You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
The Feb 2025 Radioddity Giveaway Results are In! Click Here to see who won!

Reply to thread

Message

I unhooked the base and collector legs and all lights stay on in SSB and AM, no dimming at all. Seems I have a shorted driver and final, but I would have sworn they checked OK when I pulled them from the radio earlier.
I still have good receive on SSB, but very weak on AM because I am down to my last transistor for TR5, so I left the bad one in for this test.
I can order new NEC 1306 and 1307 from RF Parts, little on the expensive side, but I don't know of any replacements.

There is a resistor on the final that measures 47.7ohms,it goes from the collector to the base, I cannot find it in the Sam's schematic at all, seems to be factory as it has a plastic sleeve over it. But I don't know.
Also there is a 100nf ceramic disc cap going from the emitter leg of the driver to chassis ground, but on the final the same size cap is going from the collector leg to ground, I cannot find these on the schematic either.
Could these be in the wrong place causing the final and driver to cause all these problems?

Thanks ExitThirteen, this is what I found when disconnecting the legs of the driver and final. Please let me know if it is the final and driver causing all my problems, and if the caps and resistor are in the right location for them. If I need to look further let me know.

At least I feel back on the right track.

Thank you very much, Mike

<blockquote data-quote="Sammitch" data-source="post: 584675" data-attributes="member: 43105">I unhooked the base and collector legs and all lights stay on in SSB and AM, no dimming at all. Seems I have a shorted driver and final, but I would have sworn they checked OK when I pulled them from the radio earlier.&nbsp; I still have good receive on SSB, but very weak on AM because I am down to my last transistor for TR5, so I left the bad one in for this test.&nbsp; I can order new NEC 1306 and 1307 from RF Parts, little on the expensive side, but I don&#039;t know of any replacements.&nbsp; There is a resistor on the final that measures 47.7ohms,it goes from the collector to the base, I cannot find it in the Sam&#039;s schematic at all, seems to be factory as it has a plastic sleeve over it. But I don&#039;t know.Also there is a 100nf ceramic disc cap going from the emitter leg of the driver to chassis ground, but on the final the same size cap is going from the collector leg to ground, I cannot find these on the schematic either.Could these be in the wrong place causing the final and driver to cause all these problems?Thanks ExitThirteen, this is what I found when disconnecting the legs of the driver and final. Please let me know if it is the final and driver causing all my problems, and if the caps and resistor are in the right location for them. If I need to look further let me know. &nbsp; At least I feel back on the right track.&nbsp; Thank you very much,&nbsp; Mike</blockquote>

[QUOTE="Sammitch, post: 584675, member: 43105"] I unhooked the base and collector legs and all lights stay on in SSB and AM, no dimming at all. Seems I have a shorted driver and final, but I would have sworn they checked OK when I pulled them from the radio earlier. I still have good receive on SSB, but very weak on AM because I am down to my last transistor for TR5, so I left the bad one in for this test. I can order new NEC 1306 and 1307 from RF Parts, little on the expensive side, but I don't know of any replacements. There is a resistor on the final that measures 47.7ohms,it goes from the collector to the base, I cannot find it in the Sam's schematic at all, seems to be factory as it has a plastic sleeve over it. But I don't know. Also there is a 100nf ceramic disc cap going from the emitter leg of the driver to chassis ground, but on the final the same size cap is going from the collector leg to ground, I cannot find these on the schematic either. Could these be in the wrong place causing the final and driver to cause all these problems? Thanks ExitThirteen, this is what I found when disconnecting the legs of the driver and final. Please let me know if it is the final and driver causing all my problems, and if the caps and resistor are in the right location for them. If I need to look further let me know. At least I feel back on the right track. Thank you very much, Mike [/QUOTE]

Top Bottom