The Talking Machine Forum — For All Antique Phonographs & Recordings

It is currently Mon May 27, 2019 3:36 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 71 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6, 7, 8  Next
Author Message
 Post subject: Re: Restoring the VE 9-55 and VE 9-25 Amplifiers
PostPosted: Wed May 08, 2019 9:47 pm 
Offline
Victor III
User avatar
Joined: Mon Oct 21, 2013 9:58 am
Posts: 574
Location: Florida
The Sencore LC103 Capacitor/Inductor tester arrived today. See photo below.

I tested the isolated choke in the Fuzz Filters of the four amps and they measured 503-525mH. (Note that previously I had ohm tested them and they all were about 80 ohms.) I performed the ringer test and all four tested BAD - 7 rings. I take it that the tester was wanting to see more rings. Does anyone know if 7 rings for this inductor is really bad?

I was very much looking forward to testing the three transformers out with this tester. I see that my 3 test buttons to choose from are "Coils", "Yokes & Flybacks", and "Switching Transformers". Am I correct in thinking the only test button that would be appropriate to test the primaries and secondaries of the three transformers is the "Coil" test button or is it that this tester is inappropriate to test transformers?

I ask the question about testing the transformers with the "Coils" button selected and then depress the "Inductor Value" button because I end up getting what I feel are, in some cases, erroneous readings. Though I do get about the same on all the transformers on all three of the amps I tested. Below are my test points related to the isolated transformers. I have included my resistance readings ranges from testing the amps, as well as the Inductor Value test readings within parenthesis.

INPUT TRANSFORMER PRIMARIES: 382 to 393 ohms, (Over Range)
INPUT TRANSFORMER SECONDARIES: 1.3K ohms, (Over Range or Open)

OUTPUT TRANSFORMER PRIMARIES: 188 to 197 ohms, (13.8 to 15.5 H)
OUTPUT TRANSFORMER SECONDARIES: .2 to .4 ohms, (13.5 mH)

POWER TRANSFORMER PRIMARIES: .6 to .8 ohms, (116 to 165 mH)
POWER TRANSFORMER TO 210 TUBE FILAMENTS: 0 to .2 ohms, (-92 to -111 uH)
POWER TRANSFORMER TO 281 TUBE FILAMENTS: 0 to .2 ohms, (-88 to -245 uH)
POWER TRANSFORMER TO 281 TUBE PLATES: 244 to 255 ohms, (Over Range)

CHOKE BETWEEN TERMINALS #6 & #9: 972 to 1K ohms, (Over Range)


Attachments:
0CA2EC7D-8F11-4375-8F48-76E0C32535EF.jpeg
0CA2EC7D-8F11-4375-8F48-76E0C32535EF.jpeg [ 2.51 MiB | Viewed 154 times ]
Top
 Profile  
 
 Post subject: Re: Restoring the VE 9-55 and VE 9-25 Amplifiers
PostPosted: Fri May 10, 2019 5:32 pm 
Offline
Victor III
User avatar
Joined: Mon Oct 21, 2013 9:58 am
Posts: 574
Location: Florida
Well, I can only assume that I should be able to do an inductance measurement on the primaries and secondaries of the three transformers in my amps. I don’t know why I get “over range” (or maybe it was “out of range”) on some as indicated in my previous post. After I verify there isn’t any continuity between coils and cores, I think I’ll just put 120 vac on the primary of the currently isolated power transformer of all the amps, and see if I get consistent voltages on the secondaries. As far as bench testing the input and output transformers, I don’t know of a way to verify them before going live with the complete system.

I just started on the Condenser Bank units of the three VE 9-55s I am working on. I am selling two of these VE 9-55s (serial#766 and #2160) one of which is pre-sold thru Raphael and the one I’m keeping that I recently discovered that ChuckA had rebuilt the amp in and now I see the Condenser Bank was as well.

