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


It is currently Dec Wed 08, 2021 10:43 am


All times are UTC [ DST ]





Post New Topic Post Reply  [ 28 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Jackson 715 Tube Tester
PostPosted: Jan Wed 09, 2019 6:13 pm 
Member
User avatar

Joined: May Fri 25, 2018 1:50 am
Posts: 841
Location: Petaluma, California
I'm going to pickup a well used Jackson Tube Tester Model 715 from a Craigslist buy. What do you look out for when you get a used tube tester? Any tests to perform like dim bulb testing? Any threads exist that cover the basics?
Thanks,
John
edit: seller has no documentation on the device.
Image

_________________
Save the Knobs!


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Wed 09, 2019 6:36 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 16793
Location: Albuquerque, NM 87123
I would not get any tube tester unless set-up data and other information was available for it.

That tester looks like it hasn't been taken care of very well; the meter is cracked and the shorts neon lamps is missing or pushed in. Does it have the cover?

Edit: I checked BAMA and eBay; only one seller on eBay has information, and that is only a technical bulletin for the 715. BAMA has nothing. I would not buy that tube tester.


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Wed 09, 2019 6:56 pm 
Member

Joined: Mar Thu 12, 2009 2:20 am
Posts: 1615
Location: Dayton, OH
Data is available

A 715 is the same as a 561. Only differing case styles

Holler if you cant find anything else and you decide you need it. I can email it when Im at home

David

Edit: Now this is (my) crusty looking Jackson: viewtopic.php?f=7&t=243724
Edit2: Its also the same as the Jackson 115.


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Wed 09, 2019 9:24 pm 
Member
User avatar

Joined: Nov Wed 30, 2016 7:35 pm
Posts: 11326
Location: Sunbury, Ohio 43074
I wouldn’t buy that one unless you know the meter is good or you really get it cheap. I’d also want to take a look inside and make sure the switches are not corroded

_________________
Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Wed 09, 2019 10:11 pm 
Member
User avatar

Joined: May Fri 25, 2018 1:50 am
Posts: 841
Location: Petaluma, California
It was cheap and the gent who sold it gave the family history: "Dad was a ham and EE, these have been in the shed since he died 15 years ago. I used to test my amp tubes on this.". I know there is a pithy Latin phrase for that story ...

_________________
Save the Knobs!


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Wed 09, 2019 10:13 pm 
Member
User avatar

Joined: Nov Wed 30, 2016 7:35 pm
Posts: 11326
Location: Sunbury, Ohio 43074
All that may well be true. But the meter shell is broken, and if it was "in the shed" for decades, you'd better hope the shed was indoors and dry. :)

At any rate, it'll be a nice project as long as you have patience

_________________
Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Wed 09, 2019 10:51 pm 
Member
User avatar

Joined: May Fri 25, 2018 1:50 am
Posts: 841
Location: Petaluma, California
dholland wrote:
Data is available

A 715 is the same as a 561. Only differing case styles

Holler if you cant find anything else and you decide you need it. I can email it when Im at home

David

Edit: Now this is (my) crusty looking Jackson: http://www.antiqueradios.com/forums/vie ... 7&t=243724
Edit2: Its also the same as the Jackson 115.


David, Thanks for that link, I'm lucky (so far) the face plate cleaned up nicely, I have to get the scrolling roller freed up a bit, it is quite sticky. The crack on the meter bezel was mended with something, it seems to be holding its own for now.
I find you had digitized the tube chart and listed the link to it back in 2014. Is it possible to send an updated location for that doc? I found the 115 user manual, if there is something 715 specific let me know.
If it is a simple as it looks, the screws around the face plate should allow one access to the innards of this thing, yes? Cover then slips off and the power cord pulls through and ...
Off we go,
John

_________________
Save the Knobs!


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Wed 09, 2019 11:00 pm 
Member
User avatar

Joined: May Fri 25, 2018 1:50 am
Posts: 841
Location: Petaluma, California
Found: https://tubesound.com/jackson-561-tube-tester/ looks to be a nice step by step on reconditioning the 561.

