05-04-2020, 07:47 PM
Lets see if I can be of some help here. Look on the rear of your counter and be sure that it's set for internal on the time-base switch. If that switch is on the external side, you'll get all zero's
Make sure that your mode switch is on the Freq A position.
Make sure that your trigger control is set to preset.
Those settings should put you in a configuration that will yield a freq reading when you drive that counter with enough input.
This is a good time to have the discussion of the cable impedance you referred to. You can use 75 ohm coax with a 50 ohm impedance counter. What it will cause is an variation in sensitivity of the counter input. But for what you're trying to do, it should work. Just for fun though, take your ohm meter and check the continuity of the cable. Shield to shield and inner conductor to inner conductor. You want to make sure that the cable is good. NEVER ASSUME ANYTHING. Assume makes an A** out of U and ME, to quote my electronics instructor. If the cables are good, you should be able to get plenty of drive out of your SG-8 (I have one here) to drive the counter. It will take a lot more drive on the low freq range to get a stable reading.
Set the output on the generator on the high setting and set the RF output adjustment just above the on position. Connect the generator and counter together on the 5hz to 50 MHz input and slowly turn up the output adjustment, until you have a reading. Once you've done that and understand what you have to do to get a reading on the counter with the generator, use a AM broadcast receiver to verify your generator and counter. Zero beat the generator against a broadcast station whose frequency you know, and then run the generator into the freq counter.
That will allow you to verify the counter for accuracy with your generator. Be aware that some generators put out a really ugly sine wave and that will sometimes will cause the counter to read wrong, even though the counter is working correctly. This Heath counter takes a fairly high level to get a stable output reading.
If you haven't done this yet, you need to get a manual for your counter an read it so you know how it works.
Make sure that your mode switch is on the Freq A position.
Make sure that your trigger control is set to preset.
Those settings should put you in a configuration that will yield a freq reading when you drive that counter with enough input.
This is a good time to have the discussion of the cable impedance you referred to. You can use 75 ohm coax with a 50 ohm impedance counter. What it will cause is an variation in sensitivity of the counter input. But for what you're trying to do, it should work. Just for fun though, take your ohm meter and check the continuity of the cable. Shield to shield and inner conductor to inner conductor. You want to make sure that the cable is good. NEVER ASSUME ANYTHING. Assume makes an A** out of U and ME, to quote my electronics instructor. If the cables are good, you should be able to get plenty of drive out of your SG-8 (I have one here) to drive the counter. It will take a lot more drive on the low freq range to get a stable reading.
Set the output on the generator on the high setting and set the RF output adjustment just above the on position. Connect the generator and counter together on the 5hz to 50 MHz input and slowly turn up the output adjustment, until you have a reading. Once you've done that and understand what you have to do to get a reading on the counter with the generator, use a AM broadcast receiver to verify your generator and counter. Zero beat the generator against a broadcast station whose frequency you know, and then run the generator into the freq counter.
That will allow you to verify the counter for accuracy with your generator. Be aware that some generators put out a really ugly sine wave and that will sometimes will cause the counter to read wrong, even though the counter is working correctly. This Heath counter takes a fairly high level to get a stable output reading.
If you haven't done this yet, you need to get a manual for your counter an read it so you know how it works.
Kim Herron W8ZV
w8zv at goldenradioservice.com
1-616-677-3706
