View Full Version : 1975? Zenith Chromacolor II model G4550P


pac.attack76
10-10-2020, 10:47 AM
Picked this one up yesterday out for trash. Missing power cord. Can't wait to start on this one. My projects are backing up tho.

JohnCT
10-10-2020, 03:07 PM
I sold one of those brand new to the father of a girl I was dating. So that would make it more like 77 I think unless they made that model for a few years. It has the single knob varactor tuner IIRC. Don't spray any kind of cleaner in it if it seems touchy.

John

DavGoodlin
10-11-2020, 04:26 PM
That's a great save, the CRT alone is money in the bank. I sold many of these after they started appearing curbside at 10-11 years old. There were usually very minor issues and of course, I replaced the HV hold-down capacitor. The 1974-78 models were ALL dependable and rugged, I even relocated the CRTs-chassis into older cabinets.

Those one-knob varactor tuners were the only annoying issue, especially when you NEEDED UHF. I forget what worked on them. The turret tuners were an issue too, along with the detent UHF tuners, that needed the shaft grounding springs cleaned.

zeno
10-12-2020, 10:28 AM
I used to HATE doing those damn springs. Then one day the boss
was doing a house call on a junker & he put a few drops of WD40
on each one. Fixed it & from then on we had 100% cure rate on
them with no risk.
The one nobbers were OK for the Boston market but a place like
Hartford you needed mostly UHF. IIRC there was a mod to change
them to 6 VHF & 12 UHF but dont remember the details. The
slide rule varactor selectors get around the problem.

73 Zeno:smoke:
LFOD !


That's a great save, the CRT alone is money in the bank. I sold many of these after they started appearing curbside at 10-11 years old. There were usually very minor issues and of course, I replaced the HV hold-down capacitor. The 1974-78 models were ALL dependable and rugged, I even relocated the CRTs-chassis into older cabinets.

Those one-knob varactor tuners were the only annoying issue, especially when you NEEDED UHF. I forget what worked on them. The turret tuners were an issue too, along with the detent UHF tuners, that needed the shaft grounding springs cleaned.

pac.attack76
07-16-2021, 03:53 PM
Well, I finally got around to testing it. I tried it with my Intellivision game 😃

zeno
07-16-2021, 06:02 PM
Looks pretty strong. I am a bit surprised it has conventional
tuners, not varactor tuners.
LFOD !

pac.attack76
07-16-2021, 06:04 PM
Is 1975 correct for the year on this one?

Popester
07-16-2021, 06:12 PM
Jug looks pretty strong on this one. Nice save from landfill. Good luck on the project.

pac.attack76
07-16-2021, 06:14 PM
Jug looks pretty strong on this one. Nice save from landfill. Good luck on the project.

Ty, definitely. I always try to save whenever possible

zeno
07-17-2021, 08:26 AM
G models are 1976. They came out in the fall of 1975.

Is 1975 correct for the year on this one?

AlanInSitges
07-17-2021, 11:56 AM
That's a great save, the CRT alone is money in the bank. I sold many of these after they started appearing curbside at 10-11 years old. There were usually very minor issues and of course, I replaced the HV hold-down capacitor. The 1974-78 models were ALL dependable and rugged, I even relocated the CRTs-chassis into older cabinets.

Those one-knob varactor tuners were the only annoying issue, especially when you NEEDED UHF. I forget what worked on them. The turret tuners were an issue too, along with the detent UHF tuners, that needed the shaft grounding springs cleaned.

Growing up we had an F chassis with the slide-up-and-down varactor tuner. It seems like it was always dirty.

pac.attack76
07-17-2021, 12:57 PM
G models are 1976. They came out in the fall of 1975.

Ah thank you 😀

pac.attack76
07-17-2021, 12:58 PM
Growing up we had an F chassis with the slide-up-and-down varactor tuner. It seems like it was always dirty.

Does anyone have a picture of this tuner style?

AlanInSitges
07-17-2021, 01:52 PM
Does anyone have a picture of this tuner style?

There are a few pics on the web of the remote version, which doesn't really look the same since it's missing the slidey knob and also the slidey volume control. Someone here has posted a pic of one once before (or maybe it was one of the FB groups) but I just spend 15 minutes searching for a pic and turned up nothing. Maybe someone has a Zenith brochure from 74 or 75?

pac.attack76
07-17-2021, 02:21 PM
There are a few pics on the web of the remote version, which doesn't really look the same since it's missing the slidey knob and also the slidey volume control. Someone here has posted a pic of one once before (or maybe it was one of the FB groups) but I just spend 15 minutes searching for a pic and turned up nothing. Maybe someone has a Zenith brochure from 74 or 75?
Ah well, thanks for trying. Maybe something will turn up. BTW I did notice this set is missing the push pull knob for the power/volume. Anybody know where I could find one?

dishdude
07-17-2021, 03:40 PM
Is this it?

https://i.imgur.com/KyWEEsq.jpg

pac.attack76
07-17-2021, 03:46 PM
Oh wow. Don't recall seeing one of those. I might have tho. It's been awhile.

dishdude
07-17-2021, 04:29 PM
iirc, the button on the left was for Chromatic and when you pushed it in a little panel inside would retract and a little photoresistor would appear.

pac.attack76
07-17-2021, 04:46 PM
iirc, the button on the left was for Chromatic and when you pushed it in a little panel inside would retract and a little photoresistor would appear.

Yup

pac.attack76
07-17-2021, 04:50 PM
iirc, the button on the left was for Chromatic and when you pushed it in a little panel inside would retract and a little photoresistor would appear.

Mines on the right.

zeno
07-18-2021, 04:25 PM
I have them but I have no scanner & if I did I would never
figure out how to send them
Anyhows they were on a slide rule with 14 positions. Any position
could be set to any band & channel ( VHF-L, VHF-H or UHF). The sets
came with a set of plastic numbers tabs from 2-83 with a few extras.
The tabs chose the band & each position had a multi turn pot
to tune the channel. Remote sets had everything behind the door.
Non remotes had a knob that slid up & down. The knob opened up
& the channels were tuned by a knob inside it if needed.
IIRC starting with G-line sets they switched over to 18 position
rotary selectors. 6 for UHF & all the VHF. That started with the
13GC10 chassis, the first in line CRTfrom Zenith & a fantastic set.
By H-line I believe all varactor sets were 18 position rotaries.
When old they did get very noisy but I dont remember any actual
complaints. More of an annoyance to the tech than anything.
Enuf fer now

Zeno:smoke:
LFOD !


Does anyone have a picture of this tuner style?

pac.attack76
07-18-2021, 04:28 PM
Ah, ok then. 👌