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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Sun 18, 2019 4:10 pm 
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Good progress.
You wouldn't see any arcing while you have a gap of an inch from a screwdriver. An inch is probably a good spacing for your body parts so they don't get zapped. Arcing for the horizontal tube cap that you can see would be about a quarter inch long. You might get an arc that is longer but it wouldn't be as visible.
The crackling might be small discharges or even dust being attracted to the high voltage charges. Check to see that the space between the outer black coating (aquadag) on the CRT and the anode connection is clean.

Power seems a bit high but reasonable. Maybe there are more caps to replace.

I don't know the cause of the cut off at the bottom. Does this CRT need an ion trap? Seems odd that it changes as the set warms, and it doesn't matter about the yoke position.

You pretty much cannot have ghosting. Ghosting was cause by by antenna issues with the analog reception.
It must be something else.

The vertical linearity (and maybe size) is off, causing the image distortion.

CONTRAST may allow the image to dissolve into grey or white, but not brightness.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Sun 18, 2019 5:50 pm 
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good job. you are truly getting a baptism by fire. this set is coming along nicely.

vertical not full size. the control that would effect the height of the picture the most is vertical height control but it does interact with the vertical linearity control. the way it starts with a full screen and then shrinks when it warms up i would say is most likely bad caps in the vertical section. since you want to do a recap start there. if that doesnt allow you to adjust the vertical properly then maybe a bad vertical tube or out of tolerance resistor but since you said you put in all new tubes a bad tube isnt likely. the squishing stretching is caused by the same problem as the above.

ghosting was caused by multipath interference in the tv signal transmission. a dvd cant produce ghosting. it is possible that your tv is picking up electrical interference that is effecting the picture. also a weak crt can cause a blurry cloudy looking picture and a gassy crt can cause a picture that has a quick silver look to it. hard to describe easy to spot if you know what to look for. one test of crt health we used to do is turn the brightness down and then back up again. if the picture seems to breath when ur doing that the crt is on its way out. never use a brightener on a good crt. if i was you when the work was done i would put in the new crt and save the old one just in case you ever need a backup.

no turning up the brightness should not white out the picture completely. you should still be able to see an image.

i would say the numbers you said you got on your kill a watt should be fine. no worries there.

if you had carona discharge you could see it in a dimly lit room and you would smell an ozone smell in the air.

i would say next step replace any paper caps in the vertical section. any ceramic or mica caps in the set should be fine but they can go bad too. i believe it was zenith used to use integrators in the vertical circuit which are a pita now since they are unobtainium. it was a few resistors and caps in a small package. you can make one up if the schematic gives the value of the components in the integrator circuit.


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Sun 18, 2019 8:35 pm 
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I realize now that with all the business about the horizontal hold coil, the tubes, the flyback, etc. that you haven't done much re-capping. I would say most of you problems now are because you need to replace the caps. It is time for the grunt work now. I suggest that you start with the capacitors that are not on the circuit boards, you need soldering practice. Hopefully you won't damage more of the foil on the circuit boards.
I looked up the CRT and it does not use a ion trap.
This is my favorite link for a place to start with re-capping.
https://www.antiqueradio.org/recap.htm

You will need to fix up that yoke cover. The yoke has to be fully toward the bell of the CRT. If it is too far to the rear the beam will strike internal elements of the electron gun, that's why the picture looked round. The rear of the yoke may have had centering magnets.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Sun 18, 2019 10:32 pm 
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Yes, it's definitely time to replace the old electrolytic and paper (and plastic-coated paper) capacitors. You may find that some of the TV's problems are magically cured when you replace the rotten old caps :)

In addition to that basic recapping article, here is one with additional advice about replacing caps on boards; scroll down to "Replacing Capacitors on Printed Circuit Boards:"

https://antiqueradio.org/PhilcoF4626MTelevision.htm

Looking back at your photos, I see a couple of pink plastic-coated tubular caps on a board; they are just paper caps in a plastic shell, and every bit as unreliable.

Regards,

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


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Mon 19, 2019 3:53 am 
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I've been working on a very similar Admiral and also had issues with the vertical. Replacing the electrolytic and paper caps in the vertical circuit fixed it. Some of the vertically mounted plastic caps tested good and seem to have a mylar plastic dielectric while others were made with paper and leaky. Hard to tell by appearance so I ended replacing all of them.

