:
:12SK7 - pin 8 should be 87, i get 75
:
:12SA7 - (the trouble one) pin 3 should be 87, i get 0 (zero), pin 4 should be 87, i get 74 and pin 5 should be -3.5, i get -.3
:
:As always, any help is appreciated and I hope i can pay it back as I build my knowledge.
:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
:HUM in the speaker........have you also ascertained that all of your audio circuitry is working by having the vol control at max and touching the center tap of the vol control with a finger held metal screwdriver to see if the AC induced signal is amplified to a big buzz?
:73's de Edd
:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
:
::Well another one of my brother in laws flea market finds has made it's way to my bench. This is a Hallicrafters 5R10 (schem link: http://www.nostalgiaair.org/Resources/818/M0008818.htm) and I can't get it going. It was DOA on arrival. I did a full recapping of it, tested all the tubes etc.
::
::When i power up I only get a hum from the speaker. I know the osc is working because I can wipe out my reference radio with the whistle. I went through all of the voltages and found some interesting numbers, and one voltage completely missing. Here is my findings (only listing the ones that are off, the voltages are in the schem)
::
::35Z5GT - Pin 8 should be 128 i get 104
::
::50L6GT - Pin 7 should be 86 i get 42, pin 6 should be 114 i get 95, pin 4 should be 87, i get 75, pin 3 should be 108, i get 90 and pin 2 should be 36, i get 18.
::
::12SQ7 - pin 6 should be 64, i get 52
::
::12SK7 - pin 8 should be 87, i get 75
::
::12SA7 - (the trouble one) pin 3 should be 87, i get 0 (zero), pin 4 should be 87, i get 74 and pin 5 should be -3.5, i get -.3
::
::As always, any help is appreciated and I hope i can pay it back as I build my knowledge.