03-18-2011, 11:26 AM
I noticed that the sensitivity of my 90 was not that great--big, local stations came in okay, but not the regional ones, and at night, only the big blow-torch stations came through, albeit very weakly. I tested my coils, and they all seemed okay, but I was still suspicious of the 1st RF, so I took it out and looked it over:[attachment=1]
Seemed okay, but it looks different than what most people describe as a 1st RF coil: the primary is inside the tube on its own spool. Here's what it looks like underneath: [attachment=0]
If I bypass this coil and hook the antenna directly to the 2nd RF, reception is much, much better, more sensitive and more clear. So there has to be something wrong with the 1st RF, right? But they all test continuous on my ohmmeter, and none of the coils shows more than 6.6 ohms resistance.
Question: how would I go about rewinding the primary on this coil? How do you get the center spool out of the form? Is this even the correct RF coil for this radio? Could someone have substituted it from something different? If the coil is okay, what could be causing the weak reception through it?
Lots of questions. Hope someone has some insight!
Mike
Seemed okay, but it looks different than what most people describe as a 1st RF coil: the primary is inside the tube on its own spool. Here's what it looks like underneath: [attachment=0]
If I bypass this coil and hook the antenna directly to the 2nd RF, reception is much, much better, more sensitive and more clear. So there has to be something wrong with the 1st RF, right? But they all test continuous on my ohmmeter, and none of the coils shows more than 6.6 ohms resistance.
Question: how would I go about rewinding the primary on this coil? How do you get the center spool out of the form? Is this even the correct RF coil for this radio? Could someone have substituted it from something different? If the coil is okay, what could be causing the weak reception through it?
Lots of questions. Hope someone has some insight!
Mike
