View Full Version : Packard Bell 17VT1


Winky Dink
06-26-2017, 10:37 AM
Subject: CRT Testing

I would never have thought of acquiring this set, but a friend (Iíll call him Philo) rescued it from someone who was putting it out with the garbage. He plugged it in and the screen lit up, so he shipped it to me. For free, Iíll try to put the set in working order. Philo will get a kick out of that.

Iíve pulled the chassis, and all the parts are there. The only shipping damage is one broken tube and a broken escutcheon, both easily repaired or replaced. And the yoke is loose on the CRT neck.

My next step will be to check continuities to ensure other significant components arenít dead. Iíve tested the tubes, including the CRT.

Iíd like an experienced person to assess my test results on the 17AVP4. With a Beltron 8080A, 6.3 heater volts:

No shorts.
Ten seconds to reach 0.45mA.
After four minutes, it reaches 0.55mA or maybe 0.65mA.
Interrupt: Current immediately decreases, reaching almost zero in seven seconds.

https://c1.staticflickr.com/5/4213/34739933323_7e48a1377d_z.jpg

So, before I spend any time on this set, what can I expect from the CRT?

Thanks all,
Henry

bandersen
06-26-2017, 11:35 AM
How long did you have thee CRT running on the tester ? I like to leave them run 30 minutes to a couple hours to "wake" them up. Often emissions, cutoff and life test will improve.

Winky Dink
06-26-2017, 02:24 PM
Thanks. I only ran it five or ten minutes. I'll run it for a couple of hours this afternoon and see what I get.

Winky Dink
06-26-2017, 05:09 PM
I checked the heater voltage from the 8080A. It was probably 6.7 volts for the previous test. I adjusted it to 6.3 volts and ran it for 90 minutes. This time it took about 2 minutes to peak at barely over 0.2 mA, then slowly decreased to 0.15 mA where it stayed for the entire test period--then dropped to less than 0.05 mA in a few seconds.

Entirely hopeless? Even if it's hopeless I'm going to play with the restorer just to see if the meter and indicator lights work.

maxhifi
06-26-2017, 05:18 PM
After you let it "cook" for a while, if it's still really weak, you can also try running it at, say, 8V for 10 minutes, then put it back down to 6.3 and test it again. Has worked for me. Only time I tried "restore" was on a Trinitron, and it made it much worse, rather than better.

Winky Dink
07-11-2017, 07:31 PM
I left the instrument on for several hours and tried increasing the voltage for 10 minutes, but had little change in subsequent test results. Then I ran the restoration procedure one time. After that the test meter rose promptly to .85mA, the minimum "good" result. When the voltage is cut, it only held that current for two or three seconds. I repeated the test two days later with the same outcome. So, I'll proceed with the electronic restoration and hope for the best.

StellarTV
07-12-2017, 11:40 AM
Since you've got the Beltron, run a clean cycle on the tube. Won't hurt a thing and it's very likely to bring that tube right back, even without running a full restore cycle on it. I just can't say enough about Beltrons. :banana:

Winky Dink
07-12-2017, 04:32 PM
After reviewing my personal notes and retrieving deleted email, I now recall that I ran a cleaning cycle first without even a flicker of the lights, then did one restore cycle. That's my story and I'm sticking to it!

Electronic M
07-12-2017, 08:06 PM
I ran a cleaning cycle first without even a flicker of the lights...

That is normal. Do you have any idea how many tubes you'd need to clean at once to make all the lights in your house flicker? :D

Winky Dink
07-13-2017, 02:54 PM
If you knew me better, you’d realize that I might take down the entire power grid by changing the batteries in a flashlight. (Just ask my wife what happened the first time I tried to fix a toilet.)

Winky Dink
01-31-2018, 09:49 PM
Well, it only took me six months to get back to this. I did a quick repair on the escutcheon and reassembled it for photos.

https://farm5.staticflickr.com/4703/26103879608_115b342fb5_z.jpg

.
. It's a 1956 Packard Bell 17VT1--a cube with a rectangular CRT in front, knobs on one side, and a simulated wood finish. Chassis V8-1.

https://farm5.staticflickr.com/4666/26103879988_794e7b6d0f_c.jpg

https://farm5.staticflickr.com/4678/39944861722_be5987077f_c.jpg

Before I pull the chassis again, I have an opening question:

Should I pull the CRT first to start the chassis work?

