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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Sun 14, 2017 12:54 am 
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Location: Martha's Vineyard, Mass.
bandersen wrote:
Probably because it is surface mount. Give this one a try - only $0.26 at Mouser.

http://www.mouser.com/ProductDetail/Vis ... bK3NPbs%3d


Cheap...and effective? 8)

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 15, 2017 3:00 pm 
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Location: Pewaukee, WI
sdyer wrote:
So I have an older Apple TV and I thought I'd hook it up to the Philco. I got an HDMI to AV converter - below. At first the picture had heavy diagonal bands over it. Removing the copy-protection-elimination thing - the gray unit in the photo - cleared that up. Mostly. There are still faint, but visible, diagonal bands over the picture.
Do any of you know how to get proper input to a set like this from HDMI?

EDIT: I noticed that on other inputs the diagonal bands were there. Unplugging the Apple TV got rid of them. So something about the Apple TV - either it's effect on the power or its output - is affecting the TV, even when the RCA switch box is not set to the Apple TV. I'll investigate more later.


With the HDMI out of the apple unplugged, try powering the apple up and see if it interferes with the TV through the power lines. Many devices made in the last ~15 years use switch mode power supply based wall warts....Switch mode supplies generate TONS of RF noise, and most makers did/do not bother to add sufficient shielding and filtering to keep the noise confined to the supply.

If the noise only occurs when the HDMI is connected then it may be a ground loop issue.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Sat 20, 2017 3:36 pm 
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I recently fixed up the high voltage cage. I scraped off the old label and "preserved" it in packing tape - for posterity only, it won't be going back on the TV. Then I soaked the back panel and cage in CLR. After a day in that stuff I scrubbed both down with wire brushes. I did not need to paint them, as they seem in good shape as-is.

I looked for a good photo of this label - for the 122 chassis - to replace it but couldn't find anything suitable. If anyone knows where there is a good image I can print out and put on, let me know.


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Case, Chassis (1).jpg
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Rusty Blotchy (1).jpg
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Hi Voltage salvage.jpg
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Hi Voltage final.jpg
Hi Voltage final.jpg [ 204.88 KiB | Viewed 3253 times ]
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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Sat 20, 2017 5:20 pm 
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Lightly dust it with some satin aluminum paint. You'll thank me later. 8)

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Sun 21, 2017 12:00 am 
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This project is truly a labor of love. I am glad that you have the tenacity to take on this challenge. Unfortunately, I would not. So, therefore, "Good On 'Ya, Mate!"

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Sun 21, 2017 10:11 pm 
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I had some shiny aluminum Rustoleum.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 22, 2017 3:30 pm 
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That's better. But paint the solid cover semi-gloss black, like original. 8)

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 22, 2017 3:42 pm 
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The back plate to the high voltage cage was not painted. At least I didn't see any evidence of it on either side as I was working with it. It was bare metal, as was the cage itself.

The back cover grate I have already repainted in semi-gloss black:


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Repainted back grate 2.jpg
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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 22, 2017 4:13 pm 
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I'm ready to declare the electronics restoration done. Recently I went through the video circuits and replaced about a dozen very high resistors. The picture is perhaps a bit crisper, and certainly not worse, but no major changes beyond that. So I'm not planning to replace any more components.

Through adjustments I've gotten rid of the snowy bands. The only remaining issues are faint retrace lines and faint buzz. I've gotten them minimized but after following the recommended procedures from you all and other tweaks, have not been able to fully eliminate them. You can see the retrace lines at about 40 seconds into the 1:04-long video I posted yesterday at:

https://www.icloud.com/sharedalbum/#B0f5n8hH4m5dr7

It's the one with the pair of shoes. The image is great at the beginning but towards the end there are some darker screens and you can see the retrace lines. Here's a still, which shows them partially:
Attachment:
Retrace lines 1 - frame 3.jpg
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Another video - the one with the WBZ test pattern - shows the remaining sound buzz. As with the retrace lines I minimized the buzz, but could not eliminate it.

Previously the feedback here is that this is as good as it gets. There is no suppression circuit for the retrace lines, and the buzz is part of the video signal, so they're there for good. Were these really there when the set was new? Was the product really sold with the retrace lines and buzz as part of the viewing experience?

I ask these questions in pursuit of the best possible picture. The set in its current state looks and sounds great, and I'd be satisfied watching it this way forever. But the perfectionist in me wonders if there's some way, some how to make it even better...


