Zenith B&W with digital tuner

[jstout66]

Saw this on eBay. I remember selling these when new and thought it odd that Zenith would put electronic keyboard tuning in a b&w set. Anyway.... thought I'd pass this along as it has got to be rare. I doubt any other maker did this. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=11074&item=3094344930&rd=1

[Chad Hauris]

I've got one of these! Its picture is in the photo gallery. It defaults to channel 2 when power is turned off...you have to tune it every time the power is turned on (like some Sony and GE sets I have, as well).

[jstout66]

my 1979 Color Zenith System 3 does that too. (defaults to channel 2) I wonder if all early electronic tuners did that?

[Chad Hauris]

It seems like RCA has a memory retention circuit as the 1970's/early 80's RCA's with the manual power switch and the keypad do remember the last channel tuned, as long as the set is plugged in. Also I have a 1979 Zenith System 3 w/ultrasonic remote and a long strip of illuminated channel numbers (varactor tuning) and channel up/down controls and this set remembers the last channel tuned...although its technology is different than the true digital tuner.

[jstout66]

my system 3 is a remote with the electronic tuning. It has a switch that you slide to "cable" and an AFC switch that you slide to "special" I wonder if it is compatible to "todays" cable system. I'll have to hook it up to cable and see.

[andy]

That system 3 should work fine with any cable system. I think the "special" AFC mode gave the AFC a wider range so it could find channels that were off frequency. Interestingly, JVC who also made Zenith's VCRs, had the same switch, or menu option. JVC used Zenith tuners in some VCRs in the mid 80's.

I have the service manual to one of those digital B/W sets if anyone is interested in seeing a schecmatic of the tuner.

[wa2ise]

It defaults to channel 2 when power is turned off...you have to tune it every time the power is turned on


It seems like RCA has a memory retention circuit as the 1970's/early 80's RCA's with the manual power switch and the keypad do remember the last channel tuned, as long as the set is plugged in.

Some RCAs from the late 70's and early 80's use a diode matrix to "program" the default channel. So one should be able to reconfigure the diodes to make the set come up on say channel 3. Thus someone could slave the set to a remove controlled cable box, and have the set's power cord plugged into a controlled outlet in the back of the cable box. Hit the remote, and have the set not come up on channel 2, but 3. Most cable boxes could output channels 3 or 4 but I've never seen one output to channel 2.

[Jeffhs]

Originally posted by jstout66
my 1979 Color Zenith System 3 does that too. (defaults to channel 2) I wonder if all early electronic tuners did that?

I think the memory retention system works only as long as there is power to the set. My RCA CTC185 (1999) will stay on the last channel it was on as long as it is plugged in. However, if there is a power outage or the set is unplugged for any reason, the tuner will reset to channel 2. I have a Zenith Sentry 2 19" TV which does this as well.

Most modern TVs, whether or not they have digital OSD or varactor tuning, will work with a cable box as long as the tuner can be set to the channel the box's output is on. (In the early '80s, when cable came to my area, I used a Zenith 13" color portable with electronic varactor tuning with a cable box for several years; no problems and excellent reception.)

My RCA and Zenith sets work well with a Motorola digital cable box that outputs to channel 4 in this area (the digital music service on channels in the 400 range is great as well). However, as I have read in a few posts here, some very old sets may run into AGC overload or sync problems when used on today's cable systems, because of the much stronger signal from the cable. Again, however, as long as the tuner can be set on the output channel for the cable box, even a vintage set should work with it, even if it means touching up the AGC or fringe lock adjustments to compensate for the stronger cable signal. The tuner or IF strip may have to be realigned, but these cases are rare except perhaps for early postwar sets (the RCA 8TK241 and others of late-'40s vintage come to mind).

[Jeffhs]

Originally posted by jstout66
Saw this on eBay. I remember selling these when new and thought it odd that Zenith would put electronic keyboard tuning in a b&w set. Anyway.... thought I'd pass this along as it has got to be rare. I doubt any other maker did this. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=11074&item=3094344930&rd=1


You're right; these TVs are indeed rare, as Zenith only made them, IIRC, a couple years. I saw one of these digitally-tuned Zenith b&w sets in the early '80s, in a TV shop in my hometown.

Digital keyboard tuning of any b&w TV is rather unusual. I never saw and have never seen anything like that, before or since, in any other small b&w set either. Maybe Zenith thought they would start the ball rolling and other manufacturers would catch on.......? :dunno:

[Jeffhs]

Originally posted by wa2ise Most cable boxes could output channels 3 or 4 but I've never seen one output to channel 2. [/B]

My barber uses a Panasonic cable box which has channel 2 output on a Philco 19" color TV in his shop. The box is technologically old (it was probably made in the '70s or early '80s), which may account for its unusual (by today's standards) low-frequency output.

[Jeffhs]

Originally posted by wa2ise Most cable boxes could output channels 3 or 4 but I've never seen one output to channel 2.


My barber uses a Panasonic cable box which has channel 2 output on a Philco 19" color TV in his shop. The box is technologically old (it was probably made in the '70s or early '80s), which may account for its unusual (by today's standards) low-frequency output.