Sears Silvertone Color - Videokarma.org TV - Video

southernguy · #1 10-10-2005, 10:16 AM

Here is one of my latest finds, This is a 1966 Sears Silvertone 21 inch color model # 61861 , chassis # 529. I acquired this set from Steve(rcaman). It has a very nice cabinet and finish. This set seems to have a problem with the horizontal hold not wanting to lock in place. You could turn the knob to the left and then to the right just a little bit and then it would lock into place. The picture would stay in place for a few seconds then the tint would shift towards green, next, the color would turn to black and white and then the picture would start rolling sideways from left to right or right to left and then HH is lost. Adjust the HH knob, it would lock back into place only to repeat the same process. Usually there is a little room before you loose sync when adjusting the Horzontal Hold from left to right but not with this set. Last night I played around with it a little bit. I swaped out a 6FQ7 in the Horizontal Osccillator section, only seemed to make the problem a little worse. So I put the origonal 6FQ7 back in. While looking at chassis I noticed that steve did a little recaping, also changed a resistor. Im still waiting for some caps to come at a local parts store here in town so I can't really mess with that now. The replacments seem to be of good Quality so maybe it could be a another bad cap or maybe something else. For the past few days ive been tempted to adjust the Horizontal Osc Coil to see if that would lock the picture into place. Coils is something I never mess with but I gave it a try. I first turned the Horizonal Oscillator Coil to the left ever so slightly. Eww crap the problem got worse crap crap crap. So I went right with it and then Boom it locked and stayed locked

. The Horizontal Hold knob now has alot more room when I adjust it now and is at dead center. Everything seems normal now. I have a nice picture on this roundie, great sound too. One little last problem If I change the channel or adjust the fine tunning out of range to the right there are a few signs of the existing problem. The picture will roll sideways for a second then lock. But it locks and stays locked, but still should not do that. Should I turn the Horiz Osc coil a little bit more to the right. Have any of you guys seen a simular problem to this. I tried to describe it as best as I could. For now Im going to enjoy it like it is. Ive got the set running now, its been on for 4 hours this morning without a problem with a very nice picture, but there could of corse be something im over looking that you guys may have come across before.

Bruce

jpdylon · #2 10-10-2005, 10:28 AM

very nice set you have. It looks to be an RCA of some kind, but then again, what do I know...

Don't overlook an AGC adjustment. This can cause horrible sync instability. Check the associated tube, as well as the sync tubes. Usually is just something simple like this.

My two cents

Chad Hauris · #3 10-10-2005, 10:35 AM

This set is very similar to an RCA Ctc-15.

blue_lateral · #4 10-10-2005, 12:06 PM

I have a similar Silvertone roundie. Mine is very much like a ctc15. Mine had a problem that required the coil to be misadjusted to achieve lock. The natural frequency of the oscillator was wrong.

The procedure goes something like this, as I recall. There is a sync test point (look on sams) that you can ground to disable all sync. You then short out the sinewave coil (that would be the upper half of the horiz oscillator coil, the one with the movable slug).

WIth the sync and sinewave coil disabled, you adjust horizontal hold for a picture that is right side up (though probably pretty unstable). Now the natural frequency is correct. My set would not do this, the "right side up" place was off one end of the horizontal hold control.

If you could get this part right, you would then remove the short from the sinewave coil and adjust the sinewave coil for a picture right side up again. What you have done is made it so the sinewave coil adds stability, without changing the natural frequency. You then remove the short from the sync test point, and the set returns to normal operation.

I couldnt get past the first part. The natural frequency was way off, and needed a misadjustment of the sinewave coil to pull it back on.

The culprit turned out to be an .0015 dip mylar capacitor that couples the horizontal oscillator to the horizontal output stage. It had gone up in value.

Here are some other possibilities: The capacitor that mainly determines the natural frequency is a 390pf 2kv ceramic disc, I think. There is also a suspicious looking 680pf polyprop in a funky cardboard shield. RCA usually used mica here I think. My polyprop was fine. It also couldnt hurt to check the resistors on each side of the horizontal hold control.

Good Luck,

John

oldtvman · #5 10-10-2005, 09:06 PM

most of the sets of this vintage were rca clones made by wells-gardner. similar to rca but with sears usual cost cutting measures in place.

holmesuser01 · #6 10-10-2005, 10:32 PM

Are you sure that number isn't 528 vs. 529? I used to do Sears service, and if I'm not mistaken, 528 was Wells-Gardner.

