RETUBED PHANTOM ARCING

[wavrider]

Sonar do some more research before you purchase an 811H, better amps available out there for a few more $$$. Just some friendly advice.

 

[Sonar]

[QUOTE="BJ radionut, post: 570251,those choke resistors most certainly have changed value...which may cause issues with tuning
View attachment 19536[/QUOTE] I've actually have noticed a tuning issue.
The last (fourth) tune knob which is one of the two that stops and won't continuously turn reaches it's max smoke at the clockwise stop point.
I really hate to ship this. It would be a shame if it gets bustedup during shipping. My choices are limited. I've decided to put the original tubes back in and take it from there. As I mentioned after the flash it sat turned off for a few hours before I decided to fire it up and key it. It worked as if nothing had happened. I believe one of the new tubes flashed. I don't think anything was damaged except the tube that flashed.
Would an option be to unsolder the wire that supports those choke resistors and send the whole thing out (choke resistors and support wires?) Thanks. 73

 

[Sonar]

I've removed the replacement tubes and reinstalled the original d&a's. I'm happy to report that after inspecting everything on the top and bottom side of the amp nothing was fried. The flash that occurred was aperantly one of the replacement tubes.
The amps been running for about four hours.
I tuned it up and modulated on and off for about 45 minutes.
The output is 200 dk (2watts) and 600 pep (17 modulated).
No issues whatsoever. The replacement tubes gave 200 watts more. My lesson for the month was "leave well enough alone". I noticed something I hadn't before. The three d&a's that are connected via the chokes have a much brighter cap as opposed to the six. Making it easy to put the tubes if not in the same socket at least in the socket section they came out of and the six where they were. You can see the difference between the three and six in the pic. Is there a reason three 6lq6''s should have a different luster top cap then the six?
I'm very happy i didn't unintentionally damage the amp.

• If a tube change were to give me 2k I'd consider replacing these d&a 6lq6"s. They are staying in the amp until they need to be replaced. Considering 2 3 or even 400 watts more isn't making a difference on the other end, why bother? I'm happy the amps working and although I don't do that much AM talking I enjoy using it when I do.

The first picture is of the replacement tubes (just installed) before the flash. The second after the flash. The third with the originals back in there. Yippee. Thanks for all the help my friends. p.s I used the chance to use a can of compressed air to clean out what I missed the first time.

 

[543_Dallas]

I do notice the plate tune cap is fully un meshed in the last 2 pics. If it peaks out that way the thing needs some work.

 

[Sonar]

I do notice the plate tune cap is fully un meshed in the last 2 pics. If it peaks out that way the thing needs some work.

I know I should do a search and if I must I will but I find explaining my ex stream lack of knowledge makes people like yourself lay it out in a way i might understand.
Please exsplain"mesh cap is fully unmeshed" and what are the possible causes and fixes?

 

[222DBFL]

Just some food for thought Sonar. It won't make a big difference, but might want to cut the amp carrier of 200 watts back to about 150 watts if possible. Gives you a better 1:4 ratio. Again, just some food for thought. Probably take a small adjustment on the dead key. Anyhow. Glad it's working again and no issues. Lesson learned. If it ain't broke, don't fix it.
Have fun with it again. And be safe!!

 

[357]

I know I should do a search and if I must I will but I find explaining my ex stream lack of knowledge makes people like yourself lay it out in a way i might understand.
Please exsplain"mesh cap is fully unmeshed" and what are the possible causes and fixes?

the 6 tubes with the darker caps are the SUPER DUTY 6lq6 that are rare, and expensive as fuck.
your tune knob is fully unmeshed, the plate are rotated 100% out of the bottom plates.
That means you are not tuned and will cook the tubes.
What you have to do is with the box unplugged and the capacitors discharged by grounding the tube cap to ground with an insulated screwdriver (to a nearby rivet), is spread the coil that goes from load to tune.
stick a big flat tip in the coils and spead each one 1/16 of an inch.
then fire the amp back up, have a coffee and then tune it up.

Take note of where the tune plates now are after tune up. If they are a 1/4 to 1/3 ways "meshed" you are good to go. If its like a tiny bit meshed, power down, discharge and spread a 1/16" more and try again till its right.

When this in complete you should see a power increase for sure and when you are done and its finally tuning right, dont forget to overcouple the load (clockwise!), till the watts drop down about 50W and you will see the most PEP that way.



UNMESHED!!!

MESHED!!

1/4 MESHED!!

 

[543_Dallas]

I know I should do a search and if I must I will but I find explaining my ex stream lack of knowledge makes people like yourself lay it out in a way i might understand.
Please exsplain"mesh cap is fully unmeshed" and what are the possible causes and fixes?

357 covered it, unmeshed is the capacitor set at minimum and full mesh would be it set to max. Sometimes squeezing or spreading the tank coil will fix it it other times you'll have to remove or add a turn from the coil. There could be other things going on too so I'm not telling you you need to do any of this.

