Tube Driver Amplifer Tuning

[W5LZ]

Injecting a tone(s) to tune an amplifier can certainly be done. The 'catch' to that is that the tone(s) have to be constant, not vary in level. That just can't be done by voice or with a microphone. You might get 'close', but even that's going to be a near miracle.
Just using a carrier, or CW, is probably the best way of doing that tuning. The typical method is to do that tuning with CW/carrier and adding just a 'skoshe bit' more 'loading'. Is that going to result in a 'perfect' tune? No, it won't. But, it's about as 'perfect' as it gets.
If done correctly, that tuning procedure will be the heaviest load the amplifier will have to put up with. Regular operating after that shouldn't really be as 'heavy' a load, or the amplifier shouldn't be working any harder after that tuning as during that tuning. And I think that's probably where any problems come into play later, the operator is just expecting too much from that amplifier. I don't care what the advertising says, no amplifier should be pushed to absolute maximum output most of the time. That maximum rating is from 'perfect' set up circumstances, which the average person never has. (That sticker on a new car's window may say 30 miles to a gallon, but it's going to be a near-miracle if you ever see it.)
- 'Doc


(I'm one of the best 'tube-flatteners' around! If I can't/haven't killed a particular tube it's because it can't be done, unfortunately. Ask my wallet, it's still crying. I think that's why several tube manufacturers went out of business, I sort of got smarter. And that's why there are still some tube manufacturers around, I ain't that smart yet.)

 

[Bionic Chicken]

If you will note the plate current before tuning with audio and then afterwards the carrier current will be lower along with grid current as usually the dead key is lower. However it is liable to go higher on voice peaks. But lets be real about this, most people who tune amps are not going to do it the proper way and leave it. (Not implying you Cajun Invader) They are looking for all the watts not to tune an amp as a amateur operator would. I've used this method for years without problems. If it's wrong I'm sure someone will be fast to jump on the bandwagon and point that out, but it has worked for me and many others through the years.
But as I posted earlier about the tubes plate color..........that is important. A 572B will show some color as stated by myself and others but not alot.
4-1000's are nice to have in the winter.........they save on heating but you spend it on wattage in another way.

BC

 

[mackmobile43]

If you will note the plate current before tuning with audio and then afterwards the carrier current will be lower along with grid current as usually the dead key is lower. However it is liable to go higher on voice peaks. But lets be real about this, most people who tune amps are not going to do it the proper way and leave it. (Not implying you Cajun Invader) They are looking for all the watts not to tune an amp as a amateur operator would. I've used this method for years without problems. If it's wrong I'm sure someone will be fast to jump on the bandwagon and point that out, but it has worked for me and many others through the years.
But as I posted earlier about the tubes plate color..........that is important. A 572B will show some color as stated by myself and others but not alot.
4-1000's are nice to have in the winter.........they save on heating but you spend it on wattage in another way.

BC

I know cajun invader and I'm sure he would like to know how to do these procedures correctly and everyone here has helped so much, his plans are to run this at a respectable level and if he needs more power he can just turn up the input carrier to a respectable level but the priority is the life of the tube/valves.

 

[Moleculo]

One thing you can do to make your life easier is to get a radio that already has 100 watt output. Then you don't have to mess around with another amplifier tuning & loading procedure. If you get a device like this:

http://www.ameritron.com/pictures/ATP-100.jpg

You can plug it into your CW port to give you either the solid CW carrier, or the two tone pulse. Either way, it holds to tone steady for you so that you can load up the amplifier quickly and safely.

 

[n8fgb]

Just remember the Dentron has max input of 100watts, not deadkey, but voice peak.Also run it in CW position on AM. Remember this was designed for SSB. If you drive those horizontal 572b's to hard, the filiments will sage and short. You could have fire a on your hands. The only one that will tell the differenc between 700 wats and 1200 watts will be the fire department. LOL
Rich

 

[mackmobile43]

Just remember the Dentron has max input of 100watts, not deadkey, but voice peak.Also run it in CW position on AM. Remember this was designed for SSB. If you drive those horizontal 572b's to hard, the filiments will sage and short. You could have fire a on your hands. The only one that will tell the differenc between 700 wats and 1200 watts will be the fire department. LOL
Rich

ten fur

 

[Cajun Invader]

Just remember the Dentron has max input of 100watts, not deadkey, but voice peak.

Well if that's the case then I can't drive the Clipperton with the Varmint. :headbang

 

[BJ radionut]

Clipperton Pwr Supply upgrade

...if the pwr supply board is original or has caps replaced you can see, I would be replacing the entire board. They are available from W8CQ.

You can purchase new Russian Svetlana 572B's from K5SVC...much better than Any China version and now require no mods to use them, if you buy current version with ceramic bases.

They will drive to full power with about 50 to 80 watts Peak on SSB! They will show output of about 6 to 700 watts in CW with about 30 watts drive.
All the Best
BJ

 

[Bionic Chicken]

Well if that's the case then I can't drive the Clipperton with the Varmint. :headbang

I never had a seconds problem from driving my Clipperton L with a Maco 200 or even a 300 at times. Of course I kept a close watch on the tubes and made sure they did not overheat. I also am not one to constantly tune on an amp for every last watt. This was also done in the SSB position for the most part. I have had the amp for 15 years and it still has full output. Sometimes I have set the amp on its side so the tubes were "standing up" to keep from what others have said about filament sag. For the most part it has set horizontal. The one problem that people have with this amp is that they expect it to perform like a SB 220. It won't do it. Using a Drake W4 meter my Dentron will key 350 and swing 900 watts all day long and will not get hot.
I'm sure others will disagree with this but this is from my actual experience from using the amp, not from reading the advertised specs of it.

 

[Cajun Invader]

Here's what has been done to it so far.

Replaced all HV filter capaciters, equalizer resistors and rectifier doides.

New Peter Dahl transformer upgrade.

 

[n8fgb]

Nice Clipp, looks like the one I saw on Epay.Mine aint quite as purdy, but is cleaning nice. Should work good, once I get the new tubes. The origional Dentrons were flat.
Rich

 

[Bionic Chicken]

Good looking Dentron. It sounds like you have all your bases covered as far as updates and repair.

BC