10L43 Predicta no hv

[whatadish]

I am having trouble with a recapped 10L43 chassis. I should tell you that while I have done a good bit of basic tube repairs...my advanced knowledge of reading waveforms, injecting signals and such is very limited to say the least. I have restored a couple of Admiral combo units but they were just recapping and basic alignment issues. I have met my challenge with this Predicta. Okay.I am at somewhat of a loss to explain the lack of my -45v at pin 5 of the 6dq6. Can someone tell me where that comes from. Is it via the 6cg7, pin6? The K7 netork has been replaced. I have a schematic but am at a dead end here. B+ voltages are good(maybe 10% high), vot, flyback have metered good, and at one point I actually had a modulated raster with good audio though some vertical lin needed tweaking. I have seen Bob Andersons and DaveWM's videos and actually have enough equipment to inject hot and vot signals if I have to. I have never done this before but dont mind learning from the experts out there. FYI I have rechecked the tubes and the crt tests near new....thanks in advance for any support you can give me. Sorry I should have given you this: pin 5 @ 6dq6 measures +6v, pin 6 @ 6cg7 measures 204v.

[DaveWM]

recheck and report back on all 6GC7 (horz multiplier). do this with the horz out tube out of the socket, you do not want to operate the set with no drive to that tube.

[whatadish]

okay Dave...thx for the quick response.

[Zenith26kc20]

The horiz output tube makes the grid go negative. Very limited operation with the cap off the horizontal output can show some negative if the horizontal oscillator is running. It is best to scope the grid of the horizontal if you can. Check the horizontal phasing (AFC) diodes for leakage. Once in a blue moon I have had them catch me.
On that set, also check your horizontal hold control for opens or leakage. Also, check continuity of the horizontal oscillator coil. A snapped wire will stop the oscillator
Plate resistors of the horizontal driver tube also.

[DaveWM]

a few things that should be automatic

tube wiggle horz osc, horz out.
tube sub new horz osc, horz out.
voltage checks
resistance checks per chart in sams

voltage and resistance checks are just starting points to narrow down problems like the above mentioned open coils etc.

of course the K network could be the issue, but I prefer to not go there unless pretty sure its the problem, clearly a leaking coupling cap in the network that couples the plate to the grid would cause this problem, but I would scope it to be sure 1st before going thru the effort to make a new network.

one last thing, consider PCB issues, breaks in the traces are not uncommon esp around the horz out due to heat and movement from pulling stuck tubes.


the tube subs are important since they can and do go bad. If you want to check the horz out (no sub) then use the analyst to supple a good grid drive to it. this will clear that tube as the issue.

good point about the pot too, they should be checked (both the hold and range pot) for proper operation. I prefer an analog VOM for this to not only check for continuity but for smooth operation.

[whatadish]

would I pull the 6cg7 and inject the grid drive to pin5\6dq6...is that correct

[DaveWM]

should not need to pull the horz osc, just inject the drive.

there could be a problem though if the coupling cap is leaking, then B+ will get there anyway.

I would try it a and see, just watch for signs of distress, (red plating of horz out).

You could also start with plate drive 1st then work back to grid drive just to make sure no issues anywhere else. the plate drive test the damper/flyback.

I am assuming you watched my video on testing a predicta with the 1076?

[DaveWM]

oh and yes pin 5 of the 6DQ6 for grid drive.

[old_coot88]

Originally Posted by whatadish

...I am at somewhat of a loss to explain the lack of my -45v at pin 5 of the 6dq6. Can someone tell me where that comes from.

For simplicity, think of the cathode and grid of the 6DQ6 as a simple diode rectifier. That's what the drive signal "sees". The "diode" can conduct in one direction only, cathode-to-anode. An excess of electrons, which equals a negative charge, appears on the grid. So voltage on the grid ('anode') is negative relative to the cathode.

In early radios, the same principle was called 'grid leak' detection.

[whatadish]

okay so I got my 10L43 chassis back from a supposed repair person in Washington State. What a huge mistake. I sent him a chassis with good sound and a partially modulated picture and got back a totally non working chassis with no sound, no hv and a red-plating hot. Some of the sloppiest "repair" work I have ever seen. Okay Dave...I have tube extenders but no scope. You wanted me to take measurements of the 6cg7 with the hot out...is that correct? Looks like the K7 was replaced with what he said was nos...not sure if that was a good idea. I have lifted the board and repaired the "hook and go" repairs. Stand by for 6cg7 measurements...and thanks.

[WISCOJIM]

Plenty of people have had trouble with RoXX MaXXXXll, myself included. His history of Predicta and eBay troubles goes back at least as far as 2006 when I won a judgement against him.

Unfortunately eBay still lets him prey on the uninformed, and through his website he finds many more victims.

He's famous for his Predicta "restorations". You send him a chassis, and he replaces only a few capacitors and returns it to you always claiming it works perfectly. You then get the chassis back and find tons of problems including that the chassis just doesn't work. I had this happen twice with him. I was a fool for using him a second time. Then my chassis disappeared, later to be seen on his eBay page "for sale" as a restored chassis.

Somehow he gets away with this over and over, and those victims such as myself that previously mentioned his full name get threats of defamation lawsuits from him and his cronies. We then have to edit him out of our posts.

He likes to call me a liar when talking of him on the forums, but he also knows that I have all the correspondences via eBay and a whole file of his personal emails saved.

If you want a laugh, read the email below that I received from him April 12, 2006. Actually it's probably not funny. It's purely pathetic.