Thanks,
Henry

kvflyer
02-01-2018, 07:46 AM
Well, it only took me six months to get back to this. ...
Before I pull the chassis again, I have an opening question:
Should I pull the CRT first to start the chassis work?
Thanks,
Henry
Henry, it would certainly make life easier. But the question is are you up to reinstalling the CRT and all that goes with it?

Your call...

Winky Dink
02-01-2018, 10:22 AM
Thanks. Did that last night. Only had to cut six (clearly colored) leads from the yoke. Yoke, ion trap, etc. stays on the neck. The yoke is loose anyway.
- Henry (formerly of Indian Head, Silver Spring, Baltimore, Columbia, and Frederick)

jr_tech
02-01-2018, 01:56 PM
Sometimes if the yoke does not slide off easily over the base cap, a little gentle heat from a hairdrier is helpful.

jr

kvflyer
02-01-2018, 02:45 PM
...
- Henry (formerly of Indian Head, Silver Spring, Baltimore, Columbia, and Frederick)

kvflyer, AKA Don Cavey. Worked C&P Telephone, Columbia, Arbutus, Cockeysville, Manor, Essex, etc. Now retired in for 15 years ... Fernandina Beach, Florida! No snow to shovel.

Electronic M
02-01-2018, 06:12 PM
Sometimes if the yoke does not slide off easily over the base cap, a little gentle heat from a hairdrier is helpful.

jr

Wrapping a thin card stock shim around the glass over the bakelite base can also help.

Winky Dink
02-02-2018, 02:25 AM
Removing the CRT with the accoutrements attached was simple. Aquadag coating (or whatever) looks intact.

https://farm5.staticflickr.com/4721/26162749018_70241da678_z.jpg

Cleaned up the chassis a bit, and now I'm checking continuities through all coils. The yoke checks out OK.


https://farm5.staticflickr.com/4620/39325331364_cbb11e86a3_c.jpg

Winky Dink
02-04-2018, 06:03 PM
Below is a photo of the wiring of one of the 'lytics. It appears to be factory-wired, but I can't reconcile it with the Sams schematic, parts list, and the info stamped on the can.

https://farm5.staticflickr.com/4704/25210208397_32efa7ca2c_c.jpg

So, please tell me that I'm reading it wrong or, if the schematic and the wiring disagree, which I should do--follow the schematic or duplicate what's already there.

Thanks,
Henry.

dieseljeep
02-04-2018, 06:20 PM
Below is a photo of the wiring of one of the 'lytics. It appears to be factory-wired, but I can't reconcile it with the Sams schematic, parts list, and the info stamped on the can.

https://farm5.staticflickr.com/4704/25210208397_32efa7ca2c_c.jpg

So, please tell me that I'm reading it wrong or, if the schematic and the wiring disagree, which I should do--follow the schematic or duplicate what's already there.

Thanks,
Henry.
The schematic is wrong!
The 6AS5 audio output tube is used a voltage divider as well. The voltages shown are way off. The voltage on the cathode should be at least 100 volts or more.
Just wire it the way you find it! It worked before! :scratch2:

Winky Dink
02-04-2018, 07:52 PM
Thank you. I'll proceed as advised and I'll keep in mind the voltage discrepancies when I get there.

dieseljeep
02-05-2018, 09:58 AM
Thank you. I'll proceed as advised and I'll keep in mind the voltage discrepancies when I get there.

The plate and the screen should read the full B+ of the set, 250 to 280 volts or so. The cathode should read 110 volts or so, to supply the IF and a few other circuits.

