View Full Version : RCA 741PCS restoration


bandersen
03-22-2024, 10:11 AM
A few months back I had this massive 300 pound set shipped to Chicago from Arizona using UShip.

Finally, got it inside recently so I thought it was time to start a restoration thread on it.

Apparently, this started out life in a bar in Minneapolis.
Then shipped to Northern Illinois in the 80s where it was purchased by the guy I got it from.
Then Boston where it was electrically restored, then Colorado now back to Illinois.

It uses that same basic system as all the RCA 5" projections sets. I find this one especially appealing as it is a TV only version with a bit of flair. It was marketed towards hotels and upscale bars.

https://live.staticflickr.com/65535/53192324518_d625897960_c.jpg (https://flic.kr/p/2p3qyTq)

Here's mine the night it arrived fall of 2023.

https://live.staticflickr.com/65535/53190407656_f4c267443b_c.jpg (https://flic.kr/p/2p3fK55)

https://live.staticflickr.com/65535/53189950067_272e70787e_c.jpg (https://flic.kr/p/2p3dp3B)

https://live.staticflickr.com/65535/53192152215_1ecf2e07d8_c.jpg (https://flic.kr/p/2p3pFEF)

https://live.staticflickr.com/65535/53191760654_c2d30c2edd_c.jpg (https://flic.kr/p/2p3nFgC)

https://live.staticflickr.com/65535/53247311490_6a8355dabe_c.jpg (https://flic.kr/p/2p8hoAE)

bandersen
03-22-2024, 10:20 AM
There are four chassis.

Power supply
Audio amp
Receiver
Deflection and HV


Also, the optical barrel.

I figured it would be easier to get in the house if I pulled the chassis out first. Plus, I wanted to examine and start working on them.

https://live.staticflickr.com/65535/53246813606_4014b1f7f8_c.jpg (https://flic.kr/p/2p8eQAs)

Awesome 30kV HV supply.
https://live.staticflickr.com/65535/53246813621_68433f35a3_c.jpg (https://flic.kr/p/2p8eQAH)

https://live.staticflickr.com/65535/53247111418_b9be419ea6_c.jpg (https://flic.kr/p/2p8gn89)

As you can see some recapping has been done. Looks like all the original electrolytics are present.
https://live.staticflickr.com/65535/53246813601_a9a919a353_c.jpg (https://flic.kr/p/2p8eQAn)

The receiver chassis proved quite challenging until I discovered the front of the cabinet is removeable!
https://live.staticflickr.com/65535/53247173484_6493810fd7_c.jpg (https://flic.kr/p/2p8gFzf)

https://live.staticflickr.com/65535/53247377198_c202556114_c.jpg (https://flic.kr/p/2p8hJ8y)

Nice chonky field coil speaker too.
https://live.staticflickr.com/65535/53245940257_10d58d1ca8_c.jpg (https://flic.kr/p/2p8amYH)

bandersen
03-22-2024, 10:27 AM
Next the optical barrel. It is heavy cast metal with a convex front surface mirror in the bottom.

A lot of hardware was missing in this set including some of the bolts that secure this to the cabinet. It's a miracle it wasn't damaged.

https://live.staticflickr.com/65535/53247111398_81396c2f82_c.jpg (https://flic.kr/p/2p8gn7N)

I discovered this hardware rolling around on the mirror! Doesn't appear to have harmed the mirror though.
https://live.staticflickr.com/65535/53247311330_7507f8b044_c.jpg (https://flic.kr/p/2p8hoxU)

https://live.staticflickr.com/65535/53247111403_786825b8bc_c.jpg (https://flic.kr/p/2p8gn7T)

I has a 4820A (AKA 5AXP4) upgraded CRT installed. I also picked up a NOS 5TP4 and the ETF
https://live.staticflickr.com/65535/53247173304_681c9ec0fc_c.jpg (https://flic.kr/p/2p8gFw9)

https://live.staticflickr.com/65535/53603941558_60823bde44_c.jpg (https://flic.kr/p/2pENdhW)

bandersen
03-22-2024, 01:44 PM
Even with all the electronics, front panel, screen cover and optics removed, it was still well over 100 pounds.

Time to tackle another issue - the wheels were not working very well.
As best I can figure, it had some sturdy wooden feet originally.
When I got it, there were four caster wheels mounted to 2x4.
Two problems - The casters could not handle the weight and had bent. Also, they were mounted too close to the skirt and were rubbing even though some material had been removed.

https://live.staticflickr.com/65535/53400929533_143584702e_c.jpg (https://flic.kr/p/2pmRHTB)

https://live.staticflickr.com/65535/53307837969_4115064002_c.jpg (https://flic.kr/p/2pdCB1D)

A friend set me up with some heavy duty casters and I glued up some poplar 3x4s.

https://live.staticflickr.com/65535/53401171355_d7d74d897d_c.jpg (https://flic.kr/p/2pmSXLX)

Runs smooth now :) May seem like a minor thing until you try to move one of these beasts.
https://live.staticflickr.com/65535/53401068764_c2ccdb2111_c.jpg (https://flic.kr/p/2pmSrh9)

bandersen
03-22-2024, 01:53 PM
Moving day
https://live.staticflickr.com/65535/53604117951_a7430377b6_c.jpg (https://flic.kr/p/2pEP7Jc)

Success! At least it's in the basement. Next, I'll clear a path to a more suitable display area.
https://live.staticflickr.com/65535/53604116581_cfcc40fd86_c.jpg (https://flic.kr/p/2pEP7jz)

Here's a look at the plastic fresnel lens screen and front surface mirror. I'll likely get that recoated once the set is working.
https://live.staticflickr.com/65535/53603240507_85dcf1b95b_c.jpg (https://flic.kr/p/2pEJBTR)