I put a couple videos up on YouTube about the project. Here's part 1 https://youtu.be/2QiSYkShSvA


Last edited by bandersen on Aug Tue 20, 2019 1:19 am, edited 1 time in total.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Mon 19, 2019 4:34 pm 
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Not a sure fire fix but a majority of the time that the bottom rolls up it is the lytic on the cathode of the vertical output tube that is responsible... change that first and change all the paper dielectric and lytic caps.


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Mon 19, 2019 7:01 pm 
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Matt, what kind of soldering/de-soldering equipment do you have?
Un-soldering parts from those printed circuit boards can be tricky. The component leads many times are bent over before they were soldered. The main reason this was done was to keep the components from falling out when the board was turned over to solder it. They used hand soldering back then. More modern methods use wave soldering where a wave of molten solder hits the board from the bottom. So what you have to do is remove as much solder as possible first, then unbend the lead while the solder is melted again. At that point the lead is free to come out of the hole in most cases. In any case you don't want to heat the copper foil any longer than necessary at one time. A solder sucker and solder wick can help remove the solder. You will need a pick or jewelers screwdriver to unbend the lead, nothing too big or it will cool the solder. A soldering iron that is not too big or small is important.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Tue 20, 2019 1:30 am 
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For soldering I have a Hakko FX888D-23BY station. I've been using the default conical tip it came with, but do have a Hakko TI8 tip pack as well (D08, D12, D24, D32, S3) that includes several chisel styles. I have different widths of 63-37 rosin core solder including 0.6mm and 1mm that I have been primarily using. I also have some Kester 44 Rosin Core Solder 63/37 .031" but find the small diameter makes it tedious to work with. I generally do put electronic flux on the points or wires before soldering to help it all stick.

For desoldering I only have a basic plastic solder sucker and desolder wick. They do sell specialized "De-Soldering Irons" for $10-$30 on Amazon that have a suctioning balloon attached to a special head like this one. Would that be a worthwhile investment? The more professional desoldering irons seem to be $150-$300.

I often find it difficult to melt the original solder and have had to increase the iron up to 750-800F to have success. I try to solder most aspects at about 600F but it just wasn't breaking through the old solder joints while still making the entire area quite hot. I also have found the way the old leads are wrapped around to be a real pain and generally resort to using a tweezers to try and straighten and pull them out while everything is liquified. I do have hook/pick and jeweler-style screwdriver sets as well as a mini needle nosed pliers so perhaps that will make it easier.

Question: Is it acceptable at times to reuse the existing solder by melting it down and feeding new capacitor through, versus attempting to clean it all off with the chance the actual pad/trace could get impacted if too much time is spent?


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Tue 20, 2019 2:49 am 
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for components on the board rca recomended crushing the body of the part with diagonal cutters gently pulling the part off the leads then soldering the new part to the old leads. this eliminates the need to solder to the copper foil. personally i prefer point to point wiring over circuit boards.

i was taught to completely clean the old solder off the terminal then apply new solder not to reuse the old solder when unsoldering parts from a terminal. on point to point wiring i would use a 75 watt soldering gun and one of the rubber ball solder suckers. a bit to heavy for printed circuit boards. i used a 150 watt gun for soldering to the chassis. i also had a 75 watt soldering iron. these are big though so hard to use in a crowded chassis. personally i never liked solder wick. in my opinion solder wick doesnt work as well as a solder sucker.

if you have problems melting the old solder your iron is probably not hot enough but if you add a small amount of new solder to the joint before unsoldering that sometimes helps. if the joint is really dirty you can put a small amount of rosin core flux on the joint heat it till it starts to melt then remove the iron and wipe the joint with a paper towel or rag. this will remove some of the surface dirt. then desolder the joint as you normally would.

the desoldering iron you linked to in your post is good for pc work. at 45 watts it may not get hot enough to work on point to point wiring. you could try it. i had one of those but only used it on pc boards.


Last edited by thomas13202 on Aug Tue 20, 2019 4:04 am, edited 1 time in total.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Tue 20, 2019 3:27 am 
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Adding a little fresh solder to an old joint will get some flux on the old solder. This will break through the thin layer of crosion that is preventing you from.getting the old solder hot enough to melt it.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Tue 20, 2019 4:08 am 
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im curious now what is the tip temperature of a 75 watt soldering gun or a 150 watt soldering gun. since a 75 watt gun was recomended for most point to point work i would think you should have the modern soldering station set to the same temperature. the one exception to the above was soldering to the chassis.