Tom9589
02-05-2018, 07:59 PM
The "half-circle" symbol next to the voltage readings indicate that these particular voltage readings are referenced to another point other than chassis ground.

dieseljeep
02-06-2018, 09:42 AM
The "half-circle" symbol next to the voltage readings indicate that these particular voltage readings are referenced to another point other than chassis ground.
I don't know where they referenced from, as all the components are going to chassis ground! :scratch2:

Winky Dink
02-19-2018, 11:46 PM
Regarding the Sams 6AS5 schematic error, I got the Rider schematic, and it shows the correct wiring and voltages. The voltage shown on the Sams schematic are measured from a 110 volt line, so that explains why they're all about 110 volts too low.

https://farm5.staticflickr.com/4665/26502163708_af4171595b.jpg

I'll be ready to power up the set in a few days. My concern is how to set up the CRT off the chassis. I can't imagine trying to check voltages with the CRT mounted on the chassis. I made a connector for the yoke wiring from an octal base and socket. It has plenty of extra length, but it'll be easy to shorten it. The solder connections are insulated with 1/4-inch irrigation tubing which fits snugly but slides on and off easily.

https://farm5.staticflickr.com/4757/26502161428_477b242625_z.jpg

The limiting factor is the six-inch high voltage line. I have some cable rated 40 kilovolts. The CRT is 15 kilovolts. Is it feasible and safe to splice 14 inches of that to extend the original 6-inch cable?

irext
02-21-2018, 12:10 AM
Temporarily extending the EHT lead won't be a problem. Just insulate it well. In Aus we had a set with a similar layout (Thorn Atlas) and that's how I used to work on them. You will also need to arrange a connection from the aquadag to the chassis. By the way I noticed the exhaust tip on one of the tubes in the tuner has been knocked off and the getter is white.

maxhifi
02-21-2018, 08:43 AM
Just a quick note to say your photography in this thread is outstanding, I wish I could take pictures like that!

Polaraligned
02-22-2018, 06:54 AM
Just a quick note to say your photography in this thread is outstanding, I wish I could take pictures like that!
It sure is. Care to share what camera you used?

Winky Dink
02-22-2018, 04:43 PM
I have a Nikon Coolpix P610. My photography secret is having no particular skill, but abundant time and patience. I may take 10 or 20 exposures for a single shot, varying the angle and lighting (flash; incandescent; LED; flash plus incandescent; etc.) Then I manipulate the jpegs (color saturation, intensity, gamma, brightness, etc.) and remove whatever I don't want in the picture--such as distracting background. Then if I don't have what I want, I start over.

Winky Dink
02-22-2018, 05:26 PM
Thanks for the advice on managing the CRT, especially the reminder to chassis-ground the aquadag. I'll also have to make a simple wooden cradle for the CRT to hold it steady and keep it from rocking back onto the neck.


I disassembled the tuner--that is, I took out the drum to access the caps and resistors. I could have skipped this step because even though some resistors are slightly outside the specs, I'm not going to replace them.

What's new to me is the capacitors used for wires going through the metal chassis into the tuner. I have a vague notion that the current passing the metal wall creates mysterious electromagnetic radiation which is suppressed by the mysterious capacitors. I took one apart, and I still can't see how they're constructed.

https://farm5.staticflickr.com/4652/38616583600_f3d1c027e4_z.jpg

I'm asking about this because I need to know how to replace the one I destroyed--or it I need to replace it at all.

Also, while I'm here, I've been meaning to ask about this for years--what kind of capacitor is this little guy. It's 4.7pF (I wrote "27" because it's C27). My tester is only reliable down to about 10pF, so I never know what to do with them.

https://farm5.staticflickr.com/4711/39511391615_74cd10373e.jpg

Thanks for the help,
Henry.

Electronic M
02-22-2018, 05:49 PM
TIP: Unless you are good at TV sweep alignment NEVER touch pf rated caps or the feedthrough caps on the tuner (unless you have a darn good reason to suspect they are bad)...Doing so can screw up the alignment.

irext
02-22-2018, 06:25 PM
When you say destroyed the feed through cap do you mean cracked the dialectric ? If so just leave it alone as long as it's not shorting to ground. I've never replaced one or seen one that needed replacing but I've seen a few that have been cracked but caused no noticeable issue. I think you would cause much more damage trying to replace it. Tread very carefully around the tuner and IF strip. Small value ceramic and styroseal caps are generally very reliable. A full IF alignment is not for the faint hearted.