Cleaned up a bit. The cabinet is a combination of Mahogany veneer, faux wood grain and naugahyde. I'm leaning towards replacing all the faux with reel veneer. That would be all the front surfaces around the screen and louvers over the speaker.
https://live.staticflickr.com/65535/53604116566_40be5c0d0c_c.jpg (https://flic.kr/p/2pEP7jj)

Yamamaya42
03-22-2024, 02:03 PM
:tears::tears:

I can't see anything yet,:no: all links here at work are blocked! :thumbsdn:

bandersen
03-23-2024, 01:45 PM
While the cabinet was still out in the garage, I removed the screen cover. It is gorgeous bookmatched flame mahogany veneer over a solid hardwood wood core. Quite heavy and badly in need of refinishing. The lacquer has deteriorated and completely missing in areas.

https://live.staticflickr.com/65535/53091144967_13ae0f77c0_c.jpg (https://flic.kr/p/2oTtZJp)

Old lacquer comes off very easily with gently scraping and lacquer thinner.
https://live.staticflickr.com/65535/53314259954_c480853d01_c.jpg (https://flic.kr/p/2pecw3w)

Filling in the grain
https://live.staticflickr.com/65535/53400930088_c697a3313c_c.jpg (https://flic.kr/p/2pmRJ4b)

https://live.staticflickr.com/65535/53400742376_f2a7d4ae73_c.jpg (https://flic.kr/p/2pmQLfL)

A little stain
https://live.staticflickr.com/65535/53401172255_74211b023b_c.jpg (https://flic.kr/p/2pmSY3t)

After a few coats of pre-cat nitrocellulose lacquer
https://live.staticflickr.com/65535/53399811697_09e177c60a_c.jpg (https://flic.kr/p/2pmKZAz)

bandersen
03-23-2024, 01:48 PM
New caps have arrived and electrical work can begin. I'll start with the audio amp.

https://live.staticflickr.com/65535/53401068859_15907655e3_c.jpg (https://flic.kr/p/2pmSriM)

https://live.staticflickr.com/65535/53399813662_f3c261fedd_c.jpg (https://flic.kr/p/2pmL1bs)

bandersen
04-08-2024, 06:26 PM
Finally got it into the display area. Now you can really see how much bigger the screen is
https://live.staticflickr.com/65535/53641647525_ffb4580213_c.jpg (https://flic.kr/p/2pJ8sXP)

Alex KL-1
04-09-2024, 06:48 AM
:tears::tears:

I can't see anything yet,:no: all links here at work are blocked! :thumbsdn:

I believe is same problem that ocurred some time ago... for some, it works; for others, not

For me, all the images in this thread are showing properly.

Chris K
04-10-2024, 10:02 PM
Your other TVs will get screen envy!

Yamamaya42
04-11-2024, 09:23 AM
I believe is same problem that occurred some time ago... for some, it works; for others, not

For me, all the images in this thread are showing properly.

I can see them from home w/o any problems, but not from work, they are ultra paranoid about images and encrypted stuff in them.

So far this year I'm having problems finding candidates for restoration in my area that are priced within reason, thus I'm in restoration withdrawal again, the ONLY possibility so far is a BW GE, that's over 2 hours away that's been clearly necked, one can tell from the missing phosphor on the center of the screen it had a violent loss of integrity. No info known on it, other than it's a GE, possibly a 21EP4, asking $75 (too much) perhaps if they will go down to 50, I may bite, as finding a new CRT will be a real pain.

Electronic M
04-11-2024, 12:25 PM
I can see them from home w/o any problems, but not from work, they are ultra paranoid about images and encrypted stuff in them.

So far this year I'm having problems finding candidates for restoration in my area that are priced within reason, thus I'm in restoration withdrawal again, the ONLY possibility so far is a BW GE, that's over 2 hours away that's been clearly necked, one can tell from the missing phosphor on the center of the screen it had a violent loss of integrity. No info known on it, other than it's a GE, possibly a 21EP4, asking $75 (too much) perhaps if they will go down to 50, I may bite, as finding a new CRT will be a real pain.

Sounds like a defense contractor! Some friends of mine used to work with a Naval supplier in the area about 7 years ago and they ended up bringing 8-track players to work....Not because of the nostalgia, but because the place was so darn restrictive that it was the easiest way to have music at their desks...As all digital media was banned and anything that could record was also banned.

bandersen
04-13-2024, 10:16 PM
Slowly putting it all back together.

https://live.staticflickr.com/65535/53652655785_562444a3c5_c.jpg (https://flic.kr/p/2pK6Tkp)

bandersen
04-19-2024, 02:17 PM
Finally, here it will reside. Fits perfectly into this angled corner.
https://live.staticflickr.com/65535/53658522227_61cdf69a93_c.jpg (https://flic.kr/p/2pKBXdX)

bandersen
04-26-2024, 09:07 PM
Electrical work has finally began with the smallest chassis - the self contained audio amp.
It has its own power supply and features a pair of 6F6 driving the single, big field coil speaker.

Started testing components and immediately ran into a problem - push-pull output transformer is open on one side of center tapped primary. Grr.

Easy enough to replace with something like a Stancor A-3823, but it won't look like the original.
https://live.staticflickr.com/65535/53681679545_8336b5c3e4_c.jpg (https://flic.kr/p/2pMED64)

https://live.staticflickr.com/65535/53681594694_ebd0e57b69_z.jpg (https://flic.kr/p/2pMEcS7)

Also discovered the original candohm resistors is gone and replace with three power resistors. I'll probably replace with three chassis mount power resistors.

https://live.staticflickr.com/65535/53681449543_832850383f_c.jpg (https://flic.kr/p/2pMDsHv)