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 22, 2017 4:24 pm 
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On the HDMI/Apple TV effort - it's not going very well. Just plugging in the apple TV or the HDMI adapter, the picture on the TV is adversely affected. Setting the input to the Apple TV (on my 4-input RCA switch box) gave a terrible picture - lots of diagonal lines and waviness. I bypassed the video decoder unit, the one that lets me play VHS tapes without the copy protection, and the video from the Apple TV is much improved, but still lousy. See the video that shows "iTunes sign in" at:

https://www.icloud.com/sharedalbum/#B0f5n8hH4m5dr7

You can see the picture undulating. (It also shows the retrace lines, I think before I'd gotten them minimized.) Here's a still from the Apple TV video:
Attachment:
Apple TV.jpg
Apple TV.jpg [ 79.96 KiB | Viewed 3182 times ]

It looks ok in the still frame, but much worse in motion in real life. This is with the decoder unit bypassed.

Does anyone know how to resolve the power and picture quality issues with HDMI/Apple TV? If not I'm going to abandon it and send the HDMI-to-AV unit back to Amazon.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 22, 2017 4:44 pm 
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The rubber feet for the chassis are shot. Does anyone know where can I get new ones?


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 22, 2017 5:18 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 5414
Location: Woodinville, WA USA
Renovated Radios makes repro rubber feet:

http://www.renovatedradios.com/product.php?product=296

Regards,

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


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 22, 2017 6:17 pm 
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Thanks Phil. I went ahead and ordered a set from them.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 22, 2017 6:44 pm 
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Re the retrace lines and audio buzz, those are pretty normal for many vintage TVs, and they tend to occur together.

When these TVs were new, people received comparatively weak signals from a TV station miles away. Modern video sources can be much stronger, causing video overload that worsens retrace lines and buzz.

Modern program content is also different. You have probably noticed that these symptoms are worst when the TV displays a scene of extremely high contrast, like big white letters on a black background. Modern programming is full of this stuff, in cable TV guides, menus, sports broadcasts, and so on. 1940s programs were not loaded with high-contrast text boxes, etc.

On some sets you can suppress retrace lines with a simple circuit. This article describes how I added the circuit to a Philco 49-1240:

https://antiqueradio.org/Philco49-1240Television.htm

Here's another article where I added retrace blanking to an Admiral 24A12:

https://antiqueradio.org/Admiral24A12Television.htm

Some old TVs are more buzz-prone than others. Careful alignment of the audio section can minimize the buzz, but on some sets you won't eliminate it entirely. Again, some of this has to do with content. You may find that you can watch the whole movie "Casablanca" without noticing any buzz, but the buzz will return when you go back to a DVD menu with a bunch of high-contrast text.

Keep in mind that 1940s TVs were designed to be viewed in a dimly lit room. Nowadays, we're used to plasma TVs, etc., that make a brilliant picture in a sunlit room, and we may crank up the brightness & contrast on vintage TVs in an attempt to match that, which worsens the problems with retrace lines and buzz. To minimize the problem, turn down your room lighting and turn down the brightness & contrast on your vintage set.

Re the Apple TV, I haven't used that device, but my experience is that some modern sources simply aren't going to work well with a vintage TV. I have an old laptop that would be very handy for playing movies, etc., on my old TVs. But its power supply creates such awful noise that I can't use it anywhere in the house without creating interference -- even on much newer TVs like the 1980s Sony color set on my desktop.

In summary, check out the retrace blanking circuits and make sure your audio section is well aligned. And understand that these TVs were designed for a particular environment. Don't expect them to do a job they were never designed for.

Regards,

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


Last edited by philsoldradios on May Mon 22, 2017 7:07 pm, edited 1 time in total.

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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 22, 2017 7:00 pm 
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Thanks Phil. I'll see if I can find instructions for the Philco. If I find them and they're simple enough, I may give it a try. BTW the links in your post are the same - to the admiral.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 22, 2017 7:08 pm 
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Oops. I fixed the link to the Philco article.

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


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Mon 22, 2017 7:25 pm 
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To add to Phil's sage advise....