_________________
Save the Knobs!


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Wed 09, 2019 11:33 pm 
Member

Joined: Mar Thu 12, 2009 2:20 am
Posts: 1615
Location: Dayton, OH
As far as I know, the only difference between the 561, 115, and 715 is only the case styles, so, nope, no differences I'm aware of.

I uploaded the bits I have for my 561 archived away, to mediafire. The website I had digitized roll charts on went away a long time ago.

Look in the Jackson561 folder off of here:

https://www.mediafire.com/dholland

(It *is* mediafire, so I'd recommend at least an adblocker. :-? - but its also free, so I can't complain too loudly.)

My understanding (from tubesound) is the 634 data is also applicable to the 561/115/175, so I have a 634 manual in the directory as well.

If the meter & transformer is good, then I think its a worthwhile tester to clean up. (My opinion is worth exactly what you paid for it. :-D )

Hope it helps,

David


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Thu 10, 2019 1:30 am 
Member
User avatar

Joined: May Fri 25, 2018 1:50 am
Posts: 841
Location: Petaluma, California
Thanks for the zip file, didn't have any issues other than the ad-block notices for which they provide a "continue anyway" button, how nice.
Inside nothing weird visually - meter looks sound, a few crusty bits around the transformer wires, but nothing huge jumps out, all the switches seem fine, no green contacts.

Image

_________________
Save the Knobs!


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Fri 11, 2019 8:31 am 
Member
User avatar

Joined: May Fri 25, 2018 1:50 am
Posts: 841
Location: Petaluma, California
Ordered the 25 mfd 25 V cap which is across the meter - I don't see any mention of that in the 561 or 115 schematics I have, any clue why it is there? It tested at 56 uf, shows no leaking, but its out of spec.
The C1 cap also was off (.50 uf) and replaced with a .1 uf 640V.
I've replaced all the carbon resistors, some were going high, others were just funky looking. I left the two Tru-Ohm brown ceramics (R1 and R2) in place, they tested OK.
Some housekeeping, cleaning up with IPA and DE-OXIT seems to have restored the feel in the push buttons and other switches.
While I wait for the 25 uf cap, I'll get the 6C4 to another tester and see how it is.
Cheers,
John

_________________
Save the Knobs!


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Fri 11, 2019 11:52 am 
Member
User avatar

Joined: Nov Wed 30, 2016 7:35 pm
Posts: 11326
Location: Sunbury, Ohio 43074
The cap across the meter is close enough for you to start playing with the tube tester, as-is. It won't change the operation or readings. It was probably a factory change, but possibly someone just added it. It has the effect of "damping" the meter a bit .... in other words, basically slows down the action. It will smooth out any oscillating voltage, and provide a bit of damping. In a nutshell, changes the ballistics slightly.

_________________
Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Fri 11, 2019 9:14 pm 
Member
User avatar

Joined: May Fri 25, 2018 1:50 am
Posts: 841
Location: Petaluma, California
Barry H Bennett wrote:
The cap across the meter is close enough for you to start playing with the tube tester, as-is. It won't change the operation or readings. It was probably a factory change, but possibly someone just added it. It has the effect of "damping" the meter a bit .... in other words, basically slows down the action. It will smooth out any oscillating voltage, and provide a bit of damping. In a nutshell, changes the ballistics slightly.


Thx Barry - It occurred to me last night that the cap might just be a damper but better to ask.

Other than the smell test, should I do a dim bulb test? just bring it up on the variac? or is that only for suspect transformers? This transformer looks intact, nothing odd visually.

_________________
Save the Knobs!


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Sat 12, 2019 12:34 am 
Member

Joined: Mar Thu 12, 2009 2:20 am
Posts: 1615
Location: Dayton, OH
It certainly isn't going to hurt to bring it up in a controlled fashion (eg: monitoring current draw...) the first time or two...

Hook it up, exercise the switches, test a few known tubes... That's what I'd do...

David


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Sat 12, 2019 2:17 am 
Member
User avatar

Joined: May Fri 25, 2018 1:50 am
Posts: 841
Location: Petaluma, California
It cleaned up nicely ...
Image

It came up on the variac, the meter works, pilot light is good, neon responded when I flipped the Y circuit between 2 and 3. Meter has a jitter, so the 25uf cap will go back on when it arrives. Meter also comes up above center then settles down to center after warming up.
So far, so good, thanks everyone! Me and the manual tonight ... :)

_________________
Save the Knobs!


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Sat 12, 2019 2:24 am 
Member
User avatar

Joined: Nov Wed 30, 2016 7:35 pm
Posts: 11326
Location: Sunbury, Ohio 43074
Lookin' good .... it's always nice when you clean one of these and it looks new-ish. You never really know whats lurking under decades of crud.

