Canadian RCA CTC-39X "Instant-PIC"
 

Hello Everyone,

First time poster here and my first TV and tube restore. I found a farm fresh Canadian CTC-39X recently. After replacing some cooked fuses I got it to power on. But curiously it will only demod sound and give a picture if "Instant-PIC" is turned on. I kind of guessed at the Sam's folder I needed and got 1284-2, but the model in there does seem to have this feature. Without it I get some low power draw when switched on, with it I get a huge inrush then quickly it settles under 300W where I expected it to sit with a funky raster and sound.

I first assumed it was an "instant on" type scenario, but there is no draw when the set is switched off. So I don't think the filaments are being kept warm or anything. Does anyone know what this feature is? I'm a first timer at this, so any tips would be appreciated.

That includes any other tips for what I should look into trying down for the wonked out vertical I am getting.

Back plate with details
 

This is a bit of an end of the line/spare parts kind of deal so here is the model in case it helps.

Caps / Tubes
 

I imagine I am also going to be tracking down a weak tube or hunting bad caps as well? I couldn't get the vertical much better than this in the few minutes I was brave enough to run it with a bypassed breaker on a current loop meter...

A few notes.
Sams never listed Canadian sets but usually there were US versions
that were near identical.

The CTC39 was almost the same as the CTC38 but I dont remember
the major difference. I dont remember any CTC38 with instant on.

I do not know the feature your set has. It sure sounds like "instant on".
Most sets with instant on will have gang on/off switch. Some would
have two or 3+ switches on the one on/off SW. Normally the set WILL draw
current when off UNLESS there is a standby/vacation SW involved.
Look at the on/off & see if it has multy switches instead of the usual
SPST switch.

BTW there is someone offering Can manuals on the list. do a search.

73 Zeno:smoke:
LFOD !

The instant-on feature on TVs of the '70s was a good idea, but a major disadvantage was the TV would still draw a small amount of current even when the set was turned off.

I personally would disable the instant-on feature, in the interest of saving electricity. I would also get in the habit of unplugging the TV from the wall socket if the user would be away from home any length of time, say on vacation. One other problem which occasionally occured with instant-on televisions was the instant-on diode would short after a lightning strike; this had the same effect as jumpering the set's power switch, which would keep the TV on as long as the cord was plugged in. This sometimes happened late at night, after the set's owner went to bed; the person was not even aware of the problem until he/she woke up the next morning and found the TV on, showing a program on the last channel viewed, or a white screen full of snow (and white noise in the speaker) when the TV station signed off for the night (this, of course, was before 24-7 TV started in the US).

This problem could be cured, sort of (!), by removing the shorted instant-on diode from across the power switch. Of course, however, this eliminated the instant-on feature, but by the end of the '70s this feature was viewed as an energy-waster anyway, so I doubt if it was missed much, or at all.

BTW, I was not aware, until now, that RCA even made television receivers for the Canadian TV market, since RCA was an American company. What was the difference, if any, between American RCA-branded televisions and those built, and marketed, in Canada?

Instant-Pic
 

I played around with it a bit today and I think everyone is correct that this is instant on, but not how it is typically setup. As far as I can tell, the master on / volume pot switches the main transformer input. The instant PIC has an on and off button, but neither can bypass the master power. When "Off", the filament heater stay on (if the master power switch is on) but nothing else. Pressing the On button, sets it to full power and I get sound/picture. Sort of the best of both worlds, given you can override the instant on with the normal power switch. I do plan on never leaving it plugged in and have been considered putting an in-line power switch right on the cord.

As for the difference with Canadian sets... I'm not really sure to be honest. So far it just seems like chassis are numbered slightly different and the TVs they go into never 100% line up with service manuals from the US. For example, this Instant-PIC function wasn't included in the CTC39X Sams folder I selected that appeared to be the closest match.

I'm really new at this stuff and have no way to measure high voltage. So pray for my flyback!

Oh, one oddball thing about this Canadian model vs the US one is that my picture tube model lines more up with a Sylvania, but is branded RCA (and is original / lowish hour I think). As well, the original tubes left in there are made in Canada. Don't see that stamped on stuff anymore!

How long did your set work after you replaced the blown fuses? If a fuse blows, you can be sure there is a reason, such as a short circuit in the set somewhere, from the power supply forward.

Whatever you do, however, do NOT bypass a blown fuse or use an overrated fuse just to get the TV to operate again. When a fuse blows, as I said above, you can be sure there is a short or some other problem which caused the fuse to blow and open the circuit. If you bypass the fuse or, worse, use an overrated fuse to get the set working again, you are asking for trouble if the condition which originally blew the fuse is still there. I read years ago, I forget where, of a rule of thumb which says allow yourself one, and only one, new fuse when you are troubleshooting a TV or other electronic device. If the replacement fuse blows, you can be sure there is a short or an overload somewhere in the set which must be cleared.

The fuses never actually reblew. It looks to have had a breaker rust then short out to the chassis ground. That caused some havok in the power section. To get it running while I wait for my nos breaker I have underrated fuses patched in place. I also throw a hall effect sensor on the wire and keep a killawatt running to to watch current entering and leaving the main transformer.

Instant PIC
 

Also, forum member Roni hooked me up with some Canadian schematics. I think I was correct in my assumptions about how this weird instant on works. S104 is the gang switch in question. I've been treating it more like an onboard variac to warm it up and limit the inrush.

Nice set and welcome to the forum. Jug looks to be in good shape. The picture of your flyback looks like it hasn’t gotten to warm. Some slight drip page of wax but it looks normal. Might want to eventually check the horizontal output current and adjust the efficiency coil. Minimum current tends to insure the flyback won’t be over stressed. Was always to be checked and adjusted if needed when HOT tube was replaced.

What sort of meter would you recommend for that? I was thinking about getting a Pomona or something for checking the HV on the tube. I've never really considered if my dinky multi-meter could handle being in line for current. I do have one of those hall-effect clamps though.

I'm still getting used to the scale of voltages and currents in these things versus the digital stuff I'm used to. haha

And yeah, the fly impressed me too. I have a feeling this set has been in storage a long time. The 75 ohm connection had never been bridged and there really wasn't much or maybe any OTA out in the country where I found it.

RCA Canada was originally in Montreal, and then moved to Ontario. Back before NAFTA, Canada had locally made products in pretty much every category. The Canadian sets were often inspired by US sets, but there were also unique models, and some parts differences. For example, I have a 12" B&W new vista which is Japanese made by Sharp. My Canadian CTC 38 is full of Japanese made RCA branded tubes, and the picture tube was made in Canada. The cabinets are assembled with square drive Robertson screws (a tell take sign of a Canadian product). And the record changes are almost always Garrard or sometimes BSR. They never used the US built RCA changers.

The best meters for tuning coils are usually old school quality VOM's
or VTVM's See the RCA Volt-Ohmist or Simpson 260. Being able
to see the slow swing on a real meter is much better than a digi meter
flashing away. The dip will show up nicely :banana:
FBT wax looks normal considering the FBT looks OEM & probably was
running 10-20 yrs.
When you measure the H. out current do it by the book. Even running the
brightness a little high can through off the reading. Be sure to do grey
scale, kine bias, HV adj etc first.

73 Zeno:smoke:
LFOD !