The Condenser Bank is composed of seven 2uF capacitors, as seen in the schematic drawing below. I took measurements between the terminals to determine the total capacitance between those points on all three Condenser Banks. With the zero values attained on the unit from the #2160 machine, I figure it’s a given I must recap it. I plan tho use the same 2.2uF caps I used in the amps, see link below. The unit from the #766 machine read good capacitances but failed two out two leakage tests when testing C6 and C7. So this unit needs a total recapping as well.

https://www.newark.com/vishay/mkp1840522404m/film-capacitor-mkp1840m-series/dp/53M8382?ost=MKP1840522404M&ddkey=https%3Aen-US%2FElement14_US%2Fsearch


Attachments:
65E98C31-8262-4277-A5B8-F5EF01A952C6.jpeg
65E98C31-8262-4277-A5B8-F5EF01A952C6.jpeg [ 2.11 MiB | Viewed 119 times ]
5842D6D3-4637-4157-BB11-258D595C13A4.jpeg
5842D6D3-4637-4157-BB11-258D595C13A4.jpeg [ 1.91 MiB | Viewed 119 times ]
Top
 Profile  
 
 Post subject: Re: Restoring the VE 9-55 and VE 9-25 Amplifiers
PostPosted: Mon May 13, 2019 1:49 pm 
Offline
Victor III
User avatar
Joined: Mon Oct 21, 2013 9:58 am
Posts: 574
Location: Florida
Painted, labeled, and retested. Ready to install. Hope I’m not boring anyone detailing every step.


Attachments:
5F0E07E8-AABE-4F2A-9F8B-236C84E81D30.jpeg
5F0E07E8-AABE-4F2A-9F8B-236C84E81D30.jpeg [ 2.62 MiB | Viewed 81 times ]
Top
 Profile  
 
 Post subject: Re: Restoring the VE 9-55 and VE 9-25 Amplifiers
PostPosted: Mon May 13, 2019 1:52 pm 
Offline
Victor IV
Edison, Columbia, Victor, Pathé...and oddball makes
Joined: Sun Jul 08, 2012 1:06 pm
Posts: 1322
Better add “REPRODUCTION 2019” or something like it to the reimagined capacitors, lest the next sap tosses and replaces them.


Top
 Profile  
 
 Post subject: Re: Restoring the VE 9-55 and VE 9-25 Amplifiers
PostPosted: Mon May 13, 2019 4:21 pm 
Offline
Victor III
User avatar
Joined: Mon Oct 21, 2013 9:58 am
Posts: 574
Location: Florida
How’s this label Peter? Although I must take a little offense to your term “reimagined”. I went thru a tremendous amount of work to restuff these cans, paint, and to recreate the original sticker. “Reimagined” is more a term used when you toss the cans and just mount new exposed caps. Perhaps I’m just a little sensitive how long this took me and that you are always pushing labeling reproduction parts. Perhaps it would be good if you demonstrate how you have labeled your reproduction parts on your machines. I am going to print a schematic with the the fuse locations and values to be stored in the accessory drawer.


Attachments:
BDD90711-353E-4FD1-85E1-7DDF40E60538.jpeg
BDD90711-353E-4FD1-85E1-7DDF40E60538.jpeg [ 2.69 MiB | Viewed 69 times ]
Top
 Profile  
 
 Post subject: Re: Restoring the VE 9-55 and VE 9-25 Amplifiers
PostPosted: Mon May 13, 2019 4:49 pm 
Offline
Victor IV
Edison, Columbia, Victor, Pathé...and oddball makes
Joined: Sun Jul 08, 2012 1:06 pm
Posts: 1322
Oh no offense intended, so please don’t be offended.

I don’t have a better word. Maybe “restuffed” is actually the best.

The only reproduction parts on any of my machines are the 10-50 bits you made for us, and some gears on my 9-40, and a fiber gear deep inside one of my Victor R’s.

The former two machines will have explanatory labels attached securely, inside. The electronics are plainly and obviously upgraded to modern components (for safety and reliability) so no notice is required, although a marked up schematic and the old parts will be left inside in sealed bags for future curiosity.

The R has the old fiber gear inside the case, and although the new one is obviously a reproduction because it’s made of black nylon, I scratched the date and other info onto its face.

