In following the schematic tuning procedure, it says to connect the high side of the sig gen through a .1mf cap to the IF grid pin of the 12BA6. I'm new at this and need to know how to identify pin they are referring to. Thanks!

Hi Stan:

The grid of the 1st IF tube (12BA6) is pin 1.

Remeber to keep the output of your test-oscillator as low as possible to avoid a-v-c action.

Also, you should use an isolation transformer on the AC line input, especially if the power chord plug is not polarized.

Gary

:In following the schematic tuning procedure, it says to connect the high side of the sig gen through a .1mf cap to the IF grid pin of the 12BA6. I'm new at this and need to know how to identify pin they are referring to. Thanks!

:Hi Stan:
:
:The grid of the 1st IF tube (12BA6) is pin 1.
:
:Remeber to keep the output of your test-oscillator as low as possible to avoid a-v-c action.
:
:Also, you should use an isolation transformer on the AC line input, especially if the power chord plug is not polarized.
:
:Gary
:
:
::In following the schematic tuning procedure, it says to connect the high side of the sig gen through a .1mf cap to the IF grid pin of the 12BA6. I'm new at this and need to know how to identify pin they are referring to. Thanks!

Thanks Gary
my sig gen is a Jackson 640 and has 2 outputs, one for RF and one for 400~ Should I be injecting an RF signal or the 400~ ?::
Hi Stan:
::
::The grid of the 1st IF tube (12BA6) is pin 1.
::
::Remeber to keep the output of your test-oscillator as low as possible to avoid a-v-c action.
::
::Also, you should use an isolation transformer on the AC line input, especially if the power chord plug is not polarized.
::
::Gary
::
::
:::In following the schematic tuning procedure, it says to connect the high side of the sig gen through a .1mf cap to the IF grid pin of the 12BA6. I'm new at this and need to know how to identify pin they are referring to. Thanks!

Hi,
Use the RF output, and you should have switch selection to select RF with Audio tone.

AF only would be used for just audio equipment, or the audio only section of a radio.

:Thanks Gary
:my sig gen is a Jackson 640 and has 2 outputs, one for RF and one for 400~ Should I be injecting an RF signal or the 400~ ?::
:Hi Stan:
:::
:::The grid of the 1st IF tube (12BA6) is pin 1.
:::
:::Remeber to keep the output of your test-oscillator as low as possible to avoid a-v-c action.
:::
:::Also, you should use an isolation transformer on the AC line input, especially if the power chord plug is not polarized.
:::
:::Gary
:::
:::
::::In following the schematic tuning procedure, it says to connect the high side of the sig gen through a .1mf cap to the IF grid pin of the 12BA6. I'm new at this and need to know how to identify pin they are referring to. Thanks!

If your signal generator is transformer powered (transformer inside the case), there is no need to use an isolation transformer on your radio. Make sure that the signal generator is not grounded in any way (except perhaps through a condenser). I had a signal generator that someone put a grounded cord on. Bad idea. Grounding the chassis of the signal generator makes connecting to AC/DC radios dangerous.

:If your signal generator is transformer powered (transformer inside the case), there is no need to use an isolation transformer on your radio. Make sure that the signal generator is not grounded in any way (except perhaps through a condenser). I had a signal generator that someone put a grounded cord on. Bad idea. Grounding the chassis of the signal generator makes connecting to AC/DC radios dangerous.

Would this, (grounding of a signal generator) also be true of a 'scope? I think my late model scope has a 3 prong grounding plug.

::If your signal generator is transformer powered (transformer inside the case), there is no need to use an isolation transformer on your radio. Make sure that the signal generator is not grounded in any way (except perhaps through a condenser). I had a signal generator that someone put a grounded cord on. Bad idea. Grounding the chassis of the signal generator makes connecting to AC/DC radios dangerous.
:
:
:Would this, (grounding of a signal generator) also be true of a 'scope? I think my late model scope has a 3 prong grounding plug.

Most newer test equipment uses grounded plugs. ALWAYS use an isolation transformer when working on AC/DC radios. ALWAYS read up on the procedures you are about to do, you will prevent damage to equipment and yourself by being informed.

Dave

Yes, this is true. Don't get me wrong...grounding the scope or the generator is a great idea with reference to the generator and any ground potential around you. If the chassis of the generator or scope is grounded, it is at the same potential as the radiators and concrete floors in your home. You won't get any shocks when touching both the scope/generator and a radiator. The problem is that AC/DC radios sometimes have one side of the line tied directly to the chassis. Connecting the grounded generator/scope to the AC/DC radio, with the radio plugged in the "wrong" way, will cause sparks and a blown fuse. If your generator/scope is grounded internally, and you do not wish to disconnect this ground, you must use an isolation transformer with an AC/DC radio. As most old generators/scopes did not come this way, a modification of this nature will more likely cause trouble than good. Simply disconnect the ground wire from the chassis within the scope/generator.

As most of us know, it is a bad idea to hold radiators or to stand on concrete floors, while working on radios anyway, so as long as you work on a carpeted or wooden floor, there is no need to ground your equipment in the first place. Dry rubber soled shoes are a plus. A wooden board on a concrete floor is a plus, too. Try to refrain from working on your projects while taking a bath.

Thomas

The transformer within the signal generator/scope serves equally well as an isolation transformer, and is equally safe. You may still receive a small shock if the generator/scope has a small condenser going from the line cord to the chassis. Placing an isolation transformer on the radio as well, seems a bit redundant, though if one is at hand, this is an ideal situation. As said before, if you do not wish to disconnect the third ground wire within your generator/scope, an isolation transformer on the radio is a must.