View Full Version : 1980 Zenith System 3 portable with electronic tuning


drh4683
08-27-2015, 07:42 AM
I got this TV from Wayne this weekend when I helped him install a new CRT and reassemble the components in his 1964 Zenith "Chancellor" roundie combo. Wayne is a great guy, I enjoyed discussing his memories of working in engineering for both Motorola and Zenith back in the 60's and 70's (respectively).

Wayne bought this set brand new from Zenith Employee Sales, which was then part of the Dickens Ave. plant. Wayne being the original owner and giving me the set makes it special and he took great care of it over the years.

This one features "Omni Electronic Tuning" which is a continuous graduated drum type VHF/UHF tuner. I've seen this model maybe once or twice in the past, but never owned one. I kind of forgot they existed. I don't think it was a very popular variety among the 1980 portables. The tuning knob has a flyweight on it, so it turns smoothly and doesn't feel "cheap". VHF/UHF is selected by a rocker switch below the tuning indicator. Incidentally, that rocker switch is the exact same type commonly seen on the earlier 4 tube hybrids!

The set doesn't have many hours on it. We were under the impression it would still work fine even though it's been years since it was last powered up. Unfortunately it appears some of the lytics may have showed their age and upon power up, the set gets only very low/weak volume, no picture and no dial light (which should light up green). Its as though it's not getting full voltage from the power supply. I'll be honest, I never worked much on System 3's, unlike the CCII's and earlier. Is there a common fault on these relating to these symptoms? Presumably some caps in the power supply? Cracked solder joints on the 9-160? I've yet to pull the back off.

https://farm6.staticflickr.com/5642/20923691645_026610c567_h.jpg (https://flic.kr/p/xSXoye)IMG_20150825_212927363 (https://flic.kr/p/xSXoye) by drh4683 (https://www.flickr.com/photos/135332734@N02/), on Flickr

https://farm6.staticflickr.com/5677/20923691305_f863221e16_h.jpg (https://flic.kr/p/xSXosn)IMG_20150825_213018917 (https://flic.kr/p/xSXosn) by drh4683 (https://www.flickr.com/photos/135332734@N02/), on Flickr

sampson159
08-27-2015, 08:10 AM
those little sets were dynamite!had a few through the years and they always delivered a stellar picture with flawless performance.my son had one in his room for 12 years until it was replaced with a larger set.

zeno
08-27-2015, 08:16 AM
Always a good idea to pull the 9-160 & resolder it.
Also do the 9-155-01 CRT board. The main cap does go
bad but it causes width then hum bars. If the
9-160 is bad ( 98%) beyond simple checks I would just
replace it. Gotta remember that design is in the top 3
for complexity along with RCA SCR & Sonys with 2 SG613's
which its the worse. In the end there are only 2 different
ones, 9-160-05 & 9-160-06. They replace all other numbers.

Didnt sell many of them. IIRC they were just a little more
than regular tuners. Maybe they were trying something to get
away with a cheap alternative to tuners but didnt get
a good response. Selectors were reliable. I only remember
changing one for a dial cord.

73 Zeno:smoke:

zeno
08-27-2015, 08:22 AM
BTW IIRC some of the 9-160's used a start transformers
& others used a multivibrator like 9-181 sets. If you upgrade
to an 05 or 06 one connector is left off. Thats from my
foggy memory:scratch2:

73 Zeno:smoke:

radiotvnut
08-27-2015, 10:45 AM
Resolder the crap out of the 9-160 module. I even recall getting some "rebuilt" boards that had crappy soldering that caused problems right out of the box.

drh4683
08-27-2015, 01:06 PM
Ok, I figured solder connections were a major culprit here. I'll investigate it this weekend when I get some extra time. Hopefully its a quick simple fix. I'd hate to swap out an original 9-160 if I don't have to.

Findm-Keepm
08-27-2015, 01:54 PM
CRSP entries for the 9-160:

drh4683
08-27-2015, 02:47 PM
Thanks Brian. It looks like this set will use either the 9-160-03 or 9-160-05.

Username1
08-27-2015, 05:56 PM
I remember seeing those new also.... People didn't like the tuning much. The
Zenith guy said they didn't sell many....

.

Jon A.
08-27-2015, 06:41 PM
Cool set, more interesting than its ordinary knob job equivalent.

dieseljeep
08-27-2015, 07:52 PM
Always a good idea to pull the 9-160 & resolder it.
Also do the 9-155-01 CRT board. The main cap does go
bad but it causes width then hum bars. If the
9-160 is bad ( 98%) beyond simple checks I would just
replace it. Gotta remember that design is in the top 3
for complexity along with RCA SCR & Sonys with 2 SG613's
which its the worse. In the end there are only 2 different
ones, 9-160-05 & 9-160-06. They replace all other numbers.

Didnt sell many of them. IIRC they were just a little more
than regular tuners. Maybe they were trying something to get
away with a cheap alternative to tuners but didnt get
a good response. Selectors were reliable. I only remember
changing one for a dial cord.

73 Zeno:smoke:
It's been ages, but I remember that the 9-160-6 was for the 25" models, where the 9-160-9 and a few others were for the smaller screen sets. They must've changed the designation later on.
The only electronically tuned set, I have of that series is an 18 position selector type.
They must've built that set, with the same basic cabinet styling for about eight years.

radiotvnut
08-27-2015, 09:35 PM
Yes, Zenith often used the same cabinet design for years and with many different chassis variations.