My original comment is intended to keep your extra work from being inadvertently discarded by a future owner because you did “too good” of a job with the cosmetics.


Top
 Profile  
 
 Post subject: Re: Restoring the VE 9-55 and VE 9-25 Amplifiers
PostPosted: Mon May 13, 2019 6:36 pm 
Offline
Victor III
User avatar
Joined: Mon Oct 21, 2013 9:58 am
Posts: 574
Location: Florida
Thanks Peter, both for your explanation and kind words.

Btw, I was wondering about an earlier comment you made during the fuse discussion. You had mentioned you were considering getting rid of the Ballast, due to its high heat, and the power transformer. Do you have to replace the transformer if you wanted to replace the Ballast with diodes? I happen to have a modified AP-952 I bought off eBay one time, that has a newer power transformer and I see the wiring to the Ballast was bypassed, though I didn’t notice any diodes. The cap cans were removed and new caps added. There’s even a fuse. I have yet to test it out in any way. See photo below.


Attachments:
120DE2F2-9F0B-4FEE-BD18-3F910193729E.jpeg
120DE2F2-9F0B-4FEE-BD18-3F910193729E.jpeg [ 2.97 MiB | Viewed 59 times ]
FFEB2A2F-9711-4B06-9125-4A9691837B74.jpeg
FFEB2A2F-9711-4B06-9125-4A9691837B74.jpeg [ 3.43 MiB | Viewed 59 times ]
Top
 Profile  
 
 Post subject: Re: Restoring the VE 9-55 and VE 9-25 Amplifiers
PostPosted: Mon May 13, 2019 6:57 pm 
Offline
Victor IV
Edison, Columbia, Victor, Pathé...and oddball makes
Joined: Sun Jul 08, 2012 1:06 pm
Posts: 1322
Well that’s coming from something Chuck mentioned during a phone call, and I plan to get the details from him and decide from there. I don’t have the proper angled chimney for the ballast and am dreading the smell and potential fire hazard from that big hot bulb, even if I find one.


Top
 Profile  
 
 Post subject: Re: Restoring the VE 9-55 and VE 9-25 Amplifiers
PostPosted: Mon May 13, 2019 7:41 pm 
Offline
Victor III
Joined: Sat Apr 20, 2013 3:01 pm
Posts: 554
Location: Coos Bay, Oregon
I probably should not put my 2 cents in on this, but it is a safety matter, so here goes. That ballast tube is a sort of regulator which drops significant voltage. If it is removed, something must go in its place which will drop a similar amount of voltage. Diodes would not drop enough voltage unless a whole bunch of them were in series since diodes have about a half volt forward voltage drop. Then there is the problem that they would cause pulsating DC to be at the primary of the power transformer, except if you put an equal number in the reverse direction. That could be a costly mod. A resistor is a reasonable alternative yet it would have to be about a 100 watt one to dissipate the heat safely. Cheers, Russie


Top
 Profile  
 
 Post subject: Re: Restoring the VE 9-55 and VE 9-25 Amplifiers
PostPosted: Mon May 13, 2019 8:15 pm 
Offline
Victor III
User avatar
Joined: Mon Oct 21, 2013 9:58 am
Posts: 574
Location: Florida
Russie,

Your 2 cents is always appreciated. Perhaps that is the purpose of the added 1500 ohm wire wound tube ceramic resistor seen circled below. Though I’m not interested in modifying any my amps to operate without the Ballast, I certainly can appreciate why Peter may want to, besides, I’m interested in the idea because it appears I have such a modified spare amp. I will trace out the wires and draw out the differences on an AP-952 schematic in the not so distant future. Btw, the AP-952 was used on the VE 10-51, VE 12-12, and VE 12-25. The AP-952Y version was one of the amps used on the VE 10-70.


Attachments:
FC62AA3F-07EF-4889-A0EA-D5E120937C75.jpeg
FC62AA3F-07EF-4889-A0EA-D5E120937C75.jpeg [ 868.61 KiB | Viewed 52 times ]
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 71 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6, 7, 8  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: Google [Bot], MTPhono and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Americanized by Maël Soucaze.