Hey, that TV has a really good picture on it. I've got a customer that has a very similar Silvertone in her living room. Its her main TV. Looks good, too. I remember Wells-Gardners having problems with burned solder connections at the horizontal output socket, and damper, alot.

oldtvman · #7 10-11-2005, 07:41 PM

Although some of the Sears models started out good, the inherent quality differences between such makers as rca and zenith showed its ugly face after a few years of service, just as the previous reply stated, the pc boards were suseptible to cracks, burn thrus, and so on.

southernguy · #8 10-12-2005, 12:20 AM

Thanks Everyone for the Information, I did try to adjust the AGC Control but it had no effect on the problem. I will try several different tubes that maybe suspect and will probably pull the chassis out and check wires, resistors, caps, and stuff when I get some time. Im thinking it might be the same problem as John mentioned. The sync test shouldn't be that hard. Today, I hooked the set into the satellite system in the living room. Wow, the picture was out of this world compared to the rabbit ears I was using. Im very impressed with the picture on this set. The Chassie # was hand written on on bottom and it says 529.6186118. It could be wrong from what it might be, I do have the sams folder for this set and it covers several model and chassis #'s. It has 528 and 529 listed. But does not list the .6186118 but this folder is correct for the set. Theres even a nice picture of a TV/AM/FM Stereo console combo on the front.

Wells Gardner, Never herd of it, Is that another brand other than Sears/Silvertone or is it the same thing with another name stamped on it.

blue_lateral · #9 10-12-2005, 12:42 AM

Wells Gardner and Warwick are two likely suspects for the producer. I'm not sure who made the Sears ctc15 clones. There were also Silvertone roundies that looked nothing like RCA inside. It seems to me there was a thread a while back and we never quite got is settled who made what.

I read somewhere that during that period Warwick was selling everything they could produce to Sears, so youre unlikely to see a similar set branded Warwick. Wells Gardner? Maybe, but I've never seen one.

John

southernguy · #10 10-12-2005, 01:41 AM

Here some pics of the chassis and also a model and chassis # list

blue_lateral · #11 10-12-2005, 02:48 AM

Ok, I'm completely speechless. That doesn't look anything like my set, which is a shameless ctc15 copy, using RCA boards, with RCA resistor and capacitor numbers silkscreened on them, even though Silvertone used different numbers on the schematic.

There were Silvertone roundies with no power transformer. Someone posted about this in an old thread. I looked through some old schematics and found one for a Silvertone 61731. It has a 10le8 single tube color demodulator. I think this was used in Olympic or maybe Motorola sets. Does anyone remember? This one didnt give a CRT number, but the setup instructions look like roundie.

While l was looking for that, I found a schematic for another transformer type set. It is a Silvertone 5170. It has a 400kb22 crt and some weird 6r-p22 color matrix tubes. The rest of the tubes are normal american types. Could It be japanese? Theres no picture of the set, but the drawings in the setup instructions suggest it is a roundie. It doesnt look like yours either.

So, when we add yours to the mix, thats at least 4 completely different types of Silvertone roundie chassis. I had no idea there were so many. What Sams are you using? Does the circuitry look like RCA?

Thats a really cool looking set BTW, and a terrific picture

John

jstout66 · #12 10-12-2005, 05:34 AM

It's the replacement RCA Hi-Lite tube that helps make the picture look so good. RCA made some great replacement tubes. What's the tube number? I'm assuming they used a "black matrix" replacement.

holmesuser01 · #13 10-12-2005, 06:32 AM

I forgot to include the Warwick brand. That chassis shown above, looks alot like a CTC-12 chassis that I just aquired.

veg-o-matic · #14 10-12-2005, 08:18 AM

I always thought Warwick manufactured for Sears and Wells-Gardner made sets for Wards. Was there really crossover?

veg

Chad Hauris · #15 10-12-2005, 01:17 PM

You can pretty much use a ctc-15 schematic and it will be almost identical to what is in this set. The circuit boards are Wells-Gardner or whoever the OEM was, but the circuit, electrically, is nearly identical to RCA. The only difference is really in the audio section but it still is fairly similar. You still get the same burned wiring and burned terminal strips due to resistor heat in these sets as in the RCA's.