RE Hum: IIRC your using a cheap consumer grade modulator....Those devices can cause hum that varies with scene content by virtue of cheap lousy design. Get a Blonder Tongue AM 40 series agile modulator (or if you wish to transmit wirelessly an AM 60 series). You can find them on ebay from old analog cable head ends.
The cheap consumer grade modulators use the AM video carrier as the FM carrier too (pro-grade stuff usually has separate oscillators to create separate carriers that are then mixed), and they over-modulate the AM video on high contrast...This also affects the FM sound carrier by periodically inverting it's carrier frequency....Which is super bad on FM. You see inverting a carrier wave periodically is the same as phase modulating it 180 degrees. Phase modulation and frequency modulation are VERY close cousins. PM and FM signals differ by a mathematical integral/derivative relationship, and you one can use a PM demodulator to recieve FM or an FM demodulator to recieve PM...The signals will be different by one of those math relationships (in practice in different systems integral/derivative math operations are electrically applied when one demod is being substituted for another).
But the easiest way to think about it is that cheap modulators modulate the audio carrier twice once with audio then with video, and the hum is you listening to the video cross-modulation.

RE the apple TV//HDMI box: You need to figure out which one it is...Either could be causing those lines. Try plugging in just the HDMI converter box to the system, and see if the hum persists. If you absolutely need an HDMI signal to check with that box, then find a DVD player with composite and HDMI out (first make sure the DVD player is good on composite before connecting any of the HDMI box stuff). If the bars appear with only the HDMI converter attached then that is the problem...If your HDMI converter uses a power brick/wall wart you can further isolate things (learn if it is the box or it's replaceable power brick) by turning the HDMI box off and leaving it plugged in if the bars persist it most likely is the brick...You can confirm by disconnecting the brick from the box and plugging it in/unplugging it (you may need to touch it's output terminal to the shield of the composite switcher to couple the noise). If it is only the power brick you can look for another one by a different maker, or make your own....You want a power transformer based wall wart and NOT a switchmode supply (which are infamous sources of RF interference) based one if possible.
If the box for the HDMI converter is the problem, order a different converter.

If the converter and it 's supply are good as checked above next check the apple TV and it's power brick using the same methods above.

I have 10-15 video sources in my main video rack and ~2-5 Blonder Tongue agile modulators (all rigged up together so I can play any source on any modulator, and dub recordings between all devices), and I reconfigure most or all of the system ~annually....With that much gear it is not uncommon for me to have to do the kind of troubleshooting described above on a MUCH grander scale to resolve power supply noise, ground loops, bad connections/cables, etc, etc.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Tue 23, 2017 5:03 pm 
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Electronic - is there something better than my current RF Modulator, but not as "pro" as the Blonger Tongue? The one I have is this one:

https://www.amazon.com/gp/product/B0021AF0AW/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

The Blonder Tongue would be great, but it's rack mounted and a bit heavy duty for this purpose - sitting in my living room (eventually) and getting turned on from time to time.


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Tue 23, 2017 5:10 pm 
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Though I'm done with the component replacement phase of the restoration, I'm still tweaking the settings - all those little screws I'm not supposed to touch. I know, I know - but I've managed to get a very clear picture, even better since my last post. I've also nearly eliminated the sound buzz by working with those little things. I've also struck a balance between the a-g-c control and the contrast control. Those retrace lines are as dim as 1948 technology makes possible.

The most major remaining issue now is - snow. Not tons of it like white noise, but bright speckles that come and go randomly about the screen. Not a killer, but it is noticeable. Does anyone know how I could get rid of these? Is it due to the strength of the incoming signal? A tube going bad? Would a new/better RF modulator help?


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 Post subject: Re: Philco 48-1000 Complete - how to restore?
PostPosted: May Tue 23, 2017 6:09 pm 
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if you have any analog broadcast left on vhf in your area one thing you could try to isolate issues is unplug every digital divice in your house including cfl and led bulbs and flurescent lights. these can cause electrical noise that drives antique electronics nuts. it is because of the power supply for modern electronics and the balast in flurescent lighting.

if you do have noise on your power lines that is being fed into your tv i have a vague recolection from when i was a child that my dad had some kind of device that would plug into the power line and the tv plugs into that to filter out power line noise. some of the older guys may remember what i am talking about and know if it is still available.

the white sparkly dots sound like some kind of interfeerance getting into the tv. could possibly be from the switching power supply used in modern electronics or from modern type light bulbs. i remember a 1941 radio i had. as soon as anyone would turn on the flurescent light in the laundry room it would buzz like crazy. the cure was to change out the fixture with an incondescent socket and bulb. no more problem.

all the bulbs in my house are incandescent but i still have to unplug the internet modem and laptop to get good reception on my tv. there is nothing else digital in my house.

no i dont think it is a bad tube that is causing your problem. an intermitant problem in a tube can cause weird problems but that isnt what is at work here.


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