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Tue 20, 2019 4:57 am 
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I picked up a ENDECO model 300 some time ago, but I seldom use it. It is a bit hard to use because you have to activate the bulb while holding the iron steady. It says it is 40 watt. As seen in an ad on this magazine page.
https://books.google.com/books?id=WiYDA ... 00&f=false
If you have to up the temperature a lot then it indicates you are not making good contact or the wattage is too small. That Hakko unit should be find wattage wise for terminals and circuit boards.
A temperature of about 600-700 degrees should be fine for 63-37 lead-tin solder. 60-40 is about the same, however I kind of wonder sometimes about just what they used on some vintage stuff. Do keep in mind that if you work on modern day electronics that manufacturer switched to lead free solder. Lead free solder melts at higher temperature, maybe 800 degrees, so high in fact that new fluxes are used, to old fluxes burns off too fast. The good news there is that the lead free mixes with the leaded and behaves more like the older stuff.
As far as cleaning the old solder off, I don't bother getting it all off but I don't leave enough to hold the new part on either.
You should be able to melt the solder in 5 - 10 seconds, longer and it isn't working right. Extra flux does help
the old solder joint melt some times. Once the solder melts finish the job and remove the iron very soon.
It is better to get the job done in several short phases, cooling between, then to cook the area for a long time. Again this is most important with the early circuit boards. Modern glass-epoxy boards are very durable.
A tip for using the solder wick; add flux to it before you use it. The wick is supposed to have some flux in it but I don't think it is enough, or else the wick tarnishes with time.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Tue 20, 2019 4:00 pm 
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Most irons will maintain fairly constant tip temp that is the same across wattage.... wattage affects how big an area of metal you can heat. I have a little 15W iron from Walmart that does fine on PCBs and smaller point to point wiring but can't melt large terminals as quick as it should, and I have a 75W iron I can use to solder a new ground wire to chassis in one fast pass. Think of the metal you're soldering as a heat sink in a computer and you counterintuitively WANT to over heat it.... the bigger the heat sink the more watts the iron needs to supply to heat it evenly.

Point to point I almost never clean the old solder, just heat while wiggling the old lead out and heat while sliding the new one in. You should clean the old solder off the PCB at the very least before installing the new part of else the hole may be plugged and when you install the new lead in the hole it can push the foil off the other side.

Personally I find lead solder works best with the original lead.


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Wed 21, 2019 1:50 am 
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My favorite de-soldering tool in 40+ years of electronics work is the spring loaded "SoldaPullt." You cock it by pressing in the end several inches, place the tip on the joint (usually after heating it with your soldering iron/gun) and press the handy button. It will suck up quite large quantities of molten solder in one go, though I've had to deploy it 2 or 3 times on some old radio tie points with half-a-dozen component leads and enough solder to make a small fishing weight. The same unit is now made by Techni-Tool. It's almost indestructible, though I've replaced the teflon tips a couple times. Works well on old PC boards as well as point-to-point wiring.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Sat 24, 2019 8:35 am 
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EDIT: After I made this splicing post, I realized how simple the setup really was and, assuming I have the arrangement correct as I believe I do (see photos) my only lingering question is about the "solder cups" and how to properly fill/bond them.

I wound up filling each half-cup to the brim and leveling it off, then adhering them together by applying a thin coating of solder to the outside of the cup/seams to fully bond the connection. Should I had simply filled each half to the top and then stuck them together enough to bond without doing anything to the outside? Or perhaps I wasn't supposed to fill the inside cups all the way? Trying to figure out the best option here and it is easy to take apart and redo if needed... (p.s., some of what is seen in the second photo is the interior white insulation that had warmed and deformed at the splice joint).

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---

(Original Message)

The kit comes with two "solder cups" where you feed the wire through the back hole and then fill the cup with solder... Two different sized short brown rubber tubes, two short hard plastic tubes with one end of each slightly beveled out, a white connector piece and a long black connector piece.

I found a seemingly identical version to mine (NTE433) that included a small schematic and another photo but it is still perplexing to me. How do both solder cups connect to complete the splice, and is this really more efficient than directly splicing the wires? Nothing really seems to fit into each other, for instance the solder cups cannot fit into the small black cylinders. Here are the instructions and photos. Are all of these pieces supposed to be squeezed into the large black cylinder piece?

I did alternatively come across Scotch Rubber Splicing Tape 23 which is rated for up to 69 kV but really I imagine this splice kit I got would suffice given it was made for this job, I just have to figure out how it all fits together.


