A potentiometer with a ganged power switch is a pretty common item. AES carries a few:

http://www.tubesandmore.com/products...Potentiometers

You could also look at suppiers such as http://www.mouser.com/, http://www.alliedelec.com/ , or http://www.digikey.com/ .

Mark Oppat also stocks controls, and he can even rebuild old ones:

http://www.oldradioparts.net/controls.html

Phil Nelson

Thanks for the tip, I will probably send in the control to get rebuilt or trade it in for one.

I have some updates, firstly I replaced most of the tubes with NOS(they were cheap) and the picture is better. Still seems like the brightness is too high even though I have it turned all the way down. It's like the text "blooms". I did adjust the HV, but it did not really help much. I posted on updated screenshot.

Also, I bought some new speaker fabric on AES. I didn't want to ruin the original in case I wanted to switch back, so I made a cardboard copy and upholstered the fabric to it. See pics. I used 2 layers of fabric, one layer was too transparent.

I think the new fabric adds a little character to the set, I'd like to add one of those red Motorola wave logos to the set also, I think it would look sharp. We'll see.

Replacement grill cloth is readily available at several different company's. Just google speaker grill cloth or fabric. One of them is at www.markertek.com that looks just like the picture you have of your faded one. Also if your putting your light bulb in series with the AC line, the bulb will light bright as the tubes will be pulling current to light the filaments. It's best to put the bulb in series with the B+ line, right before the rectifiers (diodes) which replaced the selenium's. As a compliment looks like you did a really good job replacing the old wax capacitors and resistors. If you have or can get a hold of a variac in which you can bring the line voltage up slowly, you can check things out at a much lowered voltage, especially the voltages at the filter capacitors, (electrolytic's), and of course watching for parts overheating or smoking. Take your time and I'm sure you will have a nice working relic.

I finally got everything back in the cabinet tonight, but after I turned on the TV I noticed a problem I didn't have earlier. The picture is wavy, or more like a wave travels from the bottom of the screen to the top, slowly. I didn't change anything electrically. I tried pulling the chassis again and running it outside the cab with the pic tube still installed same problem. Also reseated all the tubes.

Video below, what happened, what could cause this?:grumpy:

https://www.youtube.com/watch?v=Va4I...ature=youtu.be

You mentioned new tubes, it is likely 60Hz AC from the heater of a tube leaking to a cathode and into the deflection system. The vertical deflection frequency of the post 54' color system we feed our sets is 59.94Hz and thus when 60Hz power line frequency gets into the circuits associated with the picture it results in a horizontal bar of image disturbance that rolls vertically with respect to the image. The nature of the disturbance depends on what tube is leaking and the circuitry of the set. I'd guess it is the horizontal deflection or possibly synch tube that is the problem, but if you did not change those or putting the originals back does not fix the problem then try putting all of the originals back in one by one and power it up between each to see if the problem goes away...As soon as it goes away you will know that the last tube you changed before that power up is defective.

Thanks Tom I'll give it a shot.

I put all of the original tubes back in just to be sure but the wavy-ness is still there unfortunately.

That bend is from a power supply filter cap. Any chance one of the replacements could be miswired or too-low a value?
(An example of miswiring might be grounding a cap that should't be grounded.)

I never really considered the difference in using the 100 Watt lamp for "slow starting" a transformer-less set. The whole idea of using (normally) a 100 Watt lamp is to reduce the voltage/current available to and thus protecting a possibly expensive power transformer. This is a cheap, but effective way (for those without a variable AC source) of keeping from doing a lot of damage by introducing full line voltage to a device possibly dormant for decades. I used to do it a lot until I was lucky enough to find an old Select-a-Volt unit which is NOT an isolation transformer like a Variac, so it's not quite a safe, but just as effective. I now have an industrial size Variac, but it has some goofy plugs for input and output that I have no idea where to find, so for now I am not using the two ton monster.

Not all variacs have isolation...Mine for example is just a variable tap auto-transformer which has continuity between each respective input conductor and output conductor.

Update, I've discovered why this set had brightness issues, the 8BP4 has a G1 short in it.

I came to this conclusion after I tested a 7JP4 in the set, and the 7JP4 did allow the brightness to be turned all the way down, and there were no retrace lines. The focus was also improved.

So I tried the "remove G1 shorts" function on my Sencore CR70. It actually worked, for a few minutes. The picture was much better and I could adjust away the retrace lines and have good focus and contrast. But, after 3-5 minutes the brightness would jump back up in a couple quick steps and be back to the way it was.

I also noticed no spark during the remove short process on the CR70.

Is there anything else I can do? I tried the "extended" G1 short removal process in the Sencore manual but that actually did nothing. I also tried rotating and shaking the set around and tapping the neck of the CRT with no change...

So you were able to get your CR-70 working properly ? Does it still show a G1 short ? Given the scarcity of 8BP4s, I'd avoid being too aggressive with it.

After running the calibration tests for the CR70, I determined the "beam builder" functions all work OK, the test functions are out on my unit. Since the 7JP4 worked good, it had to be the CRT and the symptoms were exactly that of a G1 short.

You're right, I think it's not worth zapping further. I left the tv running for about 20 min, and while the G1 short is not completely gone, the performance of the 8BP4 is better than before. If I adjust it just right, now I get a pretty darn good enough picture.

Picture of it running today-:D