Winky Dink
02-27-2018, 10:23 PM
First, regarding the feed-though cap: When I say "destroyed," I mean it. Fortunately, I studied sweep alignment for two years at the Sorbonne. Unfortunately, this is not a French television set. But seriously, there's no need to despair. I want to get rid of this set as soon as I'm finished playing with it. The only way I can fail is by not doing anything at all. So, the project proceeds regardless of the outcome.

No Sharp Points?

I have a healthy degree of anxiety about high voltages. Somewhere in the Sams and Rider information there's a note to avoid sharp points in solder joints on high voltage lines. I'm not sure why, but I copied the original bulky, rounded connection to the base of the HV rectifier. What might happen if there was a sharp point? I also made the high voltage cable a foot longer (temporary) with plenty of insulation at the connection.

https://farm5.staticflickr.com/4676/39796073434_af5564f074.jpg

I envisioned a wooden cradle to keep the CRT securely positioned, but I found a more practical option.

https://farm5.staticflickr.com/4610/40468774022_3a87e563b7.jpg

I found one glitch in the tuner (besides the feed-through cap). There's no connection to the plate of the 6BC5. The circuit is open somewhere in the area shown below.

https://farm5.staticflickr.com/4663/39796074024_f26e1b32ee.jpg

I was getting inconsistent resistance readings in this circuit for days until I found one defective solder joint. After repairing it, there was still no connection to the coil or 110V line.

https://farm5.staticflickr.com/4653/39796073964_067b0ff717.jpg

https://farm5.staticflickr.com/4705/40506094491_ea263e50be.jpg

The open circuit must be between the two left contact strips in the picture, but the coil and connection are neither accessible nor visible.

https://farm5.staticflickr.com/4740/39796073614_ea8f30bf0f.jpg

It looks to me that if I can remove the single rivet, that the yellow plastic mount will slide off of the contact strips, and I'll have access to whatever is hiding behind it.

Before I attempt this, does anyone have a better suggestion?

Thanks,
Henry "The Destroyer of Caps."

Phil Nelson
02-28-2018, 01:48 AM
I can't answer your tuner questions, but regarding rounded solder joints in high-voltage areas, spiky joints could encourage corona discharge (https://en.wikipedia.org/wiki/Corona_discharge), which may lead in turn to high-voltage arcing & sparks (never a good thing).

That CRT cradle is ingenious! More secure than my usual teetering pile of old bath towel or foam bits.

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

Winky Dink
02-28-2018, 10:52 AM
Thanks, Phil. I probably would have done the bath towels if I'd thought of it.
Do you have any thoughts on compensating or replacing a missing feed-though capacitor? It's in the 6.3V line into the tuner.

jr_tech
02-28-2018, 04:16 PM
Do you have any thoughts on compensating or replacing a missing feed-though capacitor? It's in the 6.3V line into the tuner.

Non critical, just stuff the heater wire through the hole... perhaps bypass with a .001 (or so) cap to ground where the wire enters the hole.

jr

Winky Dink
02-28-2018, 05:02 PM
Thanks for the suggestion on the missing capacitor.
I was wrong about sliding the yellow plastic thing off the contacts--the hidden ends of the contacts are anchored to the plastic.

https://farm5.staticflickr.com/4608/38733506980_b36fedf9c6.jpg

I don't know what I expected to find back there, but I didn't find it. There were no hidden surprises. So I stuck it back together. Next thing is to reassemble the parts and run some electricity through the set.

Winky Dink
02-28-2018, 10:12 PM
After reassembling the tuner, I finally found the missing connection and coil.

https://farm5.staticflickr.com/4752/26676612048_ea574ccff9.jpg

Winky Dink
03-03-2018, 12:34 PM
Will wonders never cease? I got all the parts in the right places, and it works with a DVD player. I positioned the yoke retainer, yoke, and ion trap according to the dirty/clean lines on the neck, and the centering magnets according to my earliest photos. Beyond that I only had to adjust the outside controls and figure out that the DVD input plays on channel 13.