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Sat 24, 2019 3:26 pm 
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Looks to me that I would call this a splice connector rather than a permanent splice. I don't think the solder cups were meant to be soldered to one another. I think they just would be pressed together by the compression of the design. Call it done.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Sun 25, 2019 1:26 am 
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For the deflection yoke I found that the plastic casing was really not in bad or fragile condition just that the top had lost adherence. I still had a tube of sensor safe gasket maker that I had originally bought when I thought I'd have to repair the first flyback. I wound up applying this to re-adhere the top to the bottom and then put a basic coating of it around it. This seems to have made it perfectly solid and in-one-piece again.

However after doing so I regretted not checking/replacing the resistors seen on the top of it. Will there be any way to determine if the yoke itself has any issues? It seemed to function very well when I had tested it last week as far as displaying the image, rotation/zoom etc.

QUESTION: Do yokes contain any capacitors as well or other things that should be replaced on them for maintenance? I haven't seen schematics for them.

QUESTION: Am I correct that the two on top are resistors, not capacitors? Still find it hard sometimes to distinguish the old style capacitors (e.g., bumble bees) to vintage resistors. If I'm correct, the one depicted in this photo is a resistor of 560 Ohm with 10% tolerance (green-blue-brown-silver) and it appears there is a second opposite of it but I didn't review it's colors before putting the top on. This is all still removable to replace with one of the homemade solutions if need be, but assuming the internal parts are functioning fine I will leave it as is until I get the rest worked on.


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Sun 25, 2019 1:50 am 
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if my memory is correct the caps in the yoke are mica caps and are probably good although any part can go bad. the part in the yoke with the stripes on it is indeed a carbon comp resistor. a bumblebee would be longer and fatter. going by the vid you posted of the set playing i dont think you are having problems with the yoke.

did you recap the vertical section yet. if you did power up and i bet the vertical height will fill out the screen. it may require adjustment of the vertical height and linearity controls.

the other issues you had in the picture i bet are due to the weak crt.


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Sun 25, 2019 8:30 pm 
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I will try to work on the recapping over the next 1-2 weeks. I have most replacement capacitors I would need at this point (ignoring the mica and ceramic ones) but am still awaiting several others, including some electrolytics. The two canned ones on this chassis are still the most intimidating to me, but if it is essentially just disconnecting the existing leads and replacing with individual caps w/ the negatives connected for a common ground, I should be able to manage. I have read the guides about it and wonder if there are any good videos demonstrating this process, as I am more of a visual learner.

I only replaced a few caps this weekend, only one on the video board. In doing so, I noticed that one of the original caps (black plastic coated tube) had been completely removed and replaced by a wax-coated paper one behind the board at some point in history. This was one that I originally commented was not shown in the schematic. Now I see it connects to where the old one was removed. However, oddly the original schematic called for .33µ 400V but the paper one that replaced it was a .47µ 100V - I replaced it with another .47µ 400V so it "matched" the replacement that was there, but am wondering if I should more logically use the .33 if that could make any difference?

I picked up an Engineer SS-02 Solder Sucker for $25 which was pricey but was very well reviewed. I can confirm it makes a huge difference in my work. It uses flexible silicon tips that can be pressed right up against the solder point when melting and has a very good vacuum effect. The first time I used it I was shocked to see how much solder it was able to suck up in one shot, a couple of times with it and I was able to easily remove the old cap/leads without damaging the traces. The other one I had was just some dime store style from a large kit, with a hard plastic end that seemed generally worthless.

Attached is the schematic for the video sub board as well as a photo of the actual board in its current state. C24 is the one that had already been completely removed and replaced with a wax paper one behind (of differing specs), which I replaced again. C28 will be what I tackle next. Most of the others are ceramic.

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Question: What other ones on this board should I be replacing? Notice the maroon ones are bulged... I had assumed at first these were resistors (noting the color bands and similar appearance to the brown ones). But the schematic indicates apparently capacitors. What would you call these types of capacitors and I assume all of these values are in PF/MMF? The schematic does not list voltage ratings for these, e.g.:

  • C30 - 3.3 - (No Voltage Listed)
  • C31 - 22 - (No Voltage Listed)
  • C47 - 10 - (No Voltage Listed)
  • C48 - 20 - (No Voltage Listed)

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Aug Sun 25, 2019 10:36 pm 
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MattPilz wrote:
Notice the maroon ones are bulged... I had assumed at first these were resistors (noting the color bands and similar appearance to the brown ones). But the schematic indicates apparently capacitors. What would you call these types of capacitors and I assume all of these values are in PF/MMF? The schematic does not list voltage ratings for these, e.g.:

I would STRONGLY suggest that you do NOT touch these capacitors. They are most likely ceramic and are almost always good. What makes them bad? Physical damage.

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