National NC-300 RF amp damage

[AE1PT]

I am looking for a part for an NC-300 I am rebuilding.  It's billed as an "Antenna Transformer: 80 Meter band", and has a National part number of B15295.  Each band has a specially wound coil similar to this one as input to the RF amp off a rotary switch.  The RF amp in this one seems to have had a bad experience.  A hambone tube substitution was made and it seems every resistor possible in that circuit was gradually cooked out.  Including the little wound input coil I need--which is nicely toasted.

Anyone have one, or a lead on where one might be found?

PT

[KA2DZT]

I think you should try to rewind the coil.  If it is a single layer coil, rewinding it should not be too difficult.  Just figure what gauge wire it is and count the number of turns.

Fred

[N1KK]

Hello,

I had a similar problem with 160m.  I sent you an email on someone
who had a junk NC-300 and was kind enough to remove the antenna coil T7
for me.

Ken
N1KK

I am looking for a part for an NC-300 I am rebuilding.  It's billed as an "Antenna Transformer: 80 Meter band", and has a National part number of B15295.  Each band has a specially wound coil similar to this one as input to the RF amp off a rotary switch.  The RF amp in this one seems to have had a bad experience.  A hambone tube substitution was made and it seems every resistor possible in that circuit was gradually cooked out.  Including the little wound input coil I need--which is nicely toasted.

Anyone have one, or a lead on where one might be found?

PT

[Rob K2CU]

Someone probably fed her RF, if it is an input coil. Are you sure it is broken? Just because she's cooked doesn't mean it's broken. You could check it with a grid dipper first. If it is bad, and a replacement can't be found, then carefully note the number of turns and rewind it as suggested. The form should be totally reusable.

[KM1H]

I might have the correct wire since I bought all of Nationals coil winding stock at the 1992 IRS auction. Quite a bit of cloth covered and Litz was included.

Carl

[KC9LKE]

If its the same as the 303 I might have one FOC.

Regards

Ted / KC9LKE