----- Original Message -----
From: "ROXXMXXXXXLL" <roXXmXXXXXll@sbcglobal.net>
To: "tvXXXXXXXos" <tvXXXXXXXos@new.rr.com>
Sent: Wednesday, April 12, 2006 3:29 AM
Subject: Re: Message LOST CHASSIS

> Dude, i did not take advantage of you.
> Nor were to people on the damned Titanic totally prepared to handle what
> they got thrown into.
> I was good on ALL deals prior to this.
> I sent the damn thing, and ahgain, stressed and in a fucking hurry to
> SATISFY EVERYONE< but myself, forgot to file a DELIVERY CONFIRMATION on the
> box - and of course, the post office lOST it.
> That's what I GUESS has happened.
> Seems people STEAL things - for every time I put a TRACKING CONFIRMATION
> STICKER ON boxes, they never get lost.
> One in 10-15 boxes I send, and usually a Bigger BOX, "without" a
> confirmation of Delivery, gets SNAGGED.
>
> I am FLAT ruined ands broke, unless this LADY forks over 3,000 grand of a
> DOWN on my house - I am moving back to L.A. Area, and will be putting THAT
> addrss on my WEB SITE.
>
> I AM NOT hard to locate - in fact I am too easy to LOCATE.
>
> Either BEFORE or AFTER I get down there, I will take a chuink of the 3000
> grand and PAY EVERYONE I AM IN DEBT TO... other than the God Damned Credit
> Card Companies.... I am getting too old to PAY them back.
>
> By the time they CLEARED my CREDIT REPORTS and I am elgible for clean
> credit, I would be 57 F----g YEARS OLD!!!!
>
> So, at least "people" and such like you WILL be easily PAID OFF.
>
> Sorry for all this happening - it was NEVR intentional - hell, I run a TV
> repair business?
>
> WHY would I PURPOSELY SCREW SOMEONE, who can easily BAD MOUTH ME?
> Easily RUIN my PAYPAL, and EBAY, and etc, and etc, and etc, and etc????????
>
> People,.......???,,, lets all use our HEADS and quit thinking SELFISHLY
> paranoid, as IF "WE" are the only one being screwed?
>
> It's like, WHEN "they" drop that damn BOMB on IRAN soon, even p[eople in
> Tasmania, are going to eat a little crap!!!
>
> So, I lost ( the POST OFICE ) lost another chassis?
>
> This happened 3 weeks ago with another guy.
>
> I had to gut a spare TV and send ANOTHER chassis to him.
>
> That, above, plus all that has happened has added a DOMINO collaspe on me I
> could not stop.
>
> thought I could, but NOOOOOOO,... someone had to fucking STEAL or LOOSE your
> chassis on top of everything else......
>
> So, I give UP.... I am selling this DAMN house DUMP and goiung HOME.
>
> I will take care of you first, before I do.
>
> I have to at least SALVAGE my TV business -
>
> Uncle Sam's SSI and SSEC just does not PAY enough!
>
> ROXX
>
>

I never did receive my money or chassis back from him directly, but did get this nice correspondence from eBay:

----- Original Message -----
From: <service@paypal.com>
To: <tvXXXXXXXos@new.rr.com>
Sent: Friday, April 21, 2006 10:42 PM
Subject: [Norton AntiSpam] Resolution of Buyer Complaint: Case #PP-157-796-431


> Dear JXX XXXXXXg,
>
> We have concluded our investigation into your claim.
>
> We have decided in your favor have recovered funds from the seller.
> We were able to recover $180.00 USD and this amount has been credited to
> you. Please allow five business days for this adjustment to be posted.
>
> If you are due any additional amount from the seller, we will make our best
> effort to recover the balance from the seller.
>
>
> If the seller's account has insufficient funds to complete the refund owed
> to you, please be assured that we will take appropriate action against the
> seller's account, which may include limitation of the seller's account
> privileges.
>

[whatadish]

okay Dave here are the 6cg7 reads:
pin 1............196v
pin2.............-.25v
pin3............6.6v
pin4............6.3vac
pin5............0v
pin6............250v
pin7..........-9.5v
pin8............6.7
pin9............0v
hope this helps...btw, I can draw an arc when i lift the hot cap.

[whatadish]

ugh...should have asked around here first...well maybe this is salvageable. Should have probes for my scope tomorrow, but I have extremely limited knowledge of it's use. I learn pretty quickly though. I can take hi res pics of the op panel and maybe I can get some support here on learning to use it. Got all this stuff from an old Westinghouse engineer. I can use 80% of it pretty well. I am a little embarrassed about dealing with Ro** but you only get to fool me once. Thanks again in advance.

[Phil Nelson]

The 10L43 chassis is a well known item among TV people. If you are patient, the folks in this forum should be able to guide you through the wild, wacky world of Predicta restoration. This article has some notes that may be useful:

http://antiqueradio.org/PhilcoH3412L...Television.htm

When I worked on mine, I found the Philco factory manual on eBay and it was useful to have that in addition to the Sams manual. Each one has a few things that the other lacks. My article includes a few pages from the Philco manual, but I recommend getting the entire thing.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[whatadish]

thanks Phil....I am quite familiar with your site as well as the restorations performed by Dave, Bob Anderson, and you. While my technical expertise is not near as well honed as some of the experts here...I am no stranger to vintage audio gear and have restored many tube amplifiers. Currently listening to a Scott LK72. This is my second foray into tv restoration...guess I picked a good one. I also have a Holiday chassis that has been recapped as well but no crt for it. I like learning from no bs people. Thank you all in advance and I hope I can contribute to this great gathering of techies. One of my earlier posts has a link to my photobucket page...you can see some of my previous restoration ventures there.