_________________
Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Sat 12, 2019 3:35 am 
Member
User avatar

Joined: May Fri 25, 2018 1:50 am
Posts: 841
Location: Petaluma, California
OK - don't know if this is critical or not but I was following the reconditioning steps outlined at tubesound's blog ; https://tubesound.com/jackson-561-tube-tester/ and they recommend this:

Image

When I reassembled, set the pot to full left and then aligned the dial to zero.

Then I read this in the 561 manual (the text in italic worries me):
Image

Anything to worry about? If so, any idea how to tell if its out of whack?

Sheesh - John

_________________
Save the Knobs!


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Sat 12, 2019 4:42 am 
Member
User avatar

Joined: May Fri 25, 2018 1:50 am
Posts: 841
Location: Petaluma, California
I also found this interesting google book from Alan Douglas, who I've seen in old posts here at ARF:
https://books.google.com/books?id=FaFmOQyHg4sC&lpg=PA55&ots=OYZvLLARDL&dq=Jackson%20Electrical%20Manufacturing%2C%20Dayton%20Ohio&pg=PA55#v=onepage&q=Jackson%20Electrical%20Manufacturing,%20Dayton%20Ohio&f=false

He lists the 115 from 1952 at $66 retail and the 715 from 1953 at $71. This is good to know as I'm using the 115 schematic and the 561 (1957) users guide. Nice discussion of Jackson's history and different testers. I was searching for Jackson Electrical Company, Dayton Ohio.
Cheers,
John

_________________
Save the Knobs!


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Sat 12, 2019 4:59 am 
Member
User avatar

Joined: Nov Wed 30, 2016 7:35 pm
Posts: 11326
Location: Sunbury, Ohio 43074
Well, for one thing, the tubesound article says he sprayed Deoxit into the semi-sealed potentiometer. Bad idea. Spraying something into a potentiometer that has no way for extra stuff to get out, or evaporate properly, is asking for trouble.

Without making negative comments about any one in particular, it's always a good idea to gather MANY opinions on how to do something with 70 year old equipment, before doing it. On the internet, there is likely to be a lot more bad information, than good. Sometimes it's well intentioned but just wrong, sometimes you'll get someone wanting to show off how much they think they know.

That potentiometer in your tester may or may not have even needed cleaning. Sometimes just exercising it a few times is sufficient. But if cleaning were necessary, I'd have opened the pot to do so. Hopefully you'll be OK and haven't introduced any stray leakage into the system.

As far as the dial calibration, I've not personally worked with this tester. Hopefully someone has. But, do you have access to the manual? It may list the calibration procedures there.

_________________
Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


Top
 Profile  
 
 Post subject: Re: Jackson 715 Tube Tester
PostPosted: Jan Sat 12, 2019 6:09 am 
Member
User avatar

Joined: May Fri 25, 2018 1:50 am
Posts: 841
Location: Petaluma, California
The only manual found so far is for the 115, the older brother to the 715, the above is a quote from that doc. At least we've flagged that pot cleaning issue so others won't run into it. Seems the 715 is a bit of a rare bird and while there are similarities between these in this product line, I'm thinking each is a little different, why else would Jackson reissue a new model?

Good news is that I've tested 5 mini's, one was bad and four had tested good bad (per another tester) and the results matched.
I'm going to pull down some other socket types and see how they compare to previous testing.
So, on we go - this has already answered one question about a 1S5 which was worrying me, now at least I can eliminate it from the potential problems, nice!

_________________
Save the Knobs!


Last edited by sergneri on Jan Sat 12, 2019 7:20 pm, edited 1 time in total.

Top
 Profile  
 
Post New Topic Post Reply  [ 28 posts ]  Go to page 1, 2  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 14 guests



Search for:
Jump to:  




































Privacy Policy :: Powered by phpBB