I recently purchased a Eico 324 signal generator to help with trouble shooting. I printed the manual out from this website (thanks). My problem is that I'm such a novice I can't figure out how to use it. According to the manual utilizing the "AF Out" connection, I should be able to inject a 400 HZ signal into the radio. When I check the output at the signal generator with my multitester it shows 390 cps (cycles per second ?). Where/how is an easy way to see if the signal generator is working. My novice concept was that I could input the signal into a working tube radio and hear a hum in the speaker. I have several working tube radios I could test on. Thanks in advance for the help.

Brad.

Hi Brad

You signal generator is working. 390 cps is as close 400 as you can expect.

Be sure the signal generator is isolated from the AC line. Connect center wire of the signal generator to an audio stage in your radio. One place, easy to find, is the volume control. Connect radio ground to signal generator ground.

Norm

:I recently purchased a Eico 324 signal generator to help with trouble shooting. I printed the manual out from this website (thanks). My problem is that I'm such a novice I can't figure out how to use it. According to the manual utilizing the "AF Out" connection, I should be able to inject a 400 HZ signal into the radio. When I check the output at the signal generator with my multitester it shows 390 cps (cycles per second ?). Where/how is an easy way to see if the signal generator is working. My novice concept was that I could input the signal into a working tube radio and hear a hum in the speaker. I have several working tube radios I could test on. Thanks in advance for the help.
:
:Brad.

Hi Brad,
If working on an AC/DC "hot chassis" radio, there are a couple of additional precautions you should consider. First, the signal generator ground should be connected to radio ground (or common negative), but on an AC/DC radio this is not necessarily the same thing as the chassis. The easiest source for common negative is either the negative terminal of filter caps or the negative terminal of the line switch. Secondly, it is always good insurance to use a 0.1 mfd cap in series with the positive lead of your signal generator. This will protect your generator from any damaging DC voltage you might encounter when connecting it to your radio. And remember that a radio with leaky caps or shorts can have substantial DC voltage present at a point where you otherwise might not expect to find it.

Norm has mentioned isolating your signal generator from the AC line. If you are powering the radio under test with an isolation transformer, then the signal generator should be plugged directly into the AC line, and not into the isolation transformer. Some restorers make the mistake of powering both the radio and signal generator from the isolation transformer, which defeats the purpose of isolating them from each other.

Poston

:Hi Brad
:
: You signal generator is working. 390 cps is as close 400 as you can expect.
:
: Be sure the signal generator is isolated from the AC line. Connect center wire of the signal generator to an audio stage in your radio. One place, easy to find, is the volume control. Connect radio ground to signal generator ground.
:
:Norm
:
:
::I recently purchased a Eico 324 signal generator to help with trouble shooting. I printed the manual out from this website (thanks). My problem is that I'm such a novice I can't figure out how to use it. According to the manual utilizing the "AF Out" connection, I should be able to inject a 400 HZ signal into the radio. When I check the output at the signal generator with my multitester it shows 390 cps (cycles per second ?). Where/how is an easy way to see if the signal generator is working. My novice concept was that I could input the signal into a working tube radio and hear a hum in the speaker. I have several working tube radios I could test on. Thanks in advance for the help.
::
::Brad.

Thanks to both of you for your assistance. Just got back from 4th. I'll try it this afternoon.

Brad.

:Hi Brad,
:If working on an AC/DC "hot chassis" radio, there are a couple of additional precautions you should consider. First, the signal generator ground should be connected to radio ground (or common negative), but on an AC/DC radio this is not necessarily the same thing as the chassis. The easiest source for common negative is either the negative terminal of filter caps or the negative terminal of the line switch. Secondly, it is always good insurance to use a 0.1 mfd cap in series with the positive lead of your signal generator. This will protect your generator from any damaging DC voltage you might encounter when connecting it to your radio. And remember that a radio with leaky caps or shorts can have substantial DC voltage present at a point where you otherwise might not expect to find it.
:
:Norm has mentioned isolating your signal generator from the AC line. If you are powering the radio under test with an isolation transformer, then the signal generator should be plugged directly into the AC line, and not into the isolation transformer. Some restorers make the mistake of powering both the radio and signal generator from the isolation transformer, which defeats the purpose of isolating them from each other.
:
:Poston
:
:
::Hi Brad
::
:: You signal generator is working. 390 cps is as close 400 as you can expect.
::
:: Be sure the signal generator is isolated from the AC line. Connect center wire of the signal generator to an audio stage in your radio. One place, easy to find, is the volume control. Connect radio ground to signal generator ground.
::
::Norm
::
::
:::I recently purchased a Eico 324 signal generator to help with trouble shooting. I printed the manual out from this website (thanks). My problem is that I'm such a novice I can't figure out how to use it. According to the manual utilizing the "AF Out" connection, I should be able to inject a 400 HZ signal into the radio. When I check the output at the signal generator with my multitester it shows 390 cps (cycles per second ?). Where/how is an easy way to see if the signal generator is working. My novice concept was that I could input the signal into a working tube radio and hear a hum in the speaker. I have several working tube radios I could test on. Thanks in advance for the help.
:::
:::Brad.