This is my setup: Isolation transformer, variac, chassis, CRT, mirror. A couple of questions on this photo.
1. This doesn't have a rubber cup guarding the anode connection. Is this unusual?
2. What is this chain for?

https://farm5.staticflickr.com/4723/25707654397_09ed9b62c5.jpg

I posted a short video on Flickr. It only works for me when I start my computer. Then, after one or two plays it won't work until I restart the computer. Maybe it'll work for you.

https://flic.kr/p/23KQVaY

I took a couple of screen shots this morning.

https://farm5.staticflickr.com/4669/25725743867_1d7d087ecf.jpg

https://farm5.staticflickr.com/4774/26724578328_d3295bd6f4.jpg

I'll try connecting an antenna, but as it stands this is a gratifying success for me. Thanks for all the help that made it work. If you can guess both films you get extra credit.

jr_tech
03-03-2018, 02:38 PM
Congratulations! :thmbsp:


1. This doesn't have a rubber cup guarding the anode connection. Is this unusual?
2. What is this chain for?

I posted a short video on Flickr. It only works for me when I start my computer. Then, after one or two plays it won't work until I restart the computer. Maybe it'll work for you.


At that point in time, rubber cups were deemed an unnecessary expense in many monochrome sets.

Is there a place on the hv cage cover to attach the other end of the chain?

Video works fine on my iPad.

jr

Winky Dink
03-03-2018, 03:22 PM
I should've mentioned that it is attached to the HV cover.

Winky Dink
03-03-2018, 03:26 PM
Correction: I just looked at the cabinet and noticed the channel selection marker. It's not showing the DVD on channel 13. It is actually on 3.

Winky Dink
03-07-2018, 10:41 PM
Before doing the cabinet reinstallation I did final adjustments on the ion trap, centering magnets, horizontal drive, vertical linearity and height. I had a good, stable picture. But when I moved the CRT, the yoke and its retaining ring came loose. The rubber retaining was too age-hardened to grip the glass neck or the yoke.

I soaked the rubber ring in wintergreen oil overnight. I reinstalled the yoke, and the retainer was supple enough to keep it firmly in place. But with power on, I got zapped when I tried to reposition the yoke. I poked around a big and found that one (only one) of the centering rings was hot--voltage too high to read on my multimeter.

https://farm5.staticflickr.com/4776/40684014261_df3c88688e_n.jpg

From looking at the yoke, I can't see how there can be any electrical connection to the centering magnets. I'd previously handled the magnets with no problem.

I took everything apart again, rechecked the resistances and found an open circuit as shown here.

https://farm5.staticflickr.com/4771/39973744154_a835f31465_c.jpg

I corrected that, put the yoke back on, but found the magnet-electrocution risk was the same.

How and why do I have like a thousand volts at one of the centering magnets?

The whole schematic is at this link. It's hard to read online, but quite legible if you download it at the original size.

https://flic.kr/p/24Z7cYP

Thanks for looking.
- Henry

irext
03-08-2018, 05:25 PM
I would try touching it with a grounded screwdriver briefly to see whether it's just leakage or a hard connection to HV. I suspect leakage of some sort. I can't imagine how a centreing ring could come into contact with anything.

Winky Dink
03-08-2018, 10:56 PM
Actually, I think the centering ring built up a static charge. I focused on the centering ring because it was the only conductive surface I was aware of contacting, and it made the multimeter flash strange readings like FFFF for overflow.

I think this the culprit:

https://farm5.staticflickr.com/4800/39973744524_2d07975393.jpg

The exposed rivet is at the lower side of the yoke, hidden from my view. It connects the "DO NOT MEASURE" voltage to coils.

I insulated all the potential conductors which I might accidentally contact and I was still wary of the centering rings, so I made handles with epoxy putty.

https://farm5.staticflickr.com/4780/40659023942_35b6abfdc6.jpg

Now I'm proceeding with adjustments without getting electrocuted. Thanks for your thoughts on the matter.