 

[Sonar]

the 6 tubes with the darker caps are the SUPER DUTY 6lq6 that are rare, and expensive as fuck.
your tune knob is fully unmeshed, the plate are rotated 100% out of the bottom plates.
That means you are not tuned and will cook the tubes.
What you have to do is with the box unplugged and the capacitors discharged by grounding the tube cap to ground with an insulated screwdriver (to a nearby rivet), is spread the coil that goes from load to tune.
stick a big flat tip in the coils and spead each one 1/16 of an inch.
then fire the amp back up, have a coffee and then tune it up.

Take note of where the tune plates now are after tune up. If they are a 1/4 to 1/3 ways "meshed" you are good to go. If its like a tiny bit meshed, power down, discharge and spread a 1/16" more and try again till its right.

When this in complete you should see a power increase for sure and when you are done and its finally tuning right, dont forget to overcouple the load (clockwise!), till the watts drop down about 50W and you will see the most PEP that way.



UNMESHED!!!

MESHED!!

1/4 MESHED!!

the 6 tubes with the darker caps are the SUPER DUTY 6lq6 that are rare, and expensive as fuck.
your tune knob is fully unmeshed, the plate are rotated 100% out of the bottom plates.
That means you are not tuned and will cook the tubes.
What you have to do is with the box unplugged and the capacitors discharged by grounding the tube cap to ground with an insulated screwdriver (to a nearby rivet), is spread the coil that goes from load to tune.
stick a big flat tip in the coils and spead each one 1/16 of an inch.
then fire the amp back up, have a coffee and then tune it up.

Take note of where the tune plates now are after tune up. If they are a 1/4 to 1/3 ways "meshed" you are good to go. If its like a tiny bit meshed, power down, discharge and spread a 1/16" more and try again till its right.

When this in complete you should see a power increase for sure and when you are done and its finally tuning right, dont forget to overcouple the load (clockwise!), till the watts drop down about 50W and you will see the most PEP that way.



UNMESHED!!!

MESHED!!

1/4 MESHED!!

Excellent!! I'm not 100% sure of the coil your speaking of although I've an idea.
I added the picture so you could confirm. If this is an issue and I've a strong feeling it is as you say, the amp might actually hit the numbers it did when close to new.
This amp has so little hours on it and the tubes are probably stronger than I initially thought.
My thought was 'low output, bad tubes" but this might not be the case.
I add a picture of the coil that's located under the amp. The one that goes from the driver tune to the load. Is this the one? All I need to do is separate each one 1/16" from each other, correct? Re tune, check coil mesh to be 1/4"-1/3" and output after tuning. If necessary spread the coils a little further, yes?
Thanks for the information on the difference between the tubes with the dark colored caps. I thought there must be a reason the caps made the two types of 6lq6's different in some way.
I will not use the amp until I get around to separating the coil.
No soldering or test equipment needed = something I can do.
Leaving the original d&a's in there is important to me. It's actually nice to Keep it as original as possible. I thank you and all who've helped and continue to answer my sometimes verbosely ridiculous questions. ps Your explanation was excellent and anyone like myself with little to no knowledge about this will easily understand. The pictures you added will be an big help when determining if it's meshed correctly after final tuning. Thanks again.

 

[Sonar]

357 covered it, unmeshed is the capacitor set at minimum and full mesh would be it set to max. Sometimes squeezing or spreading the tank coil will fix it it other times you'll have to remove or add a turn from the coil. There could be other things going on too so I'm not telling you you need to do any of this.

I'm hoping that since the coil is original to the amp modifying it in any way won't be necessary. Thanks for responding. If there's anything you'd like to add please do. The more educated answers can only help me get edumacated. 73

 

[Sonar]

After checking out the picture I added I noticed one of those capacitors are shielded. I will still be able to see how it's meshed but is there a reason this one's shielded and the other isn't?

 

[Sonar]

Just some food for thought Sonar. It won't make a big difference, but might want to cut the amp carrier of 200 watts back to about 150 watts if possible. Gives you a better 1:4 ratio.

I actually miss wrote. The 200 watt dk is before I over couple. It actually winds up showing 100 dk and 600 pep after over coupling.
I'm going to spread that coil and have an idea those reading will all change afterwards. Depending on what I see after spreading the coil I might just drop the dk down to 11/2 or possibly 1 watt. It's very easy on the fs 2340. The adjustment is outside on the back of the rig. Thank you. 73

 

[222DBFL]

Hope you get it all sorted Sonar. Nice to have some kind gents to help along the way as well!! Helps a bunch!! Good looking out guys. And again, hope you get it all working the way it's supposed to. Be safe and don't forget to discharge that thing before you stick your hands in it!!!
73 and God Bless
222 Daytona Bch., FL.,
Sean

 

[Tallman]

I've removed the replacement tubes and reinstalled the original d&a's. I'm happy to report that after inspecting everything on the top and bottom side of the amp nothing was fried. The flash that occurred was aperantly one of the replacement tubes.

I think the tube in the lower right corner of the photo near the tuning cap is your bad tube.
The dark color is metal being deposited to glass by the arc. JMHO

 

[Sonar]

Ok. Just so I don't fxxk up. Which one should I be separating?

Top side (pic 1?) Or

Bottom side (pic 2?)i

I'll take care of it over the weekend. Once again thanks. Ps it will be unplugged and like I did before changing out the tubes I will discharge the amp. 73