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I've gotten through most of the alignment now. Most of it has gone just fine. I had cut the top off the shielding over the VCO circuit. I couldn't access the test points. Came out nice. I would have had to use my heat station to desolder this off which I figured was a high risk. I was thinking of manufacturing a small lid for this but I think it should be fine as is, still plenty of shielding left. TX has given me a few head aches. I've had to change a few of the CRAPPY adjustment pots that become flaky if you so much as look at them wrong. The output transistors were getting super hot, turns out who ever worked on this previously did not bother to open up the holes on the board and by doing so the transistors never sat flush with the heatsink which caused them to bend when the screws were put in. To compensate for this I ended up having to place some thermal transfer padding underneath them. The heat doesn't move off them as quickly as it would if they were directly on the heatsink so they do get a bit hotter but still within their safe zone. Soldering also has been done nicely this time. What would you guys say is a good top temperature on the transistors?

Among the pots I had to replace are the low power adjustment pot and one of the biasing pots.

For some reason now I have a modulation issue. On low power I only get about 80% modulation and on high power I can barely see any modulation at all. I don't know why this is happening suddenly as it was working fine and had already adjusted modulation. Not a mic issue. I tried replacing those mod pots to no avail. I'll go hunting after this issue next. It's too bad as I was pretty much ready to close this thing up. If you guys have any suggestions as to where the modulation issue may be let me know, i'd appreciate it.

<blockquote data-quote="Tolteca" data-source="post: 633554" data-attributes="member: 52008">I&#039;ve gotten through most of the alignment now.&nbsp; Most of it has gone just fine.&nbsp; I had cut the top off the shielding over the VCO circuit.&nbsp; I couldn&#039;t access the test points.&nbsp; Came out nice.&nbsp; I would have had to use my heat station to desolder this off which I figured was a high risk.&nbsp; I was thinking of manufacturing a small lid for this but I think it should be fine as is, still plenty of shielding left.&nbsp; TX has given me a few head aches.&nbsp; I&#039;ve had to change a few of the CRAPPY adjustment pots that become flaky if you so much as look at them wrong.&nbsp; The output transistors were getting super hot, turns out who ever worked on this previously did not bother to open up the holes on the board and by doing so the transistors never sat flush with the heatsink which caused them to bend when the screws were put in.&nbsp; To compensate for this I ended up having to place some thermal transfer padding underneath them.&nbsp; The heat doesn&#039;t move off them as quickly as it would if they were directly on the heatsink so they do get a bit hotter but still within their safe zone.&nbsp; Soldering also has been done nicely this time.&nbsp; What would you guys say is a good top temperature on the transistors?Among the pots I had to replace are the low power adjustment pot and one of the biasing pots. For some reason now I have a modulation issue.&nbsp; On low power I only get about 80% modulation and on high power I can barely see any modulation at all.&nbsp; I don&#039;t know why this is happening suddenly as it was working fine and had already adjusted modulation.&nbsp; Not a mic issue.&nbsp; I tried replacing those mod pots to no avail.&nbsp; I&#039;ll go hunting after this issue next.&nbsp; It&#039;s too bad as I was pretty much ready to close this thing up.&nbsp;&nbsp; If you guys have any suggestions as to where the modulation issue may be let me know, i&#039;d appreciate it.</blockquote>

[QUOTE="Tolteca, post: 633554, member: 52008"] I've gotten through most of the alignment now. Most of it has gone just fine. I had cut the top off the shielding over the VCO circuit. I couldn't access the test points. Came out nice. I would have had to use my heat station to desolder this off which I figured was a high risk. I was thinking of manufacturing a small lid for this but I think it should be fine as is, still plenty of shielding left. TX has given me a few head aches. I've had to change a few of the CRAPPY adjustment pots that become flaky if you so much as look at them wrong. The output transistors were getting super hot, turns out who ever worked on this previously did not bother to open up the holes on the board and by doing so the transistors never sat flush with the heatsink which caused them to bend when the screws were put in. To compensate for this I ended up having to place some thermal transfer padding underneath them. The heat doesn't move off them as quickly as it would if they were directly on the heatsink so they do get a bit hotter but still within their safe zone. Soldering also has been done nicely this time. What would you guys say is a good top temperature on the transistors? Among the pots I had to replace are the low power adjustment pot and one of the biasing pots. For some reason now I have a modulation issue. On low power I only get about 80% modulation and on high power I can barely see any modulation at all. I don't know why this is happening suddenly as it was working fine and had already adjusted modulation. Not a mic issue. I tried replacing those mod pots to no avail. I'll go hunting after this issue next. It's too bad as I was pretty much ready to close this thing up. If you guys have any suggestions as to where the modulation issue may be let me know, i'd appreciate it. [/QUOTE]

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