- Henry

Kevin Kuehn
03-11-2018, 04:16 PM
Nice work Henry. :thmbsp:

Winky Dink
03-17-2018, 03:07 AM
Now that the electronic restoration is complete, I'm going to do a "show and tell" to share how I dealt with a couple of cabinet problems. The first issue is repair of the broken plastic mask. This is what I saw when I first unpacked the set.

https://farm1.staticflickr.com/809/40852813031_c70d4677da.jpg

The right side of the masked was cracked in a similar fashion. I didn't think about it again until I was reassembling the set. This is what worked for me.

The plastic is quite thin. The cracked segments could be apposed, but they were slightly warped and wouldn't stay in place passively. I used just enough tape on the back side to hold everything in place. Then I roughened the surface along the cracks with coarse sandpaper and covered the cracks with a liberal coat of epoxy cement.

https://farm1.staticflickr.com/797/40811585392_6fed979f95.jpg

When the epoxy was fully cured, I applied enough epoxy to the front surface to fill any gaps, then sanded it smooth.

https://farm1.staticflickr.com/805/40852813711_d3a7f1205b.jpg

When that epoxy was fully cured, I applied spot putty (an auto supply item) to fill any defects or scratches sand sanded it smooth.

https://farm1.staticflickr.com/798/40811585282_df57ce093d.jpg

Finally, with a coat of spray paint, there's no visible evidence that it was ever damaged.

https://farm1.staticflickr.com/821/40811585132_19d816c163.jpg

In my next episode I'll show how I replaced the eight-inch-long horizontal hold control knob.

old_tv_nut
03-17-2018, 10:44 AM
Gorgeous!

kvflyer
03-17-2018, 11:38 AM
Bravo! Nice work and patience pays off. Somehow, as I get older, I find myself with LESS patience...

jr_tech
03-17-2018, 01:30 PM
Looking good! :thmbsp:

What spray paint did you use?

jr

Winky Dink
03-18-2018, 02:53 PM
I have a least a half-dozen different cans of metallic gold spray paint. I used this because it's very fast-drying, durability was not an issue, and the can was near empty. By sheer chance it turned out to be a perfect match--but it's behind tinted glass, so that didn't matter, either. It was at Craft Warehouse a few years ago.

https://farm1.staticflickr.com/784/39074830990_43bec7798c.jpg

Winky Dink
03-18-2018, 03:14 PM
This post is about a mundane repair. I'm showing it here only because I found the outcome to be esthetically pleasing.
Horizontal Hold coil was controlled with a plastic rod attached with a metal tube. The coil-end attachment was loose and wobbly. When I was removing the HV cage I bumped it and it snapped off, flew into the air, it and I never found it. So I decided to replace it. with a long nylon alignment tool that would work perfectly. But...
https://farm5.staticflickr.com/4775/40852813371_865f06df03.jpg

...this cartoon inspired me to use wood (The Idaho Forests Products Commission points out that wood is an environmentally friendly, renewable resource).

https://farm1.staticflickr.com/785/27010350218_fcc4f494f3.jpg

I had to cut the metal attachment. Readers from my generation will recognize the classic Tinker Toy construction.

https://farm1.staticflickr.com/808/40811585172_fba7b8dac4.jpg

Finally, the hole did not align with the coil. The rod was flexible enough to reach the original hole, but it wouldn't turn freely, so I made a new hole.

https://farm1.staticflickr.com/787/40852812781_97e8a486de.jpg

Ta-dah!

***I previously asked about the purpose of a short beaded chain attached to the HV cage. As it turns out, the end chain was broken but was originally to chassis. I think the purpose was to prevent a repair technician from forgetting to put the cage back.***

irext
03-18-2018, 05:44 PM
Very nice repair on the mask. I've never seen a mask damaged like that before. It looks like the set may have fallen forward and the weight of the CRT did the damage perhaps. Anyhow it looks as good as new now.