Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Sep Mon 23, 2019 12:23 pm


All times are UTC [ DST ]





Post New Topic Post Reply  [ 5 posts ] 
Author Message
 Post subject: test 811 in jackson 648s?
PostPosted: Jul Fri 19, 2019 1:18 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 758
Location: dayton oh usa
anyone have factory settings?
i played around a bit myself and came up with settings that "work".
as in a new tube testing 100.
it did differentiate from some new,good,and soft tubes.


Top
 Profile  
 
 Post subject: Re: test 811 in jackson 648s?
PostPosted: Jul Sat 20, 2019 2:56 pm 
Member

Joined: Mar Thu 12, 2009 2:20 am
Posts: 1520
Location: Dayton, OH
I don't see it listed in Jim Cross's Jackson book, nor the 572B possible substitute.

Umm, doesn't that tube take 4 amps @ 6.3v for the filament alone? - You may be pushing the testers transformer power ratings a smidge (and invalidating your test results.)

(That being said, I'll freely admit I haven't checked all the tubes the 648 can test against their filament power requirements. :D )

David


Top
 Profile  
 
 Post subject: Re: test 811 in jackson 648s?
PostPosted: Jul Thu 25, 2019 4:25 pm 
Member

Joined: Feb Mon 04, 2008 3:20 am
Posts: 1086
Location: Coopersville, MI 49404-9643
I'm pretty sure that the transformer in a Jackson 648 won't handle the current load of the 811A tube. Monitor the filament voltage on the tube when being tested and you'll see that. You'll burn up that transformer in the tester as well if you do that too much. My Hickok KS15750L1 grunts when testing that tube and it was designed for it.

As far as testing good, bad or so-so, the Jackson is only an emission tester and it's not going to give you decent data on the tube, especially if you're going to use in a linear amp in amateur radio service. You can check for shorts with an ohmmeter, and if good, it can be tested in an audio amp. Watch the plates and the bias voltages and check for output distortion with a scope.

_________________
Kim Herron
W8ZV
kim.herron@sbcglobal.net
616-677-3706


Top
 Profile  
 
 Post subject: Re: test 811 in jackson 648s?
PostPosted: Aug Sat 03, 2019 3:08 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 758
Location: dayton oh usa
seems able to handle it fine.
voltage is around 6.25 in the 6.3v position.
i realize this isnt a very useful test but i let my al-811h go in a deal.
this would have been the best test.
it did spot tubes i marked as weak in comparison to nos.
i wondered about the heater ratings but noticed there are plenty of big sweep tubes supported that also have high demands .
i limit my test time just in case.


Top
 Profile  
 
 Post subject: Re: test 811 in jackson 648s?
PostPosted: Aug Tue 06, 2019 2:53 am 
Member
User avatar

Joined: Jun Wed 08, 2011 2:33 am
Posts: 9154
Location: Ohio 45177
I had a free, marked "bad" transmitting tube with a good filament. I was curious, so I lit it up with a big bench supply. Looked OK. Then I decided to get my variable HV supply out and put an ammeter in series with the plate and see what I could draw thru it. I started to increase the voltage and saw some current. But it did not seem to increase much when I rolled the B up until, yep, it started to glow a pretty light blue. Gas. Well I have some other vintage TX tubes around and I guess I could at least check them for gas and maybe conduction. I can test stuff like 807, 6146, sweep tubes, etc. but when you start to see the fuse bulb glowing some, you know it is getting up there.

_________________
Reddy Kilowatt says; You smell smoke? Sorry about that!


Top
 Profile  
 
Post New Topic Post Reply  [ 5 posts ] 

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 3 guests



Search for:
Jump to:  




























Privacy Policy :: Powered by phpBB